Chromatography Forum

Hi guys,

I am using a GC MS and I feel I am in lack of some basic understanding of the instrument. Here are my questions:
1. Is it OK to run a water/air check with MS only (no flow)? Will that damage any part of the instrument?

2. If there's a leak in the system, for example 15% oxygen (should <= 3%) , is it safe to leave the instrument on? Or should I shut down the mass spec to protect the ion source?

3. How bad is it if I accidentally leave the column in a high temp but no gas flow, for a few hours?

Thank you very much!

Best,
Antao

Hi guys,

I am using a GC MS and I feel I am in lack of some basic understanding of the instrument. Here are my questions:
1. Is it OK to run a water/air check with MS only (no flow)? Will that damage any part of the instrument?

It won't damage anything.

2. If there's a leak in the system, for example 15% oxygen (should <= 3%) , is it safe to leave the instrument on? Or should I shut down the mass spec to protect the ion source?[/quote/
I would turn off heating of source and quad at least.

3. How bad is it if I accidentally leave the column in a high temp but no gas flow, for a few hours?

It depends on column type and especially if oxygen may enter the column by diffusion eg. through FID. Definitely should be avoided.