Chromatography Forum

Hello everyone, I have one question. Should I off the GC to save the gases if I'm not using it regularly? Let say for example, if I use it every 3 working days to analyse my samples, should I let it on between the sample run or should I off it to save the gases? I'm using GC-ECD/FPD. Will it affects the column and detector if I switch it off everytime I'm not using it?

Thanks.

Hai if you apply cool method ( making zero of all gases) automaticaly the flow will stop in to entering in to your system. We are regularly keeping off the systems for safety purpose ( any leakage , software problem). but is enough to just apply cooling method to save gases.

KALIDASS

Thanks for the reply.

You need to maintain carrier gas flow and the ECD purge.

Peter

I prefer to keep some flow through the column - it keeps air out. Since columns are carefully sealed before shipment, I have to assume that there is at least some level of concern - even if it is not a major issue.

I also prefer to keep a low flow of makeup gas through the detector(s) to help keep them clean.

I would not turn a GC off. Too many bad things can happen. You can setup a standby method with minimal flows. I'd evaluate the column temperature requirements, for example we use a lot of PLOT columns and they're better off if they stay hot.

I have stand by method with minimum of carrier gas flow in column. I never turn of GC completely.

We bad: we turn off GCs that have a stable type of column installed, like DB-5. We leave carrier on at low flow rate at low column temperature for PEG-type columns whichcan experience oxidation. Our GCMS units have carrier and temperature at all times.