Hanna Instruments | HI903-01 | Owner Manual | Hanna Instruments HI903-01 Owner Manual

Hanna Instruments HI903-01 Owner Manual
QUICK START GUIDE
HI 903
KARL FISCHER
VOLUMETRIC TITRATOR
Revision 1.11
www.hannainst.com
1
QUICK START GUIDE
Dear customer,
Congratulations on choosing a Hanna Instruments Product.
This guide has been written for the HI 903 Karl Fischer Volumetric Titrator.
Please read this Quick Start Guide carefully before using the instrument. This guide will
provide you with the necessary information for the correct use of the instrument.
The purpose of this guide is to present a quick overview of setting up and using the
instrument.
For detailed information illustrating the extensive capabilities of your titrator, please refer to
the Instruction Manual.
© 2013 Hanna Instruments
All rights are reserved. Reproduction in whole or in part is prohibited without the written consent of the copyright
owner, Hanna Instruments Inc., 584 Park East Drive, Woonsocket, Rhode Island, 02895, USA.
2
QUICK START GUIDE
Contents
INTRODUCTION ..........................................................................................................3
SAFETY MEASURES.....................................................................................................4
TITRATOR CONNECTIONS .........................................................................................5
USER INTERFACE .........................................................................................................6
HOW TO SELECT YOUR LANGUAGE ............................................................................7
HOW TO USE THE CONTEXTUAL HELP .......................................................................7
METHODS ....................................................................................................................7
BEFORE PERFORMING THE FIRST TITRATION.........................................................8
HOW TO PERFORM THE FIRST TITRATION ..............................................................9
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QUICK START GUIDE
4
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INTRODUCTION
The HI 903 Karl Fischer volumetric titrator is extremely flexible, capable of performing a
wide variety of highly accurate and precise water content titration methods.
The HI 903 finds a titration endpoint using a polarized electrode and an advanced detection
algorithm. A constant flow of current is maintained between the two platinum pins of the
titrator’s electrode. When the solution in the titration vessel contains water, a relatively
large voltage is required to maintain the flow of current between the pins. As the titration
proceeds, the water in the sample is consumed by the titrant. At the end point, all of the
water has been reacted and the cell contains excess iodine. The presence of excess iodine
within the titration cell results in a reduction in the amount of voltage required to maintain
the constant current between the pins of the electrode. The endpoint detection algorithm
incorporated in the HI 903 analyzes both the electrode response to individual additions of
titrant and the shape of the entire titration curve in order to determine the endpoint of the
titration.
Titration reports and methods can be transferred to a PC via a USB interface, saved to a USB
flash drive or printed directly from the titrator. An external monitor and keyboard can be
attached for added convenience.
How can I find certain information?
1. This Quick Start Guide will help the user learn how to operate the titrator within
a short period of time. The first analysis will be performed with the aid of the
factory stored methods.
2. The Instruction Manual provides a complete description of the operating
principles (user interface, general options, methods, titration mode, maintenance,
etc.).
3. The contextual Help screens contain detailed explanations about what kind of data
can be set or viewed in every displayed screen.
4. The Titration Theory booklet outlines the basic concepts of titration.
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QUICK START GUIDE
SAFETY MEASURES
The following safety measures must be followed:
1. Never connect or disconnect the pump assemblies with the titrator turned on.
2. Verify that the burette and the attached tubing are as described in this guide.
3. Always check that the titrant, solvent and waste bottles, as well as the titration beaker are
properly assembled.
4. Always wipe up spills and splashes immediately.
5. Avoid the following environmental working conditions:
• Severe vibrations
• Direct sunlight
• Atmospheric relative humidity above 80% non-condensing
• Environment temperatures below 10°C and above 40°C.
• Near heating or cooling sources
• Explosion hazards
6. Have the titrator serviced by qualified service personnel only.
7. Avoid inhalation of titrant/solvent vapors. Avoid contact with chemicals.
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TITRATOR CONNECTIONS
Front View
Rear View
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USER INTERFACE
Keypad
The titrators have their own keypad with 29 keys grouped in four categories, as follows:
Display
The titrators have a 5.7” graphical backlit color display. The Standby Mode screen is shown
below with short explanations.
The user interface contains several screens. In each screen, many information fields are present
at the same time. The information is displayed in an easy-to-read manner, using different size
fonts.
Virtual option keys describe the function performed when the corresponding soft key is pressed.
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HOW TO SELECT YOUR LANGUAGE
To change the language, press
from the main
screen. Highlight the Language option and then
press
. Using the
and
keys select the
language from the options listed in the Set Language
screen and press
.
Restart the titrator in order to apply the new language
setting.
HOW TO USE THE CONTEXTUAL HELP
Any information about the titrator can be easily accessed by pressing
. The contextual
help can be accesed at any time and it provides useful information about the current screen.
METHODS
The HI 903 Karl Fischer titrator can store up to 100 methods: these include up to 90
standard methods.
Standard Methods
Each titrator is supplied with a customized package of standard methods. Standard method
packs are developed at Hanna Instruments laboratories to meet analysis requirements of
specific industries.
User-Defined Methods
User-defined methods allow the user to create and save their own methods. Each new
method is typically based on an existing method which is altered to suit a specific application.
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QUICK START GUIDE
BEFORE PERFORMING THE FIRST TITRATION
Setup the Titrator
• Make sure that all of the titrator assemblies are properly installed (see Instruction
Manual, Setup section).
• Make sure that the beaker system is properly sealed against atmospheric moisture
(the fittings and tubes are correctly mounted).
• The desiccant had been properly dried.
Obtaining the Reagents
• The reagents (titrant and solvent) have to be suitable to the analysis requirements
(see Instruction Manual, Appendix 2 for list of preferred titrants and solvents).
Priming the Burette
• Remove the dispensing tube from titration beaker (unscrew the fitting and remove
the tube) and insert it in the waste bottle or separate waste container.
• From the Idle screen press
.
• Highlight the Prime Burette option and then press
.
• Enter the number of burette rinses. At least 3 rinses with the solution used for
titration are recommended (allowing air bubbles to be evacuated).
• Press
to start.
• The message “Executing...” will be displayed.
Note: Make sure you have continuous liquid flow inside the burette. Do not use
during normal filling of the burette if you are not sure that air bubbles have been
completely evacuated. For accurate results, the aspiration tube, the dispensing tube
and the syringe must be free of air bubbles.
• Carefully wipe the end of the dispensing tube to remove excess titrant.
• Insert the dispensing tube in the corresponding hole of the titration beaker and
screw the fitting to seal the beaker.
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HOW TO PERFORM THE FIRST TITRATION
Method Selection
For this analysis we will use the HI8301EN Solvent with 5mg/ml 1-component
Titrant standard method.
To select this method:
• Press
from the Idle screen. Use the
and
keys to highlight the
HI8301EN Solvent with 5mg/ml 1-component Titrant method.
.
• Press
After accomplishing these operations, the method’s name will be displayed on the top line of
the Idle screen.
Setting Method Parameters
To display the method parameters, press
. The View/Modify Method screen will be
displayed.
Only certain parameters from the standard methods can be changed.
For this titration, only the KF titrant concentration value and the size of the solvent sample
need to be entered as in the screen shown below.
To accomplish this:
• Highlight Titrant option from the View/Modify Method screen and then press
.
• The Karl Fischer Titrants screen will be displayed.
• Press
.
• Highlight “Standardized Titrant Concentration” and
press
.
• Input the correct value, then press
• Press
screen.
.
three times to return to the Idle
Setup Titration Report
Users can select the information that is stored for each titration that is performed.
To obtain proper information at the end of the titration, perform the following operations:
and the Data Parameters screen will be
• From the main screen, press
displayed.
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• Highlight the Setup Titration Report option and press
.
• Mark the fields to be included with the “*” symbol using the
press
• Press
and
keys and
to toggle the selection.
and then press
to return to the main screen.
Fill Titration Beaker with Solvent
The titration beaker must be filled with 1-component up to the MIN marker (about 50 mL of
solvent):
• From the Idle screen, press
.
• Push and hold the FILL button located on the top of the air pump.
• Wait until the beaker is filled up to the MIN marker with solvent.
• Stop the air pump by pressing
solvent in the beaker.
and then confirm the approximate amount of
Prepare the Solvent for Samples
Before beginning a titration, residual moisture inside the titration beaker and solvent must be
reacted:
• From the Idle screen, press
. The titrator will enter Pre-Titration mode, start the
magnetic stirrer, and begin dosing titrant into the titration beaker. If no titrant can be
seen moving through the anti-diffusion tip after several doses, press
and
verify that no titrant is leaking from the burette housing or from the dispensing tube
fittings.
• Once all residual moisture has been reacted (endpoint potential is reached), the
titrator will enter Drift Analysis mode (assuming Automatic Drift Entry is selected).
The titrator calculates the rate of atmospheric moisture seeping into the titration
beaker for the next minute and displays the result in the lower right corner of the
display.
• If the Drift Rate is stable and the endpoint potential is maintained, the titrator will
enter Standby mode. The titrator continues to maintain the endpoint potential and
update the background drift rate.
Preparing and Introducing the Sample
Sample Mass Preparation
Measuring the sample size by mass using an analytical balance will give the most reproducible
results.
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Solid Samples:
• Solid samples with larger pieces may need to be pulverized or ground in an analytical
mill. These samples can be added with a weighing boat by removing the sample
port plug.
• Semisolid samples with non-homogeneous water content may need to be homogenized
before addition. The sample can be added using a syringe without the needle by
removing the sample port plug.
Liquid Samples:
• Samples with low viscosity will be added using a syringe with needle (injection
through the septum).
Weigh the syringe before and after injection in order to increase precision.
Sample Volume Preparation
Liquid samples with low viscosity can be added by volume.
Samples should be added using a class A pipette.
Note: When adding samples using the weighing boat, pipette or syringe without needle, the
septum has to be removed. Therefore the adding operation should be performed quickly in
order to avoid the prolonged exposure of the beaker to atmospheric moisture.
Performing a Titration
• From the main screen press
for analyzing a sample or
for titrant
standardization. You will be prompted to enter the analyte size. Add a prepared
sample according to a preparation method outlined above. Enter the analyte size
and press
or
selected method.
. The titrator will start the analysis according to the
• At the end of the titration, the message “Titration Completed” will appear on the
titration status, together with the final concentration of the moisture in the sample,
the end point volume, and other relevant information. The titrator re-enters Standby
mode (if active) in the background.
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Understanding the Displayed Information
During a titration, the following screen is displayed:
Viewing Graph During Titration
Press
to display the real time titration graph.
The curve displayed is a plot of Electrode Potential vs. Titrant Volume.
A dashed horizontal line represents the user selected end point potential.
Titration Termination
The titration is terminated when the conditions of the Termination Criteria have been met.
The default Termination Criterion is a mV value, in which the titration is terminated after the
mV value remains below the end point potential for the selected stability time.
When the titration has ended, the titrator will display the final concentration of the moisture
together with the basic titration information.
To view the custom report or titration graph, press
To view statistics of multiple analyses, press
For titrant standardizations, press
standardization result.
When done, press
.
.
to update the active titrant with the displayed
to return to standby mode (if active).
Results
The results obtained from titration are stored in a
report file that can be displayed, transferred to a
USB storage device or a PC, or printed.
Viewing the last titration data
• Press
(while no titration is being performed).
• The Data Parameters screen will be displayed.
• From the Data Parameters screen highlight the
Review Last Titration Report option and press
14
.
QUICK START GUIDE
• The Review Result screen will be displayed.
• Use the
and
keys to display information related to the last titration performed.
See titration report on page 15.
Printing the titration report
Connect a DOS / Windows compatible printer directly to the DB 25 connector (parallel port)
located on the back of the titrator.
Note: To connect the printer, please turn off the titrator and the printer.
Printing out the report:
• From the Review Report screen, press
.
• During the information transfer to the printer, the message “Printing” will be displayed on the screen.
• Press
to return to the Data Parameters screen.
• Press
again to return to the main screen.
Saving the data on a USB storage device
This feature allows saving the results of titrations or drift logging sessions on a USB storage
device.
• Insert the USB storage device into the USB socket.
• From the Idle screen, press
. The General Options screen will be displayed.
• Highlight the Save Files to USB Storage Device option using the
and
• Press
. The List of Files on Titrator screen will be displayed.
• Use the
or
• Press
keys.
keys to select the file type: “report files”.
to transfer all available reports to USB storage device, or highlight the
name of the report file to be transferred and press
.
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QUICK START GUIDE
• Transferring a report file will automatically transfer the corresponding log file and
titration graph BMP file (if applicable).
• Press
, to return to the General Options screen.
• Press
again, to return to the Idle screen.
Titration report
While scrolling with the
and
keys, the fields below can be seen on the titrator
display or printed. The same information is available on the saved report file (KF_00003.rpt
in this example, with all report fields selected).
HI903 - Titration Report
Method Name:
Moisture in Oil
Time & Date:
12:00 Jan 01, 2011
Titration ID:
KF_00003
Company Name:
Hanna Instruments
Operator Name:
KF Technician
Electrode Name:
Probe 1
Field 1:
Any text
Field 2:
Any text
Field 3:
Any text
Titrator Software Version:
v1.0
Base Board Software Version:
v2.6
Pump Software Version:
v1.4
Titrator Serial Number:
12345678
Analog Board Serial Number:
12345678
Pump Serial Number:
12345678
Analog Calibration Date:
Aug 22, 2010
Method Parameters
Name:
Moisture in Oil
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Rate
None
Pre-Analysis Stir Time:
0 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
KF Solvent
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Oil
Sample Type:
Mass
Sample Size:
0.5000 g
Titrant:
KF Titrant
Titrant Type:
One Component
Nominal Titrant Conc.: 2.0000 mg/mL
Stdz. Titrant Conc.:
2.0000 mg/mL
Date/Time:
Jan 01, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
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Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.5000 uL
Maximum Dose:
30.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
3600 sec
Maximum Titrant Volume:
20.0000 mL
Term. Criterion:
mV End Point
mV End Point:
4 sec
Result Unit:
%
Nr
0
1
2
3
4
5
6
7
8
9
10
Volume[ml]
0.0000
0.0000
0.0028
0.0078
0.0128
0.0178
0.0228
0.0278
0.0328
0.0378
0.0428
mV
403.6
403.5
403.1
402.3
402.6
403.0
402.5
402.4
402.7
402.5
402.9
Time
00:00:00
00:00:01
00:00:03
00:00:05
00:00:06
00:00:08
00:00:09
00:00:11
00:00:12
00:00:14
00:00:16
169.7
177.4
173.7
171.1
173.4
181.1
175.5
178.2
177.6
00:06:45
00:06:47
00:06:48
00:06:50
00:06:52
00:06:53
00:06:55
00:06:56
00:06:58
.
.
.
256
257
258
259
260
261
262
263
264
0.9904
0.9904
0.9904
0.9904
0.9904
0.9904
0.9904
0.9904
0.9904
Titration Results
Method Name:
Moisture in Oil
Time & Date:
12:00 Jan 01, 2011
Sample Size:
0.5291 g
Titrant Conc.:
2.0000 mg/mL
Drift Value:
1.0 ug/min
End Point Volume:
0.9904 mL
Result:
0.3730 %
Titration Duration:
06:58 [mm:ss]
Estimated Cell Volume:
50.8 mL
Titration went to Completion
Operator Name:
Any text
Analyst
Signature:
____________________
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QS 903
10/13
18
INSTRUCTION MANUAL
HI 903
KARL FISCHER
VOLUMETRIC TITRATOR
Revision 1.11
www.hannainst.com
1
Dear customer,
Congratulations on choosing a Hanna Instruments product.
Please read this instruction manual carefully before using the instrument. This manual will
provide you with the necessary information for the correct use of the instrument.
© 2013 Hanna Instruments
All rights are reserved. Reproduction in whole or in part is prohibited without the written consent of the copyright
owner, Hanna Instruments Inc., 584 Park East Drive, Woonsocket, Rhode Island 02895, USA.
2
TABLE OF CONTENTS
Chapter 1.
INTRODUCTION
Chapter 2.
SETUP
Chapter 3.
USER INTERFACE
Chapter 4.
GENERAL OPTIONS
Chapter 5.
METHODS
Chapter 6.
TITRATION
Chapter 7.
AUXILIARY FUNCTIONS
Chapter 8.
MAINTENANCE, PERIPHERALS
Chapter 9.
OPTIMIZATION
Appendix 1. TECHNICAL SPECIFICATIONS
Appendix 2. RECOMMENDED REAGENTS
Appendix 3. TITRATOR COMPONENTS
3
4
INTRODUCTION
1
INTRODUCTION
The HI 903 is an automatic volumetric Karl Fischer titrator with high accuracy, great flexibility
and repeatability.
The titrator is designed to perform titrations for a variety of sample types.
The main attributes of this titrator are:
Flexibility
Support up to 100 titration methods (standard and user defined).
User defined titrant and standard database.
High accuracy
Precise dosing system, capable of delivering as little as 0.125 µL of titrant with a single
dose.
Precise mV measurement and current (µA) control.
Repeatability
Powerful built-in algorithms for termination criteria based on fixed mV endpoint or
absolute/relative drift.
Quick results
Pre-defined titration methods.
Pre-dispensing feature.
Dynamic dosing feature.
Balance interface for automatic weighing.
Complete report
Results are displayed directly in the selected units along with the titration information.
Titration graph can be displayed on the LCD and saved as a bitmap.
Customizable titration reports and drift analysis reports can be printed, saved on a USB
storage device or transferred to a PC via the USB interface.
Result history
Titrant standardization and sample analysis results averaging.
GLP features
Titrant age reminder.
Fields for specific annotations.
Conditioning phase
Automatic pre-titration for drying the solvent and titration beaker.
Drift analysis adjusted titration results for improved accuracy.
Sealed solvent
system
Self diagnosis and
integrated help
Allows full operation in a completely sealed system, minimizing water vapor entry.
Integrated help screens are available.
Self diagnosis features for peripheral devices including pump, valve, burette and stirrer.
Error management with warning and error messages.
Large graphical display 5.7” (320 x 240 pixels) graphical color display with backlight.
Easy to view text and graphs.
User friendly interface.
This manual provides information regarding installation and functionality of the titrator and
refined operation suggestions.
Before using the titrator it is recommended you become familiar with its various features and
functionality.
1-1
INTRODUCTION
1-2
SETUP
Chapter 2. Contents
2
SETUP ................................................................................................... 2 - 3
2.1
Unpacking ............................................................................................. 2 - 3
2.2
Safety Measures ..................................................................................... 2 - 4
2.3
Installation ........................................................................................... 2 - 5
2.3.1 Titrator Top View ........................................................................................ 2 - 5
2.3.2 Titrator Rear View ...................................................................................... 2 - 6
2.3.3 Titrator Left-side View ................................................................................. 2 - 6
2.3.4 Titrator Assembly ....................................................................................... 2 - 7
2.3.4.1
Connecting the Pumps .................................................................................2 - 7
2.3.4.2 Attaching the Burette ................................................................................... 2 - 9
2.3.4.3 Attaching the Beaker and Dispensing Tip ....................................................... 2 - 1 0
2.3.4.3.1 Beaker Top .............................................................................................2 - 1 1
2.3.4.4 Electrical Connections ................................................................................... 2 - 1 3
2.3.5 Titrant, Solvent, Waste Bottle Assembly ........................................................ 2 - 1 4
2.3.5.1
2.3.5.2
Titrant Bottle Assembly ................................................................................ 2 - 1 4
Solvent / Waste Bottle Assembly .................................................................. 2 - 1 5
2-1
SETUP
2-2
SETUP
2
SETUP
2.1
Unpacking
The titrator and the accessories are shipped in a single box containing:
1
2
3
4
5
6
7
8
9
ITEM
QUANTITY
Titrator ................................................................... 1 pc.
Dosing Pump Assembly ........................................... 1 pc.
Burette Assembly ..................................................... 1 pc.
• Burette (with 5 mL syringe)
• Aspiration Tube with Fittings and Protection Tube
• Dispensing Tube with Anti-Diffusion Tip, Fittings,
and Protection Tube
• Tube Locks
• Tool for Burette Cap Removal
• Light Protection Screen
Air Pump Assembly .................................................
Beaker Assembly .....................................................
• Glass Beaker
• Beaker Ring
• Beaker Cap
• Stir Bar
• Desiccant
• Desiccant Cartridge
• Fittings, O-rings
Beaker Support ........................................................
Pump Locking Screws with Plastic Head .....................
Titrant Bottle Assembly ............................................
• Bottle Cap
• Desiccant
• Desiccant Cartridge
• Fittings, O-rings
Solvent Bottle Assembly ...........................................
• Bottle Cap
• Desiccant
• Desiccant Cartridge
• Fittings, O-rings
• Tubes (Silicone and PTFE Tubing)
1 pc.
1 pc.
1 pc.
2 pcs.
1 pc.
1 pc.
2-3
SETUP
10 Waste Bottle Assembly .............................................
• Bottle Cap
• Desiccant
• Desiccant Cartridge
• Fittings, O-rings
• Tubes (Silicone and PTFE Tubing)
11 Calibration Key ........................................................
12 Power Supply ..........................................................
13 USB Cable ...............................................................
14 Instruction Manual Binder .........................................
15 USB Storage Device .................................................
16 HI 900 PC Application (Install Kit on USB Stick) .........
17 Quality Certificate ....................................................
18 ISO 8655 Burette Compliance Report ........................
19 Karl Fischer Dual Platinum Pin Electrode ....................
1 pc.
1
1
1
1
1
1
1
1
1
pc.
pc.
pc.
pc.
pc.
pc.
pc.
pc.
pc.
See Appendix 3 section A 3 Titrator components for pictures.
If any of the items are missing or damaged, please contact your sales representative.
Note: Save all packing materials until you are sure that the instrument functions correctly.
Any damaged or defective items must be returned in their original packing materials
together with the supplied accessories.
2.2
Safety Measures
The following safety measures must be followed:
1. Never connect or disconnect the pump assembly with the titrator turned on.
2. Verify that the burette and the attached tubing are assembled correctly (see Section 8.1
Burette Maintenance for more details).
3. Always check that the titrant, solvent, waste bottles and the titration beaker are properly
assembled.
4. Always wipe up spills and splashes immediately.
5. Avoid the following environmental working conditions:
• Severe vibrations
• Direct sunlight
• Atmospheric relative humidity above 95% non-condensing
2-4
SETUP
• Environment temperatures below 10°C and above 40°C
• Explosion hazards
6. Have the titrator serviced only by qualified service personnel.
2.3
Installation
2.3.1
Titrator Top View
2-5
SETUP
2.3.2
Titrator Rear View
2.3.3
Titrator Left-side View
2-6
SETUP
2.3.4
Titrator Assembly
Note: Assembly operations must be completed before connecting the titrator to the power supply!
2.3.4.1
Connecting the Pumps
Dosing Pump:
The dosing pump is driven by a stepper motor, which provides 40,000 steps for a single
burette volume.
The pump housing also holds the motor, which automatically positions the valve for filling
and dispensing titrant. The dosing pump’s integrated sensors electronically recognize the
volume of any Clip-lockTM exchangeable burette system syringe.
Connect the dosing pump with the following steps (see Figure 1.):
(1) Retrieve the pump cable (PUMP 1) from inside the left bay. Connect the cable to
the pump as shown in Figure 1. The pump connector is located in the lower part
of the pump, near the motor.
(2) Lower the pump into the titrator, then slide it towards the front of the titrator
chassis until it is firmly latched.
(3) Secure the pump with the locking screw.
Figure 1
Air Pump:
The diaphragm air pump system is designed to work with the specially designed bottle top
assemblies. It allows the solvent in the titration vessel to be removed and/or replaced without
opening the titration vessel and exposing the interior of the vessel to ambient moisture from
atmospheric humidity.
2-7
SETUP
Connect the air pump with the following steps (see Figure 2.):
(1) Retrieve the air pump cable (PUMP 2) from inside the right bay. Connect the cable
to the air pump as shown in Figure 2. The air pump connector is located on the
left side of the motor.
(2) Lower the pump into the titrator, then slide it towards the front of the titrator
chassis until it is firmly latched.
(3) Secure the pump with the locking screw.
Figure 2
2-8
SETUP
2.3.4.2 Attaching the Burette
The 5 mL glass syringe features a highly precise inner diameter, which has been individually
verified to produce consistent titrant dosage according to standard ISO 8655. All of the
non-glass, wetted syringe and valve components, including the shoulders and plunger cap,
are constructed from PTFE to ensure resistance to both degradation due to Karl Fisher titrant
and water vapor permeability.
Make sure that the mark from the valve actuating cap and the burette body are aligned as
shown in Figure 3. Make sure that the valve positioning wheel on the burette pump is
oriented in the proper position as shown in Figure 5.
Figure 3
While ensuring the correct coupling between the syringe plunger (A) and the pump piston
(B) (see Figure 4), slide the burette into the support on the burette pump (see Figure 5).
Figure 4
Figure 5
2-9
SETUP
2.3.4.3 Attaching the Beaker and Dispensing Tip
The titration reaction takes place in a closed, conical, glass beaker, sometimes called a
titration vessel, reaction vessel, titration cell or reaction cell.
The primary design features of the HI 903 titration vessel include the following:
• Durability, easy to use, clean and maintain.
• Conical, glass vessel body which provides strong, repeatable mixing for reaction
volumes between 50 and 150 mL.
• Tightly sealing PTFE cover with low water vapor permeability and high chemical
resistivity to Karl Fischer reagents.
• A sample port which can both be rapidly removed and replaced when adding solid
samples and incorporates a septum through which liquid samples can be injected.
• A desiccant cartridge containing molecular sieves and/or indicating silica gel to dry
the ambient air which enters the cell as solvent, titrant and sample are added to or
removed from the vessel.
• Fittings made from a highly chemically resistant material called PEEK which, in
conjuction with o-rings, create tight seals between the vessel top and the electrode,
dispensing tip, solvent and waste tubes, sample port and desiccant cartridge.
To attach the beaker assembly, see Figure 6 and follow the steps below:
• Align the beaker support (D) with the base plate and attach by rotating clockwise.
Figure 6
2-10
SETUP
•
•
•
•
Place beaker ring (C) onto beaker support with the notches on top (see Figure 6).
Insert the glass beaker (B) into the beaker ring (C).
Add the stir bar to the glass beaker (B).
Carefully place the beaker top onto the beaker (B). Secure in place by pushing the
beaker top through the beaker ring (C) with the 4 notches of the beaker ring aligned
with the 4 steel pins of the beaker top (A).
