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Peak area getting smaller and smaller with every injection!

Posted: Sun Dec 20, 2015 11:54 pm
by deanne0711
Hello
I am running US EPA 8270 method on PerkinElmer Clarus580 GC with SQ 8 S Mass Spec. I am extracting for base-neutrals only. I am seeing rapid deterioration of my responses for components and internal standards. Within 15 injections my peak area has almost halved!
I am using deactivated liners - I have tried two different types (PerkinElmer and Restek). I purchase them already deactivated and then dispose of them after use.
I have not known liners to deteriorate so quickly before (I am used to getting at least 40-50 injections out of a liner) so I am wondering if there is something else going on here.
I am kind of at a loss of what else could be the cause. If anyone could help I would really appreciate it.

Thanks!

Re: Peak area getting smaller and smaller with every injecti

Posted: Wed Dec 23, 2015 4:25 pm
by sav
I don't think that liners chemicaly degrade so quickly - probably its just "mud effect". If you use glass wool - try to minimize its quantity (split mode) or use liner with Jennings cup and increase temp of injector. If you use splitless - try to increase temp of injector and increase split flow.