6850 Series Control Module User Information

6850 Series Control Module User Information
6850 Series Control Module User Information
Contents
Introduction
Important Information ...........................4
Overview ...............................................4
Control Module elements ......................5
Navigating the screens ..........................8
Configuring the instrument .................12
To adjust the display contrast .............13
Configuring the display and
keyboard ........................................13
Setting the time and date .....................16
To configure the RS-232 port .............16
IP address settings ...............................17
Plotting a signal ..................................20
Plotting multiple signals .....................23
Methods
Designing a method ............................26
Saving the active method as a
named method ...............................27
Saving the active method as the
SERVICE method .........................29
Restoring the default method ..............29
Using PC cards ....................................29
Accessing methods in GC memory ....32
Flow and Pressure Control
Hydrogen shutdown ............................34
Column shutdown ...............................34
Electronic pneumatic control ..............35
Turning gas flows on and off ..............35
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Interpreting flow and pressure displays ..
35
Configuring the column ......................36
Column modes ....................................38
Initial column flow or pressure ...........40
Flow or pressure programming ...........41
Auxiliary channels ..............................42
Solving flow and pressure
problems ........................................46
Automation
Injector control ....................................49
Sequence parameters ...........................53
Controlling a sequence ........................54
Run Table ............................................55
Clock Table .........................................59
Split/Splitless Inlet
Using hydrogen ...................................61
Options ................................................61
Inlet Modes .........................................61
Inlet and column .................................62
Inlet setup ............................................63
Prep run ...............................................64
Setting the inlet mode .........................65
Split/Splitless terms ............................65
Pressure pulse modes ..........................66
Split mode ...........................................68
Splitless mode .....................................70
Gas saver .............................................73
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Contents
Purged Packed Inlet
Using hydrogen ...................................75
Inlet and column controls ...................75
Inlet Setup ...........................................76
Using a purged packed inlet ................77
The Programmable Temperature
Vaporization Inlet
Using hydrogen ...................................79
Inlet modes ..........................................79
Inlet and column .................................80
Inlet setup ............................................80
Setting the inlet mode .........................83
Heating the inlet ..................................83
PTV terms ...........................................85
Pulsed modes ......................................86
Split mode ...........................................93
Splitless mode .....................................97
Solvent vent mode ............................103
The Cool On-Column Inlet
Inlet temperature ...............................118
Operating the cool on-column
inlet .............................................120
Thermal Conductivity Detector
Using hydrogen .................................121
Operation conditions .........................121
TCD parameters ................................121
Makeup gas .......................................124
Polarity ..............................................125
Signal selection .................................126
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Analog output ...................................128
Using the TCD ..................................129
Flame Ionization Detector
Using hydrogen .................................130
Detector Operation Notes .................130
Jets ....................................................131
Electrometer ......................................131
Makeup gas .......................................132
Signal selection .................................133
Analog output ...................................135
Automatic reignition—Lit Offset .....135
FID parameters .................................136
Using the FID ....................................138
The Microcell Electron Capture
Detector
Linearity ............................................140
Detector gas ......................................141
Temperature ......................................141
Electrometer ......................................141
Analog Output ...................................141
Operating the Detector ......................142
Column Oven
Oven capabilities ...............................144
Oven safety .......................................144
Oven setup ........................................145
Creating an isothermal run ................146
Temperature programming ...............147
Column compensation ......................150
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Contents
The Flame Photometric Detector
(FPD)
Using hydrogen .................................153
General Information ..........................153
Using lit offset ..................................154
Igniting the flame ..............................155
Using the electrometer ......................156
Signal selection .................................157
Selecting the makeup gas mode ........159
Heater configuration .........................160
FPD Parameters ................................160
Using the FPD ...................................161
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Valves
Valve types .......................................163
Configuring valves ............................164
Sample valves ...................................164
Multi Valve with Sample Valve .......166
Controlling valves manually .............167
Setting the valve box
temperature .................................168
Service Mode
The Service Screen ...........................169
The Log Book ...................................169
Diagnostics ........................................170
Calibration ........................................177
Maintenance ......................................181
Update functions ...............................185
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Introduction
Important Information
Introduction
Important Information
©
Agilent Technologies 1998, 1999, 2000, 2002, 2004
All Rights Reserved. Reproduction, adaptation, or translation without
permission is prohibited, except as allowed under the copyright laws.
Vespel® is a registered trademark of E.I. duPont de Nemours Co., Inc.
Swagelok® is a registered trademark of Swagelok Company.
Part No. G2629-90329
First edition, March 2004
Replaces Part No. G2629-90327, G2629-90328, Control Module User
Information
Printed in USA
Overview
The Control Module provides complete programming and control of the
6850 Gas Chromatograph (the GC), the 6850 automatic injector, and valves.
When connected to a 6850 GC, the Control Module can:
•
Run analytical methods
•
Create, edit, and transfer analytical methods between GCs via a PC
memory card
•
Set GC temperatures and flows and configure GC parts (columns, inlet, detector,
etc.)
•
Display real-time signals such as oven temperature or detector output
•
Run diagnostic tests
•
Provide context-sensitive information on messages, setpoints, needed actions,
etc.
•
Perform a number of other functions
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Introduction
Control Module elements
Control Module elements
F8
F7
F6
m
F1
Esc
Figure 1.
F3
F2
F4
7
8
9
4
5
6
1
2
3
0
.
-
F5
i
Enter
The Control Module
The Control Module consists of a display, a keyboard, and a connecting cable to a
6850 GC. A slot on the left side—not visible in the figure—can
accommodate a PCMCIA flash memory card (called a PC card hereafter).
The Control Module is operated by entering instructions from the keyboard into a set
of screens in the display. These instructions can then be stored as a named method.
Screens
Figure 1 shows a typical Status screen. This is the starting point for all screen based
operations. The five labels along the bottom of this screen refer to the five keys (F1
through F5) just below them. The three labels on the right side refer to the three keys
(F6 through F8) to their right. The key label functions change from screen to screen.
A complete list of screens appears in Table 2 on page 11.
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Introduction
Control Module elements
Keyboard
The keyboard is used to navigate through the screens and enter instructions and data.
F1 to F5
Navigation keys. See the labels at the bottom of the screen.
F6 to F8
Action keys. See the labels on the right edge of the screen.
Esc(ape)
Cancel an action or return to the previous screen.
← →
Move the cursor in the display.
↑ ↓
Select settings, values, or alphanumeric characters.
m(enu)
Display additional dialogs.
i(nfo)
Context-sensitive help for the item presently selected; press
twice to see the help index.
0 to 9
Enter numbers and letters.
.
Enter a decimal point.
-
Enter a minus sign.
Enter
Accept present input entry or action.
The 0 to 9 keys, plus the. and - keys, are also used to enter alphabetic
characters. The special technique used is described later in this section.
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Introduction
Control Module elements
Status screen
All operations begin at the Status screen, shown here. To return to the Status screen
from any other screen, press Esc repeatedly.
Status
Time
Sample
Method
Status
Next run time
Messages
Status screen
labels
Announcements
Scrolling list
The Status screen elements are:
•
Time—clock time on a 24-hour basis
•
Sample—the last sample run or the one presently running
•
Method—the name of the active method. If it has been modified since it was
loaded, it is followed by a + sign.
•
Status—the present condition of the GC
•
Announcements—any current conditions that prevent the GC from
starting a run or that may affect the results.
The Warning, Faults, Shutdown, and Method announcements advise you
of potential problems. The Run Log announcement flashes to tell you to read
the Run Log. The StrtLock announcement flashes when Start has been
locked out by a Control Module or Agilent ChemStation or
Agilent Cerity Networked Data System for Chemical QA/QC.
Keyboard Locked appears along the bottom of the Control Module screen if the
keyboard is accessed while the StrtLock announcement is in effect.
•
Scrolling list—shows problems with the GC or the active method. In this example, it tells you that the GC is Not Ready because the oven temperature has not
stabilized.
•
Messages—instrument condition. The messages describe the type of run or
sequence the GC is preparing for, and whether or not it is ready.
•
Next run time—the time the active method takes to complete a run
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Introduction
Navigating the screens
•
Status screen labels—identify the function of the F1 through F5 keys below the
display and the F6 through F8 keys on the right. See Table 1.
Table 1.
Status Screen Labels
Key
Screen label
Function
F1
Settings
Things you change frequently, such as oven temperature and hold times, inlet temperatures, and so on
F2
Automation
Valve and injector control, the clock and run tables
F3
Method Files
Creating and saving sets of control values
F4
Setup
Things you don’t change very often, such as the
maximum oven temperature, choice of pressure
units, etc.
F5
Service
Log files, tests, temperature and pressure calibrations, etc.
F6
Plot
Shows a developing signal in real time on the display
F7
Stop
Stops a run or sequence
F8
Start
Starts a run or sequence
Navigating the screens
This example illustrates the use of the Control Module to set up the column so that the
instrument can convert flows to pressures and the reverse.
Example:
1.
Column Setup
Begin at the Status screen. If you are at any other screen, press Esc repeatedly
until this screen appears.
Status
F8
F7
F6
F1
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F2
F3
F4
6850 Series Control Module User Information
F5
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Introduction
Navigating the screens
2.
Press Setup (F4) to display the next screen. In this document, most screens are
preceded by the route (in this case, Status/Setup) to follow to get to them from
the Status screen.
Status / Setup
F8
F7
F6
F1
3.
F2
F3
F4
F5
Press Column Setup to get to the next screen. The second version shown
below appears with Auxiliary EPC GCs. The first screen appears with all others.
Status / Setup / Column Setup
F8
F7
F6
F1
F2
F3
F4
F5
F8
F7
F6
F1
4.
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F2
F3
F4
F5
Check that the column source and outlet connections are correct. If not, use the
← and → keys to get to the correct set of choices and the ↑ and ↓ keys for the
specific choice. Press Enter.
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Introduction
Navigating the screens
5.
The ? mark and the message in the center indicates the column is not configured. To correct this, press More (F6) to display the popup menu.
Status / Setup / Column Setup / More
F8
F7
F6
F1
6.
F2
F3
F4
F5
Use ↑ and ↓ to select Configure Column and press Enter, or press the
number 1 key.
Status / Setup / Column Setup / More / Configure Column / Enter
F8
F7
F6
F1
7.
F2
F3
F4
F5
Use ← and → to get to the three fields, type the numeric values using the units
shown on the screen, and press OK (F6). This accepts the values and returns to the
previous screen.
Status / Setup / Column Setup
F8
F7
F6
F1
8.
F2
F3
F4
F5
Notice that the? mark is gone because the column is now configured.
To get back to where you started, press Esc repeatedly to move up through the
screens. In the rest of this document, we will show the screens without the F-number
labels.
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Introduction
Navigating the screens
Table 2.
Control Module Screens
F1 Settings
F1 Inlet
F2 Oven
F3 Column
F4 Detector
F5 Auxiliary
Temperature,
ramps, temp.
mode, pressure,
flows, ramps,
modes (inlet*,
pulse*, gas
saver*, pulse/
split*, solvent
vent*), carrier
gas*, units*,
coolant info
Temperature, programs
Flow and pressure program,
column mode,
configuration
Temperature,
flows, signal, outputs, gas type
Temperature and
pressure programs, Aux EPC
settings
F2 Automation (sequence type, samples used, sequence repeat, sequence controls)
F1 Injector
F2 Valves
F4 Clock Table
F5 Run Table
Volume, pumps,
washes, depth,
dwell times, viscosity, slow
plunger
Toggle valves
Add & delete
events
Add & delete
events
F3 Method Files (view active, save active, save service, revert to default)
F3 Save Listing
F4 PC Card
F5 GC Methods
Save, load &
delete
Load & delete
F4 Setup (column compensation)
F1 Inlet Setup
F2 Oven Setup
F3 Column
Setup
F4 Automation
F5 Configure
Carrier, pressure
units, vacuum
correct, cryo control
Equilibrium time,
maximum temperature, cryo
control
Source & outlet
connections, configure, mode
Injector, sample
valve, multi
valve, auto prep
run
Oven, serial #,
mfg date, clock,
serial & LAN
comm, local UI,
display, detector
type, valve 1 & 2,
aux temp & pressure, inj. model
and
capacity, column
dimensions
F4 Maintenance
F5 Update
F5 Service (run log, start service, exit service)
F1 Log Book
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F2 Diagnostics
F3 Calibration
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Introduction
Configuring the instrument
View/Save log
book
Inlet, detector,
keyboard
Factory settings
for oven, inlet,
column, detector,
Aux EPC
Service limits,
early maintenance feedback
Update GC,
Injector, Control
Module
firmware
F6 Plot signals
F7, F8 Start & Stop Runs
* Split/Splitless and PTV inlets only
Configuring the instrument
The instrument will need to be configured
•
before the first use
•
whenever changing or adding new hardware
Configuring the instrument sets global parameters, such as date and time, and also
tells the instrument about the devices installed in it so that the GC can control them
properly.
Note that configuration settings directly affect your methods. Unconfigured devices
may be unavailable on the display, or may have no settable values. Also, these settings
control the execution of certain tasks, for example,
charging the sample loop of a gas sampling valve.
Before using the GC for the first time, configure the following items/features:
•
display contrast (see To adjust the display contrast on page 14.)
•
display and keyboard (see Configuring the display and keyboard on page 14.)
•
time and date (see Setting the time and date on page 17.)
•
IP address settings (see IP address settings on page 18.)
•
communication settings (see To configure the RS-232 port on page 17 and IP
address settings on page 18)
•
column (see Navigating the screens on page 8 and
Configuring the column on page 38.)
•
automation parameters, such as injector information (see Automation on
page 52.)
•
inlet (see the chapter for the appropriate inlet type.)
•
detector (see the chapter for the appropriate detector type.)
•
auto prep run (see Prep run on page 68.)
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Configuring the instrument
•
oven (see Oven setup on page 149.)
•
valves (see Configuring valves on page 168.)
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Introduction
To adjust the display contrast
View the current configuration
You can display a list of items describing the GC’s installed components. The list
describes the GC, listing such items as the serial number and the injector mode (if
installed). Following is an example of this screen. Press ↑ and ↓ to scroll up and down
in the list.
Status / Setup / Configure
To adjust the display contrast
1.
Display this screen.
Status / Setup / Configure / Display
2.
Use the ↑ and ↓ keys to adjust the screen contrast. Press Done when
satisfied.
Configuring the display and keyboard
The Control Module can define the functions available at the GC keyboard and display. This is useful when, for example, a GC is to be used as a dedicated
analyzer or operated by a remote ChemStation or Cerity Chemical.
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Configuring the display and keyboard
To define the GC keyboard and display functions:
1.
Display this screen.
Status / Setup / Configure / Local UI
•
Oven Temp, Message Line, Inlet Pressure, Column Flow, Signal, and Run
Time are display-only features—changing the values requires a Control
Module or a ChemStation
•
Service Mode—Allows the SERVICE method to be loaded from the
keyboard (see Service Mode on page 173)
•
Stored Methods—Places the list of methods stored in the GC in the scrolling
display so they can be selected and loaded from the keyboard
•
Run Time Mode—Controls whether the Run Time, if displayed, counts up
(time elapsed since Start) or down (time to end of run). This choice does
not affect the Run Table.
2.
Select the items you want displayed on the GC display, the actions you want to
be able to perform at the GC keyboard, and, if Run Time is selected, the Run
Time Mode.
3.
Press Beeps to display the next screen.
Status / Setup / Configure / Local UI / Beeps
4.
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Select the beep behaviors you want.
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Introduction
Configuring the display and keyboard
5.
Press Esc to return to the Local UI screen, then press Locks to display the
next screen.
Status / Setup / Configure / Local UI / Locks
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•
Lock Local Keyboard—deactivates all parameter changes from the Control
Module
•
Lock Local Start Key—deactivates the Start key on the GC
keyboard
•
Lock Remote Start—deactivates the Start function of the REMOTE connector on the back of the GC. You can still start a run using a
Control Module.
•
Host Lock—a reported value. On means that a ChemStation or other computer is controlling the GC, and you cannot change setpoints from the Control Module.
•
Sequence Lock—locks out sequence execution from the GC
•
Clock Table Lock—locks out clock table access
•
Clock Table Exec Lock—locks out execution of clock table events
•
Method & Sequence & Clock Table Lock—locks out method loading from
the GC keyboard or the Control Module, plus the Sequence and Clock Table
locks
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Introduction
Setting the time and date
Setting the time and date
The GC has an internal clock to use the time and date for tasks such as logging methods and errors. To set the time and date:
1.
Display this screen
Status / Setup / Configure / Clock Set
2.
Set the date and time and press Done.
To configure the RS-232 port
This refers to the connector labeled RS-232 on the back of the GC. It does not affect
Control Module/GC communications.
Normally, the 6850 will be configured for proper communications at the
factory. However, if you need to check or alter the communications settings, do so as
follows:
1.
Display this screen.
Status / Setup / Configure / Serial Comm
2.
Adjust the controls to meet the needs of the external device. Press Esc when finished.
3.
Set the date and time. The clock resets when you press Done.
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Introduction
IP address settings
IP address settings
The method of setting the IP address depends on the type of LAN card you have
installed in your GC.
To view the current settings, display this screen.
Status / Setup / Configure / LAN Comm
If installed, the current LAN card settings are shown for reference. The IP address,
subnet mask, default gateway, and timeout values are set when the LAN card/GC is
installed. The control modes are explained below.
Control modes
The control mode displayed on the LAN Setup screen indicates the current method of
obtaining LAN configuration settings. The available control modes depend on the
LAN card installed (see Table 3). For information on how to identify which LAN card
is installed in your GC, see
View the current configuration on page 14.
Table 3.
Available Control Modes
LAN card
Available control modes
Enter settings
J2552B
BootP
N/A
J4100A
BootP, Locally entered settings
At GC front panel
Lantronics
DHCP, Locally entered settings
At GC front panel, Control Module
•
If a J2552B or J4100A LAN card is installed, the message “Supports BootP Control Mode Only” is displayed. While it is possible to set the LAN address from
the Control Module, this practice is not recommended. The resulting connection
will be very slow.
•
Use BootP/DHCP to get address: Your GC is set to receive LAN addressing
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Introduction
IP address settings
from the BootP program or Windows NT® DHCP.
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IP address settings
•
Use locally entered settings: Your GC is set to use IP address, subnet mask, and
gateway values that you will provide via the Control Module or GC front panel.
To adjust the settings, display this screen:
Status / Setup / Configure / LAN Comm / Set IP
Automatically-assigned address settings
1.
Select BootP/DHCP to use the BootP program or DHCP to set the GC LAN
card configuration. The GC will automatically use the appropriate method.
2.
Press Done. The new settings will not take effect until the GC is restarted. To
restart now, select Yes when the following window appears:
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IP address settings
Specific IP address settings
The Control Module can be used to adjust LAN settings for 6850 GCs that use the
Lantronics LAN card. See View the current configuration on page 14 for information
on how to identify which LAN card is installed in your GC.
1.
Display this screen.
Status / Setup / Configure / LAN Comm / Set LAN
2.
Select Local to use IP address, subnet, and gateway settings that you will provide.
3.
Use ← and → to move from field to field and use the number keys to adjust the
values.
4.
Make sure the settings are correct and press Done. The new settings will not take
effect until the GC is restarted. To restart now, select Yes when the following
window appears:
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Introduction
Plotting a signal
Plotting a signal
The Control Module screen can display up to three real-time plots at the same time.
Plotting is best explained with examples.
To plot one signal
1.
Display this screen.
Status / Plot
2.
The screen is presently plotting Oven Temperature. Press Select to see a list of
the available signals.
Status / Plot / Select
Signal, in the Available Signals list, is the signal selected on the
detector screen.
It may be any of the following:
•
Detector
•
Column Comp
•
Detector - Col Comp
•
Test Chromatogram
•
Other
See the detector section for more details.
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Introduction
Plotting a signal
3.
To move a signal from one list to the other, select it and press Move. Although
you can have up to three Selected Signals, we will consider the one signal case
first.
4.
For this example, we assume that you moved Oven Temperature back to
Available Signals and move Signal to Selected Signals.
5.
After making these moves, the Selection screen reads as follows:
6.
Enter a Time Range. This is the width, in minutes, of the plot. If the run lasts
longer than this, the plot scrolls off the screen to the left.
7.
At this time, you can press Setup to set the vertical scale (Y Range). This is not
absolutely necessary because you can always rescale the plot later.
8.
Press Done to return to the signal selection screen, then press Done again to see
the plot. If you did not set a Y Range, and possibly even if you did but set it too
large, the plot may look like this.
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Plotting a signal
9.
Press Rescale. This changes the Y range so that the plot fills the window.
10. To refine the scaling, use ← and → to adjust the horizontal scale
and ↑ and ↓ to adjust the vertical scale. In this example, the vertical scale is
too sensitive and needs adjusting.
11. Inject a sample—air was used for this example—and press Start. A
vertical line marks the start of the run.
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Introduction
Plotting multiple signals
12. When the peak appears, it goes off scale. Wait for the trailing edge to appear,
then press Rescale to bring the top of the peak on scale. Press ↓ once.
13. To explore the plot in detail, press Cursor. An arrow appears on the screen, and
the values of time and Signal appear in the top right corner of the screen.
Use the ← and → keys to move the cursor. The next screen shows the retention
time and peak height of the smaller peak.
14. To remove the cursor, press Cursor again.
Plotting multiple signals
This is the rescaled plot of the detector signal described on the preceding pages. We
will add a plot of the oven temperature.
1.
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Display this screen.
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Introduction
Plotting multiple signals
Status / Plot
2.