• Twist the beaker ring (C) counter-clockwise to lock the top in place.
2.3.4.3.1 Beaker top
Warning: Do not over-tighten fittings! This may cause permanent damage to o-rings!
To assemble the 5 parts of the beaker top, see Figure 7 and follow the steps below:
Figure 7
Anti-Diffusion Dispensing Tip
The HI903 ships with the dispensing tip (A) and o-ring (B) installed. For initial setup, go to
third step:
• Push dispensing tip (A) through the dispensing tip o-ring (B) until the o-ring is at
the lip of the dispensing tip.
• Insert tip through the proper port. Orient the tip so that the angled portion is
directed toward the center of the assembly.
• Fasten the dispensing tubing from the burette assembly to the dispensing tip port
using the dispensing tip fitting (C). Ensure that the tip remains oriented toward the
center of the beaker.
2-11
SETUP
Karl Fischer Electrode
The Karl Fischer electrode consists of two parallel, platinum pins sealed into a 10mm diameter
glass body. Two steel pins connect the platinum elements to a standard BNC connector,
which allows for easy attachment to the HI 903.
Attach to the beaker top as follows:
• Carefully insert the electrode through a 10-mm fitting (E) and 10-mm o-ring (F).
• Insert electrode through proper port in beaker top (see Figure 7).
• While orienting electrode with pins aligned to the center of the beaker, fasten the
10-mm fitting (E) to the beaker top. The electrode above stirbar should be as far
down into the beaker as possible.
• Attach the electrode connector to the BNC connector on the back of the instrument.
Solvent Handling System
The HI903 ships with white plugs (G) in the solvent ports. To attach solvent bottle tubing or
waste bottle tubing, follow the steps below:
• Loosen the 5-mm fitting (H) on the solvent and/or waste port.
• Remove the desired plug/plugs (G).
• Insert the blue PTFE tubing from the solvent and/or waste bottle assemblies through
the 5-mm fittings (H) and 5-mm o-rings (I) until about 1 cm of tubing is visible
inside the beaker.
• Tighten the 5-mm fittings (H) until snug. This will cause the red silicone o-rings (I)
to seal around the tubes.
Sample Port Plug
The HI903 ships with the sample port plug assembled and installed. To reassemble, follow
the steps below:
• Insert a red rubber septum (J) into the septum holder (K).
• Fasten with a 10-mm fitting (E).
• Place the sample port plug o-ring (L) in the slit of the septum holder (K).
• Insert the assembled sample port plug into the dedicated port of the beaker top.
Desiccant Cartridge
• Insert the stem of a desiccant cartridge (M) with a plain cap (N) through a 10-mm
fitting (E) and 10-mm o-ring (F).
• Insert in the proper port of the beaker top.
• Fasten to the top with the 10-mm fitting.
2-12
SETUP
2.3.4.4
Electrical Connections
• Connect the KF electrode to the BNC connector (C).
• Connect the power adapter cable to the power input connector (B).
H
J
ON
A
Probe
USB
OFF
24VDC
Stirrer
Extension
B
c
D
E
F
G
I
Figure 8
Function
Type of Connector
A
Power switch
B
Power input (24 Vdc)
DC Power jack connector
C
KF probe
BNC socket
D
External magnetic stirrer
4-pin mini-DIN
E
Connector for expansion device
8-pin DIN socket
F
External PC keyboard
6-pin mini-DIN (Standard PS/2)
G
Analytical balance interface (RS232)
Standard DE-9 socket
H
PC interface (USB)
USB Standard Type B
I
External display
Standard VGA display 15-pin socket
J
Parallel Printer
Standard DB-25 socket
2-13
SETUP
2.3.5 Titrant, Solvent, Waste Bottle Assembly
The bottle top assemblies are equipped with desiccant cartridges containing indicating silica
gel which ensures that the air passing through the solvent handling system has been dried.
The desiccant has a limited capacity to absorb moisture and is typically exhausted after 2 to
4 weeks. Silica gel, indicating or otherwise, can be regenerated at 150 °C.
The bottle tops are constructed of PTFE and have been designed to accommodate reagent
bottles with GL-45 type threaded tops.
The waste and solvent bottle top assemblies include blue PTFE tubing blue for the handling
of liquid Karl Fischer solvent and a clear flexible silicone based tubing for use with the air
pump.
2.3.5.1 Titrant Bottle Assembly (HI 900530)
Caution: Most Karl Fischer titrants give off harmful vapors. Consult
manufacturer’s MSDS for safe handling guidelines.
To assemble the titrant bottle, see Figure 9 and follow the next
steps:
• Insert PTFE top (J) into a GL45 screw cap (E).
• Insert a desiccant cartridge (B) without hose-barbed cap (A)
through a 10-mm fitting (F) and 10-mm o-ring (G).
• Insert and screw the desiccant cartridge assembly into the
corresponding hole in the white PTFE top (J). Fasten with
10-mm fitting (F).
• Ensure that the tube protector (C) is installed on the aspiration
tubing (D).
• Insert the burette aspiration tubing (D) in the corresponding
3-mm fitting (H) and attach the 3-mm o-ring (I).
• Insert and screw the aspiration tube fitting into the corresponding
hole.
• Push the aspiration tubing fully into the titrant bottle until only
the tube protector (C) is visible outside of the titrant bottle (K).
• Screw GL45 cap (E) with full assembly onto the titrant bottle (A).
2-14
Figure 9
SETUP
2.3.5.2 Solvent / Waste Bottle Assembly (HI 900531)
Caution: Most Karl Fischer solvents give off harmful vapors.
Consult manufacturer’s MSDS for safe handling guidelines.
To assemble the solvent or waste bottle, see Figure 10 and
follow the next steps:
• Insert a PTFE top (J) into a GL45 cap (E).
• Screw on the desiccant cap with hose barb (F);
• Insert a desiccant cartridge (B) with hose-barbed cap (A)
through a 10-mm fitting (F) and 10-mm o-ring (G);
• Insert and screw the desiccant fitting into the corresponding
hole. Fasten the desiccant cartridge assembly to PTFE top (J)
with 10-mm fitting (F);
• Insert the solvent / waste tube (D) in the 5-mm fitting (H)
and attach the o-ring (I);
• Insert and screw the tube fitting into the corresponding hole.
• Screw GL45 (E) cap with full assembly onto titrant bottle.
• Add the air tube (C) to the desiccant cap (A) and connect it
to the corresponding position on the air pump. The “Fill”
position connects to the solvent bottle assembly. The “Empty”
position connects to the waste bottle assembly.
Figure 10
2-15
SETUP
2-16
USER INTERFACE
Chapter 3. Contents
3
USER INTERFACE .................................................................................. 3 - 3
3.1
Start Up................................................................................................. 3 - 3
3.2
Description ............................................................................................ 3 - 4
3.2.1 Keypad .................................................................................................... 3 - 4
3.2.1.1
Function Keys ..................................................................................... 3 - 4
3.2.1.2 Option Keys ........................................................................................ 3 - 4
3.2.1.3 Arrow Keys ........................................................................................ 3 - 5
3.2.1.4 Numeric Keys ..................................................................................... 3 - 5
3.2.1.5
Enter Key ........................................................................................... 3 - 5
3.2.2 Display .................................................................................................... 3 - 5
3.2.3 The Idle Screen ....................................................................................... 3 - 6
3.2.4 The Process Screen ................................................................................... 3 - 7
3.3
Menu Navigation ................................................................................... 3 - 8
3.3.1 Selecting an Option ................................................................................... 3 - 8
3.3.2 Selecting a Menu Item ............................................................................... 3 - 8
3.3.3 Entering Text ............................................................................................ 3 - 8
3.3.4 Saving Modifications .................................................................................. 3 - 9
3-1
USER INTERFACE
3-2
USER INTERFACE
3
USER INTERFACE
3.1
Start Up
Once the instrument is assembled and installed, follow the steps below to start the titrator:
• Connect the instrument to a power outlet with the supplied power adapter.
• Turn on the titrator using the power switch located on the back of the instrument.
• Wait until the titrator finishes the initialization process.
• Press
when prompted or wait a few seconds for titrator to start.
Note: All the performed initialization processes must be successfully completed. If one of
them is terminated by a “Failed” message, restart the titrator using the power switch.
If the problem persists, contact your dealer.
3-3
USER INTERFACE
3.2
Description
This chapter describes the basic principles of navigation through the user interface, selecting
fields and entering values from the keypad.
3.2.1
Keypad
The titrator’s keypad is grouped into five categories, as follows:
3.2.1.1
Function Keys
If one of these keys is pressed, the associated function is immediately performed. Some of
the keys are only active in specific screens:
Starts or stops titration sequence
Turns the stirrer ON and OFF (Idle mode only)
Reserved
Access the results menu
Displays contextual Help
3.2.1.2 Option Keys
These keys are assigned to the virtual keys on the display. Their functions are listed in the
boxes above the buttons and vary depending on the displayed screen.
An underlined virtual key can also be activated by pressing
3-4
.
USER INTERFACE
3.2.1.3
Arrow Keys
These keys have the following functions:
• Move the on-screen cursor.
• Increase and decrease the stirrer speed and other settings.
• In the alphanumeric screen, to select a character.
• To navigate through menu options.
3.2.1.4
Numeric Keys
Keys
to
Used for numeric entries.
Toggles between positive and negative values.
Decimal point.
Initiates entry of exponent for scientific notation.
3.2.1.5
Both
Enter Key
,
keys perform the same functions:
• Accepts alphanumeric data entry.
• Executes the default (underlined) virtual option key.
3.2.2
Display
The titrator has a large color graphical display. The standby mode screen is shown below
with short explanations of the screen segments.
The user interface contains several screens for each titrator function.
3-5
USER INTERFACE
3.2.3
The Idle Screen
After start up and initialization, the first screen displayed is the Idle Screen .
Idle Screen fields:
Method name:
Displays the name of the selected method.
Time and date:
Displays the current date and time.
Stirrer information:
Actual / Set stirrer speed is displayed in RPM. When stirrer is off,
the stirrer information is not displayed.
Titrant:
Displays the name of the current titrant.
Last Standardization:
Displays the titrant standardization date / time.
Reminders:
Indicates when a task needs to be performed and displays error
or warning messages.
3-6
USER INTERFACE
3.2.4
The Process Screen
When the user presses
while in Idle Screen, all titration related processes are started.
The titrator displays the Process Screen.
Process Screen fields:
Method name:
Displays the name of the selected method.
Time and date:
Displays the current date and time
Process stage field:
Displays the current process (Pre-titration, Drift Analysis, Standby,
Sample Analysis / Titrant Standardization).
Process status:
Displays the process status with a descriptive drawing.
mV reading:
Displays the KF electrode potential.
Dispensed titrant:
Displays the total volume of dispensed titrant.
Last dose:
Displays the last titrant dose volume.
Drift value:
Displays the drift value (when available).
Stirrer information:
Actual / Set stirrer speed is displayed in RPM.
Burette status:
A descriptive drawing is displayed indicating the burette is active
and cannot be removed.
Indicates when a task needs to be performed and displays error
or warning messages.
Reminders:
3-7
USER INTERFACE
3.3 Menu navigation
3.3.1
Selecting an Option
To select an option, simply press the option key below the
virtual key. For example, to access the Method Options
screen press the option key below it.
3.3.2
Selecting a Menu Item
To select an item from the menu screen use the arrow keys
and
to move the cursor.
When the menu is larger than the display, a scroll bar is
active on the right side. The
and
used to scroll through the pages.
keys can be
To activate the selected menu item, press
3.3.3
or
.
Entering Text
To enter text in an alphanumeric input box, first erase the
previous text by using
.
To enter a letter, highlight it using the arrow keys then
press
. Use the same procedure to enter the whole
name.
For editing, use the
and
keys.
When editing is complete, press
.
The method name will be updated and displayed in the
name field of the View/Modify Method screen.
When all the desired parameters have been set, press
3-8
.
USER INTERFACE
3.3.4
Saving Modifications
The Saving Method screen allows the user to save the
modifications. To exit from Saving Method screen without
saving, press
or highlight the Exit Without Saving
. To save the
Method option and then press
modifications highlight the Save Method option and then
press
.
Note: To access the contextual help menu, press
displayed screen. Press
or press
at any time. Help is related to the
again to return to the previous screen.
3-9
USER INTERFACE
3-10
GENERAL OPTIONS
Chapter 4. Contents
4
GENERAL OPTIONS ............................................................................. 4 - 3
4.1
Date and Time Setting ....................................................................... 4 - 3
4.2
Display Settings .................................................................................. 4 - 4
4.3
Beeper ................................................................................................. 4 - 5
4.4
Stirrer .................................................................................................. 4 - 5
4.5
Language ............................................................................................ 4 - 6
4.6
Estimated Cell Volume ........................................................................ 4 - 6
4.7
Titrant Database ................................................................................ 4 - 6
4.8
Standard Database ............................................................................. 4 - 7
4.9
Save Files to USB Storage Device ...................................................... 4 - 7
4.10 Restore Files from USB Storage Device ............................................. 4 - 9
4.11 USB Link with PC .............................................................................. 4 - 1 0
4.12 Calibration Check ............................................................................. 4 - 1 0
4.13 Setup Balance Interface ................................................................... 4 - 1 1
4.14 Printer Mode ..................................................................................... 4 - 1 2
4.15 Reset to Default Settings ................................................................. 4 - 1 3
4.16 Update Software ............................................................................... 4 - 1 3
4-1
GENERAL OPTIONS
4-2
GENERAL OPTIONS
4
GENERAL OPTIONS
The General Options screen gives access to options that are not directly related to the
from the main screen while in idle
titration process. To access this screen, press
mode. In Pre-titration, Drift Analysis, Standby or Titration process, the General Options can
be accessed by pressing the <<Home>> key on a PS/2 keyboard.
The available menus are described below:
4.1
Date and Time Setting
This screen allows the user to set the date and time.
Use the
and
keys or the numeric keys to modify the date and time.
Press
to move the cursor to the next field.
Press
or
to change the time format.
4-3
GENERAL OPTIONS
4.2
Display Settings
This screen allows the user to customize the viewing features of the display.
Option Keys:
Increases the backlight saver time interval
Decreases the backlight saver time interval
The backlight intensity can be adjusted using the
and
keys.
There are 8 levels of backlight intensity, ranging from 0 to 7.
A color palette is displayed in the center of the screen, allowing an easy selection of the
appropriate backlight intensity.
The backlight saver option protects the display during standby periods, when no keys have
been pressed for a set amount of time.
If the backlight is off, any keystroke will re-activate the backlight without performing any
action.
The range for backlight saver interval is between 1 and 60 minutes. To disable the backlight
saver increase the time to the maximum allowed. The “Off” indication will appear.
4-4
GENERAL OPTIONS
4.3
Beeper
This screen allows the user to turn the Beeper On (Enable) or Off (Disable).
The beeper will sound after a titration is completed, when an invalid key is pressed or when
a critical error occurs during titration.
4.4
Stirrer
This screen allows the user to select the internal magnetic stirrer, an external magnetic stirrer
or a user-controlled stirrer uncontrolled by the titrator (custom).
The external stirrer is automatically detected when it is connected.
Note: When the external stirrer is not connected the
“External” stirrer option.
key is not available for the
4-5
GENERAL OPTIONS
4.5
Language
Select an available language.
4.6
Estimated Cell Volume
This screen allows the user to enter the estimated volume of solution in the titration beaker.
4-6
GENERAL OPTIONS
4.7
Titrant Database
This screen allows the user to store information about all of the titrants available for use,
including the titrant name and Standardization information.
The titrant for the currently-selected method cannot be modified from this screen. For details
on the full functionality of the database, see section 5.5.12.
4.8
Standard Database
This screen allows the user to store information about all of the standards available for use,
including the standard name and concentration.
The standard for the currently-selected method can not be modified from this screen. For
details on the full functionality of the database, see section 5.5.11.
4-7
GENERAL OPTIONS
4.9
Save Files to USB Storage Device
This option allows the user to save files from titrator to a USB storage device.
On the titrator, the available file types are:
Standard Method Files
- HIxxxxyy.MTD (e.g.: HI8001EN.MTD, HI8101EN.MTD)
User Method Files
- USERxxxx.MTD (e.g.: USER0001.MTD)
Drift/Titration Report Files - DR_xxxxx.RPT, KF_xxxxx.RPT
(e.g.: DR_00001.RPT, KF_00001.RPT)
Insert the USB Storage Device into the USB port on the left side of the titrator.
Use the
and
keys to switch between the 3 file types. The number of files and each file
name on the titrator will be displayed.
Use the
and
keys to scroll through the list.
The option keys allow the following operations:
Returns to the General Options screen
Copies the highlighted file from titrator to a USB storage device
Copies all currently displayed files from titrator to a USB storage device
Deletes the highlighted file.
Deletes all currently displayed files.
The status of the transfer (“successful” / ”unsuccessful”) and the file name of the currently
processed file are displayed during copying or deleting.
Note: The saved files will be stored on the USB Key in the HI 903 folder, as follows:
- Methods: USB Drive: \ HI 903 \ Methods \ *.mtd
- Reports: USB Drive: \ HI 903 \ Reports \ *.rpt
4-8
GENERAL OPTIONS
4.10
Restore Files from USB Storage Device
This screen allows the user to transfer files from the USB storage device to the titrator.
Insert the USB Storage Device into the USB port on the left side of the titrator.
The file types that can be transferred are:
Standard Method Files
- HIxxxxyy.MTD (e.g.: HI8001EN.MTD, HI8101EN.MTD)
User Method Files
- USERxxxx.MTD (e.g.: USER0001.MTD)
Drift/Titration Report Files - DR_xxxxx.RPT, KF_xxxxx.RPT
(e.g.: DR_00001.RPT, KF_00001.RPT)
Use the
and
keys to select the file type.
Use the
and
keys to scroll through the list.
The number of files and the name of each file found on the USB storage device is displayed
on the screen.
The option keys allow the following operations:
Returns to the General Options screen.
Copies the highlighted file from the USB storage device to titrator.
Copies all currently displayed files from the USB storage device to
titrator.
Deletes the highlighted file from the USB storage device.
Deletes all currently displayed files from the USB storage device.
Note: In order to restore files from USB Key, please ensure that the methods and/or reports
you wish to transfer to the titrator are in the correct folder:
- Methods: USB: \ Drive \ HI 903 \ Methods \ *.mtd
- Reports: USB: \ Drive \ HI 903 \ Reports \ *.rpt
4-9
GENERAL OPTIONS
4.11
USB Link with PC
The USB Link feature is useful to transfer methods/reports directly to/from a PC. To use this
feature, connect the USB cable to the labeled connector on rear of titrator and connect to a
PC with HI 900 PC Application installed. The titrator automatically attempts to connect to
the PC while on this screen.
Inactive:
Active:
Ready:
Transmit:
Speed:
4.12
The titrator is not connected to the HI 900 PC Application.
The titrator is connected to the HI 900 PC Application.
The titrator is ready for commands.
It shows the progress of the current transfer.
It shows the baud rate for the communications port.
Calibration Check
This screen allows the user to verify the analog board calibration.
Two parameters can be verified, the electrode mV input and the electrode polarization current.
Both parameters can be measured on the same BNC connector using the calibration key and
a mV/µA multimeter (not included).
4-10
GENERAL OPTIONS
Disconnect the KF electrode, then connect the HI 900941 calibration key to the electrode
input (BNC connector).
Depending on which parameters you want to check, follow the indications below:
Checking the mV input accuracy:
Set the multimeter to mV mode.
If necessary, switch the calibration key to mV mode by pressing the red button.
Connect the calibration key banana plugs to the multimeter mV input.
Choose the current value using the
and
keys (from the pre-defined list).
Check if the millivolts indication is in accordance with the value displayed on the titrator
screen (within 2% accuracy).
Checking the µA output accuracy:
Set the multimeter to µA mode.
If necessary, switch the calibration key to µA mode by pressing the red button.
Connect the calibration key banana plugs to the multimeter mA input.
Check for the multimeter indication to be in accordance with the titrator µA prescribed value.
4.13
Setup Balance Interface
This screen allows the user to setup an analytical balance for automatic acquisition of sample
mass prior to titration or standardization.
The balance is connected to the titrator via RS 232 interface.
Press
to add a new balance to the list.
Press
to enable the balance interface feature.
Press
to disable the balance feature (automatic mass acquisition will not be available).
Press
to customize the serial communication parameters. The Balance Configuration
screen will open.
Press
list.
to remove the highlighted balance. Note: At least one balance must be in the
4-11
GENERAL OPTIONS
Configure the settings on the titrator Balance Configuration menu to match the settings for
your particular balance (baud rate, data bits, parity, stop bit number, request command
syntax). It may be necessary to change settings on your balance. Users should consult their
balance instruction manual.
Before leaving this screen be sure the connection with the balance is working properly by
key.
pressing the
4.14
Printer mode
This screen allows the user to select the printing mode: ANSI (default), ASCII and Text
mode.
ANSI mode:
Use this mode when your printer is set to ANSI. In this case all accepted characters /
symbols available on the titrator will be printed by your printer.
ASCII mode:
Use this mode when your printer is set to ASCII. In this case only some of the
accented characters / symbols available on the titrator will print.
Text mode:
Use this when you don’t need to print the accented characters.
4-12
GENERAL OPTIONS
4.15
Reset to Default Settings
This option restores the manufacturer settings.
Note: Please be careful!!! This will also delete all the user created methods, reports and
restore all manufacturer settings such as titrator configuration, standard method
parameters, etc.
4.16
Update Software
This screen allows the user to update the titrator software from a USB storage device
containing a software setup kit.
To update the software:
• Copy the “Setup 903” folder to a USB storage device.
• Insert the USB storage device into the titrator.
• Go to “General Options”, then “Update Spftware”. The titrator should display the current
and new software versions.
• Press
. When prompted, remove the USB storage device and restart the titrator.
4-13
GENERAL OPTIONS
4-14
METHODS
Chapter 5. Contents
5
METHODS .............................................................................................. 5 - 3
5.1
Selecting Methods ................................................................................ 5 - 3
5.2
Standard Methods................................................................................. 5 - 4
5.2.1 Upgrading Standard Methods....................................................................... 5 - 4
5.2.2 Deleting Standard Methods .......................................................................... 5 - 4
5.2.3 Restoring the Standard Methods to the Manufacturer’s Settings ....................... 5 - 5
5.3
User Methods ........................................................................................ 5 - 5
5.3.1 Creating User Methods ................................................................................ 5 - 5
5.3.2 Deleting User Methods ................................................................................ 5 - 6
5.4
View / Modify Method .......................................................................... 5 - 6
5.5
Method Options ..................................................................................... 5 - 7
5.5.1 Naming the User Method ............................................................................. 5 - 7
5.5.2 Method Revision ......................................................................................... 5 - 8
5.5.3 Method Type .............................................................................................. 5 - 8
5.5.4 Predispensing Amount ................................................................................ 5 - 9
5.5.5 Pre-Analysis Stir Time ................................................................................. 5 - 9
5.5.6 Stirring Speed ............................................................................................ 5 - 10
5.5.7 Stirbar Type ............................................................................................... 5 - 10
5.5.8 Drift Entry .................................................................................................. 5 - 11
5.5.9 Solvent Name ............................................................................................. 5 - 12
5.5.10 Sample Parameters (Sample Analysis mode only) ....................................... 5 - 12
5.5.10.1 Sample Determination ..................................................................................5 - 13
5.5.10.2 Sample Name.............................................................................................. 5 - 13
5.5.10.3 Sample Type ...............................................................................................5 - 14
5.5.10.4 Sample Size .................................................................................................5 - 14
5.5.11 Standard (Titrant Standardization mode only) .............................................. 5 - 15
5.5.11.1 Standard Name ............................................................................................ 5 - 15
5.5.11.2 Standard Type .............................................................................................5 - 15
5-1
METHODS
5.5.11.3 Concentration Unit ........................................................................................5 - 16
5.5.11.4 Water Content .............................................................................................5 - 16
5.5.11.5 Standard Size ...............................................................................................5 - 16
5.5.12 Titrant ..................................................................................................... 5 - 16
5.5.12.1 Titrant Name ...............................................................................................5 - 17
5.5.12.2 Titrant Type .................................................................................................5 - 17
5.5.12.3 Nominal Titrant Concentration ........................................................................5 - 18
5.5.12.4 Standardized Titrant Concentration ................................................................ 5 - 18
5.5.12.5 Titrant Age Reminder ....................................................................................5 - 18
5.5.13 Control Parameters ................................................................................... 5 - 19
5.5.13.1 Start Mode ................................................................................................... 5 - 19
5.5.13.2 Standby Mode .............................................................................................. 5 - 20
5.5.13.3 Standby Duration ..........................................................................................5 - 20
5.5.13.4 Imposed Current ..........................................................................................5 - 21
5.5.13.5 Dosing Parameters ....................................................................................... 5 - 21
5.5.13.6 Timed Increment .........................................................................................5 - 22
5.5.13.7 End Point Value .............................................................................................5 - 22
5.5.13.8 Signal Averaging ...........................................................................................5 - 23
5.5.13.9 Flow Rate ..................................................................................................... 5 - 23
5.5.14 Termination Parameters ............................................................................ 5 - 24
5.5.14.1 Maximum Duration ....................................................................................... 5 - 24
5.5.14.2 Maximum Titrant Volume .............................................................................. 5 - 25
5.5.14.3 Termination Criterion ..................................................................................... 5 - 25
5.5.14.4 EndPoint Stability Time ..................................................................................5 - 26
5.5.15 Result Unit .............................................................................................. 5 - 26
5.6
5-2
Printing ................................................................................................ 5 - 26
METHODS
5
METHODS
All of the parameters required to complete an analysis are grouped into a method.
The titrator is supplied with a pack of standard methods.
Standard and user methods can be upgraded, stored or deleted by connecting the titrator to
a PC using the HI 900 PC application or a USB storage device.
5.1
Selecting Methods
To select a method, press the
displayed.
key (when available). A list of available methods will be
In the Titration Methods screen, you can view the list of all available methods (standard
and user methods, if available).
. The name of the selected method
To select a method, highlight the method and press
will be displayed on the screen.
5-3
METHODS
5.2
Standard Methods
The standard methods were developed for the most common types of analysis. Also, the
standard methods can be used as a model to create new user methods.
Only specific method parameters can be modified by the user (see Section 5.5, Method
Options section).
5.2.1
Upgrading Standard Methods
To upgrade the titrator with new standard methods, follow the steps below:
From USB Storage Device:
• Insert the USB storage device into the USB port, located on the left side of the titrator.
