Chromatography Forum

Hello,

We are wanting to inject a gas sample on the 7820A GC but aren't sure how to do it. Do we need an automatic gas sampling valve? If we want to manually inject with a gas-tight syringe, where would it be injected and what kind of syringe is needed?

Thanks for your help getting us started!

How much volume are you looking to inject? If you're looking to do 250uL or below you can just inject it into the injection port through the septa and hit the start button on the GC.

What inlet do have installed in the 7820?
What will be in your sample?

If your sample will contain any of the major gases in air, I would not recommend a syringe.

If you wish to do any serious quantitative analysis, again a syringe is not the best way to go. If you look at any of the gas analyzers offered by the major GC suppliers, they will all use a gas sampling valve.

Gasman