Press Select to display the list of signals. Select Oven Temperature and
press Move. This screen appears:
3.
Use the ↑ and ↓ keys, or press 2, to highlight Oven Temperature. Press
Setup to set the Y Range for this signal. We suggest a range of 0°C to 150°C.
4.
Press Done to return to Plot selection, then press Done again to show both plots.
The two plots are superimposed but have independent Y scales. Note the small ➀
and ➁ that identify the two plots. Use the 1 and 2 keys to select these plots. As
you do so, the Y scale changes to that of the selected plot.
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Plotting multiple signals
For example, to rescale the Oven Temperature plot, press 2 to select the
plot, then press Rescale. Similarly, the ← , → , ↑ , and ↓ keys work independently for the two plots to adjust their scaling.
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Methods
Designing a method
Methods
There is always an active method in the GC memory. It is the set of control
values that are presently operating the GC, including Run Table events and automatic
injector controls.
The active method changes as you adjust conditions to perform your analysis. To save
the changes and make a permanent method:
1.
Modify the active method to suit your needs.
2.
Name the method and save it in GC memory. Five named methods and a method
named SERVICE can be stored.
This section describes how to save the active method, either as a named method or as
the SERVICE method.
We also describe the use of a PC Card to copy named methods from the GC and to
download them to the GC.
The content of the method—the details of all the things that can be
controlled—is described in the sections following this one.
Designing a method
A method is a set of control values that determines what the GC does. Methods are
created using a Control Module or ChemStation and are executed by the GC.
•
The content of many screens depends on what hardware is present. While the GC
can sense many of its components, some information (such as what carrier gas is
in use) must be entered by you. Always configure (define) instrument elements
before trying to use them.
•
When setting up a method, configure the carrier gas first, then the column, and
finally the inlet. Detectors can be set up at any time.
•
The i key on the Control Module provides information about the current screen.
Press it again to access the information system index.
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Methods
Saving the active method as a named method
Saving the active method as a named method
To name and save the active method:
1.
Display this screen.
Status / Method Files
2.
The screen displays the beginning of the active method. Use the ↑ and ↓ keys to
examine it and verify that all values are correct.
3.
Press Save to display this screen.
Status / Method Files / Save
4.
The Control Module keys have both labeled and hidden values (see
Table 4). The hidden values apply only for entering text in an
alphanumeric field, such as the Method Name field on this screen.
5.
Move the cursor to the left end of the name field. Use the keyboard to enter a
Method Name.
Released: March 2004
a.
Move the cursor using the ← and → keys.
b.
Press a labeled key multiple times to reach the hidden values. If you go too
far, keep pressing because the values loop.
c.
Do not add an extension to the method name.
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Methods
Saving the active method as a named method
Table 4.
Key Labels and Hidden Characters
Key
label
Hidden characters
1
A
B
C
2
D
E
F
3
G
H
I
4
J
5
M
6
P
Q
R
7
S
T
U
8
V
W
9
Y
Z
0
none
.
,
-
+
6.
K
L
N
;
O
X
_
:
*
/
Press OK when you finish to save the method in GC long-term memory. See
Table 5.
Table 5.
Saved Method Content
Item
Saved?
Oven controls
yes
Injector controls
yes
Injector/valve sample list
not saved
Inlet
yes
Column
yes
Detector
yes
Signal
yes
Column compensation
yes
Aux 1
yes
Run Table
yes
Sample valve
yes
Multi valve
yes
Sequence sample list
not saved
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Methods
Saving the active method as the SERVICE method
Clock table
not saved
Saving the active method as the SERVICE method
1.
Display the method using Status / Method Files.
2.
Press Service to save the active method as the SERVICE method. This
replaces the existing SERVICE method with the contents of the active method.
Restoring the default method
The default method, loaded at the factory, contains parameters that are a reasonable
starting point for many analyses. This method can be edited to better meet your needs.
To restore the original factory settings, press Default. This screen appears.
Status / Method Files / Default
•
Press Yes to load the default method. This becomes the new active method. The
previous active method is lost unless it has been saved.
•
Press No to cancel the load operation. The active method remains intact.
Using PC cards
Methods can be stored in the GC or on a PC card in the Control Module. By using
multiple PC cards, an extensive library of methods can be stored for any GC. You can
also save a listing for each method. A listing is a text file of the method’s setpoints
exactly as they appear on the control module.
To use a PC card, insert it into the Control Module before connecting to the GC. If you
would like use another PC card, you must first disconnect the Control Module before
changing cards.
PC cards are available in various memory capacities at most computer stores. A PC
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Methods
Using PC cards
card is not provided with the Control Module.
To copy a method from the GC to a PC card
1.
Display this screen.
Status / Method Files / PC Card
2.
Select a method on the right-hand list.
3.
Press Save to copy it to the PC card.
To copy a method from a PC card to a GC
Methods stored on a PC card can be downloaded to the original or a different GC.
1.
Display this screen.
Status / Method Files / PC Card
2.
Select a method name on the left-hand list.
3.
Press Load. The selected method becomes the active method on the GC.
4.
Execute Save on the Status / Method Files screen and supply a name to save the
method to the GC long-term memory.
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Methods
Using PC cards
To delete methods from a PC card
1.
Display this screen.
Status / Method Files / PC Card
2.
Select a method in the left list.
3.
Press Delete. A popup menu appears.
Status / Method Files / PC Card
4.
Select the deletion mode and press Enter.
5.
A confirmation screen will be displayed. Select Yes or No and press Enter.
To save a method listing to a PC card
If you can access data on a PC card, (using a portable computer, for example), saving
a method listing conveniently lists all method parameters and settings in text file format.
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Methods
Accessing methods in GC memory
Status / Method Files
Press Save Listing. A text file called methodname.lst is saved onto the Method
Files screen. Note that the Control Module automatically overwrites any previous version of the listing.
Accessing methods in GC memory
To view the list of methods stored in the GC
Display this screen.
Status / Method Files / GC Methods
To load a stored method
Select the desired method, then press Load. The selected method becomes the active
method.
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Methods
Accessing methods in GC memory
To delete method files from GC long-term storage
1.
Select a method and press Delete. A popup menu appears.
Status / Method Files / GC Methods / Delete
2.
Select the deletion mode and press Enter.
3.
A confirmation screen appears. Select Yes or No and press Enter.
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Flow and Pressure Control
Hydrogen shutdown
Flow and Pressure Control
Hydrogen shutdown
Hydrogen gas may be used as a carrier or as fuel for some detectors.
Warning
When using hydrogen (H2) as a carrier gas or fuel gas, be aware that hydrogen can
flow into the oven and create an explosion hazard. Be sure that the
hydrogen supply is off until all connections are made and ensure that the inlet and
detector column fittings are either connected to a column or capped at all times when
hydrogen gas is supplied to the instrument.
Hydrogen is flammable. Leaks, when confined in an enclosed space, may
create a fire or explosion hazard. In any application using hydrogen, leak test all connections, lines, and valves before operating the instrument. Always turn off the hydrogen supply at its source before working on the instrument.
The GC monitors flow rates and pressures. If a stream shuts down because it is unable
to reach its flow or pressure setpoint and if that stream is configured to use hydrogen,
the GC assumes that a leak has occurred and causes a hydrogen safety shutdown. The
effects are:
•
The carrier supply valve to the inlet closes
•
The split valve in the split/splitless inlet opens
•
The oven heater turns off. The oven flaps open fully.
•
The inlet, detector, and auxiliary heated zones are turned off.
To recover from this state, fix the cause of the shutdown (tank valve closed, serious
leak, etc.). Turn the instrument off, then back on.
Column shutdown
If the carrier gas source shuts down, the oven heater turns off to avoid column damage
from heat without carrier gas. The oven flaps open halfway.
To recover from this state, fix the cause of the shutdown (tank valve closed, serious
leak, etc.). Turn the oven and the offending inlet or auxiliary channel back on.
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Flow and Pressure Control
Electronic pneumatic control
Electronic pneumatic control
The GC electronically controls all gas flows and pressures. This provides:
•
Flow and/or pressure control for the inlet, including flow or pressure
programming for the carrier gas through the column
•
Flow control via pressure regulation across fixed restrictors for all detector gases
•
Pressure control for three auxiliary channels via pressure regulation across fixed
restrictors
•
A gas saver mode to reduce carrier gas consumption between sample runs (split/
splitless inlet)
•
Direct entry of split ratios, provided the column is configured
(split/splitless inlet)
Enter setpoints in the inlet, detector, or auxiliary screens.
Turning gas flows on and off
All gas flows have an OFF setting so they can be turned on or off without
disturbing the flow or pressure setpoints. To turn a flow off, select the setpoint and
press either the ↑ or ↓ key.
The valves in the gas control modules are designed for gas metering rather than ON/
OFF operation. When this type of valve is driven to the OFF state, there may still be a
small flow, as much as 0.2 mL/min, through it.
Interpreting flow and pressure displays
The GC measures atmospheric pressure and temperature to eliminate local conditions
as causes of retention time variability.
All flow and pressure displays are corrected to a defined set of conditions. These conditions, which we call Normal Temperature and Pressure (NTP), are 25°C and
1 atmosphere pressure. Similarly, setpoints are adjusted for the local conditions.
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Flow and Pressure Control
Configuring the column
Thus a flow displayed on the instrument and the flow measured with a bubble meter
may not agree, because the bubble meter readings are local conditions rather than NTP
conditions. However, retention times become independent of the local environment.
To convert bubble meter flow rate measurements to NTP (25°C and 1 atmosphere),
you must know the local atmospheric pressure and the bubble meter temperature at the
time of measurement.
The conversion is:
Flow rate local × 298 × Pressure local
Flow rate at NTP = ------------------------------------------------------------------------------------Temperature local
where:
Flow rate at NTP
is the flow rate in mL/min corrected to Normal Temperature (25°) and Pressure (1 atmosphere)
Flow ratelocal
is the flow rate in mL/min measured by the bubble meter
Temperaturelocal
is the temperature of the bubble meter at the time of measurement. This number is in Kelvin (Kelvin = Celsius +
273).
Pressurelocal
is the local atmospheric pressure at the time of measurement. This number is in atmospheres (1 atm = 1.01325 bars
= 760 Torr =
760 mm Hg (at 0°C) = 101.325 kPa = 14.7 psi).
Some electronic flow meters are calibrated for temperatures other than 25°C or pressures other than 1 atm. These will give readings that do not agree with the displays
unless they are corrected to NTP.
Configuring the column
To define (configure) a capillary column, enter its length, diameter, and film thickness. With this information, the GC can calculate the flow through the column.
This has great advantages when using capillary columns with a split/splitless inlet,
because it becomes possible to:
•
Enter split ratios directly and let the instrument calculate and set the appropriate
flow rates
•
Enter flow rate or head pressure. The instrument calculates the pressure needed
to achieve the flow rate, sets that, and reports both values.
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Flow and Pressure Control
Configuring the column
•
Perform splitless injections with no need to measure gas flows
•
Choose any of the four column modes (see Column modes on page 40). If the
column is not defined, your choices are limited.
To configure the column
1.
Display this screen.
Status / Settings / Column
2.
Note the question mark at the left, indicating that the column is not defined. To
define it, press More, select Configure Column, and press Enter to display the next screen.
Status / Settings / Column / More / Configure Column / Enter
3.
Enter values for Length, ID (internal diameter), and Film (thickness).
4.
Press OK.
If you do not know the column dimensions—they are usually supplied with the column—or if you do not wish to use the GC calculating features, enter 0 for either
length or ID. The column will be not defined and you will only be able to use pressure
setpoints with a split/splitless inlet, or total flow with a purged packed inlet.
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Flow and Pressure Control
Column modes
Column modes
Flow modes
Flow rates are corrected to NTP (normal temperature and pressure, 25°C and
1 atmosphere).
•
Constant flow—Maintains a constant mass flow rate of carrier gas in the column
throughout the run. If the column resistance changes due to a temperature program, the column head pressure is adjusted to keep the flow rate constant. This
can shorten runs significantly.
•
Ramped flow—Increases the mass flow rate in the column during the run according to a program you enter.
Pressure modes
Pressures are gauge pressures—the difference between the absolute pressure and the
local atmospheric pressure. Because most detectors present little
resistance to the column flow, the gauge pressure at the column head is usually the
same as the pressure difference between column inlet and exit. The mass selective
detector and the atomic emission detector are two exceptions.
•
Constant pressure—Maintains a constant gauge pressure at the head of the column throughout the run. If the column resistance changes, the gauge pressure
does not change but the mass flow rate does.
•
Ramped pressure—Increases the column head gauge pressure during the run
according to a program you enter
Column modes vs. inlet modes
The column mode selected changes the inlet mode(s) available. For example, if using
a column pressure mode, only pressure modes will be available for most inlet types.
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Flow and Pressure Control
Column modes
To select a column mode
Display this screen.
Status / Settings / Column / More
1.
Select Column Mode and press Enter to display the next screen.
Status / Settings / Column / More / Column Mode / Enter
2.
Select the column mode you want. Press OK.
This completes column mode selection.
Warning
Set your column parameters with your oven at its initial temperature.
Some pneumatic setpoints will change with oven temperature because of changes in
column resistance and in gas viscosity. This may be confusing (or alarming) if you see
pneumatic setpoints changing when the oven temperature changes. However, the flow
condition in the column remains as specified by the column mode (constant flow or
pressure, ramped flow or pressure) and the initial setpoint values.
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Flow and Pressure Control
Initial column flow or pressure
Initial column flow or pressure
Recommended starting flows and pressures
See the Table 6 and Table 7 for recommended flows and pressures for various
column sizes. These are close to optimum for a wide variety of components.
Table 6.
Column Size and Carrier Gas Flow Rate
Column type
Capillary
Packed metal
Packed glass
Column size
Carrier gas flow rate, mL/min
Hydrogen
Helium
50-µm id
0.5
0.4
100-µm id
1.0
0.8
200-µm id
2.0
1.6
250-µm id
2.5
2.0
320-µm id
3.2
2.6
530-µm id
5.3
4.2
Nitrogen
1/8-in. id
30
30
1/4-in. id
60
30-60
2-mm id
30
30
4-mm id
30-60
30-60
These flow rates, in mL/min at NTP (25°C and 1 atm) are recommended for all column temperatures.
For capillary columns, flow rates are proportional to column diameter and are 20% lower for helium than for hydrogen.
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Flow and Pressure Control
Initial column flow or pressure
Table 7.
Recommended Gas Pressures for Capillary Columns
Recommended gas pressure, psi (kPa)
Inside diameter
Length,
m
0.10 μm
0.20 μm
0.25 μm
0.32 μm
0.53 μm
10
25 (170)
6 (40)
3.7 (26)
2.3 (16)
0.9 (6.4)
15
39 (270)
9 (61)
5.6 (39)
3.4 (24)
1.4 (9.7)
25
68 (470)
15 (104)
9.5 (65)
5.7 (40)
2.3 (16)
30
83 (570)
18 (126)
12 (80)
7 (48)
2.8 (19)
50
32 (220)
20 (135)
12 (81)
4.7 (32)
60
39 (267)
24 (164)
14 (98)
5.6 (39)
Split/Splitless inlet
If the column is defined (see Configuring the column on page 38), you can enter either
flow or pressure, depending on which column mode you selected.
If the column is not defined, you can only enter pressure.
Purged packed inlet
If using a defined capillary column (see Configuring the column on page 38), you can
enter only column head pressure.
If the column is not defined, you can enter only total flow rate.
To set initial flow or pressure
Display this screen.
Status / Settings / Column
1.
Scroll to the psi (pressure mode) or mL/min (flow mode) field.
2.
Type the desired initial value, followed by Enter.
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Flow and Pressure Control
Flow or pressure programming
Flow or pressure programming
If you selected either the ramped pressure or ramped flow column mode, the column
screen contains entries for setting up a single-ramp program.
You begin with an initial value, either pressure or flow, and an initial
time. At the end of that time, the pressure or flow ramp begins and runs
until it reaches the final value. It remains at that value for
a specified time.
The oven program determines the length of the run. If a flow or pressure
program ends before the analytical run does, the flow (or pressure) remains at the last
final value. If the oven includes a Post-Run period, you can enter a
Post-Run pressure or flow for the column.
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Flow and Pressure Control
Auxiliary channels
To create a flow or pressure program
Display this screen.
Status / Settings / Column
1.
The column is in constant flow mode, which is why the ramp setpoints are grayed
out. Press More and use the Column Mode screen (see Column modes on
page 40) to change to Ramped Flow.
Status / Settings / Column
2.
Enter the starting value in the mL/min field.
3.
Use the ← and → keys and enter values in the remaining fields to
complete the ramp. If desired, enter a Post Run value.
4.
Use a similar procedure to set up a pressure program.
Auxiliary channels
Three additional auxiliary pressure control channels are available as an option. They
are controlled by the Aux 3, Aux 4, and Aux 5 entries on the Auxiliary settings screen
(Aux 1 and 2 are heater controls).
If an auxiliary channel is specified as the Inlet during column configuration (see
Configuring the column on page 38), the channel allows run time programming as well
as three-ramp pressure programming. The most common case of this is when a gas
sampling valve is used.
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Flow and Pressure Control
Auxiliary channels
Configuring thermal auxiliary type
Display this screen.
Status / Settings / Auxiliary / More
1.
Select Configure Thermal.
2.
Select the installed device type.
3.
•
Select Other for an MSD.
•
Select No Auxiliary to disable the zone.
Press OK.
Configuring pneumatics
Display this screen.
Status / Settings / Auxiliary / More
1.
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Select Configure Pnuematics.
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Flow and Pressure Control
Auxiliary channels
2.
Select the gas to use and the equilibration time (the time allowed for the pressure
to stabilize before an error occurs) for the appropriate channels. Your gas selection should be what you have physically connected to the GC.
Do not use or select air as the gas for the column input channel.
3.
Warning
Press OK.
When hydrogen is used, dangerously high flows are possible if insufficient flow resistance is provided downstream of the supply tube.
Setting auxiliary temperature and pressure
Display this screen.
Status / Settings / Auxiliary
1.
Set the temperature and pressures for the appropriate channels.
2.
Press Esc.
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Flow and Pressure Control
Auxiliary channels
Setting auxiliary temperature ramps
1.
Display this screen.
Status / Settings / Auxiliary / Ramps
2.
Select the ramp you want to set. A pressure ramp table for the selected Aux channel appears. The table for the Aux #3 Ramp is shown below. The others are identical. While this screen lists pressure values in psi units, you specify the units on
the Inlet Setup screen.
Pressure level
Time to hold
Rate
3.
Set up to three ramps, entering values for a pressure level, a time to hold that
pressure, and the rate at which to move to the next pressure level.
•
4.
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To disable a ramp and all further ramps, enter a rate of 0.0.
Press OK.
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Flow and Pressure Control
Solving flow and pressure problems
Solving flow and pressure problems
A gas does not reach the setpoint pressure or flow
If the condition persists longer than the time specified for that stream, the inlet or
detector will shut down. The time depends on the specific device involved. Possible
causes/corrections include:
•
The gas supply pressure is too low to reach the setpoint. The pressure at the supply should be at least 10 psi greater than the desired setpoint.
•
A large leak is present somewhere in the system. Use an electronic leak detector
to find leaks; correct them. Don’t forget to check the column—a broken column
is a very large leak.
•
If you are using gas saver, be sure that the gas saver flow rate is high enough to
maintain the highest column-head pressure during a run
•
The flow is too low for the column in use
•
The column is plugged or mis-installed
•
The inlet or detector pressure sensor is not operating correctly. Contact your Agilent service representative.
If you are using a split/splitless inlet
•
The split ratio is too low. Increase the amount of split flow.
•
The inlet proportional control valve is stuck because of contamination or other
fault. Contact your Agilent service representative.
If you are using a purge packed inlet
•
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The inlet control valve is stuck closed because of contamination of other fault.
Contact your Agilent service representative.
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Flow and Pressure Control
Solving flow and pressure problems
A gas exceeds the setpoint pressure or flow
Possible causes/corrections include:
•
The pressure sensor for that device is not operating properly. Contact your Agilent service representative.
If you are using a split/splitless inlet
•
The split ratio is too high. Decrease the split ratio.
•
The proportional control valve is stuck closed. Contact your
Agilent service representative.
•
The trap on the split vent line is contaminated. Contact your
Agilent service representative.
If you are using a purge packed inlet
•
The inlet proportional control valve is stuck open.
Contact your Agilent service representative.
The inlet pressure or flow fluctuates
A fluctuation in inlet pressure will cause variations in the flow rate and
retention times during a run. Possible causes/corrections include:
•
A small leak is present in the flow system. Use an electronic leak detector to find
leaks; correct them. You should also check for leaks in the gas
supply plumbing.
•
Large restrictions are present in the split/splitless inlet, such as a blockage in a
liner or the split vent trap. Make sure that you are using the correct liner. Replace
liners with large pressure drops caused by design or tight packaging. If the liner
does not appear to be causing the problem, the split vent trap may be blocked.
Contact your Agilent service representative.
•
Extreme changes in room temperature during runs. Correct laboratory temperature problem or move the instrument to a more suitable location.
•
Large volumes have been added to the system (this may occur if you are using a
sampling valve). Decrease the sample volume.
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Flow and Pressure Control
Solving flow and pressure problems
The measured flow is not equal to the displayed flow
You checked the flow at an inlet with a bubble flow meter, corrected the
measurement to NTP conditions, and find that it does not match the flow you set. Possible causes/corrections include:
•
Column length, internal diameter, or gas type is configured incorrectly. Enter the
correct information. If a considerable amount has been cut off a capillary column,
its actual length may no longer match the original.
Correct the length value.