• Access the General Options screen.
and
• Using the
keys, highlight the Restore Files from USB Storage Device
option and choose
.
• Using the
and
keys, navigate through file types to find “standard method
files”. The list with available standard methods on the storage device will be displayed.
• Press the
or
key to upgrade the titrator with the standard methods.
to return to General Options screen.
• Press
Note: See section 4.8 Restore Files from USB Storage Device.
From PC:
You can upgrade the titrator with standard methods from a PC using the HI 900 PC application
(see Section 4.9, USB Link with PC).
5.2.2
Deleting Standard Methods
Unnecessary standard methods can be removed from titrator by following the procedure
below:
From General Options screen:
• Access the General Options screen.
• Using the
press
and
keys, highlight the Save Files to USB Storage Device option and
;
• Using the
and
keys, navigate through the file types to find “standard method
files”. The available standard methods will be displayed.
• Press the
or
keys to remove unnecessary standard methods.
• Press
to return to the General Options screen.
From PC:
Unnecessary Standard Methods can be removed from the titrator using the HI 900 PC
application (see Section 4.9, USB Link with PC).
5-4
METHODS
5.2.3
Restoring the Standard Methods to the Manufacturer Settings
You can restore the standard method to the manufacturer setting by highlighting a standard
method and pressing
.
5.3
User Methods
These methods are defined by the user (usually by modifying a standard method).
The user methods can be developed in accordance with the requirements of the user. All
method parameters can be modified by the user.
5.3.1
Creating User Methods
To create a new user method start from a standard or user method, and follow these steps:
• Press
• Using the
from the main screen.
and
keys, highlight an existing method from the methods list.
• Press
. A new user method will be generated.
• Press
to activate the new created user method.
5-5
METHODS
Note: Only a limited number of user methods can be generated. The titrator can hold 100
methods (standard and user). When it is reached, a warning message will be displayed.
5.3.2
Deleting User Methods
To remove a user method, press
want to delete and press
(when available). Highlight the user method that you
. A screen will appear in order to confirm the deletion. Press
again to confirm, or press
5.4
to cancel the operation.
View / Modify Method
To modify the method’s parameters, press
from the main screen. A list of all the
parameters for the selected method will be displayed. Press the
the option that you want to modify and choose
5-6
.
and
keys to highlight
METHODS
Save method:
After making modifications highlight Save Method and press
After making modifications, press
5.5
Method Options
5.5.1
Naming the User Method
.
and select Save Method to keep the changes.
This option allows you to enter a name for the new method (up to 24 characters). Use the
arrow keys to navigate through the character table. Press
to add the highlighted
character to the method name.
5-7
METHODS
5.5.2
Method Revision
This option allows you to enter a string representing the current method revision. The
revision string format should be “X.Y”, where X and Y are numerical digits.
5.5.3
Method Type
Method type is a parameter listed in each method.
In order to conduct a titration the user has to choose between water determination in the
sample (Sample Analysis) or determination of titrant concentration (Titrant Standardization).
5-8
METHODS
5.5.4
Predispensing Amount
The titration time can be shortened by adding a large fraction of the titrant at the start of the
analysis, if the approximate water content of the sample is known.
The predispensing amount can be set to deliver between 1 and 90% of the titrant required
to reach the end point.
Setting the amount to 0% will disable the titrant predispensing feature.
5.5.5
Pre-Analysis Stir Time
To avoid erroneous results or unreacheable endpoints when analyzing samples with limited
solubility, the sample must be completely dissolved in the solvent prior to the start of a
titration.
The pre-analysis stir time can be set between 0 and 1000 seconds. After the sample is added
to the reaction vessel the titrator will stir for the set period of time before any titrant (excluding
predispensing) is added to the cell.
5-9
METHODS
5.5.6
Stirring Speed
The stirring speed can be set between 200 and 2000 RPM with a resolution of 100 RPM.
The stirrer will remain on, as long as the method is active. The speed can be adjusted at any
time by using the
5.5.7
and
keys when the stirrer is running.
Stirbar Type
Allows the user to edit the stirbar description.
5-10
METHODS
5.5.8
Drift Entry
Allows the user to choose the drift entry mode that is used during the titration process:
Automatic - the drift rate will be calculated automatically after the Pre-titration of the solvent.
User - the drift is set to a fixed value (entered by the user). The user enters the estimated
drift value. The drift analysis stage will be skipped and the user must enter the drift value
between 0.0 µg/min and 10.0 µg/min.
5-11
METHODS
5.5.9
Solvent Name
The user can enter a name for the solvent (up to 15 characters). Use the arrow keys to
navigate through the character table. Press
to add the highlighted character to the
solvent name.
5.5.10
Sample Parameters (Sample Analysis mode only)
This screen allows the user to access and configure the specific sample parameters.
5-12
METHODS
5.5.10.1 Sample Determination
This screen allows the user to select the sample determination mode.
Normal sample determination is performed through direct titration of samples that are soluble
in solvent or are finely divided and have homogeneous distribution in water.
External extraction is a method for the preparation of insoluble samples that require an
external water extraction. Using the proper solvents the sample is broken down into a fine
suspension from which, the water is extracted and released into the solvent.
External dissolution is a method for the preparation of the following types of samples:
• samples with a very high water content.
• samples that do not exhibit a homogeneous water distribution.
• slow-dissolving samples
• samples that can contaminate the titration vessel, thus reducing the accuracy, precsion,
number of titrations between solvent changes and raising the cell maintenance
requirements.
5.5.10.2 Sample Name
This screen allows the user to enter a name for the sample (up to 14 characters). Use the
arrow keys to navigate through the character table. Press
to add the highlighted
character to the sample name.
5-13
METHODS
5.5.10.3 Sample Type
This option allows the user to select the type of the sample: mass, volume or pieces.
This information is used to determine the appropriate sample size required by the titration
prior to analysis.
5.5.10.4 Sample Size
This option allows the user to enter the sample size. For external/Dissolution, enter the size
of the aliquot taken from the external vessel.
Before the titration is started, the user is asked again to enter the sample size. The sample
size (mass or volume) can be automatically acquired from the balance (when the balance
feature is enabled - see Section 4.11, Setup Balance Interface)
5-14
METHODS
5.5.10.5 External Solvent Size ( External Dissolution/Extraction Determination Modes Only).
Enter the mass of the solvent used for external dissolution or extraction of the sample.
Weigh the solvent after determining the solvent water content but before adding sample to
the solvent.
5.5.10.6 External Solvent Conc. (External Dissolution/Extraction Determination Modes Only).
5.5.10.7 Extracted Sample Size (External Extraction Determination Mode Only).
5.5.10.8 Dissoluted Sample Size (External Dissolution Determination Mode Only).
5.5.11
Standard (Titrant Standardization mode only)
This screen allows the user to define a list of Karl Fischer standards and customize related
parameters.
Using the
choose it.
and
keys, highlight the standard from the existing list and press
to
Press
if you want to create and add a new standard to the Karl Fischer standard data base.
Press
if you want to remove a Karl Fischer standard from the pre-defined list.
Press
if you want to edit the Karl Fischer standard parameters.
5-15
METHODS
Hanna Standard Methods (Titrant standardizations only) are designed to be used with standards
of specific types and water contenets. The HI903 will automatically select an appropriate
standard when such a method is selected. If there is no usable standard in the database, a
new one will be created.
5.5.11.1 Standard Name
This option allows the user to edit the name of the standard.
5.5.11.2 Standard Type
The user can select the type of the standard: Mass or Volume.
5.5.11.3 Concentration Unit
The concentration unit can be selected: %[W/W], ppm, mg/g, mg/mL.
5.5.11.4 Water Content
The concentration of the standard can be entered (content of water in the selected unit).
5.5.12
Standard Size
Enter the amount of standard used during titrant standardization.
5-16
METHODS
Before the titrant standardization is started, the user is asked again to enter the standard size.
The standard size (mass and volume) can be acquired automatically from a compatible
analytical balance (when the balance feature is enabled - see Section 4.11, Setup Balance
Interface).
5.5.13
Titrant
The user can access the Karl Fischer titrant database and customize related parameters.
Using the
choose it.
and
keys, highlight the titrant from the existing list and press
Press
to create a new titrant.
Press
to remove the titrant from the list.
Press
to edit the titrant parameters.
to
5-17
METHODS
Hanna Standard Methods are designed to be used with titrants of specific types and
concentrations. The HI 903 will automatically select an appropriate titrant when such a
method is selected. If there is no usable titrant in the database, a new one will be created.
5.5.13.1 Titrant Name
The user can edit the name for the titrant.
5.5.13.2 Titrant Type
The user can select the type of titrant.
5.5.13.3 Nominal Titrant Concentration
The user can enter the titrant concentration.
5-18
METHODS
5.5.13.4 Standardized Titrant Concentration
The user can manually enter the exact titrant concentration.
5.5.13.5 Titrant Age Reminder
The user can set a reminder that a verification of the titrant concentration is necessary.
When the set reminder period has expired, a warning message will be displayed on the main
screen. The reminder period will reset once the titrant is restandardized or the set time is
modified.
5.5.14
Control Parameters
The user can access and edit the parameters related to the titration.
5-19
METHODS
5.5.14.1 Start Mode
The user can select the starting mode for the titration. In Cautious mode, the titrant dosing
begins with the minimum dose in order to prevent over-titration. In Normal mode, the
titrant dosing begins with the median value between the minimum and maximum (i.e.
minimum dose 5 µL, maximum dose 25 µL, first dose will be 15 µL).
5.5.14.2 Standby Mode
When enabling this option the titrator will automatically revert to Standby mode after a
titration is completed.
See also the Standby Duration option.
5-20
METHODS
5.5.14.3 Standby Duration
The user can enter the period of time which the cell is kept dry and ready for subsequent
analysis after a titration has finished.
The user can set the standby period up to 72 hours.
5.5.14.4 Imposed Current
The HI 903 uses a bivoltametric electrode system. During a titration, the titrator monitors
the voltage required to maintain a constant polarization current (imposed current).
This option allows the user to select the electrode polarization current from the predefined list.
Note: Higher polarization currents will speed the contamination of the electrode and
potentially degrade samples.
5-21
METHODS
5.5.14.5 Dosing Parameters
The user can set the minimum and maximum volume of titrant / dose.
The titrant min and max dose values are determined by the type of reagent, reagent
concentration and the expected content of water in the sample. Correct determination of
these values is necessary in order to prevent over-titration and ensure the highest possible
accuracy.
5.5.14.6 Timed Increment
The user can enter the period of time between two successive doses.
The time period must be defined in accordance with the specifics of the analysis.
5-22
METHODS
5.5.14.7 End Point Value
This option defines the mV value at which the titration equivalence point (endpoint) has been
reached.
The pre-titration is completed when the mV is under the endpoint value, for a user defined
period of time (see Section 5.5.14.4, Endpoint Stability Time).
The mV value can be set from 5.0 to 600.0 mV.
5.5.14.8 Signal Averaging
This option enables averaging of the mV reading when enabled.
If 1 Reading is selected, the filtering is disabled. The titrator will take the last reading and
places it into a “moving window” along with the last 2, 3 or 4 readings (depending on the
selected option). The average of those readings is displayed and used for calculations.
Averaging more readings is helpful when a noisy signal is received from the electrode.
5-23
METHODS
5.5.14.9 Flow Rate
The flow rate for the dosing system can be set by the user in an interval of 0.1 to two times
the burette volume: 0.1 to 10 mL/min for a 5 mL burette
Note: The titrator will automatically detect the burette size and display the correct high limit
volume.
The flow rate is set for all burette operations.
5.5.15
Termination Parameters
This screen allows the user to set the control parameters related to the end of the titration.
5-24
METHODS
5.5.15.1 Maximum Duration
Specify the maximum time a titration is allowed to run. Once this point is reached the
titration will be terminated even if the end point is not reached.
The time can be set from 10 to 3600 seconds.
5.5.15.2 Maximum Titrant Volume
The maximum titrant volume used in the titration must be set according to the analysis.
If the titration end point is not reached, the titration will be terminated after the maximum
titrant volume has been dispensed. The error message (“Limits Exceeded”) will appear on
the display.
Range is from 0.100 to 50.000 mL.
5-25
METHODS
5.5.15.3 Termination Criterion
This screen allows the user to set the titration termination criterion.
mV End Point
Absolute Drift
Relative Drift
The titration is terminated when the potential remains below a set mV
value for a specified period of time (see Section 5.5.14.4, End Point
Stability Time).
The titration is terminated when the actual drift is less than the
predefined absolute drift value.
The titration is terminated when the actual drift is less than the sum
between the initial drift and the predefined relative drift.
5.5.15.4 End Point Stability Time
This screen allows users to set the time period in which the electrode potential must remain
stable.
This setting is in accordance with the mV end point termination criterion.
5-26
METHODS
5.5.16
Result Unit
The titrator provides the results based on the selected units.
5.6
Printing
To print method parameters, press
from the main screen, then
.
If no printer is connected to the dedicated socket, or if the printer is offline, an error message
will appear on the display (see Section 8.3.3, Connecting a Printer for information about
connecting a printer to the titrator).
5-27
METHODS
5-28
TITRATION
Chapter 6. Contents
6
TITRATION ........................................................................................... 6 - 3
6.1
Idle ........................................................................................................ 6 - 3
6.2
Pre-titration.......................................................................................... 6 - 3
6.3
Drift Analysis ........................................................................................ 6 - 4
6.4
Standby ................................................................................................. 6 - 5
6.5
Sample Analysis .................................................................................... 6 - 6
6.6
Titrant Standardization ........................................................................ 6 -11
6-1
TITRATION
6-2
TITRATION
6
TITRATION
6.1
Idle
The titrator first enters Idle mode when it is switched on. All of the HI 903’s software features
and adjustable parameters can be accessed from the Idle state. This includes all of the
user-adjustable method parameters, solvent handling system, file transfers, calibration checks,
software upgrades, options for interface with PC and accessories as well as burette options.
To access the titration menu (Process screen) press
.
The titration (Sample Analysis or Titrant Standardization) is performed with the selected method.
Be sure that the selected method is customized in accordance with the specifics of the application.
Before performing a titration make sure that the following conditions are met:
• All of the attached systems (e.g.: solvent system) are properly assembled.
• The right amount of solvent is present in the beaker (between the min and max
marks) for best reproducibility.
The following intermediary stages are performed automatically before starting the analysis:
• Solvent pre-titration
• Drift analysis (Automatic Drift Entry only)
When the drift analysis process is finished, the titrator enters Standby mode. At this point,
a titration can be initiated.
6.2
Pre-titration
In pre-titration the residual water on the interior surface of the titration vessel, the water
contained in the entrapped air and the small amount of water from the solvent is eliminated.
The HI 903 reacts residual water by adding titrant until the specified endpoint potential is
reached. This setting is associated with the active method. After the electrode potential has
stabilized, the titrator moves into the Drift Rate Determination Stage.
When the pre-titration is started, the stirrer is automatically turned on (when Internal or
External stirrer is selected).
6-3
TITRATION
During the pre-titration the user cannot change the currently selected method or access the
method parameters.
Note: If the pre-titration lasts longer than 30 minutes the titrator switches to Idle mode.
Errors may have occurred in your titration system (beaker is not properly sealed,
wrong or missing titrant, unconnected or bad electrode, etc.). Check the system and
start the pre-titration again.
6.3
Drift Analysis (Automatic Drift Entry only)
While in this mode the HI 903 conducts an automatic one minute analysis which determines
the amount of moisture leaking into the cell from the atmosphere. Despite the titration vessel
being tightly sealed, water will still seep into the cell. The amount of water that migrates into
the cell per unit time is known as the background drift rate, or the drift rate.
The drift rate is determined by keeping track of the number of very small, successive doses of
titrant required to maintain the ‘dryness’ of the solvent over the course of a minute. The rate at
which water leaks into the cell is then calculated and reported by the HI 903 in units of µg/
min.
The HI 903 uses the drift rate determined during this state to automatically subtract the
quantity of water which leaks into the cell during a titration from titration results. This is
especially important for titration accuracy when analyzing samples with very low water content
where the amount of water which has leaked into the cell is a considerable fraction of the
total water titrated during the analysis.
When the drift becomes stable the titrator switches to Standby mode.
During the drift analysis, if the titrator cannot maintain cell dryness, the titrator reverts to
pre-titration.
Note: If the drift entry mode is set as Manual the drift analysis stage is skipped.
6-4
TITRATION
6.4
Standby
After the drift rate has been determined, the HI 903 moves into Standby mode. In standby
mode the dryness of the titration cell is maintained and the drift rate is continuously monitored
and updated.
From Standby mode a sample analysis, titrant standardization or drift rate logging session
can be launched as well as method selection, customization of method parameters, and
general options (external keyboard only, by pressing <<Home>>).
After an initial titrator setup and prior to the first titration or standardization, the drift rate
should be allowed to settle in Standby mode for 45 min. This ensures that the drift rate is
stable and reflects the actual rate at which water vapor is entering the cell rather than
representing a slow drying of the air between the solvent and the top of the cell. The
stabilization can be verified by examining the drift rate vs. time curve which can only be
accessed from standby mode.
During standby, if the drift becomes unstable, the titrator switches back to Drift Analysis
mode.
6-5
TITRATION
6.5
Sample Analysis
While in Standby mode, press
.
Note: If the drift value is zero a warning message appears to inform the user that the
solvent may be overtitrated.
The user can choose to continue the titration by pressing
mode by pressing
or to return to Standby
in order to wait until the drift is stabilized at a higher value.
Entering estimated concentration: The user has the option to enter the estimated
concentration, which is in accordance with the pre-titration amount and the suggested
optimal limits.
Adding the sample: The user must add the sample into the titration vessel via the sample port.
Entering sample size: The user has two options to determine the sample size.
6-6
TITRATION
Manual Entering
Follow the steps below:
Sample size by mass:
1. Measure the mass of the sample in a weigh boat or syringe.
2. Slide the sample plug up out of the vessel top to open the sample port, or insert
the syringe needle through the septum.
3. Rapidly add the sample through the sample port ensuring that ALL of the sample is
transferred to the solvent. Avoid any contact between the sample and the cell
cover.
4. Replace the sample plug into the cell cover, or remove the syringe from the septum.
5. Determine the mass of the ‘empty’ weigh boat or syringe.
6. Calculate the mass of the sample added (subtract the mass of the emptied weigh
boat or syringe from the mass of the full weigh boat or syringe).
7. Enter the calculated mass of the sample.
Sample size by volume:
1. Attach a long needle (approximately 6 cm for best control) to a precision-volume
syringe large enough to hold at least one complete sample volume.
2. Rinse the syringe and needle with sample several times by drawing in a small
portion of sample, fully extending the plunger, shaking to coat the syringe interior
and expelling the sample into a waste collection container.
3. Draw enough sample into the syringe for at least one titration.
4. Dry the outside of the needle with a lint free wipe or tissue.
5. Insert the needle through the septum in the sample port. Push the syringe through
the septum until the end of the needle is approximately 1 cm from the surface of
the solvent.
6. Steadily dispense the appropriate volume of sample ensuring that the sample is
introduced directly into the solvent and does not splash or spatter onto the wall of
the titration vessel, electrode, or dispensing tip.
7. Draw a small amount of air from inside the cell into the syringe to ensure that no
sample drops remain on the tip of the needle.
8. Remove the syringe and needle from the septum taking care to not touch the
needle to the solvent or other internal cell components.
9. Enter the calculated mass of the sample.
Sample size by pieces:
1. Enter the number of pieces that were added to the titration vessel.
6-7
TITRATION
Automatic Mass Acquisition from Analytical Balance
It is available only for Sample Mass and Sample Volume types.
The sample size can be automatically acquired from the balance when connected to the
titrator using the RS232 interface.
Note: The user must make sure that the balance and the titrator are properly configured and
the balance feature is enabled (see Section 4.10, Setup Balance Interface).
Procedure
1. Place the syringe or the weighing boat containing the sample on the balance.
2. Wait until the reading is stabilized and press
.
3. Add the sample in the titrator vessel.
4. Place the empty syringe or weighing boat on the balance again.
5. Wait for the reading to stabilize and press
6-8
.
TITRATION
The titrator returns to the previous screen and the sample size is automatically updated.
Now the analysis can be started.
Start Analysis
Press
to begin analysis.
Suspend Titration
While the titration is in progress, you can temporarily stop it by pressing
will stop dispensing titrant.
To continue the titration press
. The burette
.
6-9
TITRATION
Viewing the Titration Curve
During a titration, the titration curve can be displayed on the Titration Graph screen, by
pressing
. The titration ID report is also displayed inside the graph window.
Press
to stop the titration manually and return to Idle mode.
Press
to stop the titration and return to Standby mode.
When the end point is reached the titration is finished and the following screen is displayed.
This screen displays information about the titration (duration, drift value used for compensation,
sample size, titrant concentration, dispensed titrant volume, titration report ID).
Press
to see the titration report.
Press
to see the titration graph.
Press
to print the report.
6-10
TITRATION
Averaging Sample Analysis Results
By pressing
, results will be added to the Sample Analysis History in order to obtain
an average of titration results.
Use the
Use
and
keys to scroll the concentration results list.
to choose the sample concentration results that will be used for averaging.
Note: When there are no results selected dashes will appear in the Average Sample
Concentration and the Standard Deviation fields.
6.6
Titrant Standardization
While in Standby mode, press
.
Note: If the drift value is zero, a warning message appears to inform the user that the
solvent may be overtitrated.
6-11
TITRATION
Adding the standard: The user must add the standard into the beaker and enter the
standard size. The units of sample size are determined by the method setting.
Follow the same procedure as for adding samples (see Section 6.5, Sample Analysis).
Start Standardization
Press
to begin standardization.
Note: During titrant standardization the user has the same options as a sample analysis (see
Section 6.5, Sample Analysis).
When the titrant standardization is finished the user has two options to update the titrant
concentration:
By pressing
the titrant is updated with the current result.
By pressing
6-12
the user can average the titrant concentration using more results.
TITRATION
Averaging Titrant Standardization Results
By pressing
results can be added to the sample analysis history in order to obtain an
average of titrant concentration.
Use the
Use
Press
and
keys to scroll the concentration results list.
to choose the titrant concentration results that will be used for averaging.
to update the concentration with the current average.
Note: When there are no results selected dashes will appear in the average titrant
concentration and the standard deviation fields.
is not available in this
case.
6-13
TITRATION
6-14
AUXILIARY FUNCTIONS
Chapter 7. Contents
7.
AUXILIARY FUNCTIONS ....................................................................... 7 - 3
7.1
Air Pump ............................................................................................... 7 - 3
7.1.1 Filling the Beaker ........................................................................................ 7 - 3
7.1.2 Emptying the Beaker...................................................................................7 - 3
7.2
Burette .................................................................................................. 7 - 4
7.2.1 Prime Burette ........................................................................................... 7 - 4
7.2.2 Rinse Tip ................................................................................................. 7 - 5
7.2.3 Manual Dispense .......................................................................................7 - 5
7.2.4 Purge Burette ........................................................................................... 7 - 6
7.3
Stirrer ....................................................................................................7 - 6
7.4
Results .................................................................................................. 7 - 7
7.4.1 Review Last Titration Report ...................................................................... 7 - 7
7.4.2 Review Available Reports ...........................................................................7 - 8
7.4.3 GLP Data ................................................................................................. 7 - 8
7.4.4 Meter Information ................................................................................ ... 7 - 9
7.4.5 Setup Titration Report ............................................................................... 7 - 1 0
7-1
AUXILIARY FUNCTIONS
7-2
AUXILIARY FUNCTIONS
7
AUXILIARY FUNCTIONS
7.1
Air Pump
The air pump is used to add or remove the solvent in the titration beaker without exposure
to atmospheric moisture.
To start the air pump, press
from the Idle screen.
The air pump can be stopped by pressing
7.1.1
.
Filling the Beaker
To add solvent to the titration vessel:
1. Depress the ‘fill’ button on the top of the pump housing. Pressing the rubberized
button creates a seal which provides the pressure required for the solvent to flow
into the cell. Hold the button down until the level of solvent inside the cell reaches
the ‘min’ indicator line. If the solvent is not flowing, or is flowing very slowly, verify
that the bottle top assemblies are properly assembled and tightly sealed and that
the liquid handling tubing reaches the bottom of the solvent bottle.
2. When the level of solvent inside the titration cell reaches the ‘min’ line release the
Fill button and deactivate the air pump with the
option key.
3. The HI 903 will prompt the user to verify that the titration cell has been filled to
the ‘min’ line (approx. 50 mL).
Press
7.1.2
to return to Idle screen.
Emptying the Beaker
To remove the waste from the titration vessel:
1. Loosen the waste tube fitting slightly and slide the waste tube down until it reaches
the bottom of the beaker.
2. Press and hold the Empty button until all of the waste is removed from the beaker.
3. Return the waste tube back into its original position and re-tighten the fitting.
7-3
AUXILIARY FUNCTIONS
7.2
Burette
To access the Burette screen, press
Highlight the desired option and then press
from the Idle screen.
.
Note: Do not perform burette functions with solvent below the “Min” sign. Doing so could
spray titrant on the beaker top or other components.
7.2.1
Prime Burette
After solvent has been added to the titration cell, the burette can be primed with titrant. The
priming process consists of several cycles of filling and emptying the burette with titrant. It
ensures that any air, water or water vapor in the burette or tubing is removed.
Two rinse cycles of burette are shown in the figure below. The dispensing tube is connected
on the right side and the aspiration tube on the left side.
Note: Before starting this operation, the aspiration tube must be inserted into the titrant
bottle.
7-4
AUXILIARY FUNCTIONS
To prime the burette, select Prime Burette from the Burette screen. Enter the number of
rinses and press
.
The number of burette rinses can be set between 1 and 5 (we recommend at least three
rinses to assure that the air bubbles are completely removed).
7.2.2
Rinse Tip
A 0.25 mL dose of titrant will be dispensed from the burette when this operation is selected.
This operation will eliminate any contamination from the anti-diffusion dispensing tip.
7.2.3
Manual Dispense
Manual Dispense allows a defined titrant volume to be be dosed. Select the Manual Dispense
option and press
. The Manual Volume Dispense screen will become active and the
display will prompt you to enter the desired volume to be dispensed.
7-5
AUXILIARY FUNCTIONS
The manual dispense volume must be between the limits shown below:
0.001 to
7.2.4
4.500 mL for a 5-mL burette
Purge Burette
This option allows the burette to be emptied before cleaning and/or storing.
Note: Before starting this operation, remove the aspiration tube from the titrant bottle.
