Chromatography Forum

Hi people!

I work on a GC HP 6890 with a split/splitless inlet what always works at splitless mode.
Is it necessary to change the filter of the split vent trap anyway?
What problem could I have if I don't change that?

Sorry for my bad English.

Thanks.

The purpose of the trap is to prevent solvents going into the control valves of the electronic pneumatic control unit of the capillary inlet. You usually only run the inlet in splitless mode during injection and for a certain time after injection, and then the capillary inlet reverts back to split mode to sweep out the dead volume in the inlet. It will in the long run be cheaper to replace the filter than the electronic control module.

Gasman

astroguille,

You always work in splitless? Your solvent front must look awful. I would be interested to hear about the application??

Best regards.

Hi AICMM!

I always work in splitless because I analyze pesticides at different matrixes (water, soil, fruits & vegetables).

Best regards

astroguille,

My guess is that you really run splitless/split (switch to split at something like 0.5 min) but I don't want to put words in your mouth.... That way you get the most on column but you don't get an ugly solvent peak...

Regarding split traps, in your case I would say replace it once a year as a routine since the injection mode you use should load it less than split injections. Restek has these filters in their catalog.

Best regards.

Thank you very much to everybody !!!