Loss of sensitivity during headspace GCMS runs.

[David Lewis]

My laboratory uses headspace GCMS for the analysis of drinking water samples using a Perkin Elmer turbomass system. We have a persistent problem with loss of sensitivity in this system with perhaps 80-90% of the sensitivity lost within a single 40 sample run. I wondered if anyone else had experienced a problem like this and what to do about it.

[Ron]

You have two systems here, a GCMS and a headspace sampler. I would run a series of injections with a regular autosampler to see if the issue is with the GCMS or with the headspace sampler. Once you know which unit is causing the problem then you can start troubleshooting that unit.