The figures below show the steps in a purge burette operation.
7.3
Stirrer
Note: When custom stirrer is selected (see Section 4.4, Stirrer in General Options chapter),
the commands related to the stirrer are not available.
The stirrer can be turned on and off by pressing
while in Idle mode.
During the titration process the stirrer cannot be turned off.
The stirring speed is set within the method parameters (see Section, 5.5.6 Stirring Speed).
During the titration process, the stirring speed can be manually adjusted by using the
keys.
7-6
and
AUXILIARY FUNCTIONS
7.4
Results
To access the “Data Parameters” screen, press
button.
From the Data Parameters screen you can access the following options:
7.4.1
Review Last Titration Report
The last titration report can be reviewed.
The titration graph can be reviewed by selecting
.
The information seen in the report is based on the selections made in the Setup Titration
Report screen.
The following option keys are available:
Review the titration graph.
Print the titration report.
7-7
AUXILIARY FUNCTIONS
7.4.2
Review Available Reports
Up to 100 reports can be saved on the titrator. To view one of the saved reports highlight a
report and then press
.
All of the saved reports can be reviewed and printed.
The report contains only the information selected in the Setup Titration Report screens
during report generation.
The following option keys are available:
Review the titration graph.
Print the titration report.
Delete the selected report.
7.4.3
GLP Data
GLP data can be optionally be displayed in each report.
Enter up to 20 alphanumeric characters for each option from GLP Data screen.
Company Name:
7-8
Allows the company name to be recorded in each report.
AUXILIARY FUNCTIONS
Operator Name:
Allows the operator name to be recorded in each report.
Electrode Name:
Allows the electrode name to be recorded in each report.
Fields 1, 2, 3:
Allows any additional information to be recorded in each report.
The fields must be selected from the Setup Titration Report screen (see Section 7.4.5,
Setup Titration Report) in order to be displayed in the titration report.
7.4.4
Meter Information
Displays titrator configuration data.
Titrator Serial Number: The serial number of the titrator base board.
Analog Board Serial Number: The serial number of the titrator analog board.
Dosing Pump Serial Number: The serial number of the connected pump.
Titrator Software Version: The current software version installed on the titrator.
Base Board Software Version: The current software version present on the base board
of the titrator.
Dosing Pump Software Version: The current software version for the pump.
Analog Calibration Date: Manufacturer calibration date of analog board.
Note: If more than 1 year elapsed from the calibration date of the analog board, the
message Analog Calibration Due will appear on the main screen and analog
board recalibration must be performed.
7-9
AUXILIARY FUNCTIONS
7.4.5
Setup Titration Report
Customize a unique report to record the titration results. An asterisk means that it will be
included in the titration report.
7-10
MAINTENANCE, PERIPHERALS
Chapter 8. Contents
8
MAINTENANCE, PERIPHERALS .............................................................8 - 3
8.1
Burette Maintenance ............................................................................ 8 - 3
8.1.1 Burette Assembly ......................................................................................8 - 3
8.1.2 Changing the Burette .................................................................................8 - 3
8.1.3 Disassembling the Dispensing Tube and Aspiration Tube ............................... 8 - 4
8.1.4 Assembling the Dispensing Tube and Aspiration Tube ................................... 8 - 4
8.1.5 Cleaning the Burette ..................................................................................8 - 5
8.1.6 Burette Preparation (Filling with Titrant) ...................................................... 8 - 7
8.2
Probe Maintenance ............................................................................... 8 - 8
8.3
Peripherals ............................................................................................8 - 8
8.3.1 Connecting an External Display ...................................................................8 - 9
8.3.2 Connecting an External PC Keyboard ...........................................................8 - 9
8.3.3 Connecting a Printer ..................................................................................8 - 1 1
8.3.4 Connecting to a Computer ..........................................................................8 - 1 1
8-1
MAINTENANCE, PERIPHERALS
8-2
MAINTENANCE, PERIPHERALS
8
MAINTENANCE, PERIPHERALS
The 5-mL burette included with the titrator exceeds the ISO 8655 standard for the accurate
delivery of liquids by a motor-driven piston burette.
8.1
Burette Maintenance
8.1.1
Burette Assembly
The burette is delivered with a 5-mL syringe inside and with all the accessories mounted (see
Section 2. 3. 4. 2, Attaching the Burette for assembly details). The burette assembly consists
of a rigid housing which holds the glass syringe, a 3-way valve and is connected to titrant
tubing with specially designed fittings.
Note: The dispensing tube has two fitted ends. One end is equipped with a burette fitting
and the other is equipped with a beaker fitting.
8.1.2
Changing the Burette
Remove the burette from the pump assembly by sliding it forward and then slide the new
burette into place (see the picture below).
8-3
MAINTENANCE, PERIPHERALS
8.1.3
Disassembling the Dispensing Tube and Aspiration Tube
Both the aspiration and the dispensing tubes have a fitting and a tube protector. The
aspiration tube will be mounted in the left side and the dispensing tube will be mounted in
the right side of the burette.
To remove the dispensing tube and the aspiration tube follow these steps:
• Slide the tube protector up (A);
• Remove the tube lock (B) from the burette holder;
• Unscrew the fitting (C);
• Repeat these steps for the aspiration tube.
8.1.4
Assembling the Dispensing Tube and Aspiration Tube
To attach the dispensing tube and the aspiration tube follow these steps:
• Insert the end of the dispensing tube with the tan-colored fitting (A) into the valve
outlet;
• Screw in the fitting so that the highest of its 9 cuts stays vertical in the final position;
• Bend the tube up into vertical position to enter the highest cut of the fitting;
• Put the tube lock on (B) the fitting;
• Slide down the tube protector (C) into the dedicated gap of the tube lock;
• Repeat these steps for the aspiration tube.
8-4
MAINTENANCE, PERIPHERALS
8.1.5
Cleaning the Burette
To clean the burette, follow these steps:
• If the burette is filled with titrant, remove the aspiration tube from the titrant bottle
and purge burette (see Section 7.2.4, Purge Burette).
• Insert the aspiration tube into the Karl Fischer solvent.
• Prime burette to fill the burette with solvent (use 2 rinses) (see Section 7.2.1, Prime
Burette).
• During second refilling of the burette remove the aspiration tube from the solvent or
cleaning solution and allow the air to replace the liquid in the burette. This will clean
the aspiration tube.
If this simple cleaning procedure is not adequate, continue with these steps:
• Slide the burette out from the pump assembly.
• Remove the dispensing and aspiration tubes. Clean them separately or insert new
ones.
• Remove the protective cap from the bottom of the burette assembly by using the
special tool (HI 900942).
• Remove the syringe from the burette assembly by unscrewing it with your fingers.
• Extract the piston from the syringe.
• Clean both the piston and the syringe with appropriate cleaning solution.
• Remove the excess liquid.
8-5
MAINTENANCE, PERIPHERALS
Warning: Avoid contact with the titrant with bare hands.
Avoid spilling titrant.
Clean the external side of the syringe and piston to remove aggressive chemicals.
Do not touch the PTFE part of the piston or internal walls of the burette with bare
hands or greasy materials.
Consult Manufacturer’s MSDS for safe handling instructions.
• Reinsert the piston into the syringe.
• Reinsert the syringe by screwing it in the valve with your fingers.
• Reinsert the protective cap to the bottom of the burette assembly. Carefully position
the cap into the burette.
• Slide the burette into the burette stand. Position the piston shaft to couple the pump
correctly.
• Priming the burette three times with new titrant is recommended.
8-6
MAINTENANCE, PERIPHERALS
8.1.6
Burette Preparation (Filling with Titrant)
Before starting a titration, the burette must be properly filled with titrant in order to
obtain an accurate and repeatable result. To fill the burette, follow the next steps and
recommendations:
• If necessary, clean the burette and make sure it is empty and dry.
• From the main screen press
.
• Highlight Prime Burette option and press
.
• Enter the number of times the burette needs to be rinsed (minimum three rinses are
recommended allowing air bubbles to be evacuated).
• Press
.
• Insert the aspiration tube into the titrant bottle only when the piston is going down
and has reached about ¼ from the top.
To avoid the presence of air bubbles inside the burette, make sure to have continuous liquid
flow inside the burette and a little air just above the liquid level during the first filling is
normal. The next filling will evacuate all of the air, no air will be left in the valve.
Sometimes during this process, slight finger tapping on the tubes is helpful to remove any
residual air bubbles from the tubes.
8-7
MAINTENANCE, PERIPHERALS
8.2
Probe Maintenance
Proper probe maintenance is crucial for reliable measurements and extending the life
of the probe. The frequency of maintenance will depend largely on the type of samples
that are analyzed. Maintenance may be required if any of the following are observed:
• Slow or no electrode response;
• Noisy mV readings;
• Debris on or between electrode pins
• Coating on electrode pins
If these signs are observed, the electrode pins may be dirty. Rinse the electrode with
a solvent that is appropriate for the type of sample used – methanol is usually sufficient.
Allow the probe to dry completely before re-installing.
If a more thorough cleaning is required, soak the electrode in HI 7061 Electrode
Cleaning Solution for General Use for several hours, then rinse with water followed by
methanol. Allow to dry before re-installing.
After allowing the probe to dry, inspect the glass cracks, especially near the electrode
pins. Replace the electrode if any cracks are found.
Warning: Take care to protect the electrode pins from damage! Avoid using brushes/
abrasives to clean the pins. Pins can easily bend, which will cause permanent
errors in mV readings!
8.3
Peripherals
Warning! Connection/disconnection of POWER CORD, PUMP ASSEMBLY, EXTERNAL PC
DISPLAY, PRINTER, RS232 INTERFACE or EXPANSION DEVICE must be done
only when titrator and external devices are turned off.
8-8
MAINTENANCE, PERIPHERALS
8.3.1
Connecting an External Display
The information shown on the titrator display can be viewed also on a Standard VGA display
connected with a 15-pin cable, as presented below.
Connect the external display to the display socket.
Turn on the titrator and then the external display.
8.3.2
Connecting an External PC Keyboard
This connection allows you to use an external PS/2 PC Keyboard in addition to titrator’s
keypad.
Connect an external PC Keyboard (PS/2 connector).
8-9
MAINTENANCE, PERIPHERALS
The correspondence between the Titrator’s Keypad and the United States 101-type external
keyboard are:
External PC Keyboard
(United States 101)
Titrator Keypad
Function Key F-1
Function Key F-2
Function Key F-3
Function Key F-4
Function Key F-5
Option Key 1 (from left to right)
Function Key F-6
Option Key 2 (from left to right)
Function Key F-7
Option Key 3 (from left to right)
Function Key F-8
Option Key 4 (from left to right)
Function Key F-9
Option Key 5 (from left to right)
Function Key F-10
Arrow Key: Up
Arrow Key: Down
Arrow Key: Left
Arrow Key: Right
Page Up
Page Down
Numeric Keys: 0 to 9
to
Tab
Enter
,
Home (access General Options)
Alphanumeric Keys
8-10
Allow alphanumeric entries.
MAINTENANCE, PERIPHERALS
8.3.3
Connecting a Printer
A variety of parallel printers can be connected to the parallel port of the titrator using a
standard DB25–pin cable.
Warning: The titrator and the external printer must both be OFF before they are connected.
Connect the external printer to the standard 25–pin Socket.
Turn on the titrator and then the printer.
8.3.4
Connecting to a Computer
The titrator can be connected to a computer using a USB cable. HI 900 PC application
needs to be installed on the PC.
Connect the cable to the USB port on the rear panel of the titrator.
Connect the cable to the USB port on the PC.
8-11
MAINTENANCE, PERIPHERALS
Select the USB Link with PC screen on the titrator by following the path:
General Options - USB Link with PC
Launch the HI 900 PC application and then select the appropriate USB port on the PC.
The HI 900 PC application allows the transfer of files (methods and reports) between titrator
and PC.
8-12
METHODS OPTIMIZATION
Chapter 9. Contents
9
OPTIMIZATION ..................................................................................... 9 - 3
9.1
Titrator Settings ................................................................................... 9 - 3
9.1.1 Control Parameters.................................................................................... 9 - 3
9.1.1.1 Endpoint Potential and Polarization Current ........................................................9 - 3
9.1.1.2 Dosing Parameters ..........................................................................................9 - 4
9.1.1.2.1 Minimum Dose ........................................................................................9 - 4
9.1.1.2.2 Maximum Dose .......................................................................................9 - 4
9.1.1.3 Timed Increment ............................................................................................9 - 5
9.1.1.4 Start Mode .....................................................................................................9 - 6
9.1.1.5 Signal Averaging ..............................................................................................9 - 6
9.1.1.6 Flow Rate .......................................................................................................9 - 6
9.1.2 Termination Parameters .............................................................................. 9 - 6
9.1.2.1 Stability Time ..................................................................................................9 - 6
9.1.2.2 Drift Stop Termination Criteria ........................................................................... 9 - 6
9.1.2.2.1 Relative Drift Stop ................................................................................... 9 - 7
9.1.2.2.2 Absolute Drift Stop .................................................................................. 9 - 7
9.1.3 Method Options .......................................................................................... 9 - 8
9.1.3.1 Pre-Dispensing Amount .................................................................................... 9 - 8
9.1.3.2 Pre-Analysis Stir Time ......................................................................................9 - 8
9.1.3.3 Stirring Speed ..................................................................................................9 - 8
9.1.3.4 Background Drift Rate Entry............................................................................. 9 - 8
9.2
The Sample ........................................................................................... 9 - 9
9.2.1 Proper Sampling Procedure ......................................................................... 9 - 9
9.2.2 Determining the Optimal Sample Size .......................................................... 9 - 9
9.2.3 Solid Samples ............................................................................................. 9 - 1 0
9-1
METHODS OPTIMIZATION
9.2.4 Liquid Samples ........................................................................................ 9 - 1 1
9.2.5 Sample Preparation Techniques ................................................................... 9 - 1 2
9.2.5.1 Internal Extractions .........................................................................................9 - 1 2
9.2.5.2 Dilutions ..........................................................................................................9 - 1 2
9.2.5.3 External Dissolution .........................................................................................9 - 1 3
9.2.5.4 External Extractions .........................................................................................9 - 1 3
9.2.5.5 Homogenization ..............................................................................................9 - 1 4
9.2.5.6 Heating ...........................................................................................................9 - 1 4
9.3
Karl Fischer Reagent System ................................................................ 9-15
9.3.1 Reagent System Classification ................................................................... 9 - 1 5
9.3.1.1 One-Component Reagent Systems .................................................................. 9 - 1 5
9.3.1.2 Two-Component Reagent Systems .................................................................. 9 - 1 5
9.3.1.3 Reagents for Aldehydes and Ketones ............................................................... 9 - 1 5
9.3.2 Choosing and Modifying a Solvent ............................................................... 9 - 1 6
9.3.3 Water Standards ......................................................................................... 9 - 1 6
9.3.4 Standardizing the Titrant ............................................................................. 9 - 1 7
9-2
METHODS OPTIMIZATION
9
OPTIMIZATION
9.1
Titration Settings
The default settings included with the standard methods have been developed by Hanna
Instruments in order to provide accurate results for the majority of samples without requiring
additional analyst input or method fine-tuning. However, in order to suit a wider variety of
sample types and matrices, all of the HI 903 titration parameters are customizable.
This section provides the descriptions of critical titration parameters necessary for an analyst
to modify a standard method or develop a titration method from scratch.
HI 903 methods can be modified and customized based on the requirements of the sample,
sample matrix and the Karl Fischer reagent formulation. The user changeable settings are
separated into two categories: Control Parameters, which set critical functions that determine
the course of a titration and set the way in which titrations are terminated, and Method
Options, which control lesser features not directly affecting measurements and primarily
allow advanced users to shorten titration times.
9.1.1
Control Parameters
9.1.1.1 Endpoint Potential and Polarization Current
The HI 903 uses the polarized electrode system known as bivoltametric indication. The
titrator monitors the voltage required to maintain a constant polarization current (Ipol) between
the pins of a dual platinum-pin Karl Fischer electrode during the course of a titration.
During a titration, no excess iodine is present. In order to maintain the set polarization
current the HI 903 must apply a relatively large voltage across the pins of the electrode.
At the endpoint of the titration, the amount of iodine added is equal to the amount of water
from the sample. When an excess of titrant has been added, iodine is present in the solution.
The excess iodine is easily reduced, and the resulting iodide is easily oxidized in electrode
reactions at the cathode and anode respectively. The ease of these reactions make maintaining
the constant polarization current possible at a much lower electrode potential.
In theory, a large shift in the electrode potential indicates the endpoint. In practice, a
titration endpoint is reached when the electrode potential drops below a value defined by the
user and the chosen termination criteria is met.
The choice of endpoint potential should be based, foremost, on the polarization current and,
to a lesser extent, on the composition of the Karl Fischer solvent and the sample matrix. If
the polarization current is changed, the endpoint potential must also be changed. In addition,
there are pitfalls to be avoided when choosing an endpoint potential. Selecting endpoints which
are both ‘too high’ or ‘too low’ will result in long titration times and poor reproducibility. Endpoints
which are ‘too high’ are those which result in endpoints that either precede or coincide with
equivalence point such that the concentration of excess iodine is not reliably detected. Endpoint
potentials are considered ‘too low’ when they correspond to a large excess of iodine in the
titration cell.
9-3
METHODS OPTIMIZATION
The table that follows correlates endpoint potential ranges for each of the possible polarization
current settings of the HI 903. The suggested endpoints below are applicable for reagents
formulated with methanol. Endpoint potentials should be increased by 20 to 25% when
titrating with reagent systems formulated for use with aldehydes or ketones or where methanol
has been replaced with higher alcohols or substituted ethers like diethylene glycol monoethyl
ether or 2-methoxyethanol.
Polarization
Current
En d p o i n t
Potential
1 µΑ
2 µΑ
5 µΑ
1 0 µΑ
15 µΑ
2 0 µΑ
3 0 µΑ
40 µΑ
20 to 30 m V
25 to 35 m V
50 to 70 m V
80 to 100 m V
90 to 110 m V
100 to 120 m V
130 to 150 m V
150 to 170 m V
Additionally, the duration of a titration is proportional to the polarization current. Thus,
titration time can be reduced by increasing the polarization current. While the default Ipol
value of 20 mA results in the faster titration than smaller 1, 2, 5, 10, and 15 mA options a
further increase to 30 or 40 mA does not significantly shorten a titration. However, the
choice of higher polarization currents will speed contamination of the electrode and potentially
degrade samples using special solvent systems.
9.1.1.2 Dosing Parameters
The HI 903 predicts the approaching endpoint and reduces the volumes of titrant added
until the endpoint is reached. This is a software controlled process known as dynamic dosing.
Dynamic dosing prevents the addition of titrant beyond the endpoint and provides enhanced
data density in the vicinity of the endpoint resulting in accurate endpoint determination and
faster titrations. The minimum and maximum dose volume must be set appropriately by the
user for dynamic dosing to be effective.
9.1.1.2.1
Minimum Dose
Decreasing the minimum dose increases precision but lengthens the titration time. The only
exception is when stability time has been selected as the termination criteria and there is a
high drift rate. Under these circumstances, the minimum dose must be large enough to
maintain the endpoint potential by reacting all of the water due to the drift rate over the
course of the chosen time period. Increasing the minimun dose shortens titration time but
reduces precision and increases the chance of overtitration.
9.1.1.2.2
Maximum Dose
The maximum dose volume should be adapted according to the formulation and concentration
of the titrant. The maximum dose volume should be set as high as possible without exceeding
the reaction rate of the reagent system. The table below provides suggested maximum doses
for popular reagent systems based on their relative reaction rates.
The most effective way to optimize the maximum dose volume is to consider the titration
duration and to examine the shape of the titration curve. In the case where the maximum
dose volume is too high, the iodine will be added faster than the titration reaction rate. This
9-4
METHODS OPTIMIZATION
excess iodine will result in a steep drop in electrode potential which will be interpreted by the
HI 903 as an approaching endpoint. This will in turn result in the dynamic dosing algorithm
reducing the dose size until the excess iodine has time to react. The reduced dose size
effectively interrupts the titration and adds considerable time to the titration duration. The
titration will be interrupted repeatedly in this way such that the overall titration time is
longer, even though the value of the maximum dose size is set to a large volume. The
resulting titration curve will show:
Because reaction rates are faster with two-component reagents than those observed with
one-component reagents the maximum dose volume can be set slightly higher when using
two-component systems. In the case where the maximum dose is too low, titration time will
be extended.
Karl Fischer Reagent System
Maxim um Dose Volum e
O ne-Com ponent System s
20 to 30 µL
O ne-Com ponent System s for aldehydes and ketones
20 to 25 µL
O ne-Com ponent System s form ulated with pyridine
15 to 20 µL
Two-Com ponent System s
40 to 60 µL
Two-Com ponent System s form ulated with pyridine
25 to 30 µL
9.1.1.3 Timed Increment
This setting controls the amount of time between successive titrant doses.
Setting the time increment appropriately is important to ensure that the titrant has adequate
time to mix with the sample such that the electrode measures a homogeneous solution
before the titrator makes the decision on the size of the next dose of titrant.
The value of the timed increment is dependent on the type of reagent system being used.
While the default value of 1 second is compatible for use with any reagent system, titrations
using two-component reagent systems can be expedited by decreasing the time between
successive doses.
9-5
METHODS OPTIMIZATION
9.1.1.4 Start Mode
The HI 903 can be set to either normal or cautious start mode. The cautious start feature is
designed to prevent the accidental over-titration of a sample with very low water content. In
cautious start mode, the HI 903 starts a titration using the minimum dose size specified by
the user rather than starting with half of the maximum dose size as with normal start mode.
9.1.1.5 Signal Averaging
The chosen value for the signal averaging setting determines how many readings the electronics
will average to produce a single data point on the titration curve. While higher values of 3 or
4 readings reduce the response time of the electrode, they also result in a ‘smoother’ titration
curve which may result in a faster titration (single unstable readings may cause the dose size
to be reduced).
9.1.1.6 Flow Rate
The flow rate setting specifies the volume of titrant delivered per minute. The default flow
rate should be used for the majority of titrations. In cases where the titrant is more viscous,
the flow rate can be reduced.
9.1.2
Termination Parameters
HI 903 provides a choice of three criteria by which a titration can be considered to have
reached an endpoint successfully.
9.1.2.1 Stability Time
When this termination criteria is selected, a titration is considered to have reached an endpoint
when the electrode potential stays below the specified endpoint potential for a period of time
called the stability time. Typical endpoint stability times range between 5 and 15 seconds.
In order for this criteria to successfully terminate a titration the stability time and the minimum
dose size must be set such that, at the end of a titration, the minimum dose size is large
enough to react all of the water leaking into the cell due to drift during the set stability time.
If the minimum dose volume is too small to compensate for the water introduced by the
drift, the titration will never be terminated.
9.1.2.2 Drift Stop Termination Criteria
Drift-based termination criteria, or Drift stop, terminates titrations based on the idea that at
the end of a titration, when all of the water due to the sample has been reacted, the titrator
should only be titrating the water seeping into the cell due to the background drift rate (see
section 6.3 for a detailed explanation of background drift).
Ideally, drift stop termination criteria would end a titration when a drift rate identical to that which
preceded the start of a titration is observed at the end of a titration. However, from a practical
standpoint the achievement of an identical drift rate results in very long titration times.
In order to shorten titration times while still taking advantage of the positive aspects of
9-6
METHODS OPTIMIZATION
drift-based termination, the HI 903 incorporates two drift stop termination criteria which
terminate titrations when the drift rate passes below a specified threshold. The methods
can be distinguished by the way in which the drift rate thresholds are specified.
9.1.2.2.1
Relative Drift Stop
The relative drift stop termination parameter should be the first choice termination criteria.
It is the most universally applicable, easiest to use and results in fast, repeatable titrations.
This parameter has the advantage over other termination criteria in that the relative drift rate
termination value can be set independently from the titrant concentration and the initial drift
rate.
Under this criteria a titration reaches an endpoint successfully when the HI 903 titrates all of
the water introduced with the sample and maintains a drift rate which is equal to the sum of
the initial drift (drift rate when the titration was initiated) and the set ‘relative drift stop’ value
(i.e. a slightly higher drift than the initial drift rate).
The choice of relative drift stop value influences the titration duration and reproducibility.
Choosing low relative drift stop values (5 to 10 µg/min) will result in titrations with high
reproducibly and long durations. Setting high relative drift stop values (20 to 30 µg/min)
will result in fast titrations with potentially reduced reproducibility. Reduced reproducibility
at higher drift stop values is of particular concern when using reagents that have slower
reaction rates (one-component or aldehyde and ketone reagents).
It is important to set an appropriate relative drift stop value when working with insoluble or
sparingly soluble samples. During these types of titrations, the final traces of water are
released very slowly. If the sample contains a small amount of water (the final traces are a
large fraction of the total water), the relative drift stop value should be set very low. If the
final traces can be ignored because the sample water content is large, then the titrations can
be terminated at a higher drift rate termination value.
9.1.2.2.2
Absolute Drift Stop
Under this criteria, a titration reaches an endpoint successfully when the drift falls below a
predefined threshold called the absolute drift stop value.
The absolute drift stop value does not take the initial drift rate into account but does have the
advantage of being able to be set without consideration of the titrant concentration. In
addition, for a titration to reach endpoint, the absolute drift stop threshold must be set
higher than the initial drift rate value.
The primary disadvantage associated with the absolute drift rate termination criteria is that
the actual background drift rate must be considered before setting the absolute drift rate
threshold.
When setting the absolute drift threshold, a balance must be struck between the titration
speed and accuracy. Choosing a threshold slightly higher than the initial drift rate will result
in high reproducibility and relatively slow titrations. Setting the threshold higher (>30 µg/min)
will result in very fast titrations and reduced titration reproducibility.
9-7
METHODS OPTIMIZATION
9.1.3
Method Options
9.1.3.1 Pre-dispensing Amount
It is possible to shorten titration times by adding a large fraction of the titrant at the start of
the analysis if the approximate water content of the sample is known.
When activated, the pre-dispensing amount can be set to deliver between 1% and 90% of
the titrant required to reach the titration endpoint.
A high pre-dispensing amount (around 90%) increases the chances of erroneous results.
Pre-dispensing amounts above 50% should only be used if the reaction is very rapid.
9.1.3.2 Pre-analysis Stir Time
When analyzing solid samples with limited solubility or release bound water slowly, the
sample must be stirred in the chosen solvent prior to the start of a titration, to avoid erroneously
low titration results or unreachable endpoints. The pre-analysis stir time option ensures that
after the sample is added the titration mixture is stirred for a period of time before any titrant
is added to the cell. The pre-analysis stir time can be set between 0 and 1000 seconds.
