Chromatographic Symptoms - Agilent Technologies 8860 User Manual

Chromatographic symptoms

General information
The Gas Bag Selector is an automatic sampling device, which is used to transfer
the gas samples in multiple gas bags or cylinders to the sample loop of GC GSV
according to method parameters and trigger the GC to start running. The sample
chromatogram obtained through Selector should be consistent with the sample
chromatogram obtained when the sample bag/cylinder is directly connected to GC
GSV for injection.
If there are some problems during use, it is important to distinguish whether the
problems are caused by selector or caused by GC system. For this goal, disconnect
the selector from the GC GSV, and directly inject sample in the gas bag/cylinder to
the GC GSV to ensure that the GC system can produce peaks normally. If the GC
fails to produce normal peaks, the problems may be caused by GC system. Refer to
GC troubleshooting manual to fix it.
To check the chromatographic symptoms for bag version
Peaks Not Displayed/No Peaks
1 Check if the Selector is connected correctly to the GC.
2 Check that the actuator gas supply is connected correctly to the Air/N
3 Check if the needle valve fittings on the back of the Selector is tightly closed.
4 Check that the pump is heard working during the selector loading stage. If not,
5 Connect a flow meter to the vent port to measure the sample flow rate during
6 If no issues were found from step1 to step 5, refer to the GC troubleshooting
Agilent Gas Sample Selector for 8860 and 8890 User Manual
on the back of the Selector and confirm the supply pressure is 380 kPa (55 psi).
there may be a problem with the pump assembly. Please contact Agilent for
further support.
selector loading stage and ensure that it matches the flow rate set during
installation. If the flow is zero or too low (normally the vent flow >20 mL/min),
there may be a restriction or leak in the selector system.
(See Restriction and leak check
manual to screen the GC system.
Maintenance and Troubleshooting
Chromatographic symptoms
on page 82).
5
fitting
2
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