•
A new pressure setpoint was not entered after constant flow mode was selected.
Enter a new pressure setpoint each time constant flow is turned on or off.
•
A short (<15 m) 0.58 to 0.75-µm id WCOT column is being used. Total flow is
set for a high flow rate, which creates some pressure in the inlet and causes column flow even with a setpoint pressure of zero. With short, 530 to 750 µm columns, keep the total flow rate as low as possible (for
example, 20 to 30 mL/min). Install a longer column with higher resistance (for
example, 15 to 30 m).
•
The split vent line may be partly plugged, creating an actual inlet pressure higher
than the setpoint pressure. See Split Vent Test (Split/Splitless and PTV inlets
only) on page 177.
•
A Mass Selective Detector is in use and vacuum compensation is not selected
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Automation
Injector control
Automation
This section describes how to control the automation features of the GC using the
Control Module. Items discussed are:
•
Injector control
•
The sequence
•
The run table
•
The clock table
Injector control
To set injection parameters
1.
Display this screen.
Status / Automation / Injector
2.
Enter:
Plunger Pumps—The number of times to pump the plunger with the
needle in the sample to expel bubbles before drawing up the measured sample
amount.
Sample Size—The amount to be injected. The choices depend on the syringe size
specified during setup.
Viscosity Delay—The number of seconds the plunger pauses at the top of the
pump and inject strokes. This time allows viscous samples to flow into the vacuum created by the plunger.
Slow plunger—Reduces the plunger speed during injection from
normal (about 100 µL/sec with a 10 µL syringe) to about 5 µL/sec.
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Automation
Injector control
Wash parameters
1.
Display this screen.
Status / Automation / Injector / Washes
2.
3.
The syringe can be washed with sample before drawing up the amount to be
injected. It can also be washed with solvent both before (pre-washes) and after
(post-washes) an injection. The order of events is:
•
Wash syringe with solvent A Solvent-A-Pre-Washes times
•
Wash syringe with solvent B Solvent-B-Pre-Washes times
•
Rinse syringe with sample Sample-Pre-Washes times
•
Draw up sample and make injection
•
Wash syringe with solvent A Solvent-A-Post-Washes times
•
Wash syringe with solvent B Solvent-B-Post-Washes times
Enter your choices, then press Esc to return to the previous screen.
Needle depth
1.
Display this screen.
Status / Automation / Injector / Depth Offset
2.
The default value, 0 mm, includes a small safety factor to avoid striking the bottom of the vial. This parameter can also be used to sample headspace instead of
the liquid or solid sample. See your Sampler manual.
3.
Enter your choices, then press Esc to return to the previous screen.
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Automation
Injector control
Dwell times
1.
Display this screen.
Status / Automation / Injector / Dwell Times
2.
Enter your choices. For most uses, both dwell times will be zero. This gives a fast
injection with a minimum of boil-out from a hot needle.
3.
Press Esc to return to the previous screen.
Solvent parameters
Depending on the GC firmware you have, the injector type and firmware, and the turret size of your GC, you can set various solvent parameters. To access these parameter
settings:
1.
Display this screen.
Status / Setup / Automation / Injector
Syringe Settings
Solvent Bottle
Usage Settings
Solvent Volume Settings
This screen is an example of what might appear. The screen that appears will have different settings, based on your GC’s configuration of the dependent items listed above.
2.
Set the parameters as necessary.
3.
Press Esc.
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Automation
Injector control
Syringe capacity
Enter the size of the syringe in milliliters.
Solvent bottle usage
Newer versions of the GC (firmware versions A.05.00 and higher) support extended
solvent capacity, which is useful when you run large numbers of
samples. If the method specifies solvent A or B usage, your solvent capacity can be
extended as follows:
Extended
solvent setting
Injector
Turret type
G2613A
3 vial position
Use A, B, and
B2
G2913A
1
A, A2, A3,
and B, B2,
and B3
6850 Automatic Liquid
Sampler
All
Use A, A+
and B, B+
Remember that the solvents you use (A and/or B) are set within the method. See Wash
parameters on page 53. Refer to the GC User Information CD-ROM for more information about solvent bottle positions in your autoinjector or auto sampler system.
Waste bottle usage
If the waste bottle control does not appear on the screen, press More to select that
option. The positions containing bottles to use for waste (A, B, or
Alternate between A and B).
Solvent volume
Solvent volume allows you to conserve solvent by adjusting the amount used to wash
the syringe.
Enable or disable saver mode and specify the amount of solvent to draw into the
syringe on each wash. The default, if disabled, is 80% of the syringe
volume.
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Automation
Sequence parameters
Injector fan
If the fan control does not appear on the screen, press More to select that option. Normally, leave the fan on to help cool the injector and keep your
samples stable. Note that the fan will briefly turn off once per day for a short time.
This extends fan life.
Sequence parameters
The Sequence is a list of samples to be analyzed using the active method. The samples
may be either locations of vials in an injector turret or positions of a stream selection
valve. The sequence list is not saved with a method.
To set up the sequence of samples to be analyzed
Display this screen.
Status / Automation
To enter the injector parameters
1.
Select Injector for Sequence type. The screen is shown above.
2.
Enter these parameters:
•
First and Last Vial—The lowest and highest numbered turret
position to be sampled. See your sampler manual for the numbering scheme.
•
# Inj per Vial—The number of times to analyze each sample before moving
on to the next one. Default is 1.
•
Repeat Sequence—Select repeat to have the sequence start over at the
beginning. Select no repeat to have the sequence stop after all samples
have been analyzed.
To enter the valve parameters
1.
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For Sequence type, select Valve.
6850 Series Control Module User Information
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Automation
Controlling a sequence
Status / Automation
2.
Enter these parameters:
•
First and Last Position—The lowest and highest numbered valve position to
be sampled
•
# Inj per Position—The number of analyses to make at each valve position
before moving on to the next one. Default is 1.
•
Repeat Valve Range—The number of times the valve should cycle through
its range of positions, making analyses at each position
(possibly multiple runs)
•
Repeat Sequence—Select repeat to have the sequence start over at the
beginning. Select no repeat to have the sequence stop after all streams
have been analyzed.
To operate without a sequence
For Sequence type, select None.
Controlling a sequence
To start the sequence
Press Start on the Status screen or the Status/Automation screen.
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Automation
Run Table
To pause the sequence
Press Pause on the Status/Automation screen to pause (halt) the sequence. If a run is
in progress, the GC will complete the run and then pause the sequence.
The word PAUSE will appear on the screen and blink while the sequence is paused.
Status / Automation / Pause
To resume a paused sequence
Press Pause again. The sequence will resume with the sample run following the last
one before the sequence paused.
To cancel a paused sequence
Press Stop Seq.
To stop the sequence
The Stop button on the Status screen stops the run and sequence. The Stop Seq
button on the Automation screen stops the sequence only. The current run continues.
A stopped sequence cannot be resumed.
Run Table
A Run Table is a list of events to be performed at specified times in every run. Typical
events are changing signal attenuation, rezeroing after a signal
disturbance, and switching a valve. The Run Table is saved as part of the method.
All times in the Run Table are run times, that is, the elapsed time in minutes since the
start of the run.
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Automation
Run Table
To show the present content of the Run Table, display this screen.
Status / Automation / Run table
•
To remove an event: Select the event and press Delete.
•
To add an event:
a.
Press Add to display a list of the events available. The list is a function of
the hardware installed in this GC. See Table 8 for a list of all
available events.
Status / Automation / Run Table / Add
•
Released: March 2004
b.
Select the desired event.
c.
Enter the execution time (minutes after Start) and a value, if
appropriate. Press OK. The new event will be inserted in the Run Table in
the correct time order.
To modify an event: Select and Delete the event, then Add the modified one.
6850 Series Control Module User Information
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Automation
Run Table
Table 8.
Run Table Events
Event
Event values
Signal
Valve 1
ON / OFF
Valve 2
ON / OFF
MultiPort Valve
Position
Signal Zero
-500,000 to 500,000 or none
Analog, digital
Signal Attenuation
0 to 10
Analog
Signal Range
0 to 13
Analog
Detector Negative Polarity
ON / OFF
Analog, digital
Auxiliary Temperature
ambient+25°C to 200°C
Auxiliary #3 Pressure
0 to 689 kPa, 100 psig, or 6.89
bar
Auxiliary #4 Pressure
0 to 689 kPa, 100 psig, or 6.89
bar
Auxiliary #5 Pressure
0 to 689 kPa, 100 psig, or 6.89
bar
Store Signal Value
none
Analog, digital
Signal Zero - Value
none
Analog, digital
Valve events
These events provide direct control of valve actions. Enter the times you want to
switch the valves ON and OFF in the table.
Signal Zero event
•
Enter a value to be subtracted from all future signal values.
OR
•
Leave the event value blank. The GC stores the value of the signal at the time of
the event and subtracts that value from all future signal values.
Signal Range event and Signal Attenuation event
•
The Signal Range event scales the signal available through the 0–1 V or
0–10 V, and 0–1 mV outputs.
•
The Signal Attenuation event scales the 0–1 mV output only.
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Automation
Run Table
Both events are binary scalers—a change of 1 in the event value scales the
signal by a factor of 2
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6850 Series Control Module User Information
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Automation
Run Table
Store Signal Value event and Signal zero - value event
These two events are used together to restore the baseline level after a
disturbance, such as a valve operation, has shifted it.
•
Store Signal Value—This event stores the value of the signal at the time of the
event. It should occur on baseline.
•
Signal Zero - Value—This shifts the disturbed baseline by subtracting the value
stored by a Store Signal Value event from all future signal values. When these
two events surround a baseline-shifting action, the effect is to bring the new baseline to the previous level. The Store event must occur before the baseline shift,
and the Zero - Value event must occur after the baseline has stabilized at the
shifted level. See Figure 2.
No correction
Signal
Baseline shift
Baseline-shifting event occurs
Time
Run time correction
3. Signal zero - value event occurs
Signal
2. Baseline-shifting event occurs
1. Store signal value event occurs
Time
Figure 2.
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Correcting baseline level shifts
6850 Series Control Module User Information
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Automation
Clock Table
Clock Table
The Clock Table is a list of events to be performed at specified times of day. Examples
include loading a method, making a blank run, and starting the sequence. The Clock
Table is not saved with a method.
Be aware that the Clock Table does not include a calendar. It will do the same thing
every day, including weekends, holidays, and vacations.
To show the present content of the Clock Table, display this screen. All times are
clock times, that is, the time of day as measured by the GC’s internal clock. Times are
on a 24-hour scale.
Status / Automation / Clock Table
•
To remove an event: Select the event and press Delete.
•
To add an event: Press Add to display a list of the events available. The type of
events in the list depends on the hardware installed in this GC.
Status / Automation / Clock Table / Add
Select the desired event, enter the execution time (24-hour clock) and a value, if
appropriate, and press OK. The new event will be inserted in the clock table in the
correct time order.
•
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To modify an event: Select and Delete the event, then Add the modified one.
6850 Series Control Module User Information
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Automation
Clock Table
Table 9.
Clock Table Events
Event
Event values
Valve 1
ON / OFF
Valve 2
ON / OFF
MultiPort Valve
ON / OFF
Start Blank Run
none
Start Sequence
none
Go Into Pre-Run
none
Column Compensation Run
none
Load GC Method
Method Name
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6850 Series Control Module User Information
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Split/Splitless Inlet
Using hydrogen
Split/Splitless Inlet
Using hydrogen
Warning
When using hydrogen (H2) as a carrier gas or fuel gas, be aware that hydrogen gas can
flow into the oven and create an explosion hazard. Therefore, be sure that the supply is
off until all connections are made and ensure that the inlet and detector column fittings
are either connected to a column or capped at all times when hydrogen gas is supplied
to the instrument.
Warning
Hydrogen is flammable. Leaks, when confined in an enclosed space, may
create a fire or explosion hazard. In any application using hydrogen, leak test all connections, lines, and valves before operating the instrument. Always turn off the hydrogen supply at its source before working on the instrument.
Options
There are two options for the split/splitless inlet:
•
Standard—the pressure range is 0 to 100 psi. It is appropriate for most
columns.
•
High-pressure—the pressure range is 0 to 150 psi. It is useful with very small
diameter capillary columns that offer considerable resistance to gas flow.
To determine the option that you have, check the configuration of the GC
(Status / Settings / Configure). This screen displays the pressure range for the inlet.
Inlet Modes
The inlet also has four operating modes:
•
Split—is divided between the column and a vent flow.
•
Splitless—is not divided. Most of it enters the column. A small amount is purged
from the inlet to avoid excessive peak broadening and solvent
tailing.
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Split/Splitless Inlet
Inlet and column
•
Split with a pressure pulse—is similar to split mode, except that the inlet pressure
is raised before and during injection and returned to normal at a user-specified
time. Total flow is increased so that the split ratio does not change. This special
kind of “programming” is independent of flow or
pressure programming (see Split mode on page 72).
•
Splitless with a pressure pulse—is like Split with a pressure pulse mode, but
splitless.
The split/splitless inlet has a gas saver feature that reduces the flow of carrier into the
inlet and out the split vent after the injection is complete. It does not alter the flow
through the column. See Gas saver on page 77 for details.
The septum purge line is near the septum where the sample is injected. A small
amount of carrier gas exits through this line to sweep out any bleed. This flow rate is
set automatically, as shown in Table 10.
Table 10.
Septum Purge Flows
Carrier
Septum purge
He, N2, 95%Ar/5%Me
3 mL/min
H2
6 mL/min
Inlet and column
The inlet and column controls are related, and the relationship depends on whether or
not the column is configured. We strongly recommend that you set up the GC in this
order:
1.
Configure the column (see Configuring the instrument on page 12). If you do not,
only the pressure modes of the column and inlet can be used. The flow-dependent
features of the inlet, such as setting a split ratio directly, are not available.
2.
Select the column mode (see Column modes on page 40).
3.
Program column flow or pressure, if desired (see
Flow or pressure programming on page 44).
4.
Set up the inlet (see Inlet setup on page 67).
5.
Set up the oven (Oven setup on page 149).
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Split/Splitless Inlet
Inlet setup
6.
Configure the detector (see Thermal Conductivity Detector on page 125, Flame
Ionization Detector on page 134, The Microcell Electron Capture Detector on
page 144, or The Flame Photometric Detector (FPD) on page 157).
Inlet setup
To set up the inlet:
1.
Display this screen.
Status / Setup / Inlet Setup
2.
Select the carrier gas you will use.
3.
Select the pressure units you prefer (Table 11 shows the conversions).
Table 11.
Pressure Unit Conversions
To convert
to
Multiply by
psi
bar
0.0689476
kPa
6.89476
psi
14.5038
kPa
100
psi
0.145038
bar
0.01
bar
kPa
4.
Released: March 2004
Select pressure adjustments, if needed.
•
Vacuum Correct, if the column empties into a vacuum. For example,
you may be using a Mass Selective Detector or mass
spectrometer.
•
None, if pressure is normal. This setting is the case for most
detectors.
•
Pressure Correct, if another condition is involved.
6850 Series Control Module User Information
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Split/Splitless Inlet
Prep run
Prep run
When you are performing analyses using manual injection and gas saver, splitless
mode, and/or pressure pulse, the GC will display "Waiting for prep run” and one or
more of these messages:
•
“Gas saver active”
•
“Inlet purging”
•
“Inlet pulse inactive”
In these cases, you must press the Prep Run key to reset the setpoints, wait for the
“Ready for” message, and then make the injection and press Start.
If this is not practical, you can have the GC issue an automatic Prep Run
command at the end of each run. To do so, display this screen.
Status / Setup / Automation / Auto Prep Run
Select Enable Auto Prep Run and press Esc.
This disables Gas Saver and raises the inlet pressure to the Pulse Pressure level immediately. The inlet purge valve closes. Deselect Enable Auto Prep Run when you
are finished making runs to conserve carrier gas.
It is usually best to disable Auto Prep Run. This function applies only to the split/splitless inlet in splitless mode and is equivalent to pressing Prep run.
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Split/Splitless Inlet
Setting the inlet mode
Setting the inlet mode
1.
Display this screen. This example shows that the GC is in splitless mode.
Status / Settings / Inlet / More / Inlet Mode / Enter
2.
Select the mode you prefer and press OK.
Split/Splitless terms
Following are terms used in relation to the Split/Splitless inlet. Many are fields on
screens that you see when using this inlet.
•
Flow—The flow, in mL/min, from the purge vent, at Purge Start. You will
not be able to specify this value if operating with your column not
configured.
•
Pressure—Actual and setpoint inlet pressure before and after the pressure pulse
or vent period (measured in psi, bar, or kPa). This is the starting point of a pressure program, column head or the fixed pressure if a program is not used.
•
Pulse pressure—The inlet pressure you desire at the beginning of a run. The pressure rises to this setpoint after Prep Run is pressed and remains constant until
Pulse time elapses, when it returns to Pressure.
•
Pulse time—Inlet pressure returns to its normal setpoint at this time after Start
Run.
•
Purge flow—The flow of carrier gas, in mL/min, from the purge vent, at Purge
Start. The column must be configured.
•
Purge time—The time, measured from Start Run, when sample transfer ends
(purge valve opens). Set purge start 0.1 to 0.5 minutes before pulse time.
•
Split flow—Flow, in mL/min from the split/purge vent. This field is not available
if your column is not configured.
•
Split ratio—The ratio of split flow to column flow. This field is not available if
your column is not configured.
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Split/Splitless Inlet
Pressure pulse modes
•
Temp—Actual and setpoint initial inlet temperatures.
•
Total flow—The total flow into the inlet, the sum of the split flow, column flow,
and septum purge flow, displayed during a Pre-run (Pre-run light is on and not
blinking) and during a run before Purge Start. You cannot enter a setpoint at these
times. At all other times, Total flow will have both
setpoint and actual values. When you change total flow, the split ratio and split flow
change while column flow and pressure remain the same. When a pressure pulse
is used, total flow increases to keep the split ratio constant.
Pressure pulse modes
The pressure pulse modes increase inlet pressure just before the beginning of a run
and return it to the normal value after a specified amount of time. The
pressure pulse sweeps the sample out of the inlet and into the column faster, reducing
the chance for sample decomposition in the inlet. If your chromatography is degraded
by the pressure pulse, a retention gap may help restore peak shape.
Pressure pulses may be used in either split or splitless mode and can be
combined with column pressure or flow programming. The pressure pulse takes precedence over the column pressure or flow ramp, as shown in Figure 3.
The pressure pulse must start before the sample is injected. The GC will do this automatically if you are using an automatic injector or a sequence.
If you are using manual injection, you must press Prep Run to start the pulse and
wait for the "Ready for manual inj" message.
Actual
pressure
Pressure pulse
Pressure (or flow) program
0
1
2
3
4
5
6
7
8
Time (min)
Figure 3.
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Pressure pulse and column flow or pressure
6850 Series Control Module User Information
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Split/Splitless Inlet
Pressure pulse modes
To set up a pressure pulse
1.
Set up the flow conditions through the column, including a flow or
pressure program (see Flow or pressure programming on page 44) if desired.
Then display this screen.
Status / Settings / Inlet / More
2.
Select Pulse Mode and press Enter to display the next screen.
Status / Settings / More / Pulse Mode / Enter
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6850 Series Control Module User Information
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Split/Splitless Inlet
Split mode
3.
4.
Select Pulsed. Enter values for Pressure and Time.
•
Pressure—the inlet pressure from Prep Run to Pulse Time.
•
Time (minutes after Start)—the time when the inlet pressure changes
from Pulse Pressure to the pressure called for by the flow or pressure
program (see Flow or pressure programming on page 44).
Press OK to accept these values or Esc to cancel.
Split mode
Pneumatics
During a split injection, a liquid sample is rapidly vaporized in a hot inlet. A small
amount of the vapor enters the column while the rest exits through the split/purge
vent. Split ratio, which is the ratio of column flow to split flow, is controlled by the
user. Split injections are mainly used for high concentration samples when you can
afford to lose most of the sample out the split/purge vent. It is also used for samples
that cannot be diluted.
Figure 4 shows the pneumatics for this inlet in split mode operation.
Flow
limiting
frit
Total flow
control loop
Septum holder Pressure
sensor
FS
ProportionalFlow
valve 1 sensor
PS
Septum purge
regulator (not
adjustable)
SPR
Vent
Column head pressure
control loop
Split vent flo
Trap
Purge Proportional
valve 2
valve
open
To detector
Safety shutdown mode:
Proportional valve 1 closed
Proportional valve 2 open
Purge valve open
Figure 4.
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Split flow pneumatics
6850 Series Control Module User Information
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Split/Splitless Inlet
Split mode
To use split mode with the column configured
1.
Verify that the column is in split mode and either Constant Flow or Ramped Flow
mode. See Column modes on page 40.
2.
Display this screen.
Status / Settings / Inlet
3.
Set Temp.
4.
Enter either the ratio or column flow. The instrument calculates and displays the other value.
5.
Set column mL/min.
To use split mode with the column not configured
Display this screen.
Status / Settings / Inlet
1.
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If necessary, change the inlet mode to split mode.
6850 Series Control Module User Information
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Split/Splitless Inlet
Splitless mode
2.
Set Temp and Pressure. Measure flow out of the split vent using a flow meter.
Split vent
Septum purge
Subtract split vent flow and septum purge flow (see Table 10 for nominal septum
purge flows by carrier gas type) from Total flow to get column flow.
3.
Calculate the split ratio. Adjust as needed.
Split ratio =
Split flow
Column flow
Splitless mode
Pneumatics
In this mode, the purge valve is closed during the injection and remains so while the
sample vaporizes in the liner and transfers to the column. At a time after injection that
you specify, the purge valve opens to sweep any vapors left in the liner out the split
vent. This avoids solvent tailing that would occur due to the large inlet volume and
small column flow rate. See Figure 5.