9.1.3.3 Stirring Speed
The HI 903’s stirring speed can be set between 200 and 2000 RPM with 100 RPM resolution.
The stirring system is equipped with an optical feedback mechanism to ensure that the
stirring motor is rotating at the speed set by the user.
The optimum stirring speed is obtained when a small vortex is visible. If the stirring speed is
too low, the titrant will not react with the sample before reaching the electrode resulting in
over-titration and poor titration reproducibility. If the stirring speed is too high, bubbles will
form in the solution. Bubbles can destabilize or falsify the measured electrode potential.
The default stirring speed for commercially available standard Karl Fischer reagents used
within the operable volume range of the standard Hanna Instruments cell and with the
supplied magnetic stirring bar is 900 RPM. Samples which result in a titration solution with
higher or lower viscosity may require stir speed adjustment.
9.1.3.4 Background Drift Rate Entry
This option provides a choice between the HI 903’s automatic drift rate determination and
assigning a fixed value to be used by the titrator as the drift rate.
The primary benefit of bypassing the automatic drift rate feature is saving time. This is
appropriate when titrating samples with high water content where the drift rate is too low to
affect titration results or in diagnostic situations where there is no advantage in waiting for
the HI 903 to conduct a drift rate analysis.
9-8
METHODS OPTIMIZATION
9.2
The Sample
9.2.1
Proper Sampling Procedure
Proper sampling is essential for accurately determining the water content of bulk materials,
particularly with non-homogeneous samples. Many standard methods detail instructions to
ensure proper sampling. As a general rule, the following guidelines should be followed:
1. The sample must be representative. The water content of the sample taken is the
same as the average water content of the bulk material.
2. Avoid exposing samples to the contaminating effects of atmospheric moisture.
Take samples as quickly as possible and protect the sample during transport and/or
storage.
3. Take samples from the interior of bulk materials. Surfaces of hygroscopic materials
may contain higher levels of moisture relative to the rest of the material. Surfaces
of materials which release water may contain less water relative to the rest of the
material.
4. Taking large samples of bulk materials will result in a more representative sample.
9.2.2
Determining the Optimal Sample Size
The proper choice of sample size is critical to achieving accurate and repeatable titration
results. As a general rule, the sample size should be selected such that about 30-70% of the
burette volume is consumed during a titration. This provides enough titrant to ensure good
accuracy while conserving reagents and minimizing the generation of waste.
The table below illustrates the relationship between titration reproducibility, the volume of
titrant consumed during a titration, the amount of water contained in a sample, the size of a
sample and the water content of a sample.
9-9
METHODS OPTIMIZATION
The ideal sample size can be estimated using the table by drawing a line from the expected
water content to the amount of water in the sample corresponding to the desired titration
reproducibility (relative standard deviation). The ideal sample size is indicated by where the
drawn line intersects the ‘size of sample’ scale.
Consider the line on the table as an example. The line was drawn for a user with a sample
having approximately 1% water who required the best possible reproducibility. The intersection
of the red line with the size of sample column indicates that in order to introduce the optimal
10 mg of water into the titration cell the user must add 1g of sample.
The amount of sample required to introduce 10 mg of water into the titration cell can also be
calculated directly using the equation below.
9.2.3
Solid Samples
Sample water must be available to react with the titrant. This typically means that the sample
must be adequately dissolved in the solvent. This is achieved by choosing an appropriate
solvent system, proper preparation of the sample and optimization of the reaction conditions.
After ensuring that the sample is soluble in the choice of solvent or solvent mixture, dissolution
of a solid sample can be aided by grinding the sample into a fine powder, increasing the
pre-analysis stir time or heating the solvent during a titration with an optional jacketed
titration cell and water circulator.
Solid samples are added to the titration cell by removing the sample plug. The quantity of
solid sample added can be entered into the HI 903 as a mass or by number of pieces if, for
example, pills are to be analyzed.
The most accurate way to determine the mass of the sample added to the cell can be
achieved by an analytical technique called back-weighing. Back-weighing consists of the
following steps:
1. Measure the mass of a sample in a weigh boat.
2. Initiate the titration sequence on the HI 903 using the ‘start analysis’ option key
from standby mode. This will bring up the ‘add sample’ screen.
3. Slide the sample plug up out of the vessel top to open the sample port.
4. Rapidly add the sample through the sample port ensuring that ALL of the sample is
transferred to the solvent. Avoid any contact between the sample and the cell walls
or top.
5. Replace the sample plug into the vessel top.
6. Determining the mass of the ‘empty’ weight boat.
7. Calculate the mass of the sample added (subtract the mass of the emptied weigh
boat from the mass of the full weigh boat).
8. Enter the calculated mass of the sample into the HI 903.
9. Start titration using the option key ‘start analysis’ from the add sample screen.
9-10
METHODS OPTIMIZATION
Care should be taken to add a solid sample as fast as possible in order to minimize the
amount of time that the sample port is open. It is also important to be sure that all of the
sample reaches the solvent and does not make contact with, or stick to, the inner sides of the
vessel cap. Losing even a small fraction of the sample mass will result in a high sample water
content.
In some cases solid samples may require one of the additional preparatory steps listed in the
sections that follow. Specific sample preparation instructions are included with each standard
method.
9.2.4
Liquid Samples
As with solids, the water contained in liquid samples must be available to react with the
titrant. It is important to select a solvent system or mixture with which the sample is miscible.
Liquids are typically added through the septum in the sample port via a syringe and needle
using the following steps:
1. Attach a long needle (approximately 6 cm long, 21-gauge) to a syringe large
enough to hold at least one complete sample volume.
2. Rinse the syringe and needle with sample several times by drawing in a small
portion of sample, fully extending the plunger, shaking to coat the syringe interior
and expelling the sample into a waste collection container.
3. Draw enough sample into the syringe for at least one titration.
4. Dry the outside of the needle with a lint free wipe or tissue.
5. Determine the mass of the syringe and sample.
6. Initiate a titration from standby mode by pressing the ‘start analysis’ option key.
7. Insert the needle through the septum in the sample port. Push the syringe through
the septum until the end of the needle is approximately 1 cm from the surface of the
solvent.
8. Steadily dispense the contents of the syringe ensuring that the sample is introduced
directly into the solvent and does not splash or spatter onto the wall of the titration
vessel electrode or dispensing tip.
9. Draw a small amount of air from inside the cell into the syringe to ensure that no
sample drops remain on the tip of the needle.
10. Remove the syringe and needle from the septum taking care to not touch the
needle to the solvent or other internal cell components.
11. Determine the mass of the syringe and needle.
12. Calculate the mass of the sample added to the titration cell (subtract the mass of
the syringe after the sample has been added from the mass of the syringe before
sample addition).
13. Enter the calculated mass of the sample into the HI 903.
14. Start titration using the option key ‘start analysis’ from the add sample screen.
As indicated above, when adding a liquid sample with a needle and syringe, it is important that
the sample is introduced directly into the solvent. Sample that is deposited on the sides of the
9-11
METHODS OPTIMIZATION
vessel or other internal components of the cell may not be titrated with the rest of the sample.
It is equally important that no drops remain on the tip of the needle. ‘Hanging drops’ will end
up on the bottom of the septum. This will result in false low results for the determination.
Liquid samples with high viscosity like honey can be added via a syringe without needle
through the sample port following the steps outlined above.
In some cases liquid samples may require one of the additional preparatory steps listed in
the sections that follow. Specific sample preparation instructions are included with each
standard method.
9.2.5
Sample Preparation Techniques
While many samples can be introduced directly into the titration vessel (see section 6.5
Sample Addition), others require preparatory steps. It is critical that samples are not
contaminated with additional water or lose water during the preparation phase.
The steps required for the most common sample preparation techniques are outlined below.
For detailed application-specific instructions, consult the instructions included with applicable
standard methods.
The HI 903 provides options for the automatic calculation of samples prepared normally,
using external extraction and external dissolution.
9.2.5.1 Internal Extractions
Internal extractions are carried out using the ‘normal’ sample type option within the ‘sample
parameters menu’. This type of sample preparation is suitable for solid samples which release
their water relatively quickly (during the pre-analysis stir time) and exhibit limited or no
solubility in Karl Fischer solvents. Internal extraction should be used preferentially over
external extraction techniques because the extracted water is titrated immediately, which
favors complete extraction by Le Chatlier’s principle.
An outline of the general procedure follows:
1. Add methanol or an appropriate solvent to the titration cell and pre-titrate to
dryness.
2. Adjust the pre-analysis stir time to be sufficiently long enough to complete the
extraction. Appropriate set times will be sample and solvent specific. Consult an
applicable standard method or experiment by increasing the pre-analysis stir time
and titrating samples until the resulting water content no longer increases.
3. Reduce the samples to as fine of a powder as possible to ensure that sample water
is extracted quickly.
4. Add the sample to the titration vessel using the back weighing method.
9.2.5.2 Dilutions
It is very difficult to accurately add very small amounts of sample to the titration vessel. In
order to produce accurate and reproducible results, samples having water content greater
than 50% should therefore be diluted with a dry solvent before being introduced into the
9-12
METHODS OPTIMIZATION
titration vessel. Dilutions are carried out using the ‘external dissolution’ sample type option.
Anhydrous methanol is the solvent of choice for sample dilutions. If the sample contains fats
or oils, then a mixture of methanol and chloroform can be used to promote solubility of the
sample.
The following outlines a generic dilution procedure:
1. Determine the mass of a dry flask equipped with a septum stopper.
2. Transfer approximately 1 g of sample to the flask and measure the mass of the
flask and the sample together.
3. Add 30 grams of dilution solvent to the flask. Re-seal and mix the flask contents.
4. Determine the moisture content of the dry solvent used as the diluent in a separate
titration.
5. Add the diluted sample as per the instructions for adding liquid samples in this
section.
9.2.5.3 External Dissolution
External dissolutions are recommended for titrations which require a large amount of soluble
solid sample due to inhomogeneous water distribution or very low water content. External
dissolution reduces the error typically associated with the titration of low water content solids
by collecting the water released by a large amount of solid sample by dissolving it in a
relatively small amount of solvent. A small portion of the solvent can then be injected into
the titration vessel.
Sample preparation and choice of solvent or solvent mixture is sample specific. Consult an
applicable standard method for procedural details.
The HI 903 will conduct the necessary calculations automatically when ‘external dissolution’
is selected from the sample type menu.
9.2.5.4 External Extraction
External extraction is recommended for insoluble solid samples which release water slowly.
The HI 903 will conduct the necessary calculations automatically when ‘external extraction’
is selected from the sample type menu.
An outline of a general procedure follows:
1. Determine the mass of an extraction bottle or flask equipped with a septum.
2. Add the extraction solvent to the bottle and determine the mass of the bottle and
the solvent. In order to maximize the effectiveness of the extraction, the water
content of the solvent should be as low as possible. When choosing an extraction
solvent, one must carefully consider the limit of water saturation for a possible
solvent.
3. Determine the water content of the solvent.
4. Determine the mass of the solvent remaining in the extraction bottle.
5. Add a finely crushed sample to the solvent in the extraction bottle. The amount of
sample added should be large enough so that the amount of water in the sample is
much greater than that in the solvent before the extraction.
9-13
METHODS OPTIMIZATION
6. Facilitate extraction by shaking the solution or placing the solution on a stirring
plate or in a sonicator.
7. Allow the insoluble portion of the sample to settle to the bottom of the extraction
bottle.
8. Titrate an appropriately sized sample of the supernatant (solvent above the settled
solid sample).
9.2.5.5 Homogenization
Homogenization is recommended for non-aqueous or mixed phase liquid samples as well as
solids with inhomogeneous distributions of water. Water can be evenly distributed throughout
a collected sample by the use of high speed, high shear mixers called homogenizers.
In mixed phase (oil and water) non-aqueous samples, water tends migrate to the surface of
the sample solution, adhere to the inner walls of or sink to the bottom of the sample bottle.
This is particularly problematic when sampling is done at high temperatures and the specimen
is subsequently allowed to cool to room temperature prior to analysis.
Solid samples typically exhibit inhomogeneous water distributions and must therefore be
thoroughly reduced to powder or homogenized. The procedure for homogenization depends
upon the characteristics of the specific sample.
Homogenization is particularly suited for semi-solid samples and suspensions and is the only
method that can disrupt plant and tissue cells in order to release water present inside the
cells. Homogenization is typically carried out externally in a dry flask with the addition of a
suitable solvent, preferably methanol.
9.2.5.6 Heating
Sample heating is used for the analysis of solid or liquid samples that cannot be extracted or
that interfere with the Karl Fischer reaction. These include plastics, minerals, petrochemical
products which contain additives, and starting materials for pharmaceutical products.
Samples are heated in a special oven while a dry stream of carrier gas passes through the
sample chamber or, for liquid samples, the sample itself. The carrier gas is introduced into
the titration vessel.
The heating temperature is sample specific and can be found in applicable standard methods.
The temperatures are chosen to be as high as possible without decomposing the sample,
which can result in contamination of the titration vessel.
9-14
METHODS OPTIMIZATION
9.3
Karl Fischer Reagent System
A wide variety of Karl Fischer reagents exist on the market today, each designed and formulated
for specific sample matrices and titration conditions. Karl Fischer reagent systems consist of a
solvent and a titrant. The solvent is the liquid to which the sample is added in the reaction
vessel. The titrant is the iodine-containing liquid pumped into the cell during the titration.
9.3.1
Reagent System Classification
Reagent systems are classified as either one-component or two-component depending on whether
the sulfur dioxide and base are included in the titrant or with the solvent. In one-component
systems, also known as composites, the titrant contains all of the reactants needed to conduct
the titration (iodine, sulfur dioxide and a base) dissolved in an alcohol or ether. In a twocomponent reagent system, the solvent already contains the sulfur dioxide and the base
while the titrant is typically a solution consisting of iodine and methanol.
9.3.1.1 One-Component Reagent Systems
One-component reagents are less stable than two-component systems, typically having only a
two-year shelf life, but they provide several significant advantages. The major advantage is that
the titrant is providing the sulfur dioxide and the base. The constant supply of reaction components
from the titrant allows a high level of flexibility with respect to the chemical composition of the
solvent and provides a nearly limitless solvent capacity for water. One-component solvent systems
can be easily customized, creating mixtures specially adapted to specific sample characteristics
without having to worry about providing appropriate levels of sulfur dioxide and buffer
components. Common solvent mixtures include ethanol, chloroform, xylene, toluene, and
long chain alcohols such as hexanol and decanol.
9.3.1.2 Two-Component Reagent Systems
Two-component reagents have advantages of their own. They are more stable and have a
longer shelf life than one-component systems. The sulfur dioxide is pre-mixed in excess with
an alcohol-based solvent, therefore the necessary reactive sulfite esters are present in vast
excess prior to the start of a titration. This results in higher titration speeds and greater
accuracy for low levels of water. In addition, having the base present in excess in the solvent
prior to sample addition results in a higher solvent buffer capacity.
9.3.1.3 Reagents for Aldehydes and Ketones
The addition of a sample containing aldehydes or ketones to a methanol-based Karl Fischer
solvent results in side reactions that adversely affect titration results. When alcohols react
with the carbonyl groups of aldehydes and ketones they form acetals and ketals via a reaction
that releases water. The generation of water during a titration will falsely inflate water content
results and could lead to vanishing endpoints.
While ketones are less reactive than aldehydes, the reactivity of both species is inversely
proportional to carbonyl chain lengths. The formation of acetals and ketals is also dependent
9-15
METHODS OPTIMIZATION
on the type of alcohol included in the solvent. As the chain length of an alcohol’s alkyl or
substituted alkyl group increases, the alcohol’s reactivity toward ketones and aldehydes
decreases (i.e. methanol is the most reactive).
Acetal or ketal formation can be prevented by the use of methanol-free reagents specially
produced for this purpose. Reagents for aldehyde and ketone analysis replace methanol with
higher alcohols, ethers, halogenated alkanes or similar combinations.
9.3.2
Choosing and Modifying a Solvent
The solvent plays an important role in the KF titration. It must react with sulfur dioxide to
form the reactive methyl sulfite species, dissolve the sample and/or extract water, and it
should help prevent side reactions from occurring. The most common solvent is methanol.
Co-solvents can be added to increase sample solubility in one-component solvents, as long
as the mixture contains at least 20 - 30% methanol. In a two component reagent system,
50% solvent for two component system and 50% co-solvent can be used. This ensures that
there is enough sulfur dioxide and base for the Karl Fischer reaction to take place.
In general a solvent should be chosen in accordance with the sample composition:
Fats, oils and long-chain hydrocarbons have limited solubility in methanol. Co-solvents of
long-chain alcohols (n-decanol) or chloroform should used;
Carbohydrates and proteins have poor solubility in methanol, formamide can be used as a
co-solvent;
Analyzing acids or bases may take the pH outside the optimal range and additional buffering
may be required; a commercial Karl Fischer ‘Buffer’ reagent can be added or extra imidazole
can be added for acid samples and salicylic acid can be added to the solvent for basic samples;
For analysis of ketones or aldehydes, the methanol can be replaced with special “K” reagents
that contain mixtures including 2-chloroethanol, chloroform, ethanol or 1-methoxy-2-propanol.
9.3.3
Water Standards
Water standards are used to standardize the titrant and to verify the titrator’s performance
and analyst technique. Water standards are an integral part of ISO 9000, GMP, GLP and FDA
guidelines for water determination.
The most commonly utilized water standard for volumetric Karl Fischer titration is sodium
tartrate dihydrate. Available as a highly-purified, non-hygroscopic powder, sodium tartrate
dihydrate has a stable water content of 15.66 ± 0.05%. The compound is, however, sparingly
soluble in methanol requiring at least 3 minutes of stirring for complete dissolution.
If high precision or NIST traceability is required, water standards sealed in glass ampules
are also commercially available. Although they are more expensive, sealed standards come
pre-analyzed and certified by the manufacturer and are available in a wide range of
concentrations.
The experienced analyst can also use very small volumes of deionized water as a standard.
Due to the very water-sensitive nature of a Karl Fischer titration, only a few milligrams of
water are required for a typical standardization or system verification. A great deal of skill is
therefore required in determining the mass of the water introduced into the titration vessel in
order to achieve highly accurate results.
9-16
METHODS OPTIMIZATION
9.3.4
Standardizing the Titrant
Standardizing the Titrant, or determining the titer, is a routine and necessary part of
accurate Karl Fischer analyses. The titrant should be standardized daily for greatest
accuracy. Standardization serves to standardize the combination of parameters selected
as part of a particular method and serve as a system check. It is recommended that the
titrant be re-standardized if the method to be used for an analysis is very different from
that which was used to standardize the titrant initially. The titrant can be standardized
using hydrated salt, liquid water standards or tiny amounts of pure water.
A general procedure for titrant standardization:
1. Setup titrator according to the instruction manual. Ensure the titrator is set up with
the same reagents, solvents, working conditions, temperature and titrator settings
to be used for subsequent sample analyses.
2. Select the appropriate standardization method included with the HI 903.
Using a Sodium Tartrate Dihydrate Standard:
3. Back-weigh between 30 and 200 mg of standard. Be sure that the salt is a high
quality standard, which has been stored properly and exists as a fine, free flowing
powder.
4. Repeat the standardization at least three times and update the titrant concentration
using the averaged result value via the statistics screen if the variability between
the standardizations is small.
Using a Prepared Liquid Water Standard (Ampule):
3. Break open an ampule of standard. Rinse a syringe with a small portion of standard.
4. Draw up the remainder of the standard into the syringe, weight and titrate about
one third of the standard in the syringe.
5. Conduct two more standardizations with the standard remaining in the syringe.
6. Review the set of results on the ‘average results’ statistics screen. The titrant
concentration should be updated with the averaged results as long as there is not
excessive variability between standardization results.
With pure water standards:
3. Draw approximately 10 µL of pure water into a glass micro-liter syringe.
4. Introduce the water standard by back-weighing using an analytical balance with
0.01 mg resolution. Because of the extremely small sample size, it is important to
strictly follow the procedure for the addition of liquid samples outlined in the
section ‘addition of liquid samples’ above.
5. Review the set of results on the ‘average results’ statistics screen. The titrant
concentration should be updated with the averaged results as long as there is not
excessive variability between standardization results.
9-17
METHODS OPTIMIZATION
9-18
APPENDIX 1
Appendix 1. Contents
A1
TECHNICAL SPECIFICATIONS .............................................................. A1-3
A1-1
APPENDIX 1
A1-2
APPENDIX 1
A1
TECHNICAL SPECIFICATIONS
Range
Resolution
Result Units
Sample Type
Determination
Pre-Titration Conditioning
Background Drift Correction
Endpoint Criteria
Dosing
Result Statistics
100 ppm to 100%
1 ppm to (0.0001%)
%, ppm, mg/g, µg/g, mg, µg, mg/mL, µg/mL,
mg/pc, µg/pc
Liquid or Solid
Automatic
Automatic or User Selectable Value
Fixed mV persistence, Relative drift stop or Absolute drift
stop
Dynamic with optional pre-dispensing
Mean, Standard Deviation
Clip-LockTM Exchangeable Burette System
Dosing Pump
Resolution
1/40000 of the burette volume (0.125 µL per dose)
Accuracy
± 0.1% of full burette volume
Syringe
5-mL precision ground with PTFE plunger
Valve
Motor-driven 3-way, PTFE liquid contact material
Tubing
PTFE with light block and thermal jacketing
Dispensing Tip
Glass, fixed position anti-diffusion
Titration Vessel
Conical with operating volume between 50-150 mL
Solvent Handing System
Sealed system, integrated diaphragm air pump.
Electrode
Type
Connection
Polarization Current
Voltage Range
Voltage Resolution
Accuracy
Stirrer
Type
Speed
Resolution
External Stirrer
Peripheral Devices
PC
Dual platinum pin, polarization electrode
BNC
1, 2, 5, 10, 15, 20, 30 or 40 µA
2 mV to 1000 mV
0.1 mV
± 0.1%
Magnetic, Optically regulated, digital stirrer
200- 2000 RPM
100 RPM
4-pin mini DIN Connection allows for the control of an
external stirring apparatus
Transfer methods and reports via USB connection to
a PC using the HI 900 PC Software
A1-3
APPENDIX 1
USB Flash Drive
Laboratory Analytical Balance
Printer
Monitor
Keyboard
Methods and reports can be easily transferred between devices
using a USB Flash Drive. Software upgrades are made easy.
RS-232 to connect any laboratory balance
Parallel port is used to connect a printer which allows printing
from the titrator
Instrument status and titrations can be viewed on a larger
screen using any VGA-compatible external monitor
Alphanumeric text can be entered using an optional PS/2
keyboard
Graphic Display
5.7” (320 x 240 Pixel) Color LCD
Power Supply
100-240 Vac, 50/60 Hz
Power Draw
0.5 Amps
Languages
English, Portuguese, Spanish, French
Titration Methods
Up to 100 (standard and user) methods
Data Storage
Up to 100 complete titration reports and drift rate reports can
be stored
GLP Conformity
Good Laboratory Practice and Instrumentation Data Storage
and printing
Enclosure Material
ABS plastic and Steel
Keypad
Polycarbonate
Dimensions
Width x Depth x Height = 390 x 350 x 380 mm
(15.3 x 13.8 x 14.9 in)
Weight
Approx. 22 lbs. (10 kg)
Operating Environment
10 to 40°C, up to 95% relative humidity
Storage Environment
-20 to 70°C, up to 95% relative humidity
A1-4
APPENDIX 2
Appendix 2. Recommended Reagents
A2
RECOMMENDED REAGENTS ................................................................ A2-3
A2.1 Titrants ................................................................................................A2-3
A2.1.1 1-component Titrants .............................................................................. A 2 - 3
A2.1.2 2-component Titrants............................................................................... A 2 - 3
A2.2 Solvents ............................................................................................... A 2 - 3
A2.2.1 1-component Solvents ............................................................................. A 2 - 3
A2.2.2 1-component Solvents ............................................................................. A 2 - 4
A2.3 Standards ...................................................................................A2-4
A2-1
APPENDIX 2
A2-2
APPENDIX 2
A2 RECOMMENDED REAGENTS
A2.1 Titrants
A2.1.1 1-component Titrants
Sigma-Aldrich®
34805
34806
34816
34827
HYDRANAL®
HYDRANAL®
HYDRANAL®
HYDRANAL®
Composite
Composite
Composite
Composite
5
2
5K
1
GFS Chemicals®
1600 WaterMark® Pyridine-Free Single Solution, 5 mg/mL
1601 WaterMark® Pyridine-Free Single Solution, 2 mg/mL
J.T. Baker®
8890 HYDRA-POINT™ Comp 5
8891 HYDRA-POINT™ Comp 2
A2.1.2 2-component Titrants
Sigma-Aldrich®
34723 HYDRANAL® Titrant 2E
34811 HYDRANAL® Titrant 2
GFS Chemicals®
1603
1604
1616
1970
J.T. Baker®
8844 HYDRA-POINT™ Titrant 5
8845 HYDRA-POINT™ Titrant 2
WaterMark® Stable, 2 mg/mL, Non-hygroscopic
WaterMark® Stable, 5 mg/mL, Non-hygroscopic
WaterMark® 5 mg/mL, in Methanol
WaterMark® Stable, 0.5 mg/mL, Non-hygroscopic
A2.2 Solvents
A2.2.1 1-component Solvents
Sigma-Aldrich®
34697
34698
34734
34738
34741
34855
HYDRANAL®
HYDRANAL®
HYDRANAL®
HYDRANAL®
HYDRANAL®
HYDRANAL®
Solver (Crude) Oil Working Medium
Medium K Working Medium
CompoSolver E Working Medium
KetoSolver Working Medium
Methanol Dry Working Medium
LipoSolver CM Working Medium
A2-3
APPENDIX 2
A2.2.2 2-component Solvents
GFS Chemicals®
1609 WaterMark® Solvent, Methanol-Free
1610 WaterMark® Solvent, General Purpose
J.T. Baker®
8855 HYDRA-POINT™ Solvent G
A2.3 Standards
Sigma-Aldrich®
34803
34828
34847
34849
GFS Chemicals®
2302 KF Water Standard, 1.0 mg/g
A2-4
HYDRANAL®
HYDRANAL®
HYDRANAL®
HYDRANAL®
Standard Sodium Tartrate Dihydrate
Water Standard 1.00
Water Standard 0.10
Water Standard 10.0
APPENDIX 3
Appendix 3. Accessories
A3
TITRATOR COMPONENTS .................................................................... A3-3
A3-1
APPENDIX 3
A3-2
APPENDIX 3
A3
TITRATOR COMPONENTS
HI 900100
Pump assembly
HI900522
Beaker for HI903
HI900570
Aspiration Tubing
HI900580
Dispensing
Tubing and fitting
HI900520
Beaker Assembly
HI900505
5 mL Burette Assembly
HI900942
Tool for Burette Cap
Removal
HI900180
Air Pump
A3-3
APPENDIX 3
HI900523
Dispensing tip, 2pcs
HI900528
Solvent Port Plugs,
2pcs
A3-4
HI900534
Waste Bottle
HI900535
2 x Tubing for Solvent/
Waste Handling
HI900536
2 x Tubing for Air Pump
HI900530
Titrant Bottle Top
Assembly
HI900540
O-Ring Set
HI900531
Solvent/Waste Bottle
Top Assembly
HI900527
Septum, 5pcs
HI900532
Desiccant Cartridge for
Beaker or Titrant
HI900550
Desiccant, 250 g
HI900533
Desiccant Cartridge for
Solvent or Waste
HI900946
Power Pack
APPENDIX 3
HI900941
Calibration Key
HI900803
Manual (English) for
HI 903
HI900900U
PC Application on USB
Flash Drive
HI920013
USB Cable
A3-5
APPENDIX 3
MAN HI903
10/13
A3-6
GENERAL APPLICATIONS BROCHURE
HI 903
KARL FISCHER
VOLUMETRIC TITRATOR
Revision 1.00
www.hannainst.com
1
Method ID: HI8001EN
5.0 mg/mL Titrant Standardization using a Liquid Water Standard
for one-component titrant
Description:
Method for the standardization of 5.0 mg/mL OneComponent Karl Fischer Titrant using a Liquid Water
Standard. The results are expressed in mg/mL.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 10 mg/g Liquid Water Standard
 Dry Methanol
Other Accessories:
 A clean, dry 3-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8001EN Stdz
5mg/mL w/ water Std.’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant to be
standardized and verify that no air bubbles are
present in the burette or tubing. If necessary prime
until all air has been removed completely.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with the water
standard.
