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hplc-MS contamination
Posted: Thu Mar 24, 2016 7:24 pm
by hplcnewuser1
Hi I am running a peptide on hplc/ms and keep getting this contaminant on MS that is 135m/z appart ex: 1332, 1197.... also 1376, 1241....
What could this polymer be/
thanks for any help.
Re: hplc-MS contamination
Posted: Fri Mar 25, 2016 6:38 pm
by JMB
I think that we need a little more information with this, namely...
1) what is the mobile phase ?
2) is this a synthetic peptide ?
3) are these m/z values [M+H] or sequence ions
JMB
Re: hplc-MS contamination
Posted: Fri Apr 29, 2016 7:59 pm
by hfredricks
check out this paper,
Keller, B.O.; Sui, J.; Young, A.B.; Whittal, R.M. Interferences and contaminants encountered in modern mass spectrometry.
Analytica Chimica Acta (Review/tutorial, Special Issue on Mass Spectrometry), 2008.
The supplementry data excel file is a must-have for contamination issues - it says 135 is "NaCF3CO2, sodium trifluoroacetate clusters" valid in wither pos or neg mode.
[quote="hplcnewuser1"]Hi I am running a peptide on hplc/ms and keep getting this contaminant on MS that is 135m/z appart ex: 1332, 1197.... also 1376, 1241....
What could this polymer be/
thanks for any help.[/quote]
Re: hplc-MS contamination
Posted: Thu May 05, 2016 11:23 am
by lmh
NaTFA is 136, not 135 I think???
Re: hplc-MS contamination
Posted: Thu May 05, 2016 8:12 pm
by sav
It's just peptides. May be
Check n+ (n = 2 - 3) and MSMS (isCID or CID).
Re: hplc-MS contamination
Posted: Tue May 24, 2016 8:34 pm
by BostonFSE
135 repeating in positive mode = Sodium trifluoroacetate clusters
clean the source
on occasion, spraying the source with methanol over night 0.1 ml/min flow can help reduce contamination
this paper was cited by another user and the xls is awesome to have for MS contam issues.