Varian 4000 GC, Hardware Operation Manual

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Saturated filters on the GC may produce an increase in the air/water background.
Replace the filters at regular intervals, and whenever moisture or other
background from the GC becomes a problem.
GC Troubleshooting
NOTE: Please refer to the GC Operator’s Manual for information about GC
troubleshooting and diagnostics procedures not described in this section.
This section describes chromatographic troubleshooting, with particular
emphasis on GC/MS applications. You will be able to investigate most of the
problems addressed in this section by running the COLTEST mixture
(03-920273-00).
The following procedure describes the chromatographic conditions and the
expected results when running the COLTEST sample with a 30-m vf5ms column
(0.25 mm ID, 0.25 µm film thickness).
Using the COLTEST Sample for Troubleshooting
The Coltest sample provides a good mechanism for identifying a variety of
chromatography problems. A COLTEST method can be found in the
C:\VarianWS\4000 MS Service directory of the software.
Running the COLTEST Sample
Flow Pressure Conditions
Use a constant flow of 1.0 mL/min.
Injector Conditions
•
1177 Injector:
Use an isothermal temperature of 240 °C.
Set up the following split program conditions:
Time Split State 1 Split Ratio
initial On 100
0.01 Off Off
1.00 On 100
MS Temperature Conditions
1. Set the transfer line temperature to 250 °C.
2. Set the trap temperature to 150 °C.
3. Set the manifold temperature to 40 °C.
4. Set the source temperature to 150 °C if the 4000 MS is in external mode.
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