 Weigh the syringe, needle and water standard.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 1.00 g (about 1 mL) of standard into the
titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual standard by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of standard is seen on the end of
the needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added standard mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration, the “Standardization
Result” screen is displayed. The results are
expressed in mg/mL.
Method Parameters:
Name:
Stdz 5mg/mL w/ water Std
Method Revision:
1.0
Type:
Titrant Standardization
Predispensing Amount:
25 %
Pre-Analysis Stir Time:
5 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Standard:
Liquid 10 mg/g
Type:
Liquid by mass
Concentration Unit:
mg/g
Water Content:
10.0000 mg/g
Standard Size:
1.0000 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.500 uL
Maximum Dose:
20.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
1200 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
7.0 ug/min
Calculations:
Titrant units:
Titrant volume consumed:
Final Results Units:
Standard Concentration:
Standard mass:
mg/mL
V (mL)
mg/mL
10.0000 mg/g
1.0000 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8001EN
5.0 mg/mL Titrant Standardization using a Liquid Water Standard
for one-component titrant
Results:
Titration Report
Method Name:
Stdz 5mg/mL w/ water Std.
Time & Date:
12:00 Jan 1, 2011
Standard Size:
1.0000 g
Standard Conc.:
10.0000 mg/g
Drift Value:
5.4 ug/min
End Point Volume:
2.0341 mL
Result:
4.9276 mg/mL
Titration Duration:
4:19 [mm:ss]
Estimated Cell Volume:
55.88 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8002EN
2.0 mg/mL Titrant Standardization using a Liquid Water Standard
for one-component titrant
Description:
Method for the standardization of 2.0 mg/mL OneComponent Karl Fischer Titrant using a Liquid Water
Standard. The results are expressed in mg/mL.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 2 mg/mL One-Component KF Volumetric Titrant
 1.00 mg/g Liquid Water Standard
 Dry Methanol
Other Accessories:
 A clean, dry 3-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8002EN Stdz
2mg/mL w/ water Std.’ and press “Select”.
 Install a 5-mL burette filled with 2 mg/mL KF
Titrant to be standardized and verify that no air
bubbles are present in the burette or tubing. If
necessary prime until all air has been removed
completely.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with the water
standard.
 Weigh the syringe, needle and water standard.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 2.00 g (about 2 mL) of standard into the
titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual standard by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of standard is seen on the end of
the needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added standard mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Standardization
Result” screen is displayed. The results are
expressed in mg/mL.
Method Parameters:
Name:
Stdz 2mg/mL w/ water Std
Method Revision:
1.0
Type:
Titrant Standardization
Predispensing Amount:
25 %
Pre-Analysis Stir Time:
5 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Standard:
Liquid 1.0 mg/g
Type:
Liquid by mass
Concentration Unit:
mg/g
Water Content:
1.0000 mg/g
Standard Size:
2.0000 g
Titrant:
Composite 2
Titrant Type:
One Component
Nominal Titrant Conc.:
2.0000 mg/mL
Std. Titrant Conc.:
2.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
1.000 uL
Maximum Dose:
20.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
1200 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
7.0 ug/min
Calculations:
Titrant units:
Titrant volume consumed:
Final Results Units:
Standard Concentration:
Standard mass:
mg/mL
V (mL)
mg/mL
1.0000 mg/g
2.0000 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8002EN
2.0 mg/mL Titrant Standardization using a Liquid Water Standard
for one-component titrant
Results:
Titration Report
Method Name:
Stdz 2mg/mL w/ water Std.
Time & Date:
12:00 Jan 1, 2011
Standard Size:
2.0000 g
Standard Conc.:
1.0000 mg/g
Drift Value:
5.0 ug/min
End Point Volume:
1.0605 mL
Result:
1.9103 mg/mL
Titration Duration:
5:10 [mm:ss]
Estimated Cell Volume:
60.11 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8003EN
1.0 mg/mL Titrant Standardization using a Liquid Water Standard
for one-component titrant
Description:
Method for the standardization of 1.0 mg/mL OneComponent Karl Fischer Titrant using a Liquid Water
Standard. The results are expressed in mg/mL.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 1 mg/mL One-Component KF Volumetric Titrant
 1 mg/g Liquid Water Standard
 Dry Methanol
Other Accessories:
 A clean, dry 3-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8003EN Stdz
1mg/mL w/ water Std.’ and press “Select”.
 Install a 5-mL burette filled with 1 mg/mL KF
Titrant to be standardized and verify that no air
bubbles are present in the burette or tubing. If
necessary prime until all air has been removed
completely.
 Connect the solvent bottle top assembly to the
bottle of methanol (or solvent) according to the
manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with the water
standard.
 Weigh the syringe, needle and water standard.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 2.00 g (about 2 mL) of standard into the
titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual standard by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of standard is seen on the end of
the needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added standard mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Standardization
Result” screen is displayed. The results are
expressed in mg/mL.
Method Parameters:
Name:
Stdz 1mg/mL w/ water Std
Method Revision:
1.0
Type:
Titrant Standardization
Predispensing Amount:
25 %
Pre-Analysis Stir Time:
5 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Standard:
Liquid 1.0 mg/g
Type:
Liquid by mass
Concentration Unit:
mg/g
Water Content:
1.0000 mg/g
Standard Size:
2.0000 g
Titrant:
Composite 1
Titrant Type:
One Component
Nominal Titrant Conc.:
1.0000 mg/mL
Std. Titrant Conc.:
1.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
2.000 uL
Maximum Dose:
40.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
1200 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
7.0 ug/min
Calculations:
Titrant units:
Titrant volume consumed:
Final Results Units:
Standard Concentration:
Standard mass:
mg/mL
V (mL)
mg/mL
1.0000 mg/g
2.0000 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8003EN
1.0 mg/mL Titrant Standardization using a Liquid Water Standard
for one-component titrant
Results:
Titration Report
Method Name:
Stdz 1mg/mL w/ water Std.
Time & Date:
12:00 Jan 1, 2011
Standard Size:
2.0000 g
Standard Conc.:
1.0000 mg/g
Drift Value:
5.0 ug/min
End Point Volume:
1.8732 mL
Result:
1.0824 mg/mL
Titration Duration:
5:30 [mm:ss]
Estimated Cell Volume:
64.20 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8011EN
5.0 mg/mL Titrant Standardization using Disodium Tartrate Dihydrate
for one-component titrant
Description:
Method for the standardization of 5.0 mg/mL OneComponent Karl Fischer Titrant using Disodium
Tartrate Dihydrate water standard. The results are
expressed in mg/mL.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Disodium Tartrate Dihydrate, 15.66% H2O (w/w)
 Dry Methanol
 Dry Formamide
Other Accessories:
 A clean, dry weigh boat
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8011EN Stdz
5mg/mL w/ Tartrate’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Titrant to be standardized and
verify that no air bubbles are present in the burette
or tubing. If necessary prime until all air has been
removed completely.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare at least 200 mL of solvent by mixing 2
parts dry methanol and 2 parts dry formamide in a
solvent bottle.
 Attach the solvent bottle top assembly to the bottle
according to the instruction manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Add 0.050 g to 0.100 g of tartrate standard to a
weigh boat.
 Weigh the weigh boat and tartrate standard.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Quickly remove the sample port plug from the
beaker assembly, pour the tartrate into the titration
vessel, and replace the sample port plug. Pay
attention not to get any sample on the electrode or
beaker walls. If necessary swirl the titration vessel
by hand.
 Weigh the weigh boat again in order to determine
the added standard mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Standardization
Result” screen is displayed. The results are
expressed in mg/mL.
Method Parameters:
Name:
Stdz 5mg/mL w/ Tartrate
Method Revision:
1.0
Type:
Titrant Standardization
Predispensing Amount:
15 %
Pre-Analysis Stir Time:
30 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
MeOH Form. 2:1
Standard:
Sodium Tartrate
Type:
Solid by mass
Concentration Unit:
%
Water Content:
15.66 %
Standard Size:
0.1000 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
2.000 uL
Maximum Dose:
40.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
1200 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
7.0 ug/min
Calculations:
Titrant units:
Titrant volume consumed:
Final Results Units:
Standard Concentration:
Standard mass:
mg/mL
V (mL)
mg/mL
15.66 %
0.1000 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8011EN
5.0 mg/mL Titrant Standardization using Disodium Tartrate Dihydrate
for one-component titrant
Results:
Titration Report
Method Name:
Stdz 5mg/mL w/ Tartrate
Time & Date:
12:00 Jan 1, 2011
Standard Size:
0.1000 g
Standard Conc.:
15.66 %
Drift Value:
4.0 ug/min
End Point Volume:
3.1185 mL
Result:
5.0329 mg/mL
Titration Duration:
8:48 [mm:ss]
Estimated Cell Volume:
69.26 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8101EN
Moisture Determination in Dairy Cream
Description:
Method for the determination of moisture in Dairy
Cream. The results are expressed in % mass and
should be between 70 and 80 %.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
 Dry Chloroform
 Dry Formamide
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8101EN Moisture in
Dairy Cream’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant, follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Prepare at least 200 mL of solvent by adding 2
parts dry chloroform, 2 parts dry methanol, and 1
part dry formamide in a solvent bottle. Attach the
solvent bottle top assembly to the bottle according
to the instruction manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with the sample.
 Weigh the syringe, needle and cream.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.0200 g to 0.0250 g of dairy cream into
the titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the
needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
Method Parameters:
Name:
Moisture in Dairy Cream
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
30 %
Pre-Analysis Stir Time:
30 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Cream Solvent
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Dairy Cream
Sample Type:
Mass
Sample Size:
0.0250 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 01, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.500 uL
Maximum Dose:
30.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
900 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
15.0 ug/min
Result Unit:
%
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
0.0250 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8101EN
Moisture Determination in Dairy Cream
Results:
Titration Report
Method Name:
Moisture in Dairy Cream
Time & Date:
12:00 Jan 01, 2011
Sample Size:
0.0241 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
4.7 ug/min
End Point Volume:
3.4567 mL
Result:
71.5481 %
Titration Duration:
8:36 [mm:ss]
Estimated Cell Volume:
65.72 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8102EN
Moisture Determination in Milk
Description:
Method for the determination of moisture in Milk.
The results are expressed in % mass and should be
between 80 and 95 %.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8102EN Moisture in
Milk’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with the sample.
 Weigh the syringe, needle and milk.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.0150 g to 0.0200 g of milk into the
titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the
needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
Method Parameters:
Name:
Moisture in Milk
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
30 %
Pre-Analysis Stir Time:
15 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Milk
Sample Type:
Mass
Sample Size:
0.0200 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.5000 uL
Maximum Dose:
40.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
900 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
15.0 ug/min
Result Unit:
%
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
0.0200 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8102EN
Moisture Determination in Milk
Results:
Titration Report
Method Name:
Moisture in Milk
Time & Date:
12:00 Jan 01, 2011
Sample Size:
0.0188 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
4.5 ug/min
End Point Volume:
3.2614 mL
Result:
86.5886 %
Titration Duration:
6:18 [mm:ss]
Estimated Cell Volume:
60.03 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8103EN
Moisture Determination in Honey
Description:
Method for the determination of moisture in Honey.
The results are expressed in % mass and should be
between 15 and 20 %.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
Method Parameters:
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
Other Accessories:
 A clean, dry 1-mL syringe (no needle)
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8103EN Moisture in
Honey’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe with the sample.
 Weigh the syringe and honey.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Remove the sample port plug and dispense
0.0500 g to 0.1000 g of honey (about 2-3 small
drops) into the titration vessel through the sample
port. Replace the sample port plug as quickly as
possible to prevent humidity from entering the
titration beaker. Pay attention not to get any
sample on the electrode or beaker walls. If
necessary swirl the titration vessel by hand.
 Weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
Name:
Moisture in Honey
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
None
Pre-Analysis Stir Time:
60 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Honey
Sample Type:
Mass
Sample Size:
0.1000 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.5000 uL
Maximum Dose:
20.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
900 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
10.0 ug/min
Result Unit:
%
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
0.1000 g
Results:
Titration Report
Method Name:
Moisture in Honey
Time & Date:
12:00 Jan 1, 2011
Sample Size:
0.0916 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
3.8 ug/min
End Point Volume:
3.4523 mL
Result:
17.2345 %
Titration Duration:
7:06 [mm:ss]
Estimated Cell Volume:
57.16 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8104EN
Surface Moisture Determination on White Sugar
Description:
Method for the determination of the surface moisture
content of white sugar. The results are expressed in
ppm and should be between 250 and 350 ppm.
Electrode:
 HI 76320 Double Platinum Pin Electrode
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in ppm of water.
 Use fresh solvent after every 2 to 3 titrations.
Method Parameters:
Reagents:
 1 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
 Dry Chloroform
Other Accessories:
 A clean, dry weigh boat
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8104EN Surface
Moisture - Sugar’ and press “Select”.
 Install a 5-mL burette filled with 1 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8003EN 1.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Prepare at least 200 mL of solvent by adding 2
parts dry chloroform to 1 part dry methanol in a
solvent bottle.
Attach the solvent bottle top
assembly to the bottle according to the instruction
manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the weigh boat with 7.5 to 10 g of sample.
 Weigh the weigh boat and sample.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Remove the sample port and use the weight boat
to transfer the solid sample into the titration
vessel. Replace the sample port plug as quickly
as possible to prevent humidity from entering the
titration beaker. Pay attention not to get any
sample on the electrode or beaker walls. If
necessary swirl the titration vessel by hand.
 Weigh the weigh boat again in order to determine
the added sample mass (by difference of the two
measurements.)
Name:
Surface Moisture - Sugar
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
None
Pre-Analysis Stir Time:
120 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
CHCl3 MeOH 2:1
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Sugar
Sample Type:
Mass
Sample Size:
7.5000 g
Titrant:
Composite 1
Titrant Type:
One Component
Nominal Titrant Conc.:
1.0000 mg/mL
Std. Titrant Conc.:
1.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
1.000 uL
Maximum Dose:
30.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
900 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
20.0 ug/min
Result Unit:
ppm
Calculations:
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
ppm
1.0000 mg/mL
7.5000 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8104EN
Surface Moisture Determination on White Sugar
Results:
Titration Report
Method Name:
Surface Moisture - Sugar
Time & Date:
12:00 Jan 1, 2011
Sample Size:
7.5231 g
Std. Titrant Conc.:
1.0000 mg/mL
Drift Value:
5.7 ug/min
End Point Volume:
2.4292 mL
Result:
319 ppm
Titration Duration:
4:42 [mm:ss]
Estimated Cell Volume:
62.4 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8105EN
Moisture Determination in Cooking Oil
Description:
Method for the determination of moisture in cooking
oil. The results are expressed in ppm and should be
between 200 and 800 ppm.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 1 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
 Dry Chloroform
Other Accessories:
 A clean, dry 25-mL syringe
 A clean, dry 18-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8105EN Moisture in
Cooking Oil’ and press “Select”.
 Install a 5-mL burette filled with 1 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8003EN 1.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Prepare at least 200 mL of solvent by adding 1
part dry chloroform to 1 part dry methanol in a
solvent bottle.
Attach the solvent bottle top
assembly to the bottle according to the instruction
manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with sample.
 Weigh the syringe, needle and oil.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 3 g to 5 g of cooking oil into the titration
vessel through the septum using the needle. Pay
attention not to get any sample on the electrode or
beaker walls. If necessary swirl the titration vessel
by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the




needle, dip the end of the needle briefly in the
solvent.
Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in ppm of water.
Change the solvent after every 3 to 4 titration or if
phase-separation occurs.
Method Parameters:
Name:
Moisture in Cooking Oil
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
None
Pre-Analysis Stir Time:
15 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
CHCl3 MeOH 1:1
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Oil
Sample Type:
Mass
Sample Size:
4.0000 g
Titrant:
Composite 1
Titrant Type:
One Component
Nominal Titrant Conc.:
1.0000 mg/mL
Std. Titrant Conc.:
1.0000 mg/mL
Date/Time:
Jan 1, 2010 12:01
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Cautious
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
1.000 uL
Maximum Dose:
30.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
900 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
10.0 ug/min
Result Unit:
ppm
Calculations:
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
ppm
1.0000 mg/mL
4.0000 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8105EN
Moisture Determination in Cooking Oil
Results:
Titration Report
Method Name:
Moisture in Cooking Oil
Time & Date:
12:00 Jan 1, 2011
Sample Size:
4.0296 g
Std. Titrant Conc.:
1.0000 mg/mL
Drift Value:
3.4 ug/min
End Point Volume:
2.6808 mL
Result:
660 ppm
Titration Duration:
6:30 [mm:ss]
Estimated Cell Volume:
58.11 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8106EN
Moisture Determination in Butter
by external dissolution
Description:
Method for the determination of moisture in Butter by
external dissolution. The results are expressed in %
mass and should be between 15 and 20 %.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Solvent for KF Volumetric Titration
 Dry Methanol
 Dry Chloroform
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
 100-mL dissolution bottle with septum
 Magnetic stirrer and stirbar
External Dissolution Procedure:
 To an external dissolution bottle with septum, add
a magnetic stir bar. Weigh the bottle and record
this value.
 Add 15 g of dry methanol and 25 g of dry
chloroform to the bottle and stir for 15 to 20
minutes.
 Determine the moisture content of the solvent mix.
For the determination of the exact concentration of
the solvent mix, follow HI8301EN Solvent w/
5mg/mL 1-comp.
 Enter the solvent moisture concentration by
pressing
Method
Options,
then
Sample
Parameters, then External Solvent Concentration.
Use the numeric keypad to enter the exact
concentration. Press Accept or Enter.
 Weigh the dissolution bottle to determine the
weight of the remaining solvent (by subtracting the
empty bottle mass). Enter the exact mass by reentering Sample Parameters and selecting
External Solvent Size. Use the numeric keypad to
enter the exact mass. Press Accept or Enter.
 Add 2.0 to 4.0 g of butter to the bottle. Weigh the
bottle to determine the exact dissoluted sample
weight. Enter the exact mass by re-entering
Sample Parameters and selecting Dissoluted
Sample Size. Use the numeric keypad to enter
the exact mass. Press Accept or Enter.
 To dissolve the butter, mix for 20 to 30 minutes.
The resulting solution will be used to determine
the water content.
Note: Titrate the solution immediately.
Titration Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8106EN Moisture in
Butter’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the titration solvent
and the titration vessel moisture.
Allow the
background drift rate to stabilize before
proceeding to the next step.
 Fill the syringe and needle with the sample
solution.
 Weigh the syringe, needle and sample solution.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.5000 g to 1.0000 g of sample solution
into the titration vessel through the septum using
the needle. Pay attention not to get any sample
on the electrode or beaker walls. If necessary
swirl the titration vessel by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the
needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
 The use of external dissolution increases the
precision and drastically lowers the load of the
solvent, allowing you to run more titrations without
changing the solvent. Use fresh titration solvent
after every 10 - 12 titrations.
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8106EN
Moisture Determination in Butter
by external dissolution
Method Parameters:
Results:
Name:
Moisture in Butter
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
None
Pre-Analysis Stir Time:
10 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Sample Parameters:
Sample Determ.:
External Dissolution
Sample Name:
Butter
Sample Size:
0.7500 g
External Solvent Size:
40.0000 g
External Solvent Conc.:
0.0100 %
Extracted Sample Size:
3.0000 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.5000 uL
Maximum Dose:
40.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
720 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
15.0 ug/min
Result Unit:
%
Titration Report
Method Name:
Moisture in Butter
Time & Date:
12:00 Jan 01, 2011
Sample Size:
0.7841 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
4.6 ug/min
End Point Volume:
2.4497 mL
External Solvent Size:
38.4979 g
External Solvent Conc.:
0.0167 %
External Sample Size:
3.1222 g
Result:
19.3903 %
Titration Duration:
6:54 [mm:ss]
Estimated Cell Volume:
61.0 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
External Solvent Size:
External Solvent Conc.:
External Sample Size:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
40.0000 g
0.0100 %
3.0000 g
0.7500 g
(
)
(
)
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8107EN
Moisture Determination in Margarine
by external dissolution
Description:
Method for the determination of moisture in
Margarine by external dissolution. The results are
expressed in % mass and should be between 15
and 30 %.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Solvent for KF Volumetric Titration
 Dry Methanol
 Dry Chloroform
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
 100-mL dissolution bottle with septum
 Magnetic stirrer and stirbar
External Dissolution Procedure:
 To an external dissolution bottle with septum, add
a magnetic stir bar. Weigh the bottle and record
this value.
 Add 20 g of dry methanol and 20 g of dry
chloroform to the bottle and stir for 15 to 20
minutes.
 Determine the moisture content of the solvent mix.
For the determination of the exact concentration of
the solvent mix, follow HI8301EN Solvent w/
5mg/mL 1-comp.
 Enter the solvent moisture concentration by
pressing
Method
Options,
then
Sample
Parameters, then External Solvent Concentration.
Use the numeric keypad to enter the exact
concentration. Press Accept or Enter.
 Weigh the dissolution bottle to determine the
weight of the remaining solvent (by subtracting the
empty bottle mass). Enter the exact mass by reentering Sample Parameters and selecting
External Solvent Size. Use the numeric keypad to
enter the exact mass. Press Accept or Enter.
 Add 2.0 to 4.0 g of margarine to the bottle. Weigh
the bottle to determine the exact dissoluted
sample weight. Enter the exact mass by reentering Sample Parameters and selecting
Dissoluted Sample Size. Use the numeric keypad
to enter the exact mass. Press Accept or Enter.
 To dissolve the margarine, mix for 20 to 30
minutes. The resulting solution will be used to
determine the water content.
Note: Titrate the solution immediately.
Titration Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8107EN Moisture in
Margarine’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the titration solvent
and the titration vessel moisture.
Allow the
background drift rate to stabilize before
proceeding to the next step.
 Fill the syringe and needle with the sample
solution.
 Weigh the syringe, needle and sample solution.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.5000 g to 1.0000 g of sample solution
into the titration vessel through the septum using
the needle. Pay attention not to get any sample
on the electrode or beaker walls. If necessary
swirl the titration vessel by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the
needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
 The use of external dissolution increases the
precision and drastically lowers the load of the
solvent, allowing you to run more titrations without
changing the solvent. Use fresh solvent after
every 12 - 16 titrations.
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8107EN
Moisture Determination in Margarine
by external dissolution
Method Parameters:
Results:
Name:
Moisture in Margarine
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
None
Pre-Analysis Stir Time:
10 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Sample Parameters:
Sample Determ.:
External Extraction
Sample Name:
Margarine
Sample Size:
0.7500 g
External Solvent Size:
40.0000 g
External Solvent Conc.:
0.0100 %
Extracted Sample Size:
3.0000 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
1.0000 uL
Maximum Dose:
50.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
720 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
15.0 ug/min
Result Unit:
%
Titration Report
Method Name:
Moisture in Margarine
Time & Date:
12:00 Jan 01, 2011
Sample Size:
0.7402 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
4.1 ug/min
End Point Volume:
3.1402 mL
External Solvent Size:
39.9262 g
External Solvent Conc.:
0.0141 %
External Sample Size:
3.1118 g
Result:
27.6339 %
Titration Duration:
5:30 [mm:ss]
Estimated Cell Volume:
64.4 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
External Solvent Size:
External Solvent Conc.:
External Sample Size:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
40.0000 g
0.0100 %
3.0000 g
0.7500 g
(
)
(
)
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8108EN
Moisture Determination in Mayonnaise
by external extraction
Description:
Method for the determination of moisture in
Mayonnaise by external extraction. The results are
expressed in % mass and should be between 40
and 60 %.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Solvent for KF Volumetric Titration
 Dry Methanol
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
 100-mL extraction bottle with septum
 Magnetic stirrer and stirbar
External Extraction Procedure:
 To an external extraction bottle with septum add
magnetic stir bar. Weigh the bottle and record this
value.
 Add 40 g of dry methanol to the bottle and stir for
5 minutes.
 Determine the moisture content of the solvent mix.
For the determination of the exact concentration of
the solvent mix, follow HI8301EN Solvent w/
5mg/mL 1-comp.
 Enter the solvent moisture concentration by
pressing
Method
Options,
then
Sample
Parameters, then External Solvent Concentration.
Use the numeric keypad to enter the exact
concentration. Press Accept or Enter.
 Weigh the extraction bottle to determine the
weight of the remaining solvent (by subtracting the
empty bottle mass). Enter the exact mass by reentering Sample Parameters and selecting
External Solvent Size. Use the numeric keypad to
enter the exact mass. Press Accept or Enter.