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Split/Splitless Inlet
Splitless mode
If you are using gas saver, the gas saver time should be after the purge time (see Gas saver
on page 77 for details on the gas saver).
Flow
limiting
frit
Inlet pressure control loop
Flow
sensor
FS
Septum purge
Septum holder
Pressure regulator (not
adjustable)
sensor
Vent
PS
SPR
Proportional
valve 1
Trap
Purge Proportional
valve valve 2
closed
To detector
Safety shutdown mode:
Proportional valve 1 closed
Proportional valve 2 open
Purge valve open
Figure 5.
Splitless flow diagram, prerun to purge time
Splitless mode injections
A successful splitless injection consists of these steps:
1.
Vaporize the sample and solvent in a heated inlet.
2.
Use a low flow and low oven temperature to create a solvent-saturated zone at the
head of the column.
3.
Use this zone to trap and reconcentrate the sample at the head of the
column.
4.
Wait until all, or at least most, of the sample has transferred to the column. Then
discard the remaining vapor in the inlet—which is mostly solvent—by opening a
purge valve. This eliminates the long solvent tail that this vapor would otherwise
cause.
5.
Raise the oven temperature to release the solvent and then the sample from the
head of the column.
Some experimentation is needed to refine the operating conditions. Starting values for
the critical parameters are shown in Table 12.
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Split/Splitless Inlet
Splitless mode
Table 12.
Splitless Mode Inlet Parameters
Parameter
Allowed setpoint range
Suggested starting value
Oven temperature
No cryo, 0°C to 375°C
CO2 cryo, -20°C to 375°C
30°C below solvent
boiling point
Oven initial time
0 to 999.9 minutes
≥ Inlet purge time
Inlet purge time
0 to 999.9 minutes
Liner volume / Column
flow
Gas saver time
0 to 999.9 minutes
After purge time
Gas saver flow
15 to 1000 mL/min
15 mL/min greater than
maximum column flow
To use splitless mode with the column configured
1.
Verify that the column, carrier gas, and flow or pressure program (if used) are
configured correctly.
2.
Display this screen.
Status / Settings / Inlet
3.
If necessary, change the inlet mode to splitless. See Setting the inlet mode on
page 69.
4.
Enter values for Temp and column mL/min.
5.
Use Prep Run (see Prep run on page 68) before manually injecting a
sample.
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6850 Series Control Module User Information
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Split/Splitless Inlet
Gas saver
To use splitless mode with the column not configured
1.
If necessary, change the inlet mode to splitless.
2.
Display this screen.
Status / Settings / Inlet
3.
Enter values for Temp (the maximum is 375°C) and Pressure.
4.
Use Prep Run (see Prep run on page 68) before manually injecting a
sample.
Gas saver
Gas saver reduces carrier gas flow from the split vent after the sample is on the column. Column head pressure and flow rate are maintained, while purge and split vent
flows decrease. Flows—except column flow—remain at the reduced level until you
press Start (sequence or auto injector operation) or Prep Run (manual injection).
See Figure 6.
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6850 Series Control Module User Information
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Split/Splitless Inlet
Gas saver
Gas saver time (3 min)
Start
Split mode
Regular flow
Prep run
50
Run ends
40
Split vent 30
flow
(mL/min) 20
Gas saver
flow
Gas saver flow
10
-2
-1
0
1
2
Start
Splitless mode
50
4
5
6
7
Prep run
8
Time (min)
Gas saver time (5 min)
Purge time
(2 min)
40
Split vent
30
flow
(mL/min) 20
3
Run ends
Purge flow
Gas saver
flow
Gas saver flow
10
-2
Figure 6.
-1
0
1
2
3
4
5
6
7
8
Time (min)
Gas saver operation
To configure gas saver
Display this screen.
Status / Settings / Inlet / More / Gas Saver / Enter
1.
2.
Released: March 2004
Select Gas Saver. Enter values for Flow and Time.
•
Flow—is the reduced flow level between sample runs.
•
Time (minutes after injection)—is when the normal flow changes to saver
Flow. It remains at the reduced level until the next Prep Run event,
whether manual or automatic.
Press OK to accept these values or Esc to cancel.
6850 Series Control Module User Information
Page 78 of 193
Purged Packed Inlet
Using hydrogen
Purged Packed Inlet
Using hydrogen
Warning
When using hydrogen (H2) as a carrier gas or fuel gas, be aware that hydrogen gas can
flow into the oven and create an explosion hazard. Therefore, be sure that the supply is
off until all connections are made and ensure that the inlet and detector column fittings
are either connected to a column or capped at all times when hydrogen gas is supplied
to the instrument.
Warning
Hydrogen is flammable. Leaks, when confined in an enclosed space, may create a fire
or explosion hazard. In any application using hydrogen, leak test all connections,
lines, and valves before operating the instrument. Always turn off the hydrogen supply at its source before working on the instrument.
Inlet and column controls
The inlet and column controls are related, and the relationship depends on whether or
not the column is configured. Set up the GC as described below.
1.
If you are using a packed column, or an unconfigured wide-bore capillary
column, only the flow modes are available. This is the default control method for
the purged packed inlet.
If you are using a wide-bore capillary column, you can configure the column (see
Configuring the column on page 38) and use column and inlet pressure modes
instead of flow modes.
2.
Select the column mode (see Column modes on page 40).
3.
Program column flow or pressure, if desired (see
Flow or pressure programming on page 44).
4.
Set up the inlet (see Inlet Setup on page 80).
5.
Set up the oven (see Oven setup on page 149).
6.
Set up the detector (see Thermal Conductivity Detector on page 125, Flame Ionization Detector on page 134; The Flame Photometric Detector (FPD) on
page 157, or The Microcell Electron Capture Detector on page 144).
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Purged Packed Inlet
Inlet Setup
Inlet Setup
To set up the inlet, display the following screen.
Status / Setup / Inlet Setup
1.
Select the carrier gas you will use.
2.
Select the pressure units you prefer (see Table 13 for conversions).
Table 13.
Pressure Unit Conversions
To convert
To
Multiply by
psi
bar
0.0689476
kPa
6.89476
psi
14.5038
kPa
100
psi
0.145038
bar
0.01
bar
kPa
3.
Released: March 2004
Select pressure adjustments, if needed.
•
Vacuum Correct, if the column empties into a vacuum. For
example, you may be using a Mass Selective Detector or mass spectrometer.
•
none, if pressure is normal. This setting is the case for most detectors.
•
Pressure Correct, if another condition is involved.
6850 Series Control Module User Information
Page 80 of 193
Purged Packed Inlet
Using a purged packed inlet
Using a purged packed inlet
This inlet is used with packed columns when high-efficiency separations are not
required. It can also be used with wide-bore capillary columns, provided that flows
greater than 10 mL/min are acceptable.
If a capillary column is used and the column is configured, the inlet is
pressure-controlled. If the column is not configured (packed columns and unconfigured capillary columns), the inlet is flow-controlled.
Figure 7 compares these modes.
Flow-controlled mode (for packed and unconfigured capillary columns)
Flow
Septum purge
limitingProportional Flow Pressure Septum holder regulator (not
frit
valve sensor sensor
adjustable)
Purge Ven
SPR
FS
PS
Flow
Total flow
control loop
To column
and detector
Pressure-controlled mode (recommended for configured capillary columns)
Flow
limiting Proportional Flow Pressure
valve sensor sensor
frit
FS
Inlet pressure
control loop
Figure 7.
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Septum purge
Septum holder regulator (not
adjustable
SPR
PS
Purge Ven
Flow
To column
and detector
Purged packed inlet flow diagram
6850 Series Control Module User Information
Page 81 of 193
Purged Packed Inlet
Using a purged packed inlet
Packed column or undefined capillary column
To program the inlet when using a packed column or an unconfigured capillary column, display this screen.
Status / Settings / Inlet
In the example above, notice that:
•
Setpoint and actual temperatures and flows are displayed
•
The inlet pressure is measured and displayed for your reference
1.
Set the inlet temperature.
2.
Set the total flow rate through the inlet. The total flow is the column flow rate
plus the septum purge flow rate.
With configured capillary columns
To program the inlet when using a configured capillary column:
1.
Display this screen.
Status / Settings / Inlet
2.
Released: March 2004
Set the inlet temperature and pressure for the method.
•
Setpoint and actual temperatures and pressures are displayed.
•
The total flow rate is measured and displayed for your reference.
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Using hydrogen
The Programmable Temperature Vaporization Inlet
Using hydrogen
Warning
When using hydrogen (H2) as a carrier gas or fuel gas, be aware that hydrogen gas can
flow into the oven and create an explosion hazard. Therefore, be sure that the supply is
off until all connections are made and ensure that the inlet and detector column fittings
are either connected to a column or capped at all times when hydrogen gas is supplied
to the instrument.
Warning
Hydrogen is flammable. Leaks, when confined in an enclosed space, may
create a fire or explosion hazard. In any application using hydrogen, leak test all connections, lines, and valves before operating the instrument. Always turn off the hydrogen supply at its source before working on the instrument.
Inlet modes
The Agilent Programmed Temperature Vaporization (PTV) Inlet System has five
operating modes:
•
The split mode is generally used for major component analyses.
•
The pulsed split mode is like the split mode, but with a pressure pulse applied to
the inlet during sample introduction to speed the transfer of material to the column.
•
The splitless mode is used for trace analyses.
•
The pulsed splitless mode allows for a pressure pulse during sample
introduction.
•
The solvent vent mode is used for large volume injection. Either single or multiple injections can be made for each run.
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The Programmable Temperature Vaporization Inlet
Inlet and column
Inlet and column
The inlet and column controls are related, and the relationship depends on whether or
not the column is configured. We strongly recommend that you set up the GC in this
order:
1.
Configure the column (see Configuring the instrument on page 12). If you do not,
only the pressure modes of the column and inlet can be used. The flow-dependent
features of the inlet, such as setting a split ratio directly, are not available.
2.
Select the column mode (see Column modes on page 40).
3.
Program column flow or pressure, if desired (see
Flow or pressure programming on page 44).
4.
Set up the inlet (see Inlet setup on page 84).
5.
Set up the oven (Oven setup on page 149) and detector (see the
appropriate chapter.).
Inlet setup
To configure the inlet, display the following screen.
Status / Setup / Inlet Setup
1.
Select the carrier gas you will use.
2.
Select the pressure units you prefer (see Table 14 for conversions.)
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Inlet setup
Table 14.
Pressure Unit Conversions
To convert
To
Multiply by
psi
bar
0.0689476
kPa
6.89476
psi
14.5038
kPa
100
psi
0.145038
bar
0.01
bar
kPa
3.
Select pressure adjustments, if needed.
•
Vacuum Correct, if the column empties into a vacuum. For
example, you may be using a Mass Selective Detector or mass
spectrometer.
•
none, if pressure is normal. This setting is the case for most
detectors.
•
Pressure Correct, if another condition is involved.
4.
Press More, select Coolant Type and press Enter.
5.
Set the type of coolant and press OK. To disable inlet cryo cooling or if no cryo
cooling is available, select No Coolant. Press OK.
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Inlet setup
6.
If you selected Liquid CO2, press More, and select
Coolant Settings. The following screen appears. Enter information as
applicable and press OK.
•
Cryo Enable—When selected, this enables cryogenic cooling of the inlet as
soon as the column oven reaches its initial temperature.
Unselected disables cooling.
•
Timeout—Cryo timeout occurs, and the inlet temperature shuts down, when
a run does not start within this specified time (range 5 to 120 minutes,
default 30 minutes) after the oven equilibrates. Turning cryo timeout off disables this feature. We recommend that it be turned on because cryo timeout
conserves coolant at the end of a sequence or if automation fails. A Post
Sequence method could also be used.
•
Ambient—If Cryo is enabled, this is the upper limit of temperatures at
which cryo cooling is used to hold the inlet at its setpoint. If the
setpoint is higher than this limit, cryogenic cooling is used to bring the inlet
down to its setpoint but is not used to hold it at the setpoint.
•
Cryo Fault—Select to enable shut down of the inlet if it does not reach setpoint in 16 minutes of continuous cryo operation. Note that this is the time
to reach the setpoint, not the time to stabilize and become ready at the setpoint.
Shutdown behavior
Both Cryo timeouts and Cryo faults can cause cryo shutdown. Cryo shutdowns conserve coolant when the GC is unable to start a run. The cryogenic cooling system may
still be working properly. A cryo timeout occurs if your specified cryo timeout period
expires before the oven reaches its temperature setpoint. A cryo fault occurs if cryo
cooling has been on for over 16 minutes but the oven has not reached its temperature
setpoint. If this happens, the inlet heater is turned off and the cryo valve closes. The
GC beeps and displays Inlet cryo shut off.
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Setting the inlet mode
The inlet heater is monitored to avoid overheating. If the heater remains on for over
the allowed duration and the inlet is not at setpoint, the heater is shut down. The GC
beeps and displays Inlet heating slow.
To recover from either condition, turn the GC off, then on, or enter a new
setpoint.
Setting the inlet mode
Before you do programming, set the inlet mode you want. To do so:
1.
Display this screen. The example below shows an inlet in Splitless mode.
Status / Settings / Inlet / More / Inlet Mode / Enter
2.
Select the mode you prefer and press OK to return to the previous screen.
Heating the inlet
Temperature can be programmed with an initial temperature and up to 3 rates and plateaus. Rates between 0.1 and 720°C/min can be selected.
Caution
If the initial inlet temperature and the oven initial temperature are too close, the inlet
may be unable to maintain its setpoint. We recommend a difference of at least 6°C,
either higher or lower.
For most purposes, the PTV is designed to hold the sample in the inlet liner until the
entire sample—there could be several injections—has been injected. Then the PTV is
heated rapidly to transfer the sample to the column. This can be accomplished with an
initial hold, a single ramp, and a hold at the end to complete sample transfer.
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The Programmable Temperature Vaporization Inlet
Heating the inlet
Two additional ramps are available and have several possible uses:
•
The inlet can be heated to a high temperature to thermally clean the liner for the
next run.
•
The inlet can be programmed downward—just set the Final temp below the previous temperature—to reduce thermal stress on the inlet.
•
Downward programming can be used to prepare the inlet for the next run. This
can reduce cycle time for greater sample throughput.
To program a PTV temperature ramp:
1.
Display this screen.
Status/Settings/Inlet/Ramps/Ramp 1
Final temp
Start temp
Start time
Final time
Rate
2.
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•
Start temp—Actual and setpoint inlet temperatures.
•
Start time—The time, measured from Start Run, when the initial inlet temperature hold ends. Usually later than Vent End.
•
Rate—Temperature program rate for inlet thermal ramps 1, 2, and 3. The
maximum is 720°C per minute.
•
Final temp—Final inlet temperature for ramps 1, 2, and 3. The range is -30°C to 375°C, and is a duration, not a measurement from Start Run.
•
Final time—Hold time at Final temp 1, 2, and 3.
Enter the ramp. This is similar to Temperature programming on page 151.
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
PTV terms
PTV terms
Following are terms used in relation to the PTV inlet. Many are fields on screens that
you see when using this inlet.
•
Flow—The flow, in mL/min, from the purge vent, at Purge Start. You will
not be able to specify this value if operating with your column not
configured.
•
Pressure—Actual and setpoint inlet pressure before and after the pressure pulse
or vent period (measured in psi, bar, or kPa). This is the starting point of a pressure program, column head or the fixed pressure if a
program is not used.
•
Pulse pressure—The inlet pressure you desire at the beginning of a run. The pressure rises to this setpoint after Prep Run is pressed and remains constant until
Pulse time elapses, when it returns to Pressure.
•
Pulse time—Inlet pressure returns to its normal setpoint at this time after Start
Run.
•
Purge flow—The flow of carrier gas, in mL/min, from the purge vent, at Purge
Start. The column must be configured.
•
Purge start—The time, measured from Start Run, when sample transfer ends
(purge valve opens). Set purge start 0.1 to 0.5 minutes before pulse time.
•
Split flow—Flow, in mL/min from the split/purge vent. This field is not available
if your column is not configured.
•
Split ratio—The ratio of split flow to column flow. This field is not
available if your column is not configured.
•
Temp—Actual and setpoint initial inlet temperatures.
•
Total flow—The total flow into the inlet, the sum of the split flow, column flow,
and septum purge flow, displayed during a Pre-run (Pre-run light is on and not
blinking) and during a run before Purge Start. You cannot enter a setpoint at these
times. At all other times, Total flow will have both
setpoint and actual values. When you change total flow, the split ratio and split flow
change while column flow and pressure remain the same. When a pressure pulse
is used, total flow increases to keep the split ratio constant.
•
Vent End—The time, measured from Start Run, when solvent venting ends. For
large volume injections, this time is normally later than the time for the injection
to complete.
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The Programmable Temperature Vaporization Inlet
Pulsed modes
•
Vent flow—The flow of carrier gas out the split vent during the vent period.
Higher flows sweep the liner more quickly and reduce the time for solvent elimination. For most columns, 100 mL/min vent flow eliminates solvent at an acceptable rate but puts minimal material on the column.
•
Vent pressure—The inlet pressure during the vent period. By decreasing the inlet
pressure while venting, solvent elimination proceeds faster. Also, the pressure
reduction decreases the amount of carrier gas—and solvent vapor—that enters
the column during this time.
Users select from 0 to 100 psig. If 0 is chosen, the inlet uses the lowest pressure
possible at the given vent flow. Table 15 shows approximate
values for this minimum at various vent flows of helium. Pressures less than
those in the table are not possible unless the flow is reduced.
Table 15.
Minimum attainable pressures
Vent flow
(mL/min)
Actual vent pressure
at “0“psig setpoint
Actual vent pressure
at “0” kPa setpoint
50
0.7
5
100
1.3
10
200
2.6
18
500
6.4
44
1000
12.7
88
Pulsed modes
The pressure pulse modes (split and splitless) increase inlet pressure just before the
beginning of a run and return it to the normal value after a specified amount of time.
The pressure pulse sweeps the sample out of the inlet and into the column faster,
reducing the chance for sample decomposition in the inlet. If your chromatography is
degraded by the pressure pulse, a retention gap may help restore peak shape.
You must press Prep Run before doing manual injections in a pressure pulse mode.
You can do column pressure and flow programming when in the pressure pulse mode.
However, the pressure pulse will take precedence over the column
pressure or flow ramp. See Figure 8.
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Pulsed modes
Actual
pressure
Pressure pulse
Pressure (or flow) program
0
1
2
3
4
5
6
7
8
Time (min)
Figure 8.
Pressure pulse and column flow or pressure
To set up a pressure pulse
1.
Set up the flow conditions through the column, including a flow or
pressure program (see Flow or pressure programming on page 44) if desired.
Then display this screen.
Status / Settings / Inlet / More
2.
Select Pulse Mode and press Enter to display the next screen.
Status / Settings / More / Pulse Mode / Enter
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Pulsed modes
3.
4.
Select Pulsed. Enter values for Pressure and Time.
•
Pressure—the inlet pressure from Prep Run to Pulse Time.
•
Time (minutes after Start)—the time when the inlet pressure changes
from Pulse Pressure to the pressure called for by the flow or pressure
program (see Flow or pressure programming on page 44).
Press OK to accept these values or Esc to cancel.
To use pulsed splitless mode with the column configured
1.
2.
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44
Display this screen.
Status / Settings / Inlet
3.
Set the inlet temperature and any desired ramps.
4.
Press More and select Pulse Mode.
5.
Select Pulsed Mode.
6.
Enter values for Pulse Pressure and Pulse time and press OK.
7.
Press More and select Inlet Mode.
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Pulsed modes
8.
Select Splitless.
9.
Enter the Purge Start when you wish the purge valve to open.
10. Enter a Purge flow. Press OK.
11. Turn Gas saver on, if desired. Set the time after the Purge Start and press
OK.
Select
gas saver
Gas saver time
12. Press Prep Run (see page 68) before manually injecting a sample.
To use pulsed splitless mode with the column not configured
1.
Released: March 2004
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Pulsed modes
2.
Display this screen.
Status / Settings / Inlet
3.
Set the inlet temperature and any desired ramps.
4.
Press More and select Pulse Mode.
5.
Select Pulsed for the Mode.
6.
Enter values for Pulse pressure and Pulse time and press OK.
7.
Press More and select Inlet Mode.
8.
Enter the Purge Start when you wish the purge valve to open.
9.
Press OK.
10. Press Prep Run (see page 68) before manually injecting a sample.
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Pulsed modes
To use pulsed split mode with the column configured
1.
2.
Verify that the:
•
column is configured (see Navigating the screens on page 8 and
Configuring the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44)
•
inlet is in pulsed split mode (see Setting the inlet mode on page 87 and To
set up a pressure pulse on page 91)
Display this screen. It may appear differently (certain fields may or may not be
editable), depending on how the column is configured.
Status / Settings / Inlet
3.
Set Temperature. Set column mL/min. Then enter the Ratio or, if you
prefer, the split mL/min. In either case, the instrument calculates and displays the other value.
4.
Turn on the gas saver, if desired, by pressing More and choosing Gas Saver.
Set the Saver time later than Pulse time. Press OK.
Select
gas saver
5.
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Gas saver time
Press Prep Run (see page 68) before injecting a sample manually.
6850 Series Control Module User Information
Page 95 of 193
The Programmable Temperature Vaporization Inlet
Pulsed modes
To use pulsed split mode with the column not configured
1.
2.
