gc/ms carryover

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Ltrainsc
Ltrainsc's picture
gc/ms carryover

I am having a carryover issue with one of my instruments.  I have a 4552 autosampler hooked up to a 4660 eclipse to a 6890/5973 gc/ms.  I am having massive alcohol carryover in my waters and soils.  I have changed all the sample lines, replaced 26ml syringe/plunger, water sample needle, burket valves/manifold on front side, pencil traps, column, weldment, etc.  These carry just does not seem to go away. any ideas?

Greg Pronger
Greg Pronger's picture
Which alcohol? It sounds like

Which alcohol? It sounds like you've gone through most of the path. I assume if you cycle the GCMS without the purge-and-trap, you do not see the problem. Assuming this to be the case, is it there if you simply go straight to desorb?

In other words, work backwards, from the GCMS, through the system. At point you'll go from not having the problem to it reappearing.

Hope this helps.