 Add 0.8 to 1.2 g of mayonnaise to the bottle.
Weigh the bottle to determine the exact extracted
sample weight. Enter the exact mass by reentering Sample Parameters and selecting
Extracted Sample Size. Use the numeric keypad
to enter the exact mass. Press Accept or Enter.
 To extract the water from the mayonnaise, mix for
20 to 30 minutes. The resulting supernatant will
be used to determine the water content.
Note: Titrate the supernatant immediately.
Titration Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8108EN Moisture in
Mayonnaise’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the titration solvent
and the titration vessel moisture.
Allow the
background drift rate to stabilize before
proceeding to the next step.
 Stop stirring the sample in the extraction bottle
and allow any particulate matter to settle.
 Fill the syringe and needle with the supernatant.
Do not draw particulate from the bottom.
 Weigh the syringe, needle and supernatant.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.5000 g to 1.0000 g of supernatant into
the titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the
needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
 The use of external extraction increases the
precision and drastically lowers the load of the
solvent, allowing you to run more titrations without
changing the solvent. Use fresh solvent after
every 10 - 12 titrations.
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8108EN
Moisture Determination in Mayonnaise
by external extraction
Method Parameters:
Results:
Name:
Moisture in Mayonnaise
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
None
Pre-Analysis Stir Time:
10 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Sample Parameters:
Sample Determ.:
External Extraction
Sample Name:
Mayonnaise
Sample Size:
0.7500 g
External Solvent Size:
40.0000 g
External Solvent Conc.:
0.0100 %
Extracted Sample Size:
1.0000 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.5000 uL
Maximum Dose:
20.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
720 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
10.0 ug/min
Result Unit:
%
Titration Report
Method Name:
Moisture in Mayonnaise
Time & Date:
12:00 Jan 01, 2011
Sample Size:
0.7500 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
4.6 ug/min
End Point Volume:
2.2010 mL
External Solvent Size:
40.0000 g
External Solvent Conc.:
0.0100 %
External Sample Size:
1.0000 g
Result:
58.9770 %
Titration Duration:
7:18 [mm:ss]
Estimated Cell Volume:
60.0 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
External Solvent Size:
External Solvent Conc.:
External Sample Size:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
40.0000 g
0.0100 %
1.0000 g
0.7500 g
(
)
(
)
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8201EN
Moisture Determination in Shampoo
Description:
Method for the determination of water in Shampoo.
The results are expressed in % mass and should be
between 70 and 90 %.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 18-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8201EN Moisture in
Shampoo’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with the sample.
 Weigh the syringe, needle and shampoo.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.0150 g to 0.0200 g of shampoo into
the titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the
needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
Method Parameters:
Name:
Moisture in Shampoo
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
40 %
Pre-Analysis Stir Time:
15 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Shampoo
Sample Type:
Mass
Sample Size:
0.0200 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.5000 uL
Maximum Dose:
20.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
600 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
10.0 ug/min
Result Unit:
%
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
0.0200 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8201EN
Moisture Determination in Shampoo
Results:
Titration Report
Method Name:
Moisture in Shampoo
Time & Date:
12:00 Jan 1, 2011
Sample Size:
0.0200 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
5.4 ug/min
End Point Volume:
3.2010 mL
Result:
79.9207 %
Titration Duration:
7:19 [mm:ss]
Estimated Cell Volume:
106.37 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8202EN
Moisture Determination in Hand Cream
Description:
Method for the determination of moisture in Hand
Cream. The results are expressed in % mass and
should be between 50 and 75 %.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
 Dry Chloroform
needle, dip the end of the needle briefly in the
solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water.
Method Parameters:
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 18-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8202EN Moisture in
Hand Cream’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Prepare at least 200 mL of solvent by adding 2
parts dry chloroform to 1 part dry methanol in a
solvent bottle.
Attach the solvent bottle top
assembly to the bottle according to the instruction
manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Fill the syringe and needle with the sample.
 Weigh the syringe, needle and shampoo.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.0200 g to 0.0250 g of hand cream into
the titration vessel through the septum using the
needle. Pay attention not to get any sample on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual sample by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of sample is seen on the end of the
Name:
Moisture in Hand Cream
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
40 %
Pre-Analysis Stir Time:
15 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
CHCl3 MeOH 2:1
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Hand Cream
Sample Type:
Mass
Sample Size:
0.0200 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Normal
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.500 uL
Maximum Dose:
20.000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
900 sec
Maximum Titrant Volume:
10.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
10.0 ug/min
Result Unit:
%
Calculations:
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
0.0200 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8202EN
Moisture Determination in Hand Cream
Results:
Titration Report
Method Name:
Moisture Hand Cream
Time & Date:
12:00 Jan 1, 2011
Sample Size:
0.0244 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
5.4 ug/min
End Point Volume:
2.6925 mL
Result:
67.3125 %
Titration Duration:
6:48 [mm:ss]
Estimated Cell Volume:
106.37 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8301EN
Moisture Determination in Solvent with 5 mg/mL Titrant (One-Comp.)
for external dissolution or extraction
Description:
Method for the determination of moisture in
extraction/dissolution solvent using 5 mg/mL OneComponent Titrant. The results are expressed in %
mass and should be less than 0.1%.
Electrode:
 HI 76320 Double Platinum Pin Electrode
Reagents:
 5 mg/mL One-Component KF Volumetric Titrant
 Dry Methanol
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Solvent Bottle
Titration Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8301EN Solvent w/
5mg/mL 1-comp.’ and press “Select”.
 Install a 5-mL burette filled with 5 mg/mL OneComponent KF Volumetric Titrant and verify that
no air bubbles are present in the burette or tubing.
If necessary prime until all air has been removed
completely.
For the determination of the exact concentration of
the titrant, follow HI8001EN 5.0 mg/mL Titrant
Standardization using Liquid Water Standard.
 Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.
 Stop stirring the solvent in the extraction/
dissolution bottle.
 Fill the syringe and needle with the
extraction/dissolution solvent.
 Weigh the syringe, needle and solvent.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.7500 g to 1.0000 g of solvent into the
titration vessel through the septum using the
needle. Pay attention not to get any solvent on
the electrode or beaker walls. If necessary swirl
the titration vessel by hand.
 Clear the needle of residual solvent by intaking a
small volume of air from the titration vessel. If a
“hanging drop” of solvent is seen on the end of the
needle, dip the end of the needle briefly in the
titration solvent.
 Remove the needle from the titration vessel and
weigh the syringe again in order to determine the
added sample mass (by difference of the two
measurements.)
 Use the numeric keypad to enter the exact weight
and press “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in % mass of water. Record this value
as the “External Solvent Concentration”.
Method Parameters:
Name:
Solvent w/ 5mg/mL 1-comp.
Method Revision:
1.0
Type:
Sample Analysis
Predispensing Amount:
None
Pre-Analysis Stir Time:
0 Sec
Stirring Speed:
900 RPM
Stirbar Type:
Medium
Drift Entry:
Automatic
Solvent:
Methanol
Sample Parameters:
Sample Determ.:
Normal
Sample Name:
Solvent
Sample Type:
Mass
Sample Size:
1.0000 g
Titrant:
Composite 5
Titrant Type:
One Component
Nominal Titrant Conc.:
5.0000 mg/mL
Std. Titrant Conc.:
5.0000 mg/mL
Date/Time:
Jan 1, 2011 12:00
Titrant Age Reminder:
2d:00h:00m
Control Parameters:
Start Mode:
Cautious
Standby Mode:
Enabled
Standby Duration:
720 minutes
Imposed Current:
20 uA
Minimum Dose:
0.2500 uL
Maximum Dose:
5.0000 uL
Timed Increment:
1 second
End Point Value:
180.0 mV
Signal Averaging:
3 Readings
Flow Rate:
10.0 mL/min
Termination Parameters:
Maximum Duration:
600 sec
Maximum Titrant Volume:
5.0000 mL
Term. Criterion:
Relative Drift
Relative Drift:
10.0 ug/min
Result Unit:
%
Calculations:
Titrant units:
Titrant volume consumed:
Final results units:
Titrant concentration:
Sample mass:
mg/mL
V (mL)
% Mass
5.0000 mg/mL
1.0000 g
Titrator Application Methods: General Methods - r. 0.4
Method ID: HI8301EN
Moisture Determination in Solvent with 5 mg/mL Titrant (One-Comp.)
for external dissolution or extraction
Results:
Titration Report
Method Name:
Solvent w/ 5mg/mL 1-comp.
Time & Date:
12:00 Jan 01, 2011
Sample Size:
0.9580 g
Std. Titrant Conc.:
5.0000 mg/mL
Drift Value:
4.0 ug/min
End Point Volume:
0.1157 mL
Result:
0.0595 %
Titration Duration:
2:06 [mm:ss]
Estimated Cell Volume:
57.5 mL
Titration went to Completion
Operator Name:
Analyst Signature: ________________________
Titrator Application Methods: General Methods - r. 0.4
TITRATION THEORY
TITRATION THEORY
Principles
HI 903
KARL FISCHER
VOLUMETRIC TITRATOR
Revision 1.0
www.hannainst.com
1
TITRATION THEORY
2
TITRATION THEORY
Contents
1
1.1
1.2
1.3
GENERAL REVIEW OF TITRATION THEORY .............................................................................
Introduction to Titrations ..................................................................................................
Uses of Titrations ..............................................................................................................
Advantages and Disadvantages of Titrations ....................................................................
5
5
5
6
2
2.1
2.1.1
2.1.2
2.1.3
2.2
2.2.1
2.2.1.1
2.2.1.2
2.2.1.3
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
2.3
2.3.1
2.3.2
TYPES OF TITRATION ........................................................................................................... 7
Titrations According to The Measurement Method ............................................................. 7
Amperometric Titrations .......................................................................................................... 7
Potentiometric Titrations ......................................................................................................... 7
Spectrophotometric Titrations .................................................................................................. 8
Titrations According to The Reaction Type ........................................................................ 9
Karl Fischer Titration ............................................................................................................... 9
History of Karl Fischer Titrations ............................................................................................... 9
Visual Indication of Karl Fischer Titrations ................................................................................. 10
Electrometric Indication of Karl Fischer Titrations ....................................................................... 10
Acid - Base Titrations .............................................................................................................. 11
Argentometric Titrations .......................................................................................................... 12
Complexometric Titrations ....................................................................................................... 12
Ion Selective Titrations ............................................................................................................ 13
Non-aqueous Solvent Acid - Base Titrations ............................................................................... 13
Precipitation Titrations ............................................................................................................ 14
Redox Titrations ..................................................................................................................... 14
Titrations According to The Titration Sequence ................................................................ 15
Back Titrations ....................................................................................................................... 15
Multiple End Point Titrations .................................................................................................... 15
3
3.1
3.2
INTRODUCTION TO TITRATION APPARATUS AND TYPICAL TITRATION PROCEDURE ................ 17
Manual Titration ............................................................................................................... 17
Automatic Titration .......................................................................................................... 18
4
4.1
4.2
4.3
4.3.1
4.3.2
4.3.2.1
4.3.2.2
4.3.3
4.3.4
TITRATION RESULTS .......................................................................................................... 19
Accuracy .......................................................................................................................... 19
Repeatability .................................................................................................................... 19
Sources of Error ............................................................................................................... 19
Sampling Errors ..................................................................................................................... 19
Errors with Titrant and Standard .............................................................................................. 19
Preparation Errors .................................................................................................................. 19
Dispensing Errors ................................................................................................................... 20
Chemical Reaction Errors .................................................................................................. 20
End Point Determination Errors ........................................................................................ 20
5
5.1
5.1.1
5.1.2
5.1.3
5.1.4
5.1.5
5.1.6
5.1.7
5.1.8
5.1.9
5.2
5.2.1
5.2.2
5.2.3
5.2.4
5.2.5
CALCULATIONS .................................................................................................................. 21
Equations Used in Karl Fischer Titrations ........................................................................... 21
Calculation of water content as % mass from samples measured by mass .................................... 21
Calculation of water content as % mass from samples measured by volume ................................. 21
Calculation of water content as % volume from samples measured by volume .............................. 21
Calculation of water content subtracting Background Drift Rate .................................................... 21
Calculation of water content in external dissolutions samples ...................................................... 22
Calculation of water content in external extraction samples ......................................................... 22
Calculation of water content in gaseous samples ....................................................................... 22
Calculation of Titer (water equivalent of the titrant) using sodium tartrate dihydrate containing 15.66% water
by mass................................................................................................................................. 22
Calculation of Titer (water equivalent of the titrant) using water standards ................................... 23
Equations Used in Titrations ............................................................................................. 23
Sample Calculation ................................................................................................................. 23
Standardize Titrant ................................................................................................................. 23
Blank Titration ........................................................................................................................ 24
Multiple End Point Titration ...................................................................................................... 24
Back Titration ......................................................................................................................... 25
6
GLOSSARY ........................................................................................................................ 26
3
TITRATION THEORY
4
TITRATION THEORY
1
GENERAL REVIEW OF TITRATION THEORY
1.1 Introduction to Titrations
A titration is a quantitative, volumetric procedure used in analytical chemistry to determine
the concentration of an analyte (the species being measured) in solution. The concentration
of the analyte is determined by slowly adding a titrant (reagent) to the solution. As the titrant
is added, a chemical reaction occurs between the titrant and the analyte.
Titration reactions are relatively fast, simple reactions that can be expressed using a chemical
equation. The titration reaction continues as the titrant is added until all of the analyte is
consumed and the analyte reacts completely and quantitatively with the titrant.
The point at which all of the analyte has been reacted is called the equivalence point, also
known as the theoretical or stoichiometric endpoint. This point is accompanied by an abrupt
physical change in the solution, which sharply defines the endpoint of the reaction. The
physical change associated with the titration endpoint can be produced by the titrant or an
indicator and can be detected either visually or by some other physical measurement.
Titrations cannot be used to determine the quantity of all analytes. The chemical reaction
between the titrant and analyte must fulfill four requirements:
•
The reaction must be fast and occur within approximately one second after the
titrant is added;
•
The reaction must go to completion;
•
The reaction must have well-known stoichiometry (reaction ratios);
•
A convenient endpoint or inflection point.
Titrations are highly precise and can provide many advantages over alternative methods.
Titrations are quickly performed and require relatively simple apparatus and instrumentation.
1.2 Uses of Titrations
Titrations can be used in many applications, including:
•
Acid content of plant effluents, food (i.e. cheese and wine), plating and etching
baths, petroleum products, drugs;
•
Base content of fertilizer (containing ammonia), bleach, minerals;
•
Hardness in water;
•
Metal content of alloys, minerals, ores, clays, waters, plating baths, paints,
paper, plant materials, biological fluids, petroleum products;
•
Moisture content in butter, dairy cream, food grade oil, honey, margarine,
mayonnaise, milk, powdered milk, sugar;
•
Redox reagent concentrations such as available chlorine in potable water,
peroxide, traces of oxidants and reductants in food, reductants in high
temperature or high pressure boiler water, vitamin analysis.
5
TITRATION THEORY
1.3 Advantages and Disadvantages of Titrations
Some advantages of titrations, as an analytical technique, are:
•
More precise results than many instrumental methods, such as measurement
by electrode, the accuracy of the measurement is up to 0.1%;
•
Simple methods, reasonable capital costs, and easy training;
•
Suitability to measure major components of a mixture or product;
•
Automation can reduce time and labor spent on each analysis.
Some disadvantages of titrations are:
6
•
Time it takes to prepare standards and titrants;
•
Good technique is required to achieve precise results (training and practice
required);
•
Not suitable for determining trace or minor components of a mixture or product;
•
Limited dynamic range, it may require additional sample preparations (dilution)
and repeat analyses.
TITRATION THEORY
2
TYPES OF TITRATIONS
2.1 Titrations According to The Measurement Method
2.1.1 Amperometric Titrations
An amperometric titration is performed by placing two electrodes (often a metal electrode and a
reference electrode) into the sample solution and holding the potential of the metal electrode at
a selected voltage. The current that flows, due to the oxidation or reduction of a reactant or
product, is plotted vs. volume of titrant to provide the titration curve and locate the equivalence
point. Changes in the current are due to changes in the concentration of a particular species
(being oxidized or reduced at the electrode).
Generally the reaction between the analyte and titrant forms a new species. Depending on the
titration, the reactants are electroactive and the products are not, or vice-versa. Amperometric
titration curves look like two straight lines intersecting at the equivalence point, this is due to the
change in the electroactivity of the solution.
Many metal ions can be amperometrically titrated using a precipitation, complexation or redox
reaction. Some metal ions and species that can be determined in this manner include silver,
barium, halides, potassium, magnesium, palladium, molybdate, sulfate, tungstate, zinc, bismuth,
cadmium, fluoride, indium, thallium, iodine, and gold.
Figure 1 shows four amperometric titrations and their endpoints. In graph “A” the analyte is
electroactive and gives current but the reacted species does not. In “B” the reactant is not active
but the titrant is. In “C” both the analyte and titrant are active and both give current flow. Graph “D”
shows the same situation as “B”; however, the current has an opposite sign (the titrant is reduced).
Figure 1.
2.1.2 Potentiometric Titrations
Potentiometric titrations are done by measuring the voltage across the solution using an electrode
system. An electrode system consists of an indicator electrode and a reference electrode. As
titrant is added the variations in the potential of the indicator electrode, with respect to the reference
7
TITRATION THEORY
electrode, are monitored to show the progress of the titration.
Potentiometry is the measurement of a potential under conditions of zero current flow. The
measured potential can then be used to determine the analytical quantity of interest, generally a
component concentration of the analyte solution. The potential that develops in the electrochemical
cell is the result of the free energy change that would occur if the chemical phenomena were to
proceed until the equilibrium condition has been satisfied.
There are many types of titrations where potentiometry can be used,e.g., pH electrodes for acidbase titrations, platinum ORP electrodes in redox titrations, ion selective electrodes, such as chloride
or fluoride for a specific ion titration, and silver electrodes for argentometric (silver-based) titrations.
2.1.3 Spectrophotometric Titrations
The name comes from the method used to detect the endpoint of the titration, not its
chemistry. Highly colored indicators that change color during the course of the titration are
available for many titrations. More accurate data on the titration curve can be obtained if the
light absorption is monitored instrumentally using a light source, a simple monochromator
and a photodetector, rather than visually determining the color or light absorption change.
Light absorption by either an indicator or by one of the reactants or products can be used to
monitor the titration.
In the first titration curve, Figure 2 “A”, the absorption of a metal-indicator complex is being
monitored. The absorption is constant while the metal is complexed by the EDTA titrant. The
metal indicator complex was stripped, causing a sharp break in the titration curve. The point
where all the metal is complexed and stripped from the indicator is the equivalence point. This point
is marked by “e.p.” on the graph.
In the second titration curve, Figure 2 “B”, the metal complex is being measured while being
titrated with EDTA. The new complex being formed is not colored and does not absorb light.
The extrapolated intersection of the two lines determines the equivalence point.
Figure 2.
8
TITRATION THEORY
2.2 Titrations According to The Reaction Type
2.2.1 Karl Fischer Titrations
This method is based on a well-defined chemical reaction between water and the Karl Fischer
reagent. The chemistry provides excellent specificity for water determination. The method
can be used to determine free and bound water in a sample matrix. The Karl Fischer method
is widely considered to produce the most rapid, accurate and reproducible results and has
the largest detectable concentration range spanning 1 ppm to 100%.
The determination of water content is one of the most commonly practiced methods in
laboratories around the world. Knowledge of water content is critical to understanding chemical
and physical properties of materials and ascertaining product quality. Water content
determination is conducted on many sample types including pharmaceuticals and cosmetics,
foods and natural products, organic and inorganic compounds, chemicals, solvents and
gases, petroleum and plastic products as well as paints and adhesives. The KF method is
verifiable and can be fully documented. As a result, Karl Fischer titration is the standard
method for analysis of water in a multitude of samples as specified by numerous organizations
including the Association of Official Analytical Chemists, the United States and European
Pharmacopoeia, ASTM, American Petroleum Institute, British Standards and DIN.
2.2.1.1
History of Karl Fischer Titrations
Water determination by Karl Fischer titration is based on the reaction described by Bunsen in
1853 in which sulfur dioxide is oxidized by iodine in the presence of water.
I2 + SO2 + 2 H2O g 2 HI + H2SO4
In Karl Fischer’s 1935 article, “a new procedure for the titration of water,” he presented a
modified form of the Bunsen reaction adapted for use in determining the water content of
non-aqueous solutions. His titrations were conducted in methanol in the presence of excess
sulfur dioxide and pyridine in order to neutralize the acidic reaction products and drive the
reaction to completion.
2 H2O + SO2 • (C5H5N)2 + I2 + 2 C5H5N g (C5H5N)2 • H2SO4 + 2 C5H5N • HI
Two key developments have since lead to the currently accepted description of the Karl
Fischer reaction. First, pyridine acts as a pH buffer and does not play a direct role in the
reaction. This has allowed reagent formulators to replace pyridine with bases which are both
less toxic and result in pH ranges that facilitate faster and more accurate titrations. Second,
the species that reacts with water is not sulfur dioxide but the monomethyl sulfite ion resulting
from the reaction between sulfur dioxide and methanol. Subsequently, researchers showed
that higher alcohols can be used in place of methanol. The Karl Fischer reaction can therefore
be described by the following generalized reaction sequence in which the H2O, I2, SO2 and
RN species react in a 1:1:1:3 stoichiometry.
ROH + SO2 + RN g (RNH)•SO3R
(RNH)•SO3R + I2 + H2O g (RNH)•SO4R + 2(RNH)I
The maximum rate of the Karl Fischer reaction is reached between the pH range of 5.5 to 8
where all of the sulfur dioxide is available as methyl sulfite. If the pH drops below 5, the rate
9
TITRATION THEORY
of reaction decreases and titration endpoint become increasingly difficult to reach. If the pH
exceeds 8, side reactions begin to occur between iodine and hydroxide or methylate ions,
changing the titration stoichiometry.
While solvents not containing alcohols can be used for Karl Fischer analysis, they also have
an effect on reaction stoichiometry. When alcohols are not present, the reaction resembles
the Bunsen reaction stoichiometry where the consumption ratio of water to iodine is 2:1. In
solvents containing higher alcohols, uneven ratios can be observed due to the relative abilities
of higher alcohols to form the sulfite ester that reacts with water. Issues resulting from
solvent-induced variation in stoichiometry are not typically encountered during routine analysis
for two reasons. First, titrant standardization and sample analysis are carried out in the same
titration medium and under the same conditions, effectively compensating for any variation
in reaction behavior. Second, most Karl Fischer reagent system are formulated to support
standard KF reaction stoichiometry.
2.2.1.2
Visual Indication of Karl Fischer Titrations
Visual methods, originally used by Karl Fischer, are limited in application, require a high
degree of skill and have been made obsolete by electrometric indication. For successful
visual indication, titration samples must be colorless. Additionally, the solution coloration
varies between polar and non-polar titration media.
After the titration equivalence point all of the water in the titration solution has been reacted.
The next drop of titrant added to the solution after the equivalence point contains iodine that
will remain in the titration solution. Thereafter, the concentration of iodine in the titration
solution increases and the solution develops a yellow, and eventually brown, color. It is
difficult, even for an experienced analyst, to generate reproducible endpoint coloration between
successive titrations.
2.2.1.3
Electrometric Indication of Karl Fischer Titrations
Biamperometric and bivoltametric indication are the two types of electrometric detection
methods commonly used for indication of Karl Fischer titrations. Both methods use either a
double platinum pin or a double platinum ring electrode to detect excess iodine in a titration
solution. After the titration equivalence point, all of the water in the titration solution has
been reacted. The next dose of titrant added to the solution contains iodine, which reacts at
the electrode according to the reactions below.
At the cathode:
I2 + 2e-g 2IAt the anode:
2I-g I2 + 2eThe excess iodine is easily reduced at the cathode, and the resulting iodide is oxidized at the
anode.
Both electrometric methods of indication rely on electrons (current) being carried through a
titration solution by the oxidation-reduction reactions described above.
Biamperometric indication involves monitoring the flow of current through the titration solution
while a constant voltage is applied across the platinum elements of the electrode. When
water is present in the titration solution and there is no excess iodine, only a minimal current
flows between the electrode elements. After the equivalence point, when iodine is present,
the current flow increases to a few µA.
10
TITRATION THEORY
Bivoltametric indication involves measuring the voltage required to maintain a constant current
flow between electrode elements. A small direct or alternating current called a polarization
current (Ipol) is applied between the electrode pins or rings and the resulting voltage is
measured in order to monitor the titration progress.
L-shaped titration curves are generated for both methods by plotting either the electrode
current or voltage against the volume of titrant added during the titration.
Karl Fischer Titration, Bivoltametric Indication vs. Titrant Volume
450
400
350
Potential (mV)
300
250
200
150
0
0.2
0.4
0.6
0.8
1
Titrant Volume (mL)
Electrometric methods result in over-titration or titration past the equivalence point where excess
iodine is present in the titration solution. Titration past the equivalence point is acceptable for two
reasons. First, due to the sensitivity of the electrometric methods, titrations are always carried
out to the exact same, slight excess of iodine resulting in highly reproducible titrations. Second,
the accuracy of electrometrically indicated titrations are not affected by the over-titration because
the slight excess of iodine has been accounted for during the standardization of the titrant.
2.2.2 Acid-Base Titrations
Acid–base titrations are the most common type of titrations. Acid–base titrations are based
upon a reaction between an acid and a base, a stoichiometric neutralization, or the exchange
of protons. Virtually all acid-base titrations are carried out using a strong acid or a strong
base as the titrant. The endpoint of a titration carried out with a weak acid or a weak base,
would be difficult to detect due to a small change in pH at the equivalence point.
Chemical indicators are often used to determine the endpoint. The indicator will change
color to signify that the end of the titration has been reached. When choosing the proper
indicator you should select one that has a pKa as close to the endpoint of the titration. The
color-change region of the indicator is usually ± 1 pH unit around the pKa. The theoretical
titration curve is useful for illustrating how the solution will change during the real titration,
and allowing the proper selection of an endpoint or an indicator.
11
TITRATION THEORY
Figure 3
pCl
Figure 3 shows a traditional titration curve. The curve is obtained by plotting the pH value
against the volume of NaOH added.
2.2.3 Argentometric Titrations
Argentometric titrations use silver (nitrate) as the titrant and are generally precipitation titrations,
as many silver salts are insoluble. These titrations are commonly used to titrate and determine
the concentration of bromide, chloride, cyanide, iodide, and sulfide.
