Chromatography Forum

Hi,

I am setting up a GC-FID system within my already existing GC-MS.
The column in the front injector, with helium as carrier gas, goes straight to the MS, while the column in the back injector goes straight to an FID.
I would like to use hydrogen instead of helium only for this second column.

Are there any indications against using both gases?

Thank you

No. I set up a GC that could feed either H2 or He to either the front or back injector, and there were no safety or operational issues for a well-designed carrier gas system..

The only thing about 2 column GC systems is to remember to either have carrier through both columns when at elevated temperature, or remove and plug the Injector/Detector of the column you aren't using. It's easy if there is a single user, but more difficult with multiple users.

Please keep having fun,

Bruce Hamilton

Thank you very much for the fast response.
It was that I thought but I just wanted to be sure!

offcourse no objection for running helium for ms and hydrogen for fid but:
- why choosing hydrogen knowing that it is a danger gas? why not thinking of nitrogen?
- to reserve your colums the flow of carier gas must be in both of them while running either u do not need the other.