Varian 4000 GC, Hardware Operation Manual

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Setting Flows of CI Reagents in Internal Configuration
After any leaks have been located and fixed, set the delivery pressure of the CI
reagent by doing the following:
1. Ensure that the CI Gas solenoid valves are closed. If necessary, click on the
CI icon in the Control and Status field of the Manual Control tab dialog in
System Control. When the valves are closed, the CI button is black or red -
not green.
2. Open the main valve on the lecture bottle. Using the pressure adjustment
valve on the regulator, set the head pressure to about 20 psi.
You are now ready to operate the system in the CI mode. Read the respective
users guides for more detailed operational information.
Internal Mode Default Parameters for CI Reagents
Reagent Gas Methane Isobutane Acetonitrile d3-Acetonitrile Methanol
Reagent Low Mass (m/z) 15 35
35 35 25
Reagent High Mass (m/z) 45 65
60 60 50
Reaction Storage Level (m/z) 35 35
33 33 25
Ejection Amplitude (v) 15 15
15 15 15
Target TIC 5000 5000
5000 5000 5000
Maximum Ionization Time (
μ
sec)
2500 2500 2500 2500 2500
Maximum Reaction Time (
μ
sec)
100 100 100
20*
100
*
Use short reaction times for deuterated reagents. Longer reaction times allow
more H/D exchange with background water and the resulting spectrum will show
more [M+H]
+
and less [M+D]
+
.
External Mode Default Parameters for CI Reagents
Reagent Gas Methane Isobutane Ammonia Acetonitrile d3-Acetonitrile Methanol
CI Background (m/z) 45 65
35 60 60 50
Target TIC 5000 5000 5000 5000 5000 5000
Maximum Ionization Time (
μ
sec)
2500 2500 2500 2500 2500 2500
Maximum Reaction Time (
μ
sec)
100 100 100 100
20*
100
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