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44)
•
inlet is in pulsed split mode (see Setting the inlet mode on page 87 and To
set up a pressure pulse on page 91)
Display this screen.
Status / Settings / Inlet
3.
Set the inlet temperature and any desired ramps.
4.
Press More and select Pulse Mode.
5.
Select Pulsed Mode.
6.
Enter values for Pulse Pressure and Pulse time and press OK.
7.
Set the total flow into the inlet. Measure flows out of the split vent and
septum purge vent using a flow meter.
8.
Subtract the septum purge flow from the total flow.
9.
Calculate the split ratio. Adjust as needed.
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Split mode
Split mode
The two split modes—with or without a pressure pulse—divide the gas stream entering the inlet between the column flow, the split vent flow (flow, in mL/min, from the
split/purge vent) through the solenoid valve, and the septum purge flow. The ratio of
the split vent flow to the column flow is called the split ratio.
The graphic below shows the flows with the septum head. Flows with the
septumless head are the same except that the septum purge flow bypasses the head
(lower left).
Flow
limiting
frit
Total flow
control loop
Septum purge
regulator Septum
purge
PS
SPR
vent
Column head pressure
control loop
Pressure
sensor
Septum
head
FS
Proportional Flow
valve 1 sensor
Trap
SolenoidProportional
valve valve 2
open
Split
vent
Glass liner
Flows with septumless head
PS
To detector
FS
Septumless
head
The total flow is the sum of the split flow, column flow, and septum purge flow. When you
change the total flow, the split ratio and split flow change while the column flow and pressure
remain the same.
Temperature considerations
Cold split introduction
For cold split sample introduction, use an initial inlet temperature below the normal
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6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Split mode
boiling point of the solvent. If the liner volume is enough to hold all the vaporized solvent, start the first inlet temperature ramp at 0.1 minutes with a high heating rate
(500°C/min or higher). The final temperature should be high enough to volatilize the
heaviest analytes from the liner and should be held for at least 5 minutes. A final temperature of 350°C for 5 minutes has proven
sufficient to quantitatively transfer C44.
For larger injection volumes or to eliminate the solvent, hold the initial
temperature long enough to vent the solvent through the Split vent and then begin the
first ramp. Use a fast rate for thermally stable analytes. Slower rates may help minimize thermal degradation in the inlet.
A single temperature ramp is enough for the injection process. The remaining ramps
may be used to clean the liner or to reduce the inlet temperature in
preparation for the next injection.
Hot split introduction
For hot split introduction, set an initial temperature high enough to volatilize the analytes. No additional thermal parameters are required as the inlet will maintain the setpoint throughout the run.
Because of the small liner volume (about 120 microliters), the PTV has a
limited injection capacity with hot split introduction. Injection volumes exceeding 1
μL in the hot split mode may overflow the inlet causing analytical problems. Cold
split introduction avoids this potential problem.
To use split mode with the column configured
1.
Released: March 2004
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44
•
inlet is in split mode (see Setting the inlet mode on page 87)
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Split mode
2.
Display this screen. It may appear different (certain fields may or may not be
editable), depending on the mode the column is in.
Status / Settings / Inlet
Column flow
3.
Set Temp, the initial inlet setpoint.
4.
Enter the initial pressure or total flow.
5.
Enter the desired split ratio or column flow.
6.
If desired, turn on the Gas Saver by pressing More and selecting Gas Saver.
Then, enter values for the parameters on the following screen and press OK.
Status / Settings / Inlet / More / Gas Saver
7.
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Press Prep Run before manually injecting the sample if the Gas Saver is on
(see page 68).
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Split mode
To use split mode with the column not configured
1.
2.
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see
Flow or pressure programming on page 44
•
inlet is in split mode (see Setting the inlet mode on page 87)
Display this screen.
Status / Settings / Inlet
3.
Set the inlet temperature.
4.
Set total flow or pressure into the inlet. Measure flows out of the split vent and
septum purge vent using a flow meter.
5.
Subtract the septum purge flow from Total flow to get split flow.
6.
Calculate the split ratio. Adjust as needed.
See Figure 3 for a graphic of the pressure pulse and column flow or pressure.
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The Programmable Temperature Vaporization Inlet
Splitless mode
Splitless mode
Flow pattern
In these modes—with or without a pressure pulse—the solenoid valve is closed during
injection and vaporization of the sample and stays so while the sample transfers to the
column (see Figure 9). At a specified time after
injection, the valve opens to sweep vapors left in the liner out the split vent (see
Figure 10). This avoids solvent tailing due to the large inlet volume and small column
flow rate.
Figure 9 shows the flows with the septum head. Flows with the septumless head are
the same except that the septum purge flow bypasses the head (lower left).
Figure 11 graphs flow, pressure, and temperature over time during this
process.
Column head pressure control loop
Flow
limiting
frit
Septum
head
FS
ProportionalFlow
valve 1 sensor
With the solenoid
valve closed, the
sample and solvent
transfer to the
PS
Pressure
sensor
Septum purge
regulator
Septum
purge
SPR
vent
Trap
SolenoidProportional
valve valve 2
closed
Split
vent
Glass liner
Flows with septumless head
PS
FS
Septumless
head
Figure 9.
Stage 1. Sample injection
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6850 Series Control Module User Information
To detector
Page 101 of 193
The Programmable Temperature Vaporization Inlet
Splitless mode
Flow
limiting
frit
Total flow
control loop
Septum
head
Pressure
sensor
Septum purge
regulator
Septum
SPR
purge
PS
vent
Column head pressure
control loop
FS
ProportionalFlow
valve 1 sensor
After the sample has
transferred to the column,
the solenoid valve opens to
purge remaining solvent
vapor from the system.
Trap
SolenoidProportional
valve valve 2
open
Glass liner
Flows with septumless head
PS
FS
Split
vent
To detector
Septumless
head
Figure 10. Stage 2. Purging
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The Programmable Temperature Vaporization Inlet
Splitless mode
SPLITLESS OPERATION
Split vent flow
Purge
flow
Saver
flow
Inlet is
pressure
controlled
Prep
Run
Inlet pressure
Start
Run
Purge
Time
Saver
Time
Stop
Run
Post
Time
Stop
Run
Post
Time
Post
Pres
Column flow program
Inlet
Pres
Inlet
temperature
Prep
Run
Start
Run
Purge
Time
Prep
Run
Start
Run
Purge
Time
Final
temp 1
Init
temp
Figure 11. Flows, pressures, and temperatures
Temperature considerations
Cold splitless introduction
For cold splitless introduction, use an initial inlet temperature below the
normal boiling point of the solvent. For most solvents, starting the first inlet temperature ramp at 0.1 minutes provides good transfer and reproducibility. A program rate of
500°C/min or higher is appropriate for thermally stable
analytes. A final temperature of 350°C, held for 5 minutes, has quantitatively transferred up to C44 alkane.
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The Programmable Temperature Vaporization Inlet
Splitless mode
A main advantage of temperature programmability is that the inlet can be heated gently to transfer delicate analytes. If the oven is initially low enough to refocus the analytes on the column, the inlet heating rate can be made slower (e.g., 120°C/min). This
reduces thermal degradation from the inlet and can improve peak shape and quantitation.
For most applications of cold splitless, a single temperature ramp is enough. The
remaining ramps can be used to clean the liner or to decrease the inlet temperature to
prepare for the next injection.
Hot splitless introduction
For hot splitless introduction, select an initial temperature high enough to
volatilize the analytes. No additional temperature parameters are required as the inlet
will maintain the setpoint throughout the run.
Because of the small liner volume (about 120 μL), the PTV cannot contain vapor
resulting from large liquid injection volumes. Injection volumes greater than 1 μL
may overflow vapor from the inlet, causing analysis variations. Cold splitless introduction avoids this problem.
Starting values
A successful splitless injection consists of these steps:
1.
Inject the sample and temperature program the inlet to vaporize it.
2.
Use a low column flow and low oven temperature to create a
solvent-saturated zone at the head of the column.
3.
Use this zone to trap and reconcentrate the sample at the head of the
column.
4.
Wait until all, or at least most, of the sample has transferred to the column. Then
discard the remaining vapor in the inlet—which is mostly solvent—by opening a
purge valve. This eliminates the long solvent tail that this vapor would otherwise
cause.
5.
Raise the oven temperature to analyze the sample.
Some experimentation is needed to refine the operating conditions. Table 16 provides
starting values for the critical parameters.
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The Programmable Temperature Vaporization Inlet
Splitless mode
Table 16.
Splitless Mode Inlet Parameters
Parameter
Allowed setpoint range
Suggested starting
value
Oven temperature
No cryo, ambient+10°C to 350°C
CO2 cryo, –30°C to 350°C
10°C below solvent
boiling point
Oven initial time
0 to 999.9 minutes
≥ Inlet purge start
Inlet purge start
0 to 999.9 minutes
Liner volume*
x5
Column flow
Gas saver time
0 to 999.9 minutes
After purge start
Gas saver flow
15 to 1000 mL/min
15 mL/min greater than
maximum column flow
Inlet temperature
No cryo, oven temp + 10°C to
375°C
CO2 cryo, –30°C to 350°C
10°C below solvent
boiling point for 0.1
min,
then ramp up
* Liner volume is about 120 μL
To use splitless mode with the column configured
1.
2.
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44
Display this screen. It will vary based on your current settings.
Status / Settings / Inlet
3.
Set the inlet temperature and any desired ramps.
4.
Enter column mL/min.
5.
Press More and select Inlet Mode.
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The Programmable Temperature Vaporization Inlet
Splitless mode
6.
Select Splitless.
7.
Enter a Flow and a Purge Start.
8.
Press OK.
9.
Turn on the gas saver, if desired, by pressing More and choosing Gas Saver.
Set the Saver time later than the Purge Start.
Select
gas saver
Gas saver time
10. Press OK.
11. Press Prep Run (see page 68) before manually injecting a sample.
To use splitless mode with the column not configured
1.
Released: March 2004
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44
•
inlet is in splitless mode (see Setting the inlet mode on page 87)
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
2.
Display this screen It will vary depending on your current settings.
Status / Settings / Inlet
3.
Set the inlet temperature and any desired ramps.
4.
Press More and select Inlet Mode.
5.
Select Splitless.
6.
Enter a Purge Start and Flow. Press OK.
7.
Press Prep Run (see page 68) before manually injecting a sample.
Solvent vent mode
Flow pattern
The sample is injected into a cold inlet. If conditions are properly chosen and the sample is suitable, analytes deposit in the inlet liner while the solvent
evaporates and is swept out. Large or multiple injections can be used to concentrate
sample in the inlet before transferring to the column for analysis.
The graphic below shows the flows with the septum head. Flows with the
septumless head are the same except that the septum purge flow bypasses the head
(lower left).
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Stage 1. Sample and vent
Flow
limiting
frit
Pressure
sensor
Total flow
control loop
Septum
head
FS
ProportionalFlow
valve 1 sensor
During sampling and venting
solenoid valve is open. Inlet is
at Init temp, at or below
solvent boiling point. Solvent
vapors are swept out the vent,
while sample deposits on the
liner walls or packing.
Flows with septumless head
FS
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Septum purge
regulator
Septum
purge
SPR
PS
vent
Column head pressure
control loop
Trap
SolenoidProportional
valve
valve 2
open
Split
vent
Glass liner
PS
To detector
Septumless
head
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Stage 2.
Sample transfer
Septum purge
regulator Septum
Column head pressure control loop
Flow
limiting
frit
Septum
head
FS
ProportionalFlow
valve 1 sensor
FS
Stage 3.
SPR
Trap
SolenoidProportional
valve
valve 2
open
When solvent venting ends,
solenoid valve closes and inlet heats to Final temp 1.
The sample transfers to the
capillary column.
Flows with septumless head
PS
Pressure
sensor
purge
vent
Split
vent
Glass liner
PS
To detector
Septumless
head
Purge and cleanup
The solenoid valve opens again and the system returns to the Stage 1
configuration but with different setpoints. The PTV inlet is flushed. Additional ramp
rates are available to thermally clean the inlet or to reduce inlet temperature after sample transfer. This can extend the life of the liner.
Temperature, pressure, and flow considerations
The solvent vent mode goes through three distinct pneumatic states; venting, sample
transfer, and purging. The vent portion allows the inlet pressure and the vent flow to
be adjusted to optimize solvent elimination. The transfer state mimics traditional splitless operation and transports the analytes from the liner to the column. The purging
mode allows the user to prepare the inlet for the next run.
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
A fundamental difficulty with solvent vent mode is the potential loss of volatile analytes with the solvent. Several solutions are possible for this situation:
•
The inlet liner can be packed with a more retentive material, such as Tenax. This
greatly improves volatile analyte recovery but may impact recovery of higher
boiling materials.
•
Some of the solvent can be left in the liner when sample transfer begins. The
residual solvent acts like a stationary phase and retains volatile
material, but at the expense of a larger solvent peak.
•
The inlet temperature can be reduced. This reduces the vapor pressure of the volatile analytes and permits higher recoveries.
Solvent removal can be speeded up by:
•
Reducing pressure in the inlet during sample introduction—the Vent pressure parameter
•
Increasing flow through the inlet—the Vent flow parameter
While all these possibilities do complicate use of the PTV, they provide increased
flexibility and new potential to solve difficult problems.
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Sequence of operations
These are the steps in a typical analysis using the solvent vent mode.
Ste
p
1
Before injection
Parameter
Value
Flow at split vent
Either Purge flow or Saver flow
Inlet pressure
Derived from column setpoint
The system is resting, with Purge flow (or Saver flow, if on) through the inlet.
2
Prep Run begins
Flow at split vent
Vent flow setpoint
Inlet pressure
Vent pressure setpoint
Setpoints change to prepare for injection. When GC is ready, the sample is
injected. Inlet and oven temperature program Init times begin. Solvent venting
and analyte trapping begin.
3
At Vent End
Flow at split vent
None, solenoid valve closed
Inlet pressure
Column pressure setpoint
Solvent venting ends, analyte transfer begins as inlet heats up.
4
At Purge Start
Flow at split vent
Purge flow setpoint
Inlet pressure
Column pressure setpoint
Analyte transfer ends, inlet is purged of residual vapor. Analysis begins.
5
At Saver time
Flow at split vent
Saver flow setpoint
Inlet pressure
Column pressure setpoint
Analysis ends, carrier flow reduced to save gas (if Saver is on).
Some important points
•
The flow through the column is governed by the pressure in the inlet. This is controlled, during the analysis part of the process, by the flow or
pressure setpoint or program entered for the column.
•
Vent End and Purge Start must come before Saver time.
•
Vent End must occur before the inlet starts to heat and release analytes.
•
Purge Start must occur before the oven begins to heat and move
sample through the column.
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Time lines
Time increases downward; all other quantities increase to the right. Table 12 diagrams
this relationship.
Time
Oven temp
Inlet temp
Between runs
Prep Run
Start Run
Init time
Inlet pressure
Split vent flow
Saver or
(Controlled by
Purge
column flow or
flow
pressure setpoint
or program)
Vent
pressure
Vent flow
Vent End
i5-23
Final temp 1
Final time 1
Purge Start
Rate 1
Saver time
(Inlet is
pressure
controlled
Rate 1
Init time
Other rates,
temps, and
times, if
desired.
Final temp 1
Final time 1
Purge
flow
(Controlled by
column flow or
pressure setpoint
or program)
Other rates,
temps, and
times, if
desired.
Figure 12.
Saver
flow
(if on)
Time relationships
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
When is start run?
Both the inlet and oven temperature programs begin at Start Run. All times—such as
Purge Start—are measured from Start Run. When does Start Run occur?
•
If the sample is injected manually, Start Run occurs when the user presses the
Start Run key.
•
If a single injection per run is made using an autosampler, Start Run occurs when
the syringe carrier moves down to make the injection.
•
If multiple injections per run are made using an autosampler, Start Run occurs
when the syringe carrier moves down to make the first injection of the set. There
are no Start Runs for the rest of the injections in the set.
These additional injections take time. To allow for this, adjust the inlet and oven
temperature programs (mainly the ramp Start Time values). Also, you must
adjust the various time values that control the inlet operation. This is discussed in
more detail under Large volume injection on page 115.
To use solvent vent mode with the column configured
1.
2.
Verify that the:
•
column is configured (see Navigating the screens on page 8 and Configuring
the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44
Display this screen. It will vary based on your current settings.
Status / Settings / Inlet
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
3.
4.
Press More. Select Inlet Mode.
a.
Select Solvent vent for the Mode.
b.
Enter vent Pressure, Flow, and Vent End. Vent End should be set
to a time earlier than any ramp’s starting time.
c.
Enter Purge Start and Flow. Press OK.
d.
Set the inlet temperature and ramps, as desired.
e.
If desired, turn Gas saver on and press OK. Make certain the time is set
after the Purge Start
Press Prep Run (see page 68) before manually injecting a sample.
To use solvent vent mode with the column not configured
1.
Released: March 2004
Verify that the:
•
column is not configured (see Navigating the screens on page 8 and Configuring the column on page 38)
•
carrier gas is configured (see Inlet setup on page 84)
•
flow or pressure program, if used, is configured (see Flow or pressure programming on page 44
6850 Series Control Module User Information
Page 114 of 193
The Programmable Temperature Vaporization Inlet
Solvent vent mode
2.
Display this screen. It will vary based on your current settings.
Status / Settings / Inlet
3.
4.
Press More. Select Inlet Mode.
a.
Select Solvent Vent for the Mode.
b.
Enter a vent Pressure and Vent End. Vent End should be set to a time
earlier than any ramp’s starting time.
c.
Enter a Purge Start. Press OK.
d.
Set the inlet temperature and ramps, as desired.
Press Prep Run (see page 68) before manually injecting a sample.
Large volume injection
This feature requires a G2613A or G2880A injector. It also requires an Agilent Data
System:
•
GC ChemStation (rev. A.10.01 or higher with the 6850 patch)
•
Cerity Chemical (rev. 4.07 or later).
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Most vaporizing inlets are designed for liquid injections in the 1 to 5 μL range. With
larger injections, the vapor cloud created when the sample vaporizes may overflow the
inlet and degrade the chromatography. Table 17 lists the nominal liner liquid capacities.
Table 17.
Liner capacities
Liner
Nominal liquid
capacity
Inertness
Open baffle
5 μL
High
Glass wool
packed
25 μL
Lower, because of greater surface
area
In the solvent vent mode, analytes are thermally trapped in the liner while the solvent
is removed. With the solvent gone, the liner volume can be used for another injection.
Injection can be repeated several times to concentrate the analytes from a large sample
volume. After injection and solvent removal, the analytes are transferred to the column. This can replace the need for offline concentrating and minimize loss of sample.
The control parameters you specify are:
•
The full volume of the syringe (0.1 to 100 μL; default is 10 μL).
•
If the sampler should make multiple injections into the inlet for each run according to the other parameters (single or multiple; default is single). For multiple, it
issues a Start Run command at the first injection only. For single, issues a Start
Run command for each run.
•
The amount to inject, specified as the product of X (amount to inject in μL) and Y
(the number of injections to make). (X: 0.1 to 0.5 multiplied by syringe volume; Y:1 to
100; defaults are 0.1 x syringe volume (for X) and 1 (for Y)).
•
The pause time, in seconds, between injections. This is added to the
minimum hardware cycle time (0 to 100; default is 0).
•
The number of times to wash the syringe with solvent and/or sample before the
first injection. No washes are performed before the rest of the injections in a multiple
injection set (0 to 15; default is 0).
•
The number of times to wash the syringe with solvent after the last
injection. No washes are performed after the rest of the injections in a multiple
injection set (0 to 15; default is 0).
•
The number of times to pump the syringe plunger before drawing up the measured sample. Pumps are performed only before the first injection of a multiple
injection set (0 to 15; default is 0).
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Calculated values
The software calculates and displays:
•
Product of X (Volume per injection) and Y (Injections per run).
•
The approximate total time, in minutes, to make a set of multiple
injections based on the parameters entered and the mechanical cycle time of the
sampler. Includes the delay between injections, pre- and
post-injection dwell times, and viscosity delays.
An example
These values were used for a sample with a broad range of boiling points.
General parameters
Name
Value
Sample
C10 to C44 hydrocarbons in hexane
Mode
Solvent vent
PTV liner
Glass wool packed
Injection
volume
One 10.0 μL injection (25 μL syringe)
Injection
speed
Fast
Column
30 m x 320 μm x 0.25 μm HP5, p/n 19091J-413E
Column flow
4 mL/min constant flow
Inlet parameters
Name
Value
Name
Init temp
40°C
Rate 2 (off)
Init time
0.3 min
Pressure
15.6 psig
Rate 1
720°C/min
Vent pressure
0.0 psig
Final temp 1
375°C
Vent flow
100 mL/min
Final time 1
5 min
Vent End
0.2 min
Rate 2
100°C/min
Purge Start
2.0 min
Final temp 2
250°C
Purge flow
50 mL/min
Final time 2
0 min
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Value
6850 Series Control Module User Information
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Oven parameters
Name
Value
Init temp
40°C
Init time
2.5 min
Rate 1
25°C/min
Final temp 1
320°C
Final time 1
10.0 min
Rate 2 (off)
Detector parameters
Name
Value
Detector
FID
Detector temp
400°C
Hydrogen
flow
40 mL/min
Air flow
450 mL/min
Makeup (N2)
45 mL/min
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
C20
i5-26
Figure 13.
Chromatogram from one 10 μL injection
The results shown in Figure 13 were compared with a splitless analysis of the same
sample, which should produce 100% recovery of all analytes. The data showed that,
under these conditions, compounds above C20 were completely recovered and that the
recovery was independent of injection size; Compounds lower than C20 were partially vented
with the solvent.
