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LC MS/MS Peak
Posted: Fri Jul 21, 2006 7:56 am
by Sunjay
In LC MSMS, is it normal to have peaks slightly bifurcated at the top or this is not acceptable like HPLC?
Plsease help as i am not a LC MSMS expert but have to review thwe LC MSMS data.
Regards
Re: LC MS/MS Peak
Posted: Tue Jul 25, 2006 3:58 pm
by gckiv
I'm assuming you're talking about the total ion current (TIC) or base peak (BP) trace, as the MS/MS data will be displayed in centroid, not profile mode. This isn't that uncommon, as ion intensity is less stable than, say, UV. Ionization propensities vary, even for a single compound, which can result in what appears to be 2, or sometimes more, MS peaks. Complementary UV data helps, but have the analyst check for minor differences between the two sides of the peak. Sometimes a modified form of a peptide, such as an asparagine deamidation (+1 Da), might co-elute and show up as a shoulder or split peak. Hope this helps.
Posted: Fri Jul 28, 2006 11:42 am
by Sunjay
Dear gckiv,
Thanks for ur reply.
Actually i am QA guy, do not having much knowlegde about LC MS/MS tecnique. I was reviewing the validation report with respect to previously approved protocol by my senior who has has left the company.
UR inputs will be very helpful for me.
The peak splitted at the top was observed for the analyte peak only, there is no splitting for the internal standard, so i had this query.
Regards