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A very strange baselines of QQQ

Posted: Wed Nov 12, 2008 12:42 am
by haiedc
Hi all,

I am now having a problem of baselines operating on Trible Quad 6410 Agilent.
I run on MRM mode, it's OK for one parent ion and 2 (or 3) daughter ions. But when I run 2 parent ions and each parent ion has 2 (or 3) daughter jions, the baselines is terrible, just like sawtooth and the amplitude is high, higher than the peak itself.
Strangly enough, I can still get the chromatogram after the run normally without any sawtooth and do the quantitation.

Who has ever met with this and know why?

Posted: Wed Nov 12, 2008 4:57 pm
by matthew
Hi haeidc,

Can you provide a screenshot? Are you referring to the data acquisition software?

In MRM mode, the screen in the data acquisition software is pretty useless when doing MRMs; the developers seemed to focus their attention on the qual and quant software. That said, when the screen is buggy I reset the software with the 'remove all processes' script (the shortcut with the little exclamation mark).

Posted: Wed Nov 12, 2008 7:24 pm
by Kostas Petritis
Although you say that you are operating in MRM mode, your description of the "baseline" reminds of somekind of data dependent aquisition. Are you sure that at any point you do not have a full scan in your sequence?

Posted: Thu Nov 13, 2008 12:57 am
by haiedc
Although you say that you are operating in MRM mode, your description of the "baseline" reminds of somekind of data dependent aquisition. Are you sure that at any point you do not have a full scan in your sequence?
It's only in MRM mode, no scan at any point.