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Possible adjustments
Depending on what you are trying to accomplish, you have a number of
possible adjustments available.
To eliminate more solvent
•
Increase the Vent End, inlet initial time, and Purge Start. This will not affect analytes that are quantitatively trapped but will eliminate more of the solvent peak.
•
Increase the vent flow to sweep the liner more rapidly with the same inlet timing.
Increasing vent flow raises vent pressure if it is set to 0. This puts more solvent
onto the column.
•
Raise the inlet initial temperature to vaporize more solvent and allow more to be
eliminated. This also increases the loss of volatile analytes since their vapor pressures also increase.
To improve recovery of low boiling analytes
•
Reduce inlet temperature to lower the vapor pressure of the analytes and trap
them more effectively. This also reduces solvent vapor pressure and more time
will be needed to eliminate it.
•
Use a retentive packing in the liner. Materials such as Tenax permit higher recovery of volatile analytes but may not release higher boiling
compounds. This must be considered if quantitation on these high boiling peaks
is desired.
•
Leave more solvent in the liner. The solvent acts as a pseudo stationary phase and
helps retain volatile analytes. This must be balanced against the detector’s tolerance for solvent.
An example—continued
The single injection example shown on the last few pages makes it clear that a 10-μL
injection does not overload the glass wool packed liner. This means that multiple 10μL injections are possible.
It was decided to make 10 injections per run, each of 10-μL size. This would increase
analytical sensitivity substantially. No adjustments were made to improve recovery of
the low boilers since the purpose of this analysis was to detect and measure the high
boiling components.
The ChemStation estimated that 10 injections would require a total of 1.3 minutes.
The following timing changes were made:
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The Programmable Temperature Vaporization Inlet
Solvent vent mode
Parameter
Increased from
To
Inlet Init time
0.3 minutes
1.6 minutes
Vent End
0.2 minutes
1.5 minutes
Purge Start
2.0 minutes
3.0 minutes
Oven Init time
2.5 minutes
3.0 minutes
The result is shown in Figure 14.
C20
Figure 14.
Chromatogram from ten 10 μL injections
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The Cool On-Column Inlet
Inlet temperature
The Cool On-Column Inlet
Using a Cool On-Column Inlet
Warning
This inlet introduces liquid sample directly onto a capillary column. To do this, both
the inlet and the oven must be cool at injection, at or below the boiling point of the
solvent. Because the sample does not vaporize immediately in the inlet, problems with
sample discrimination and sample alteration are minimized. If done properly, cool-on
column injection also provides accurate and precise results.
You can operate the inlet in track oven mode, where the inlet temperature
follows the column oven, or you can program up to three temperature ramps. There is
also a cryogenic cooling option that uses liquid CO2 to reach
sub-ambient temperatures.
Flow
limitingProportional Pressure
frit
sensor
valve
Septum holder
PS
Septum purge
regulator (not
adjustable)
SPR
Inlet pressure
control loop
Purge vent
To detector
Figure 15. Cool on-column capillary inlet with EPC
Inlet temperature
CryoBlast (optional)
CryoBlast shortens the cycle time between runs. If you have a CO2 cryogenic valve and
the CryoBlast feature, you can cool the inlet to –17°C in track oven mode and –20°C in temperature program modes.
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The Cool On-Column Inlet
Inlet temperature
Track oven mode
In the Track oven mode, the inlet temperature stays 3°C higher than the oven
temperature throughout the oven program. You cannot enter a
temperature setpoint—it is set automatically. If you have CryoBlast, the inlet will
track oven temperatures to –17°C; without CryoBlast, the lower limit is set by room
temperature.
Temperature programming mode
In this mode, you can enter up to three temperature ramps so that the inlet and the
oven operate independently.
At these very low oven temperatures, the inlet temperature should be at least 20°C
higher than the oven temperature. This will be more than adequate for solvent focusing.
At temperatures greater than ambient, the inlet should always be at least 3°C warmer
than the oven for proper control of the inlet temperature.
The oven temperature program controls the run. If it is longer than the inlet temperature program, the inlet will remain at its final temperature until the oven program (and
the run) ends.
Setpoint ranges
The table below lists setpoint ranges for the inlet parameters.
Temperature
Allowed setpoint range
Track oven
3°C higher than the oven temperature to a maximum of
375°C. If you have CryoBlast, the inlet can maintain
temperatures down to —17°C, although allowable oven
setpoints are —60°C.
Ramped temp without
CryoBlast
Ambient to 375°C
Ramped temp with CryoBlast
—20°C to 375°C
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The Cool On-Column Inlet
Operating the cool on-column inlet
Operating the cool on-column inlet
Verify that a column and suitable insert and septum nut or cooling tower are installed.
Make certain you are using a needle that will fit the column.
1.
Verify that the column, carrier gas, and flow or pressure program (if used) are
configured correctly. See Flow and Pressure Control on page 36.
Pressure can be set from either the column or inlet table. In constant or ramped
flow mode, the pressure will be determined from the flow
requirements. It is best to set flow only.
2.
Press Inlet.
Track oven mod
Select for temp.
programming mo
3.
Choose the temperature mode
•
Press Track to use oven track mode.
•
Press Ramps to define temperature ramps. You program ramps
similarly to oven ramps. See Temperature programming on page 151.
4.
Enter the initial temperature (temperature programming only).
5.
Enter the desired inlet pressure or flow value.
6.
Inject a sample.
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Thermal Conductivity Detector
Using hydrogen
Thermal Conductivity Detector
Using hydrogen
Warning
When using hydrogen (H2) as a carrier gas or fuel gas, be aware that hydrogen gas can
flow into the oven and create an explosion hazard. Therefore, be sure that the supply is
off until all connections are made and ensure that the inlet and detector column fittings
are either connected to a column or capped at all times when hydrogen gas is supplied
to the instrument.
Warning
Hydrogen is flammable. Leaks, when confined in an enclosed space, may
create a fire or explosion hazard. In any application using hydrogen, leak test all connections, lines, and valves before operating the instrument. Always turn off the hydrogen supply at its source before working on the instrument.
Operation conditions
The detector will not work if the:
•
filament is broken or shorted
•
reference gas flow is set less than 5 mL/min
TCD parameters
Use the same gas for the reference gas, makeup gas, and carrier gas. Configure your
inlet and detector accordingly. Refer to Table 19 for maximum gas flow.
Use Table 18 to select temperatures and flows for the TCD. Use Figure 16 and Figure
17 to find minimum source pressures.
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Thermal Conductivity Detector
TCD parameters
Table 18.
Recommended Flow Rates and Temperatures
Gas type
Flow range
Carrier gas
(hydrogen, helium, nitrogen)
Packed column: 10–60 mL/min
Capillary column: 1–5 mL/min
Reference
(same gas type as carrier)
15–60 mL/min
See Figure 16 to select a value
Capillary makeup
(same gas type as carrier)
Packed column: 2–3 mL/min
Capillary column: 5–15 mL/min
Detector temperature
If <150°C, you cannot turn the filament on.
Detector temperature should be 30°C to 50°C greater than highest oven ramp
temperature.
Table 19.
Gas
Maximum Gas Flows
Maximum flow, mL/min
Reference
gas
Makeup gas
Nitrogen
100
12
Helium
100
12
Hydrogen
100
12
Argon
100
12
Use Figure 16 to select a value for reference gas flow rate for capillary and packed
columns. Any ratio within ±0.25 of that in the graph is suitable. For example, for a
combined column and makeup gas flow of 30 mL/min, your reference gas flow rate
should be 1.5 to 2.0 times greater, or 45 to 60 mL/min.
When using packed columns, we recommend a small makeup gas flow (2 to 3 mL/
min) to get the best peak shapes.
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Ratio of Reference Flow
to Column + Makeup Flow
Thermal Conductivity Detector
TCD parameters
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
10
20
30
40
50
Column + Makeup Flow, mL/min
60
Figure 16. Selecting the reference gas flow
70
60
Hydrogen
Helium
50
Reference
40
gas flow
(mL/min)
30
Nitrogen
20
10
0
Pressure (psig)
(kPa)
20
138
30
207
50
345
60
414
70
483
Hydrogen
12
Makeup
gas flow
(mL/min)
40
276
10
9
Helium
6
4
2
0
Pressure(psig)
(kPa)
20
138
30
207
40
276
50
345
60
414
* Pressures include an allowance for the pressure drop in the pneumatics m
Figure 17. Typical source pressure/flow relationships, makeup and
reference gases at 25°C and 1 atmosphere pressure
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Thermal Conductivity Detector
Makeup gas
Makeup gas
Makeup gas enters the detector near the end of the column. It speeds the
sample through so that the separation achieved by the column is not lost by remixing
in the detector. Makeup gas is not required with packed columns.
If the capillary column is not configured, the makeup flow is constant. See Configuring the column on page 38 for how to configure a column.
If the capillary column is configured, you have a choice of two makeup gas modes.
To select the makeup gas mode
The Constant Makeup mode gives a constant flow of makeup gas to the detector.
The Constant Combo mode gives a variable flow of makeup gas to the detector.
As column flow changes, the makeup flow adjusts to provide a constant combined
flow to the detector.
Display this screen.
Status / Settings / Detector / More / Makeup Mode / Enter
Select a makeup mode and press OK.
Status / Settings / Detector
Makeup gas flow
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Thermal Conductivity Detector
Polarity
To set the makeup gas flow
The detector screen now reflects your makeup gas mode choice. Enter either the Constant Makeup flow or the Constant Combo flow.
Polarity
Attempts to analyze for helium and hydrogen using nitrogen or argon carrier gas give
negative peaks. While some GC systems can integrate negative peaks, a better solution is to invert that region of the signal and process the resulting positive peaks.
Signal inversion is usually done using Run Table entries (see Run Table on page 58),
but can be done manually as shown here.
To invert the detector signal
1.
Display this screen.
Status / Settings / Detector / More / Polarity
2.
Press Enter to display the next screen.
Status / Settings / Detector / More / Polarity / Enter
3.
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Select normal or inverted Signal.
6850 Series Control Module User Information
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Thermal Conductivity Detector
Signal selection
Analyzing for hydrogen
Hydrogen is the only element with thermal conductivity greater than helium, and
small amounts of hydrogen (<20%) in helium at moderate temperatures have thermal
conductivities less than either component alone. If you are using helium carrier gas, a
hydrogen peak may appear as positive, negative, or as a split peak.
There are two solutions to this problem:
•
Use nitrogen or argon as carrier gas. This eliminates problems inherent with
using helium as carrier, but reduces sensitivity to components other than hydrogen.
•
Operate the detector at higher temperatures—from 200°C to 300°C
To find a suitable detector operating temperature, analyze a known range of hydrogen
concentrations, raising the detector temperature until the hydrogen peak shows normal
shape and is always in the same direction (negative relative to response to air or propane) for all concentrations.
Since hydrogen peaks are negative, you must use signal inversion at appropriate times
during the analysis.
Signal selection
Several types of signals can be selected as the signal output. The selected
signal type is available as the SIG connector on the rear panel for processing by an
integrator, strip chart recorder, or other external device. The selected signal is also
digitally output through the RS-232 connector and optional LAN communications
card.
To select the output signal
1.
Display this screen.
Status / Settings / Detector / More / Signal
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Thermal Conductivity Detector
Signal selection
2.
Press Enter to display the next screen.
Status / Settings / Detector / More / Signal / Enter
3.
Select one of the four signals in the list.
•
Detector—the raw signal produced by the detector.
•
Column Comp—the stored column compensation profile for this detector.
•
Detector - Column Comp—the result of subtracting the column compensation profile from the detector signal.
•
Test Chromatogram—stored in the instrument. It provides a reproducible
signal to test external signal processing equipment.
The signal type can be changed to other types by the ChemStation or
Cerity Chemical.
To zero the signal
•
Enter a value in the Zero field. The value is subtracted from all future
signal values.
OR
•
Leave the Zero field blank, then press the Zero key. The GC saves the present
value of the signal and subtracts it from all future signal values.
The peak width (PW) window
This window displays the optimal peak width for the displayed digital signal data rate.
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Thermal Conductivity Detector
Analog output
Analog output
To scale a signal to fit on a strip chart recorder:
1.
Display this screen.
Status / Settings / Detector / More / Analog Output
2.
Press Enter to display the next screen.
Status / Settings / Detector / More / Analog Output / Enter
3.
Enter appropriate values for your output signal. Both Range and Attenuation are
binary (powers of 2) scalers. A change of 1 unit in either direction alters the signal by a factor of 2.
•
Range scales the signal available through the three analog outputs.
•
Attenuation scales only the 0–1 mV output.
Fast Peaks is not available for use with TCD.
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Thermal Conductivity Detector
Using the TCD
Using the TCD
Display this screen.
Status / Settings / Detector
1.
Set the detector temp (see Recommended Flow Rates and Temperatures on
page 126). Avoid temperatures above the column limit because part of the column extends into the detector block.
2.
Enter a value for the Reference gas flow (see Figure 16 for selecting the reference gas flow).
3.
Verify that the makeup gas type is the same as that plumbed to your
instrument
•
If your capillary column is not configured, enter a constant makeup gas flow rate
•
If your capillary column is configured, select a makeup mode and flow rate (see
Makeup gas on page 128)
•
If you are using a packed column, either turn off the makeup gas or set a
small flow rate of 2–3 mL/min.
4.
Turn the filament on. Allow about 30 minutes for thermal stabilization.
5.
If necessary, use signal inversion (see Polarity on page 129) to invert
negative-going peaks. When a sample contains components giving both positiveand negative-going peaks, use Run Table events to switch
signal inversion on and off during the run.
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Flame Ionization Detector
Using hydrogen
Flame Ionization Detector
Using hydrogen
Warning
When using hydrogen (H2) as a carrier gas or fuel gas, be aware that hydrogen gas can
flow into the oven and create an explosion hazard. Therefore, be sure that the supply is
off until all connections are made and ensure that the inlet and detector column fittings
are either connected to a column or capped at all times when hydrogen gas is supplied
to the instrument.
Warning
Hydrogen is flammable. Leaks, when confined in an enclosed space, may
create a fire or explosion hazard. In any application using hydrogen, leak test all connections, lines, and valves before operating the instrument. Always turn off the hydrogen supply at its source before working on the instrument.
Detector Operation Notes
The detector will not work if:
•
Air or hydrogen flow is set at Off or set at 0.0
•
The flame won’t light.
Detector Shutdown
If the GC shuts a detector gas down due to a pneumatics or ignition failure, it also
turns off all detector functions except the heater and the makeup gas flow.
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Flame Ionization Detector
Jets
Jets
Your detector is shipped with a capillary column jet. If you are doing simulated distillation or high-temperature runs, or are using a packed column, you must change the
jet. Refer to Table 20.
Table 20.
Jets for the FID
Jet type
Part no.
Jet tip id
Capillary
19244-80560
0.29 mm
(0.011-inch)
Packed
18710-20119
0.47 mm
(0.018 in.)
Packed wide-bore
(use with high-bleed applications)
18789-80070
0.030 in.
High-temperature
(use with simulated distillation)
19244-80620
0.47 mm
(0.018-inch)
Electrometer
The electrometer amplifies the current produced when the sample burns. You do not
need to turn the electrometer on and off when operating your FID. The only time you
need to turn off the electrometer is when cleaning the detector. Otherwise, leave it on.
Caution
Do not turn off the electrometer during a run. It will cancel detector output.
To turn the electrometer on or off
1.
Display this screen.
Status / Settings / Detector / More / Electrometer / Enter
2.
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Turn the electrometer ON or OFF using the arrow keys. Press OK.
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Flame Ionization Detector
Makeup gas
Makeup gas
Makeup gas enters the detector near the end of the column. It speeds the
sample through so that the separation achieved by the column is not lost by remixing
in the detector.
Makeup gas mode
If the column is not configured, the makeup flow is constant (see Configuring the column on page 38 for how to configure a column).
If the column is configured, you have a choice of two makeup gas modes.
•
The Const Makeup mode gives a constant flow of makeup gas to the detector.
•
The Constant Combo mode provides a variable flow of makeup gas to the
detector. As column flow changes, the makeup flow adjusts to provide a constant
combined flow to the detector.
To select a makeup gas mode
1.
Display this screen.
Status / Settings / Detector / More / Makeup Mode / Enter
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Flame Ionization Detector
Signal selection
2.
Select either Constant Makeup or Constant Combo. Press OK to return to
the FID screen.
Status / Settings / Detector
Flow Value
3.
Enter the flow value and press enter.
4.
Press Esc to return to the previous screen.
To set the makeup gas flow
The detector screen now reflects your makeup gas mode choice. Enter either the Constant Makeup flow or the Constant Combo flow.
Signal selection
Several types of signals can be selected as the signal output. The selected signal type
is available as the SIG connector on the rear panel for processing by an integrator,
strip chart recorder, or other external device. The selected signal is also digitally
output through the RS-232 connector and optional LAN
communications card.
To select the output signal
1.
Display this screen.
Status / Settings / Detector / More / Signal / Enter
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Flame Ionization Detector
Signal selection
2.
Select one of the four signals in the list.
•
Detector—the signal produced by the detector.
•
Column Comp—the stored column compensation profile (see
Column compensation on page 154).
•
Detector - Column Comp—the result of subtracting the column compensation profile from the detector signal.
•
Test Chromatogram—stored in the instrument. It provides a reproducible
signal to test external signal processing equipment.
Signal type can be changed to other types by the ChemStation or Cerity Chemical.
3.
Press OK.
To zero the signal
•
Enter a value in the Zero field. The value is subtracted from all future
signal values. Then, press OK.
OR
•
Leave the Zero field blank, then press the Zero key. The GC saves the present
value of the signal and subtracts it from all future signal values. Then, press OK.
The Peak Width window
This window displays the digital signal data rate.
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Flame Ionization Detector
Analog output
Analog output
These controls scale a signal to fit on a strip chart recorder.
To adjust the output signal
1.
Display this screen.
Status / Settings / Detector / More / Analog Output / Enter
2.
Enter appropriate values for your output signal. Both Range and
Attenuation are binary (powers of 2) scalers. A change of 1 unit in either direction alters the signal by a factor of 2.
•
Range scales all three analog outputs
•
Attenuation scales only the 0–1 mV output
3.
Select the Fast Peaks feature, if desired. Fast Peaks allows detection of peaks as
narrow as 0.004 minutes, while the minimum width for the
standard speed is 0.01 minutes. To use the Fast Peaks feature, your
integrator must be fast enough (at least a 15 Hz bandwidth) to process the data coming
from the GC.
4.
Press OK.
Automatic reignition—Lit Offset
Lit Offset is the expected difference between the FID output with the flame lit
and the output with the flame off. If the output falls below this value, the FID assumes
that the flame is out and tries to reignite several times. If the output does not increase
by at least the Lit Offset, the detector shuts down all functions except temperature and makeup gas flow.
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Flame Ionization Detector
FID parameters
The default setting for Lit Offset is 2.0 picoamps. This value is good for all but
very clean gases and systems. You may want to change this setpoint if:
•
your detector is attempting to reignite when the flame is still on, thus
producing a shutdown
•
your detector is not trying to reignite when the flame is out
To adjust the Lit Offset
1.
Display this screen.
Status / Settings / Detector / More / Lit Offset / Enter
2.
Adjust the value as indicated by the discussion above. If you enter zero, the box’s
contents change to Off. Press OK.
FID parameters
Use the information in Table 21 when selecting flows. Select a minimum source pressure from Figure 18.
Table 21.
Recommended Flows
Gas type
Flow range
mL/min
Carrier gas
(hydrogen, helium, nitrogen)
Capillary columns: 1 to
5
Packed columns: 10 to
60
Suggested flow
mL/min
Detector gases
Hydrogen
24 to 60*
40
Air
200 to 600*
450
Column plus capillary makeup
Recommended: nitrogen
Alternate: helium
10 to 60
50
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Flame Ionization Detector
FID parameters
* The hydrogen-to-air ratio should be between 8% and 12% to keep the flame lit.
80
70
Hydrogen
60
Helium
50
FLOW
(mL/min)40
Nitrogen
30
20
10
0
Pressure(psig)
kPa
20
138
30
207
40
276
50
345
60
414
70
483
80
552
70
483
80
552
700
600
500
400
FLOW
(mL/min) 300
Air
200
100
0
Pressure (psig)
kPa
20
138
30
207
40
276
50
345
60
414
* Pressures include an allowance for the pressure drop in the pneumatics manifold.
Figure 18. Typical source pressure/flow relationships for FID gases at 25°C and
1 atmosphere pressure
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Flame Ionization Detector
Using the FID
Using the FID
Warning
Verify that a column is installed or the FID column fitting is plugged before turning
on the air or hydrogen. An explosion may occur if air and hydrogen are allowed to
leak into the oven.
1.
Display this screen.
Status / Settings / Detector
Makeup gas mode
Makeup gas type
Detector
temperature
Hydrogen flow rate Air flow rate
Makeup gas flow rate
2.
Set the detector temperature. The temperature must be greater than 150°C for the
flame to light and should be approximately 20°C higher than the highest oven
temperature.
3.
Enter values for the hydrogen and air flow rates.
4.
Verify that the makeup gas type is the same as that plumbed to your
instrument.
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•
If your capillary column is not configured, enter a makeup gas flow. Only constant flow is available in this case. See Configuring the column on page 38 for
how to configure a column.
•
If your capillary column is configured, press More, select Makeup Mode, and
press Enter to display the next screen.
•
If you are using a packed column, turn the makeup gas flow off.
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Flame Ionization Detector
Using the FID
Status / Settings / Detector / More / Makeup Mode / Enter
5.