Argentometric titrations can be done with Mohr’s indicator, when all of the chloride has reacted,
a red silver chromate precipitate is formed or the titration can be easily followed with a silver ISE
(or chloride ISE for chloride titrations) and a reference electrode.
Figure 4
Figure 4 shows the titration of 50 mL of 0.1N NaCl with 0.1N AgNO3. The potentiometric
signal is from a chloride ISE, and is plotted as pCl (- log [Cl-]).
2.2.4 Complexometric Titrations
A complex is a species where a central metal ion is covalently bonded to one or more electron
donating groups called ligands. In a complexometric titration, metal ions are titrated using a
12
TITRATION THEORY
titrant that binds strongly to it. Often these titrants contain EDTA or CDTA, polydentate ligands
that form very stable coordination compounds with metal ions. The complexation reaction
must be fast in order to be useful for direct titration. Some metal ions react too slowly with
EDTA for a direct titration.
An indicator electrode that responds to the metal ion can be used to monitor the titration progress.
The titration curve will appear similar to a usual potentiometric titration. Complexation indicators
change color at the endpoint as all metal ions are “consumed”, or complexed by the titrant.
The titration curve will appear similar to a potentiometric titration, when using an indicator
electrode that responds to the metal ion (see Figure 5).
Figure 5.
2.2.5 Ion Selective Titrations
The most popular ion selective titration is an acid-base titration. The hydrogen ion concentration
is specifically measured and monitored during the titration process to locate the equivalence
point. Using an ion selective electrode (ISE) as the indicator electrode, the potentiometric signal
(in mV) is used to directly follow a specific ion’s concentration (or activity).
Examples of ISE titrations include titrating fluoride with an aluminum titrant using a fluoride ISE,
chloride with silver nitrate using a chloride ISE, sodium with a sodium ISE, etc. The equivalence
point can be determined by plotting the mV value vs. the amount of titrant added.
2.2.6 Non-aqueous Solvent Acid-Base Titrations
Non-aqueous solvents must be used to titrate very weak acids and bases due to the inherent
leveling effect water has on all acids and based dissolved in it. A wide variety of weak acids and
bases can be titrated using non-aqueous solvents. Mixtures of acids or bases can often be individually
analyzed in a single sequential titration.
Titration of Acids
Weak acids with pKa’s up to about 11 can be titrated in non-aqueous solvents. These include
13
TITRATION THEORY
carboxylic acids, enols, phenols, imides, sulfonic acids, and inorganic acids. Water or lower
alcohols are suitable for titrating medium to strong acids (pKa less than 5). Titrating a weaker
acid with a strong base titrant requires a solvent less acidic than water or ethanol/methanol.
Solvents such as acetone, acetonitrile, t-butyl alcohol, dimethlyformamide, isopropanol and
pyridine have been found to work well for acid-base titrations of strong, medium and weak acids/
bases. Titrants include alcoholic potassium hydroxide and various sodium or potassium alkoxides
in a 10:1 mixture of benzene/methanol. The best titrants are quaternary ammonium hydroxides
(such as tetrabutylammonium hydroxide) due to good solubility of tetraalkylammonium salts of
the titrated acids and the clean potentiometric titration curve obtained (see Figure 6)
Titration of Bases
Weak bases with pKb’s up to about 11, which do not ionize with water, can be titrated in nonaqueous solvents. These bases include aliphatic and aromatic amines, basic nitrogen
heterocycles, alkali metal and amine salts of acids, and many other organic basic compounds.
Titrating a weak base with a strong acid titrant requires a basic solvent that is as weak as possible.
Water and alcohols allow the titration of medium strength bases such as aliphatic amines (pKb
= 4 to 5), but not the titration of weaker bases such as pyridine (pKb = 8.8). Glacial acetic acid
works well for weak bases and has been used extensively. Less basic solvents such as acetone,
acetonitrile, and nitromethane extend the range of titrable compounds.
The endpoint for non-aqueous titrations are usually determined potentiometrically using a pH
glass electrode, a modified calomel or double junction reference electrode with a low-flow rate
reference junction. Good potentiometric titration curves are obtained in most solvents, except
those with very low dielectric constants such as benzene, chloroform and others, when high
electrical resistance of the solvent causes unstable potentials.
2.2.7 Precipitation Titrations
Precipitation titrations allow for faster analysis compared to the old gravimetric analysis, where
a precipitate is formed, filtered, dried and weighed to analyze a compound. Typically silver halides,
silver thiocyanate and a few mercury, lead, and zinc salts are titrated using this method. The
chemical reactions must form an insoluble salt and precipitate out quickly in order to be analyzed
by this method. When the reaction is not quick, a back titration can be used. A measured excess
of the precipitating reagent (titrant) is added to force the reaction to occur, and then unreacted
titrant is then titrated with a standard solution of another reagent.
2.2.8 Redox Titrations
There are a number of oxidation-reduction reactions that can be used to determine unknown
concentration by titration. If the reaction goes to completion, is fast and has an analytical signal
available to follow it, a titration can be performed. The term “fast” means that each addition of
titrant is reacted completely and the sensing electrode is able to detect the change in solution in
less than one second.
Redox titrations are potentiometric titrations where the mV signal from a combination ORP (redox)
electrode (usually with a platinum indicator electrode) is used to follow the reaction of oxidant/
reductant. The electrode potential is determined by the Nernst equation and is controlled by the
oxidant reductant ratio.
14
TITRATION THEORY
Figure 6.
Figure 7.
Visual indicators such as Ferrion are also available. The oxidized and reduced form of the
indicator will have different colors and can be used to determine the end point.
Various reductants can be determined by titrants with oxidants such as potassium permanganate,
potassium chromate or iodine. Commonly used reductants that are used as titrants include sodium
thiosulfate, and ferrous ammonium sulfate.
As with Acid-Base titrations the potential changes dramatically at the equivalence point.
2.3 Titrations According to The Titration Sequence
2.3.1 Back Titrations
Back titrations are generally used when a reaction is too slow to be directly accomplished
during a “direct” titration, where the reaction goes to completion within a few seconds. In a
back titration, a large excess of a reagent is added to the sample solution, helping a slow
reaction to go to completion. The un-reacted, excess reagent is then titrated. The difference
in the total volume of the first reagent added and amount determined from the second
titration is the quantity of reagent required to complete the first reaction.
2.3.2 Multiple End Point Titrations
Under certain conditions, some titrations can exhibit more than one equivalence point and be
titratable to the individual end points to determine the concentration of each individual
component. Examples of these types of titrations include acid-base, where different strength
acid or bases are in a mixture; redox, where each species has a different reduction potential;
complexometric, where different species are separately titratable; and acid-base, using
polyprotic acids (the pKa of the different protons varies enough to separate them).
Figure 8 shows three different types of multiple end point titrations. “A” shows the titration of
a polyprotic acid. The different acid strengths of the first and second proton can be determined.
“B” illustrates a mixture of two different metal redox species, where the different redox
potentials allow the species to be separated. “C” is the titration of a solution containing
strong, weak, and very weak acids.
15
TITRATION THEORY
Potential, glass electrode, mV
Figure 8.
A
B
C
16
TITRATION THEORY
3
INTRODUCTION TO TITRATION APPARATUS AND TYPICAL
TITRATION PROCEDURE
3.1 Manual Titration
Apparatus required for manual titration include:
• Volumetric Burette, for precisely controlled delivery of titrant to the reaction vessel;
• An Erlenmeyer, or similar flask, that facilitates constant mixing or swirling required to
ensure solution homogeneity;
• Volumetric pipettes for the precise addition of samples and indicator solutions;
• Standard titrant solutions of known concentration;
• A visual or instrumental indicator for detecting the completion of the reaction.
A typical manual titration consists of the following steps:
1. A volumetric pipette is typically used to add a known volume of sample to the flask;
2. An indicator solution or instrument probe is added to the flask;
3. A burette is used to measure the addition of titrant to the flask and dispense titrant in
a controlled manner;
4. Titrant is added via the burette until the method indication signals the reaction endpoint;
5. The concentration of analyte is calculated based on the concentration and volume of
titrant required to reach the endpoint and the reaction stoichiometry.
17
TITRATION THEORY
3.2 Automatic Titration
Automatic titrators are high-precision analytical instruments that deliver the titrant, monitor
the physical change associated with the titration reaction, automatically stops at the endpoint
and calculates the concentration of the analyte. Automatic titrators are best for repetitive
titrations and high-accuracy analyses.
An automatic titrator must have an accurate liquid dispensing system. In high accuracy
systems like the HI 900-series titrators, the liquid dispensing system consists of a stepper-motor
driven piston syringe burette capable of accurately and precisely dispensing very small volumes
of titrant, a valve system to switch between titrant intake and outlet and an anti-diffusion
dispensing tip. These three main subsystem components must be as accurate as possible,
with very low gear backlash in the burette pump, minimal piston seal flexing, precision
ground inner diameter of the glass syringe, a low dead volume valve, minimal evaporation/
permeation, and chemically resistant tubing.
Apparatus required for automatic titration include:
• An automatic titrator, equipped with a burette;
• A beaker;
• An electronic stirring system, either a propeller stirrer or a magnetic stir bar and stir
plate;
• Volumetric pipettes for the precise addition of samples;
• Standard titrant solutions of known concentration;
• An electrode system that can be used to determine the endpoint of the titration.
A typical automatic titration consists of the following steps:
1. Set up the automatic titrator according to the manufacturer’s instructions;
2. A volumetric pipette is typically used to add a known volume of sample to the beaker;
3. Submerge the propeller stirrer or add the stir bar to the beaker, and turn on;
4. Start the titration, the titrator will automatically stop at the endpoint and determine
the concentration of the analyte.
18
TITRATION THEORY
4
TITRATION RESULTS
4.1 Accuracy
The factors most critical to achieving accurate results with the HI 900 titration systems are
the concentration of the sample, size of the sample and having an optimized set of method
parameters.
4.2 Repeatability
Repeatability, or the agreement between replicate determinations, is expressed quantitatively
as the relative standard deviation (RSD).
4.3 Sources of Error
One of the advantages of volumetric analysis is excellent accuracy and precision. The sources
of error can be grouped into sampling, titrant and standards, chemical reactions, endpoint
determination and calculations.
4.3.1 Sampling Errors
• Selection of a non-homogeneous or non-representative sample;
• Sample changed or was contaminated during collection, storage or transfers;
• Poor technique when transferring sample to beaker or flask;
• Errors in the balance, calibrate and check balance regularly.
4.3.2 Errors with Titrant and Standard
4.3.2.1
Preparation Errors
Incorrect preparation due to:
• Poor technique in weighing the salt or when transferring to volumetric glassware;
• Low-purity of salts or water used to make titrant and standard;
• Dirty or wet glassware;
• Improper storage of titrant or standard which allows water gain, evaporation or
deterioration;
• Failure to standardize frequently to adjust for change in titrant;
• Failure to flush titrator tubing with a volume of titrant before standardizing;
• Volume errors from pipettes and volumetric flasks, grade A glassware is required;
• Balance errors when weighing out salts, calibrate and check balance regularly.
19
TITRATION THEORY
4.3.2.2
Dispensing Errors
Incorrect dispensing due to:
• Dead valve volume and leaking valve;
• Inaccuracy in motor drive and gear lash/ backlash;
• Poor burette/ piston seal;
• Non-uniform diameter of burette glass cylinder;
• Chemical incompatibility with tubing or bubble generation;
• Density/ temperature changes in titrant.
• Inadaquate volume to cover electrode.
4.3.3 Chemical Reaction Errors
• Inappropriate solvent or sample resulting in side reactions;
• Poor mixing of the titrant and solvent or sample in the titration vessel;
• Reaction between titrant and sample is not rapid;
• Reaction does not go to completion;
• Reaction has side reactions.
4.3.4 Endpoint Determination Errors
Most manual titrations use a visual indicator to indicate when the endpoint is reached and the
titration should be stopped. Automatic titrators can use potentiometric electrodes to determine
the end of a titration and the equivalence point. There are two predominant methods used to
determine the equivalence point, first derivative and second derivative.
The inflection point of a potentiometric curve (mV vs. Volume) is normally assumed to be
the equivalence point. The first derivative is often used to determine the inflection point. The
maximum value of the first derivative (D mV vs. D V) corresponds to the theoretical equivalence
point. During a titration it is rare to have a data point exactly at the first derivative maximum,
the maximum value is determined by interpolating the first derivative data points.
The second derivative (D2 mV vs. DV2 ) can also be used to determine the equivalence point,
and can offer advantages over the first derivative method. Second derivatives have increased
sensitivity to smaller inflection points and easier numerical evaluation of the actual equivalence
point. The value where the second derivative is equal to zero is the equivalence point. The
second derivative requires fewer points located near the equivalence point, where data is
often not obtained or not as reliable.
Errors in determining the endpoint can result from:
• Incorrect signals from the sensor;
• Sensor drift;
• Sensor or instrument has slow response, keep sensors in good condition;
• Inappropriate setting on the titrator.
20
TITRATION THEORY
5
CALCULATIONS
5.1 Equations Used in Volumetric Karl Fischer Titrations
5.1.1 Calculation of water content as %
mass from samples measured by mass
C sample
V titrant
Titer
m sample
Concentration of Sample (% w/w)
Volume of Titrant (mL)
Titrant Titer (mg/mL)
Mass of Sample (g)
5.1.2 Calculation of water content as % mass from samples measured by volume
C sample
V titrant
Titer
V sample
d sample
Concentration of Sample (% w/w)
Volume of Titrant (mL)
Titrant Titer (mg/mL)
Volume of Sample (mL)
Density of Sample (g/mL)
5.1.3 Calculation of water content as % volume from samples measured by
volume
C sample
V titrant
Titer
V sample
d water
Concentration of Sample (% v/v)
Volume of
Titrant (mL) Titrant Titer (mg/mL)
Volume of Sample (mL)
Density of Water at Analysis Temperature (g/mL)
5.1.4 Calculation of water content as % mass subtracting Background Drift
Rate
C sample
Concentration of Sample (% w/w)
V titrant
Volume of Titrant (mL)
Titer
Titrant Titer (mg/mL)
Drift
Background Drift Rate (µg/min)
t
Titration Duration (min)
m sample
Mass of Sample (g)
21
TITRATION THEORY
5.1.5 Calculation of water content in External
Dissolution Samples
C sample
m solvent
m sample
C solution
C solvent
Concentration of Sample (% w/w)
Mass of Solvent (g)
Mass of Sample (g)
Water Content of Dissoluted Sample (w/w)
Water Content of Solvent (w/w)
5.1.6 Calculation of water content in External Extraction Samples
Concentration of Sample
(% w/w)
Mass of Solvent (g)
Mass of Sample (g)
Water Content of Supernatant (w/w)
Water Content of Solvent (w/w)
C sample
m solvent
m sample
C supernatant
C solvent
5.1.7 Calculation of water content in Gaseous Samples
The water content of gases is normally reported in units of µg/L or mg/L.
C sample
Concentration of Sample (mg/L)
V titrant
Volume of Titrant (mL)
Titer
Titrant Titer (mg/mL)
Flow Rate
Sample Flow Rate (L/min)
Flow Duration
Sample Extraction Time (min)
To calculate the water content in %w/w the mass of the gas introduced into the titration vessel
must be known. This can be determined by calculations using ideal gas laws or by measuring
the mass of the sample container before and after a titration.
5.1.8
Calculation
of titer
(water equivalent
of the
titrant)
using
sodium
tartrate
dihydrate containing 15.66% water by mass
C titrant
m sample
C tartrate
V titrant
Titrant Titer (mg/mL)
Mass of Sample (g)
Water Content of Tartrate (156.6 mg/g)
Volume of Titrant (mL)
22
TITRATION THEORY
5.1.9 Calculation of titer (water equivalent of the titrant) using water
standards
C titrant
m sample
C standard
V titrant
Titrant Titer (mg/mL)
Mass of Sample (g)
Water Content of Standard (mg/g)
Volume of Titrant (mL)
5.2 Equations Used in Titrations
The main variables used in calculating a result from a titration are the sample volume, the
concentration of the titrant, and the volume of titrant required to reach the equivalence
point. At the equivalence point, an equal number of equivalents of the analyte and titrant has
been added.
5.2.1 Sample Calculation
By Mass
C sample
V titrant
C titrant
Ratio
FW analyte
m sample
Sample Concentration (g/100g)
Volume of titrant
Titrant Concentration (eq/L)
Equivalence ratio of analyte/ titrant (mol analyte/ eq titrant)
Formula Weight of the Analyte (g/mol)
Mass
of sample
(g) By Volume
Sample Concentration (g/100mL)
Volume of titrant
Titrant Concentration (eq/L)
Equivalence ratio of analyte/ titrant (mol analyte/ eq titrant)
Formula Weight of the Analyte (g/mol)
Volume of Sample (mL)
C sample
V titrant
C titrant
Ratio
FW analyte
V sample
5.2.2 Standardize Titrant
Titrant standardization is the second most important calculation in titrations. A primary
standard is titrated in order to determine the concentration of the titrant. This is essentially a
typical titration calculated in “reverse”, where the concentration of the solution is known and
the titrant is unknown.
23
TITRATION THEORY
By Mass
C titrant
m standard
Ratio
FW standard
V titrant
Titrant Concentration (N)
Mass of Standard (g)
Equivalence ratio of titrant/standard (eq titrant/ mol standard)
Formula Weight of the Standard (g/mol)
Volume of Titrant (L)
By Volume
C titrant
V standard
C standard
V titrant
Concentration of titrant (N)
Volume of Standard (mL)
Concentration of standard (eq/L)
Volume of Titrant (L)
5.2.3 Blank Titration
In a blank titration a pre-titration is performed,
often times on the solvent to be used for the
sample titration, and the titrant volume required to reach the endpoint is noted. This blank
value nullifies error due to titrant required to react with the components of the titration solution
matrix. The basic titration equation can be used for a blank titration, with the single modification
that the volume of titrant used in the blank titration should be subtracted from the regular
titration titrant volume.
C Sample
Sample Concentration (g/100g)
C titrant
Titrant Concentration (eq/L)
V sample
Volume of Titrant required for the sample (L)
V blank
Volume of Titrant required for the blank (L)
Ratio
Equivalence ratio of analyte/ titrant (mol analyte/ eq titrant)
FW analyte
Formula Weight of the Analyte (g/mol)
of sample
m sample Mass
(g)
5.2.4 Multiple End Point Titration
Some titrations have two or more endpoints, each corresponding to the equivalence point
for a specific reaction. Multiple endpoint titrations are similar to a blank titration in that the
volume of titrant required to reach the first endpoint is subtracted from the titrant volume
used to reach the next sequential endpoint.
24
TITRATION THEORY
C sample1
C sample2
C sample3
V titrant 1
V titrant 2
V titrant 3
C titrant
Ratio
FW analyte 1
FW analyte 2
FW analyte 3
m sample
Sample 1 Concentration (g/100g)
Sample 2 Concentration (g/100g)
Sample 3 Concentration (g/100g)
Volume of titrant required to reach the first end point (L)
Volume of titrant required to reach the second end point (L)
Volume of titrant required to reach the third end point (L)
Concentration of titrant (N)
Equivalence ratio of analyte/ titrant (mol analyte/ eq titrant)
Formula Weight of the Analyte 1 (g/mol)
Formula Weight of the Analyte 2 (g/mol)
Formula Weight of the Analyte 3 (g/mol)
Weight of Sample (mL)
5.2.5 Back Titration
The equation used in back titration calculations is also similar to the equation for a blank
titration. Instead of subtracting the initial amount of titrant needed to react with the blank,
the amount of second titrant needed to react with the excess titrant added in the first titration
is subtracted from the amount of the first titrant added. The difference between the two
amounts
is the amount
of titrant
necessary
to reach the first equivalence point.
C sample
Sample Concentration (g/100mL)
C titrant 1
V titrant 1
C titrant 2
V titrant 2
Ratio
FW analyte
V sample
Concentration of titrant 1 (N)
Volume of titrant 1 (L)
Concentration of titrant 2 (N)
Volume of titrant 2 (L)
Equivalence ratio of analyte/ titrant (mol analyte/ eq titrant)
Formula Weight of the analyte (g/mol)
Volume of sample (mL)
25
TITRATION THEORY
6
GLOSSARY
Acid
A chemical species that can donate one or more protons (hydrogen ions).
Acid-Base Titration
Stoichiometric neutralization titrations, based upon the reaction that occurs between
an acid and base.
Activity
A physical property corresponding to the concentration of all ions in a solution.
Electrodes respond to activity.
Amperometric Titration
Titrations where the current flow between two electrodes (often a metal electrode and
a reference electrode) are used to monitor the titration progress.
Analyte
The chemical species being measured in a titration.
Argentometric Titration
Titrations that use silver (nitrate) as the titrant. These titrations are typically precipitation
titrations.
Automatic Titrator
An instrument designed to automatically carry out a titration. It will add the appropriate
amount of titrant, determine the end-point and calculate the results.
Back Titration
A type of titration where an excess amount of titrant is added to a sample forcing a
sluggish reaction to go to completion. The excess reagent is then “back” titrated with
a second titrant.
Base
A chemical species that can accept one or more protons (hydrogen ions).
Biamperometric Indication
Uses a double platinum pin electrode to measure the current flow through a titration
solution.
Bivoltametric Indication
Uses a double platinum pin electrode to measure the voltage required to maintain a
constant current flow through a titration solution while constant voltage is applied
across the platinum elements of the electrode
Burette
A graduated cylindrical piece of laboratory glassware that is used to dispense precise
amounts of solution.
Complex Ion
A species where a central metal ion is covalently bonded to one or more electron
donating groups called ligands.
Complexometric Titrations
Metal ions are titrated using a titrant that binds strongly to it. The titrants often
contain Ethylenediaminetetraacetic Acid (EDTA) or Cyclohexylenedinitrilotetraacetic
Acid (CDTA).
26
TITRATION THEORY
End point
The point where a titration is stopped because a physical change in the solution has
indicated a completed titration. Titration end points typically coincide with the equivalence
point. A fixed value end point (pH or mV), can be used as well. The titration will stop
at the desired point regardless if the titration is complete.
Equivalence point
The point where the quantity of titrant is stoichiometrically equal to the quantity of
analyte.
Formal
The theoretical number of equivalents per liter of the solution. It is used in solutions
where the exact concentration of a species may be affected by the other ions present,
therefore the stated concentration by not be exactly correct.
Gravimetric Analysis
A quantitative determination of an analyte based on the mass of the solid.
Indicator Electrode
An electrode that responds to the species of interest. The electrode potential is
proportional to the concentration or activity of that ion in the solution being measured.
Indicators
Chemical indicators are typically organic dyes that change form under different physically
conditions, causing a color change that can be seen by an analyst. Typically used in
manual titrations. Chemical indicators have been replaced with electrometric indicators,
which are used with automatic titrators.
Inflection Point
The point on a titration curve were the second derivative curve changes signs.
Ion Selective Electrode (ISE)
An electrode that responds to a specific ion, the electrode potential is proportional to
the concentration or activity of that ion in the solution being measured.
Karl Fischer Titration
A titration that uses a chemical reaction that is specific for determining water.
Manual Titration
A titration that is carried out by hand, the analyst must add the appropriate amount of
titrant, determine the end point and calculate the results.
Molar
The concentration of a solute in a solution.
Mole (mol)
A quantity of a chemical species. The molecular weight of a substance in grams is
equal to the mass of one mole of the substance. One mole is equal to 6.022 x 1023
atoms or molecules.
Monochromator
A device that allows only a narrow range of wavelengths to pass though it by separating
the light into different wavelengths.
Multiple End Point Titration
A titration that reacts multiple species in solution sequentially using the same titrant.
The concentration of each analyte can be determined from their respective end points.
Nernst Equation
The fundamental equation relating cell voltage to the concentration of a solution.
27
TITRATION THEORY
Neutralization
A chemical reaction where an acid and a base react to form a neutral salt and water.
Non-aqueous
A solution that does not contain water.
Non-aqueous Titration
A titration that is preformed in non-aqueous solutions. Typically used to titrate very
weak acid and bases to eliminate the leveling effect water has on all acids and bases
dissolved in it.
Normal
The concentration of a solution which accounts for any stoichiometric difference between
the various species in a solution.
Oxidation/ Reduction Potential (ORP)
A voltage generated in a solution which is a result of the ratio of the oxidized to
reduce species. Typically measured potentiometrically with an ORP sensor.
Oxidant
The species that is accepting electrons in a redox reaction.
Pipette
Scientific apparatus that is used to deliver precise volumes of liquids.
Polyprotic Acid
Acids that are capable of donating more than one proton per acid molecule
Potentiometric Titration
A titration in which the endpoint is determined by monitoring the voltage of the
solution using an electrode.
Precipitation Titration
A titration in which the analyte reacts with the titrant to form an insoluble compound.
The end point is typically detected with an ISE sensitive to either the analyte or titrant.
Reagent
The chemical added in a titration that causes the given reaction to occur.
Reduction-Oxidation Reaction (redox)
A chemical reaction in which the atoms involved in the reaction have their oxidation
numbers changed. Reduction is the gain of electrons, which decreases the oxidation
number. Oxidation is the loss of electrons, which increases the oxidation number.
Reductants
The electron donor in a redox reaction.
Reference Electrode
An electrode that supplies a constant electrode potential. It is used in combination
with an “indicator” electrode, allowing for the “indicator” electrode potential to be
measured.
Relative Standard Deviation (RSD)
A measure of the amount of relative variation in a set of data. It is calculated by
dividing the standard deviation by the mean: RSD = (Standard Deviation of X) * 100
/ (Mean of X)
Repeatability
The variation in sample measurements taken by a single person or instrument under
the same conditions.
28
TITRATION THEORY
Spectrophotometric Titration
A titration in which the end point is marked by a change in the color and/or color
intensity.
Stoichiometry
The quantitative relationship of the reactants and products in a chemical reaction.
Titrant
The chemical added in a titration that causes the given reaction to occur.
Titration
A quantitative, volumetric procedure used in analytical chemistry to determine the
concentration of an analyte in solution. The concentration of the analyte is determined
by slowly adding a titrant to the solution. As the titrant is added, a chemical reaction
between the titrant and the analyte occurs.
Titration Curve
A graph containing the physical data obtained for a titration. The data plotted is often
an independent variable (volume of titrant) vs. a dependent variable (pH of the solution).
From the titration curve, the equivalence point or end point can be determined.
29
TITRATION THEORY
Titr THEORY 903
09/12
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