Select a makeup mode. Press OK to return to the previous screen. Enter the
makeup or combo flow rate.
6.
Press the Flame key to turn on the air and hydrogen and initiate the ignition process. The signal typically increases to 5 to 20 pA after ignition.
Verify that the flame is lit by holding a cold, shiny surface, such as a mirror or
chrome-plated wrench, over the collector exit. Steady condensation indicates that
the flame is lit.
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The Microcell Electron Capture Detector
Linearity
The Microcell Electron Capture
Detector
General Information
Anode gas
Detector
Vent
restrictor
Filter
frit
Pressure
control loop
Proportional
valve
PS
Pressure
sensor
Makeup gas
restrictor
Column
Figure 19. μECD pneumatics
Linearity
The μECD response factor versus concentration curve is linear for four orders of magnitude or more (linear dynamic range = 104 or higher) for a broad range of compounds. You should still run a calibration curve on your samples to find the limits of
the linear range for your materials.
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The Microcell Electron Capture Detector
Detector gas
Detector gas
The μECD operates with either nitrogen or argon/methane as the makeup and anode
gas.
Because of the high detector sensitivity, carrier and makeup gas must be dry and oxygen-free. Moisture, chemical, and oxygen traps in good condition should be installed
in carrier and makeup gas supply lines.
Temperature
To prevent peak tailing and to keep the cell clean, the detector temperature should be
set higher than the highest oven temperature used—the setpoint should be based on
the elution temperature of the last compound. If you
operate at excessively high temperatures, your results will not necessarily improve
and you may increase sample and column decomposition.
Electrometer
The detector configuration contains an on/off setpoint for the electrometer. Keep the
electrometer on all the time when operating your detector.
Analog Output
If you intend to use the analog output from the μECD, you must set the output Range
to 10, as follows:
1.
Display this screen.
Status / Settings / Detector / More / Analog Output / Enter
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The Microcell Electron Capture Detector
Operating the Detector
2.
Enter appropriate values for your output signal. Both Range and
Attenuation are binary (powers of 2) scalers. A change of 1 unit in either direction alters the signal by a factor of 2.
•
Range (value: 10) scales all three analog outputs
•
Attenuation scales only the 0–1 mV output
3.
Select the Fast Peaks feature, if desired. Fast Peaks allows detection of peaks as
narrow as 0.004 minutes, while the minimum width for the
standard speed is 0.01 minutes. To use the Fast Peaks feature, your
integrator must be fast enough (at least a 15 Hz bandwidth) to process the data coming
from the GC.
4.
Press OK.
Operating the Detector
Use the information in Table 1 when selecting temperatures and flows.
Maximum source pressure must not exceed 100 psi. Use the maximum source pressure to achieve maximum makeup flow rate.
Table 1.
Operating Parameters
Gas
Recommended flow range
Carrier gas
Packed columns
(nitrogen or argonmethane)
Capillary columns
(hydrogen, nitrogen,
or argon-methane)
Capillary makeup
(nitrogen or argonmethane)
30 to 60 mL/min
0.1 to 20 mL/min,
depending on diameter
10 to 150 mL/min
(30 to 60 mL/min typical
Temperature
250°C to 400°C
Typically set Detector Temperature 25°C greater than the
highest oven ramp temperature.
Notes
•
If the carrier gas type is different from the makeup gas type, the makeup gas flow
rate must be at least three times the carrier gas flow rate.
•
μECD sensitivity can be increased by reducing the makeup gas flow rate.
•
μECD chromatographic speed (for fast peaks) can be increased by increasing the
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The Microcell Electron Capture Detector
Operating the Detector
makeup gas flow rate.
Verify that your detector gases are connected, a column is properly installed, and the
system is free of leaks. Set the oven temperature and the inlet
temperature and flow. Make sure your carrier gas type is the same as that plumbed to
your GC.
1.
Display this screen.
Status / Settings / Detector
Detector
Temperature
Makeup Gas Flow Makeup Gas Type
2.
Caution
Set the detector temperature. To keep the μECD cell clean, this temperature must
be higher than the oven temperature.
Detector electronics depend on the correct gas configuration.
3.
Verify that the makeup gas type is the same as that plumbed to your
instrument. Change the gas type, if necessary.
4.
Enter a value for the makeup gas.
If you are using packed columns, turn off the makeup gas.
If your capillary column is configured, select a new flow mode, if desired, and set the
makeup or combined gas flow.
If your capillary column is not configured, only constant makeup flow is
available. Enter a makeup gas flow.
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Column Oven
Oven capabilities
Column Oven
Oven capabilities
•
Temperature range 5°C above ambient to 350°C
With CO2 cryo: –20°C to 350°C
•
Temperature programming - up to six ramps with seven plateaus
•
Maximum run time - 999.99 minutes
•
Temperature ramp rates - 0 to 120°C/min
•
The oven accommodates one inlet, one detector, and one column.
Oven safety
Manual shutdown
Raising the oven lid turns off power to the oven heater, fan, and cryogenic valve (if
installed) but maintains the setpoints in memory. Closing the oven lid returns the oven
to normal operation.
Automatic shutdown
If the oven cannot attain or maintain an entered setpoint temperature during normal
operation, the GC turns the oven fan and heater off, flashes the
shutdown announcement on the Status screen, and displays a message.
Possible problems include:
•
The oven vent flaps are not working
•
The oven fan, heater, or temperature sensor is not working properly
•
There is an electronic problem
When an automatic shutdown occurs, the oven remains off until it is reset using the
Control Module (Status / Settings / Oven). You may need to turn the instrument
power off, then on again.
The oven also automatically shuts down when the lid is opened.
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Column Oven
Oven setup
Oven setup
To configure the oven:
1.
Display this screen.
Status / Setup / Oven Setup
2.
3.
Caution
Enter values for Equib Time and Max Temp.
•
Equib Time—When the oven temperature reaches ± 1°C of setpoint. The
GC waits for the time specified before declaring the oven ready.
•
Max Temp—The oven temperature limit. Most columns and many accessories have specific temperature limits. When configuring Max Temp, these
limits should be considered to prevent damage.
If a cryogenic valve is installed and you wish to use it, select Enable Oven
Cryo. Enter values for Cryo ambient temp and
Cryo Timeout.
If you are using cryogenic oven cooling, the flanged column hanger must be used to
avoid column cold spots.
When cryogenic cooling is not needed or cryogenic coolant is not
available, do not select this item. If this is not done, proper oven temperature control may not be possible, particularly at temperatures near ambient.
•
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Cryo ambient temp—The temperature in the laboratory. This setpoint determines
the temperature at which cryogenic cooling begins. For regular cryo operation, the
temperature is Cryo ambient temp + 25°C. For Quick Cryo Cool,
the temperature is Cryo ambient temp +45°C.
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Column Oven
Creating an isothermal run
•
4.
Cryo Timeout—Timeout occurs, and the oven shuts off, when a run does not
start within a specified time (10 to 120 minutes) after the oven equilibrates.
Turning Cryo Timeout off disables this feature. We recommend that it
be turned on to conserve coolant at the end of a method or if automation
fails.
If available, enable or disable Cryo Fault and Quick Cryo Cool.
•
Cryo Fault—Shuts the oven down if it does not reach (stabilization will
take longer) setpoint temperature after 16 minutes of continuous cryo operation
•
Quick Cryo Cool—This feature is separate from Enable Oven Cryo.
Quick Cryo Cool makes the oven cool faster after a run. This feature is useful when maximum sample throughput is necessary; however, it uses more coolant.
Quick Cryo Cool turns off soon after the oven reaches its setpoint and
Enable Oven Cryo takes over, if needed.
Creating an isothermal run
An isothermal run is one in which the oven is maintained at a constant temperature. To
create an isothermal run, set the programming rate (°C/min) to zero.
To set up an isothermal oven program
Display this screen.
Status / Settings
Isothermal temperature
Rate
Isothermal time
1.
Enter the oven temperature for the run in the isothermal temperature field (°C).
Press Enter.
2.
In the Isothermal time (min) field, enter the number of minutes that you want the
oven to stay at this temperature. This time is the duration of the run (maximum
999.99 minutes). Press Enter.
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Column Oven
Temperature programming
3.
Set the Rate (°C/min) to 0.00. Press Enter. This completes the
isothermal run setup.
4.
Enter a Post-Run temperature and time if you want to flush remaining high-boiling components out of the column.
Temperature programming
You can program the oven temperature from an initial temperature to a final temperature using up to six ramps during a run.
Total length of a run is determined by its oven temperature program. The
maximum allowable time for a run is 999.99 minutes. If the program is still
running at that time, the run terminates.
The highest temperature programming rate that you can achieve depends on many factors, including the room temperature, temperatures of the inlet and detector, the
amount of material inside the oven (columns, valves, etc.), and whether or not this is
the first run of the day. Typical values are in Table 22.
Table 22.
Oven Ramp Rates*
Temperature range
(°C)
Maximum-ramp rates (°C/
min)
50 to 75
120
75 to 115
95
115 to 175
65
175 to 300
45
300 to 350
35
* These rates are for the standard GC. For the fast GC, maximum ramp rates are approximately
three times faster.
If cryogenic oven cooling is installed, the higher ramp rates may not be
possible.
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Column Oven
Temperature programming
Single-ramp temperature program
A single-ramp temperature program (see Figure 20) changes the oven
temperature from an initial value to a final value at a specified rate and holds at the
final temperature for a specified period of time.
Final temp
Final time
Rate
Initial temp
Isothermal hold
Figure 20. Single ramp
To create a single-ramp program
The example on the following screen begins at 50°C, holds that temperature for 2 minutes, then increases temperature to 150°C at a rate of 10°C/min and stays there for
5 min.
1.
Display this screen.
Status / Settings / Oven
Initial temperature
Rate
Initial time
Final temperature
Final time
Post run temperature
Post run time
2.
Enter the starting conditions—Initial temperature (50°C) and Initial time (2
min).
3.
Enter the rate (10°C/min) at which the oven temperature is to increase.
4.
Enter the Final temperature and Final time (150°C for 5 min).
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Column Oven
Temperature programming
5.
If you wish to clean out the column before cooling to the starting
temperature, enter Post Run temperature and Post Run time.
6.
If you are certain that the most recent program used a single ramp, you can skip
the remaining steps. If you are not sure, continue by pressing Ramps.
Status / Settings / Oven / Ramps
7.
Select Ramp 2 and press Enter.
Status / Settings / Oven / Ramps / Ramp 2
8.
To ensure that the program is single-ramp, set the °C/min value to OFF
(0°C), then press OK. The program ends when it encounters a rate of OFF.
Creating multiple-ramp temperature programs
A multiple-ramp temperature program (see Figure 21) changes the oven
temperature from an initial value to a final temperature, but with various rates, times,
and temperatures in between. Multiple ramps can be programmed for temperature
decreases as well as increases.
Final temp 2
Final time 2
Rate 2
Final temp 1
Final time 1
Rate 1
Temp
Isothermal hold
Figure 21. Multiple ramp
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Column Oven
Column compensation
To create a multiple-ramp program
The example from the previous section begins at 50°C, holds that temperature for 2
min, then increases temperature to 150°C at a rate of 10°C/min and stays at 150°C for
5 min. It then continues with a second ramp in this section by
rising at 4°C/min to 200°C and holds for 2 min.
1.
Set up the first oven ramp as described on the preceding page.
2.
When setting up Ramp 2, enter 4 in the °C/min field, 200 in the °C field, and 2
in the min field.
Status / Settings / Oven / Ramps / Ramp 2
3.
Press OK to return to the previous screen
4.
If you are certain that the most recent program used only two ramps, you can skip
the remaining steps. If you’re not sure, continue by pressing Ramps. Select
Ramp 3 and press Enter.
5.
Set the °C/min value to OFF, then press OK. The program ends when it encounters a rate of OFF.
6.
Add more ramps, up to a maximum of six, in the same way.
Column compensation
Although temperature programming improves peak shapes, it also causes a
rising baseline that may make integration difficult. This is usually not a
problem with a thermal conductivity detector because of its low sensitivity, but it can
be a severe problem with a flame ionization detector.
Column compensation corrects for baseline rise by storing a profile of a blank run—
one made with no sample injection. This profile is subtracted from
subsequent sample runs to eliminate the rising baseline. Figure 22 illustrates the concept.
All conditions must be identical in the compensation run and the real run: same detector and column, same temperature and gas flow conditions.
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Column Oven
Column compensation
Chromatogram
with a rising
baseline
Chromatogram
with column
compensation
Blank column
compensation run
Figure 22. Column compensation
To create a column compensation profile
1.
Display this screen.
Status / Setup
2.
Load the method for which the blank run profile is to be created. Press COMP.
The GC will wait until it has equilibrated, make one blank run (no sample injected),
and store the data as the column compensation profile.
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Column Oven
Column compensation
To apply the column compensation profile
Display this screen. It will vary based on the detector you have.
Status / Settings / Detector / More / Signal / Enter
1.
Select Detector - Column Comp and press OK.
2.
The output signal is now the detector output minus the stored column compensation profile.
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The Flame Photometric Detector (FPD)
Using hydrogen
The Flame Photometric Detector (FPD)
Using hydrogen
Warning
When using hydrogen (H2) as a carrier gas or fuel gas, be aware that hydrogen gas can
flow into the oven and create an explosion hazard. Therefore, be sure that the supply is
off until all connections are made and ensure that the inlet and detector column fittings
are either connected to a column or capped at all times when hydrogen gas is supplied
to the instrument.
Warning
Hydrogen is flammable. Leaks, when confined in an enclosed space, may
create a fire or explosion hazard. In any application using hydrogen, leak test all connections, lines, and valves before operating the instrument. Always turn off the hydrogen supply at its source before working on the instrument.
General Information
The sample burns in a hydrogen-rich flame, where some species are reduced and
excited. The gas flow moves the excited species to a cooler emission zone above the
flame where they decay and emit light. A narrow bandpass filter selects light unique to
one species, while a shield prevents intense carbon
emission from reaching the photomultiplier tube (PMT).
The light strikes a photosensitive surface in the PMT where a light photon knocks
loose an electron. The electron is amplified inside the PMT for an
overall gain of up to a million.
The current from the PMT is amplified and digitized by the FPD electronics board.
The signal is available either as a digital signal on the communications output or as a
voltage signal on the analog output.
The FPD should not be stored at temperatures above 50°C, based on the
original manufacturer’s specifications for the PMT.
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The Flame Photometric Detector (FPD)
Using lit offset
Linearity
Several mechanisms produce sulfur emission. The excited species is diatomic, so that
emission intensity is approximately proportional to the square of the sulfur atom concentration.
The excited species in the phosphorus mode is monatomic, leading to a linear relationship between emission intensity and atom concentration.
Filter ProportionalPressure
valves sensors Restrictors
frits
Air
Vent
Emission zone
PMT
Shield
Wavelength
filter
H2
Window
Makeup
Figure 23. Schematic of a flame photometric detector
Using lit offset
Lit offset is the expected difference between the FPD output with the flame lit and the
output with the flame off. It is used to determine whether an attempted ignition has
succeeded and to detect a flame-out condition.
If the output with the flame on minus the output with the flame off is greater than Lit
offset, the flame is considered lit.
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The Flame Photometric Detector (FPD)
Igniting the flame
The default setting for Lit offset is 2.0 picoamps. This is a good working value
for all but very clean gases and systems. You may want to change this
setpoint if:
•
Your detector is attempting to reignite when the flame is still on, thus
producing a shutdown.
•
Your detector is not trying to reignite when the flame is out.
Changing the lit offset setpoint
1.
Press More and select Lit Offset.
2.
Enter a number. The default is 2.0 pA. Enter 0 to disable the automatic reignite
function. The setpoint range is 0 to 99.9 pA.
3.
Press OK.
Igniting the flame
When either of the flame ignition methods on the next page is used, the FPD automatically performs this sequence:
1.
Turns all detector gases—air, hydrogen, makeup—off. Carrier remains on.
2.
Sets air flow to 200 mL/min.
3.
Turns the glow plug ignitor on.
4.
Ramps the hydrogen flow from 10 to 70 mL/min.
5.
Resets the air flow to the air flow setpoint.
6.
Resets the hydrogen flow to the hydrogen flow setpoint.
7.
Turns the makeup gas on.
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The Flame Photometric Detector (FPD)
Using the electrometer
8.
Compares the signal change with the lit offset value. If the change is
greater than lit offset, declares the flame on (lit). If it is less, declares the
flame off (not lit).
For this process to work, there must be enough air pressure to the pneumatics module
to provide 200 mL/min flow. We recommend a supply pressure of
90 psi.
Manual ignition
To start the flame ignition sequence, display this screen and press Flame.
Status / Settings / Detector
Flame on/o
Automatic ignition
If the FPD output with the flame on falls below the flame-off output plus the lit offset
value, this is interpreted as a flame-out condition. The FPD runs the flame ignition
sequence to relight the flame. If this fails, it runs the sequence again. If the second
attempt also fails, the detector shuts down all functions except temperature and
makeup gas flow.
Using the electrometer
The Configure Detector contains an electrometer on/off setpoint. It is not
necessary to turn the electrometer on or off unless you are performing a
maintenance procedure.
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The Flame Photometric Detector (FPD)
Signal selection
Table 23.
Caution
Electrometer settings
Settin
g
Description
On
High voltage and signal processing circuits are on. If the photomultiplier tube
is exposed to room light with the electrometer on, the tube will be
destroyed.
Off
High voltage and signal processing circuits are off. In this condition, it is safe
to expose the photomultiplier tube to room light.
Always turn the electrometer off before removing the PMT housing to avoid destroying the tube.
Signal selection
Several types of signals can be selected as the signal output. The selected signal type
is available as the SIG connector on the rear panel for processing by an integrator,
strip chart recorder, or other external device. The selected signal is also digitally
output through the RS-232 connector and optional LAN
communications card.
To select the output signal
1.
Display this screen.
Status / Settings / Detector / More / Signal / Enter
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The Flame Photometric Detector (FPD)
Signal selection
2.
3.
Select one of the five signal options in the list.
•
Detector—the signal produced by the detector.
•
Column Comp—the stored column compensation profile (see
Column compensation on page 154).
•
Detector - Column Comp—the result of subtracting the column compensation profile from the detector signal.
•
Test Chromatogram—stored in the instrument. It provides a
reproducible signal to test external signal processing equipment.
•
Other—ChemStation or Cerity Chemical sets the signal.
Press OK.
To zero the signal
•
Enter a value in the Zero field. The value is subtracted from all future
signal values. Then, press OK.
OR
•
Leave the Zero field blank, then press the Zero key. The GC saves the present
value of the signal and subtracts it from all future signal values. Then, press OK.
The Peak Width window
This window displays the digital signal data rate.
Data rates
Analog output for the FPD can be presented at either of two speeds. The faster speed
allows minimum peak widths of 0.004 minutes, while the standard speed allows peak
widths of 0.01 minutes.
Using fast peaks
If you are using the fast peaks feature, your integrator must be fast enough to process
the data coming from the GC. It is recommended that your integrator bandwidth be at
least 15 Hz.
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The Flame Photometric Detector (FPD)
Selecting the makeup gas mode
To use fast peaks:
1.
Press More and select Analog output.
2.
Select Fast Peaks.
The fast peaks feature does not apply to digital output.
Selecting the makeup gas mode
The Constant Makeup mode gives a constant flow of makeup gas to the detector.
The Constant Combo mode gives a variable flow of makeup gas to the
detector. As column flow changes, the makeup flow adjusts to provide a
constant combined flow to the detector.
1.
Display this screen.
Status / Settings / Detector / More / Makeup Mode / Enter
2.
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Select a makeup mode and press OK.
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The Flame Photometric Detector (FPD)
Heater configuration
Using the Detector
Heater configuration
The FPD burner module has a heated zone for the detector body.
FPD Parameters
Table 24 gives the flows for the maximum sensitivity FPD flame, which is
hydrogen-rich and oxygen-poor. It is difficult to light the flame with these flows, particularly in the sulfur mode. Helium, used as carrier or makeup gas, may cool the
detector gases below the ignition temperature. We recommend using nitrogen rather
than helium.
Table 24.
Recommended Temperature and Flow
Sulfur mode flows
mL/min
Phosphorus mode
flows
mL/min
Carrier (hydrogen, helium, nitrogen, argon)
Packed columns
10 to 60
10 to 60
Capillary columns
1 to 5
1 to 5
Hydrogen
50
150
Air
60
110
Carrier + makeup
60
60
Detector gases
Supply pressure
Air supply pressure: at least 90 psi for the ignition sequence. All others: adequate to achieve
desired flows.
Detector temperature
Below 120°C, flame will not light.
Set temperature about 25°C higher than highest oven temperature—limit is 250°C.
Lit offset
If the detector output (with the flame on) minus the output (with the flame off) falls below
this value, the FPD attempts to re-ignite twice. If output does not increase by at least this
much, the detector shuts down.
The recommended setting is 2.0 pA. A setting of 0 or Off disables autoignition.
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The Flame Photometric Detector (FPD)
Using the FPD
If the flame will not light with the sulfur mode flows shown, change to the phosphorus
mode values. After the flame lights, gradually reduce the flows toward the sulfur
mode values. Some experimentation will be required to find flows for your particular
detector.
Using the FPD
Verify that all detector gases are connected, a column is installed, and the
system is free of leaks. Check the oven temperature, inlet temperature, and
column flow.
Warning
Verify that a column is installed or the FPD column fitting is plugged before turning
on the air or hydrogen. An explosion may occur if air and hydrogen are allowed to
leak into the oven.
1.
Display the following screen.
Status / Settings / Detector
Detectortemperature
Hydrogenflow rate
Airflow rate
Flame on/off
Use for capillary columns only.
(Turn off for packed columns.)
Displays output value.
Makeup gas type
2.
Set the detector temperature. The temperature must be greater than 120°C for the
flame to light.
3.
Enter the hydrogen flow rate.
4.
Enter the air flow rate.
5.
If you are using packed columns, turn off the makeup gas and proceed to step 8.
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The Flame Photometric Detector (FPD)
Using the FPD
6.
If you are using capillary columns:
a.
If your capillary column is configured, select a new flow mode, if desired,
and set the makeup gas flow or combined flow. See Selecting the makeup
gas mode on page 163.
b.
If your capillary column is not configured, enter a makeup gas flow. Only
constant flow is available.
c.
Verify that makeup gas type is the same as that plumbed to your instrument.
Change the gas type, if necessary.
7.
Press Flame. This turns on the air and hydrogen and initiates the ignition
sequence. On ignition, the signal increases. Typical levels are 4 to 40 pA in sulfur
mode, 10 to 70 pA in phosphorus mode. Verify that the flame is lit by holding a
cold, shiny surface, such as a mirror or chrome-plated wrench, over the vent exit.
Steady condensation indicates that the flame is lit.
8.
Press OK.
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Valves
Valve types
Valves
The 6850 Series Gas Chromatograph holds either one gas or one liquid
sampling valve in a heated valve box on top of the oven. A stream-selection valve (the
Multi Valve), mounted outside the GC, can be controlled.
Valves can be controlled:
•
Automatically, using a valve sequence (see To enter the valve parameters on
page 56)
•
Manually (see Controlling valves manually on page 171)
•
Using Run Table events. Mainly used with switching valves (see Valve events on
page 60)
•
Using Clock Table events. To perform analyses when you will not be present
(see Clock Table on page 63)
Valve types
There are four possible valve types:
•
Gas sample valve—a two-state (load and inject) valve. In the load state, an external gas stream (up to 300 psi) flows through an attached sampling loop and out to
waste. In the inject state, the filled sampling loop is inserted into the carrier gas
stream. Sample loops are available in various sizes.
•
Liquid sample valves—similar to the gas sample valve but with different physical
construction, they can handle liquefied gases at pressures up to 300 psi and are
available in 0.5-µL and 1-µL capacities.
•
Switching valves—used to backflush a column, to select a column, and other uses
depending on how it is plumbed.
•
Multiposition valve (Multi Valve)—provided by the user. A Multi Valve selects
one from a number of sample streams and feeds the selected stream to a sample
valve. See Multi Valve with Sample Valve on page 170 for an example of this
combination.
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Valves
Configuring valves
Configuring valves
To configure the GC for valves
1.
Display this screen:
Status / Setup / Automation
2.
Select the types for Valve 1 and Valve 2.
Sample valves
Plumbing
There are two ways to plumb a sample valve:
•
Inserted between an inlet flow module and the inlet. The sample flows through
the inlet to the head of the column.
•
Inserted between a purged packed inlet flow module and the head of the column
(a split/splitless inlet cannot be used). The sample bypasses the inlet.
With this arrangement and an unconfigured column, you can only set flow modes
for the column. Total flow setpoint and readings work as expected.
If the column is configured, the GC corrects column flow setpoints and readings
for the septum purge flow. With no inlet, that value is zero. The actual column
flow is 1 to 2 mL/min less than the setpoint in the flow modes. In the pressure
modes, the Total flow is the actual column flow.
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Valves
Sample valves
To configure a sample valve
1.
Display this screen.
Status / Setup / Automation / Sample Valve
2.
Enter the Load time in minutes.
3.
You may enter the Sample Loop Volume. This entry is for reference only; it
has no effect on the valve.
4.
Enter the Inject time in minutes.
5.
Press Esc to save the values and return to the previous screen.
Sample valve cycle
1.
The sampling valve changes to the Load state. Load min begins. Valve is not
ready.
Load state—The between-runs rest state. The loop is flushed with a stream of the
sample, either constantly by plumbing it directly or with a gas or liquid syringe.
The column is flushed with carrier gas.
2.
Load min ends. The valve becomes ready.
3.
If everything else is ready, the GC becomes ready.
4.
The user loads the sample loop (if there is no sample stream plumbed to the
valve) and presses Start.
5.
The sampling valve changes to the Inject state. Inject min begins. The run
begins.
Inject state—The activated state. The filled loop is inserted into the carrier gas
stream. The sample is flushed onto the column. The run starts
automatically. After Inject min ends, the valve changes back to Load.
6.
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Inject min ends. Return to step 1.
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Valves
Multi Valve with Sample Valve
Multi Valve with Sample Valve
If both a Sample Valve and a Multi Valve are configured, the GC assumes that they
will be used with the Multi Valve (Valve 2) feeding the Sample Valve (Valve 1).
Several manufacturers provide multiposition valves that can be driven by the 6850
GC. If a valve is configured as a Multi Valve and has a BCD position output connected to the GC, the valve position can be selected directly.
The GC reads the present position of the valve from the BCD input. If the desired
position is different, it cycles the driver (close contacts, open contacts) one time and
rechecks position. This repeats until the valve reaches the correct position. If the valve
does not move, takes too long to move, or does not report that it is in the correct final
position, an error will occur.
To configure a Multi Valve
1.
Display this screen.
Status / Setup / Automation / Multi Valve
2.
Enter a Switching Time in seconds. Viscous samples may require longer
times. The default time is 1.0 second.
3.
Select Normal or Invert BCD. Invert complements the BCD input—1’s
become 0’s and 0’s become 1’s. This accommodates coding convention
differences among valve manufacturers. The default value is Normal.
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Valves
Controlling valves manually
Controlling valves manually
When developing a valve-based method, it may be necessary to operate the valves
manually.
To move a valve manually
1.
Display this screen.
Status / Automation / Valves
This GC has a sample valve (Valve 1) and a multiposition valve (Valve 2).
2.
Select the valves to be controlled and the directions of the moves. Press ACTION
to make the changes. Press RESET to clear the screen without performing any
actions.
Sample valves and switching valves toggle between their two possible states. With a
multiposition valve, you can enter the desired position (1 to 16) in the Next field.
When ACTION is pressed, the valve will advance to that position if the BCD sensing
is connected—it is not in this example—and the external
driving circuitry is correct.
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Valves
Setting the valve box temperature
Setting the valve box temperature
The valve box contains a heated block with one valve mounting location. The temperature is controlled by the Auxiliary heater.
1.
Display this screen.
Status / Settings / Auxiliary
2.
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Enter the desired temperature (range is 10°C to 200°C). Press Esc to close the
screen.
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Service Mode
The Service Screen
Service Mode
The Service Screen
This screen displays the Run Log. This is a detailed list of errors that occurred during
the most recent run. It is cleared at the start of each run.
Status / Service
To enter the Service Mode
Press Service. This stores the active method in memory and loads the
SERVICE method.
To exit the Service Mode
Press EXIT Service. This loads the previously stored active method.
The Log Book
The GC maintains a Log Book of significant events that occurred. These events
include shutdowns, faults, firmware updates, and leak test results. To view the log
book, display this screen.
Status / Service / Log Book
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Service Mode
Diagnostics
Normally, the most recent 25 events are listed. You can also view the most recent 50,
100, or 250 events.
To save the entire logbook (up to 1024 entries) to a text file on a PC card, press Save
Logbook. (See also Using PC cards on page 31.)
Diagnostics
To view the diagnostic status
Display this screen.
Status / Service / Diagnostics
The detector test is only available if you are using an FID.
The atmospheric pressure shown is the value measured by the instrument and used in
all calculations.
Two Inlet Tests are available: the Leak Test and the Split Vent Test.
Leak Test (All inlets)
The Leak Test pressurizes the inlet and checks the pressure decay over time. The test
should be performed after routine inlet maintenance and under
normal operating conditions (temperature). If the inlet fails the test, check all fittings
for leaks.
The Leak Tests results are entered in the Log Book.
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Service Mode
Diagnostics
Table 25.
Leak Test Parts
Item
Part no.
1/8-inch brass nut
5180-4103
1/8-inch Vespel/graphite blank
ferrule
0100-1372
Column nut
5181-8830
Vespel/graphite blank ferrule
5020-8294
To run the Leak test:
1.
Display this screen. It may differ depending on the inlet you have.
Status / Service / Diagnostics / Inlet Test
2.
Press the Leak Test key.
3.
Remove the column, if one is installed. Plug the column fitting with a
column nut and a no-hole ferrule (for capillary columns) or with a Vespel® plug
(for packed columns). Press OK.
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Service Mode
Diagnostics
4.
Cap the septum purge vent with a 1/8-inch Swagelok® cap and press OK.
5.
After you cap the septum purge vent, the Inlet Leak Test screen appears (there
may be a slight delay):
When the GC reaches operating conditions, the test starts automatically. Normally, wait for the test to start. If you want to start the test without waiting for the
inlet to reach operating temperature, press Test Now.
If you select Yes, the test begins immediately. It will take approximately
5 minutes to complete.
6.
When completed, the test result is shown.
The possible test results are:
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Service Mode
Diagnostics
•
Passed—No leaks at operating temperature
•
Failed—Check for leaks at all fittings. Refer to the GC user
information for more information.
•
Override—The inlet passed the test, but the test was started using the Test
Now key before the inlet reached operating temperatures. The inlet is leak
free as tested, but may leak at operating temperatures.
7.
Reload the method from beginning of this procedure.
8.
Remove the caps, reinstall the column and configure it as needed, and reset the
pressure and low rate.
Split Vent Test (Split/Splitless and PTV inlets only)
The Split Vent Test checks the inlet liner and vent trap for restrictions. Over time, the
vent trap and inlet liner can become restricted with sample
condensation. If the inlet fails the test, the most likely causes are the vent trap, inlet
liner and the gold seal. See your Agilent 6850 User Information manual for further
details.
Split vent test results are entered in the Log Book.
Table 26.
Split Vent Test Parts
Item
Part no.
Column nut
5181-8830
Vespel/graphite blank ferrule
5020-8294
To run the Split Vent Test
1.
Display this screen.
Status / Service / Diagnostics / Inlet Test
2.
Press Split Vent Test.
3.
Follow the instructions on the screens.
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Service Mode
Diagnostics
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6850 Series Control Module User Information
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Service Mode
Diagnostics
4.
After you cap the septum purge vent, the Inlet Leak Test screen appears:
When the GC reaches operating conditions, the test starts automatically. Normally, wait for the test to start. If you want to start the test without waiting for the
inlet to reach operating temperature, press Test Now.
If you select Yes, the test begins immediately.
5.
When completed, the test result is shown.
The possible test results are:
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•
Passed—No leaks at operating temperature
•
Failed—Check for leaks at all fittings. Refer to the 6850 GC user
information for more information.
•
Override—The inlet passed the test, but the test was started using the Test
Now key before the inlet reached operating temperatures. The inlet is leak
free as tested, but may leak at operating temperatures.
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Service Mode
Diagnostics
Detector (Jet) Test
The FID jet test should be performed when the flame does not ignite or when it unexpectedly re-ignites during a run. The test checks for restrictions in the jet tip. If the jet
fails the test, replace or clean it. See your 6850 user information manual for further
details.
Jet test results are entered in the Log Book.
To be sure that the test results are valid, perform the test under operating
conditions.
Table 27.
Jet Test Parts
Item
Part no.
Column nut
5181-8830
Vespel/graphite blank ferrule
5020-8294
To run the detector test
1.
Display this screen.
Status / Service / Diagnostics / Detector Test
2.
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Press Jet Test and follow the instructions on the screen.
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Service Mode
Diagnostics
3.
After you cap the detector column fitting, the FID Jet Test screen appears:
When the GC reaches operating conditions, the test starts automatically. Normally, wait for the test to start. If you want to start the test without waiting for the
detector to reach operating conditions, press Test Now, then select Yes to
begin the test immediately.
4.
When completed, the test result is shown.
The possible test results are:
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•
Passed—The jet is sufficiently clear or restrictions
•
Failed—Clean or replace the jet
•
Override—The jet passed the test, but the test was started using the Test
Now key before the detector reached operating temperatures. The jet may
be acceptable as tested, but may still be restricted at
operating temperatures.
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Service Mode
Calibration
Keyboard Test
1.
Display this screen.
Status / Service / Keyboard Test
2.
Press each key on the Control Module. Its screen image should turn gray.
Calibration
To view the calibration status
Display this screen. The dates of custom calibrations, which overrule the
original factory calibrations, are shown.
Status / Service / Calibration
To restore the factory calibration(s)
On the above screen, select the item(s) and press Enter.
Flow and pressure sensors
The slopes (sensitivities) of these sensors are quite stable, but the zero offset should be
checked periodically.
The split/splitless inlet module uses a flow sensor. Select the Enable Auto Flow
Zero feature (see To zero the inlet sensors on page 183) to
automatically zero this sensor after each run.
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Service Mode
Calibration
All gas control modules use pressure sensors. These sensors must be zeroed manually.
Table 28 gives the recommended zero intervals.
Table 28.
Flow and Pressure Sensor Zero Intervals
Sensor type
Column size
Zero interval
Flow
All
Use Enable Auto Flow
Zero
Pressure
Small capillary columns
(id 320 µm or less)
Every 12 months
Large capillary columns
(id > 320 µm)
At 3 months, at 6 months, then
every 12 months
Packed columns
Every 12 months
To zero the inlet sensors
1.
Display this screen.
Status / Service / Calibration / Inlet Cal
2.
Select Enable Auto Flow Zero to automatically recalibrate the zero at the
end of every run.
3.
To zero the flow sensor manually, press ZERO FLOW. The inlet flow will be
momentarily interrupted. The process takes about 2 seconds.
4.
To zero the pressure sensor, turn the carrier gas off at the source. Separate one of
the connections in the supply tubing to be certain that there is no pressure trapped
in the plumbing. Press ZERO PRESS.
5.
Restore normal carrier gas flow.
To calibrate the inlet sensors
1.
Establish a known pressure (70 to 100 psig or 480 to 690 kPa) or known flow
(500 to 1000 mL/min) at the inlet.
2.
Enter the known pressure or flow in the appropriate field of the screen.
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Service Mode
Calibration
3.
Press Enter to recalibrate the sensor.
To recalibrate the oven temperature sensor
1.
Attach a thermocouple to the column hanger as shown here. This is the position
used at the factory. Be sure that it is suspended in air and not touching anything
in the oven.
Thermocouple
1-inch
Figure 24. Thermocouple and column hanger
2.
Set the oven temperature to a typical value that you use. Let the oven
stabilize at that temperature for at least 5 minutes.
3.
Subtract the true temperature (the thermocouple measurement) from the instrument reading to obtain the Correction.
4.
Display this screen and enter the Correction value (–10.00 to +10.00).
Status / Service / Calibration / Oven Cal
5.
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Press OK.
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Service Mode
Calibration
To calibrate a column
If one or more of the column dimensions are unknown and impractical to
measure, use this function to estimate the missing information.
1.
Display this screen.
Status / Service / Calibration / Column Cal
2.
Mount the column in the oven. Establish a flow of carrier gas.
3.
On the left side of the screen, select the dimension(s) you need to
estimate.
•
To estimate column length or diameter, you will need to input either the
measured column flow rate or the unretained peak elution time
•
To estimate both length and diameter, you need to input the measured
column flow rate and the unretained peak elution time
4.
To determine Measured Flow: This is the flow exiting the column, and can be
measured at the detector exit. (Be sure to turn off detector gases.) An electronic
flow sensor is preferred, but you can also use a bubble meter and stopwatch.
Make several measurements and average the results. Be sure to convert your
measurements to NTP conditions.
5.
To determine Unretained Peak: This is the time in minutes from injection to
appearance at the detector of a peak that does not interact with the
column.
6.
Enter the data in the appropriate fields, pressing Enter after each one. The
instrument will calculate and display the column dimensions.
7.
Press OK to close the screen.
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Service Mode
Maintenance
To zero the detector flows
1.
Display this screen.
Status / Service / Calibration / Detector Cal
2.
With the gases on, press each of the ZERO keys separately. Allow enough time
between key presses for the zero operation to occur. Ten seconds minimum is
recommended.
Maintenance
The 6850 GC incorporates a feature called Early Maintenance Feedback (EMF),
which you can use to track the usage of the inlet septum, inlet liner, the column, and
the syringe. By setting a usage limit on these items, you can have the instrument
prompt you when it is time to change or service them. For example, the GC can
prompt you to change the septum after every 200
injections.
Early maintenance feedback works by tracking the number of automatic
injections that have taken place since the last time you changed/serviced each item. It
does not count manual injections. You set an upper limit for an item—for example,
the septum—and when this limit of injections is reached, a
“service warning” message appears on the GC front display. This message does not
affect GC readiness; the message is for information only. You can still use the GC
normally. Also, each EMF item is activated and set independently.
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Service Mode
Maintenance
Using early maintenance feedback
To use early maintenance feedback, display this screen.
Status / Service / Maintenance
Each of the trackable items is displayed, along with an indicator for percent of useful
life remaining. As an example, we will set the septum service limit.
1.
Press Service Limits.
2.
Select the Septum field, then use the keyboard to enter a value. In this example,
we will use 200 injections.
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Service Mode
Maintenance
3.
Return to the previous screen. Note that the status bar for the septum shows
100%, and the number of injections remaining is 200.
The GC will now track septum usage.
Resetting the service limits
When the service limit for an item expires, a warning message appears on the GC display and on the Control Module. To clear the message, you must either turn off EMF
for that item, or reset the counter.
Reset the counters as described below.
1.
Wait until you are not in a run or sequence and are ready to replace/service the
item(s), then display the following screen.
Status / Service / Maintenance / Start Service
2.
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Select the item(s) that you will service, and press OK.
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Service Mode
Maintenance
3.
4.
The following screen appears. Select Yes or No.
•
Yes—The GC will load the SERVICE method for you, so the inlet and oven
are cooled to safe handling temperatures (See your 6850 GC Information
CD-ROM for details about the settings in a good
SERVICE method.)
•
No—Does not load the SERVICE method. You do not normally need to
cool the GC to service the syringe, for example. If handling hot parts, be
sure to protect yourself from burns.
The following screen appears. When you have serviced the item(s), press Yes to
reset the counters you selected above. If you press No (for
example, if you did not make any changes), the counters will not be reset and the
service warning message(s) will remain.
Determining service limits
The service limits to use for the septum, syringe, inlet liner, and column depend on
your usage. Pick limits that prompt you to change or service the parts before you
expect to see degradation in performance due to a leaky septum or syringe, contamination due to septum coring, etc.
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Service Mode
Update functions
Update functions
To see the current GC, injector and Control Module model number, serial
number, and firmware information, display this screen:
Status / Service / Update
We recommend that you copy this information to some other location so that it is
available if you call Agilent service.
Contact Agilent service for firmware upgrades. To update any firmware, you need a
Control Module and a PC card containing the update files.
Do not update firmware during a run.
GC Update
When you update GC firmware, all stored methods and local LAN addressing information is lost. Before beginning the update:
•
Record all your GC methods for re-input, or store them on a PC card using the
Control Module. (See To copy a method from the GC to a PC card on page 32.)
•
If using local LAN addressing control (see IP address settings on page 18), go to
Status / Service / LAN Comm and record the LAN information for re-entry.
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Service Mode
Update functions
To update the GC firmware:
1.
Disconnect the Control Module from the GC.
2.
Insert the PC Card with the GC firmware in the Control Module and
connect the module to the GC.
3.
Display this screen.
Status / Service / Update / GC Update
4.
Caution
Select the GC update file (.asc extension) and press Execute.
Do not turn off GC power, disconnect the GC power cord, or disconnect the Control
Module from the GC until the update process is either completed or cancelled. A disruption to the Control Module during the firmware update can make the GC unusable!
5.
When the confirmation screen appears, reply:
•
Yes to load the new GC firmware. The process takes about
10 minutes.
•
No to cancel the firmware load. The existing firmware remains.
6.
When loading is complete, the GC will restart using the new firmware.
7.
Restore your methods and local LAN addressing information (if used).
To update the injector firmware
Control Module firmware version A.03.00 or greater is required to update the injector.
If not available, contact Agilent.
1.
Disconnect the Control Module from the GC.
2.
Insert the PC Card with the Control Module firmware in the Control
Module and connect the module to the GC.
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Service Mode
Update functions
3.
Display this screen.
Status / Service / Update / Injector Update
4.
Caution
Select the Injector update file and press Execute.
Do not turn off GC power, disconnect the injector power cord from the GC, or disconnect the Control Module from the GC until the update process is either completed or
cancelled. A disruption to the Control Module during the
firmware update can make the injector unusable!
5.
6.
When the confirmation screen appears, reply:
•
Yes to load the new injector firmware. The process takes about
2 minutes.
•
No to cancel the firmware load. The existing firmware remains.
When loading is complete, the injector will restart using the new firmware.
end
To update the Control Module firmware
1.
Disconnect the Control Module from the GC.
2.
Insert the PC Card with the Control Module firmware in the Control
Module and connect the module to the GC.
3.
Display this screen.
Status / Service / Update / Mod Update
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Service Mode
Update functions
4.
Caution
Select the Control Module update file and press Execute.
Do not disconnect the Control Module from the GC or turn off the GC until the update
process is either completed or cancelled. Doing so can destroy the
programs in the Control Module and make the Control Module unusable.
5.
6.
When the confirmation screen appears, reply:
•
Yes to load the new Control Module firmware. The process takes about 2
minutes.
•
No to cancel the firmware load. The existing firmware remains.
When loading is complete, the Control Module will restart using the new firmware.
end
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