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Unknown peak co eluting with main peak ( pka 2.0)
Posted: Sat Jul 11, 2015 5:27 pm
by Lakshimohan
hi,
Am facing a problem of co elution of unknown peak along the main peak , which has a high concentration of ion pair reagents in mobile phase & the unknown peak is not coming repeatedly it comes some time & some time not, it's an upload method , any suggestion ?
Re: Unknown peak co eluting with main peak ( pka 2.0)
Posted: Sat Jul 11, 2015 10:48 pm
by tom jupille
Not without a lot more information.
What is the k' value of your main peak? and what is the k' value of the unknown peak when it occurs?
How wide is the unknown peak compared to the main peak?
Do you see the unknown peak if you inject a mobile phase blank?
Re: Unknown peak co eluting with main peak ( pka 2.0)
Posted: Mon Jul 13, 2015 2:48 pm
by Lakshimohan
Hi ,
The k' value of main peak is 6.3 and the main peak is 6.1 . The unknown peak is not wide as the main peak. In the blank injection there is no unknown peak.
Thanks
Re: Unknown peak co eluting with main peak ( pka 2.0)
Posted: Mon Jul 13, 2015 7:52 pm
by Vlad Orlovsky
What is the nature of your analytes? You can try to play with pH, if they are ionizable, in order to explore the difference in ionic properties
Re: Unknown peak co eluting with main peak ( pka 2.0)
Posted: Wed Jul 15, 2015 1:05 pm
by Lakshimohan
What is the nature of your analytes? You can try to play with pH, if they are ionizable, in order to explore the difference in ionic properties
The analyte is an amino aromatic carboxylic acid, the mobile phase is with two different pH according to the dual pka of the analyte,
Re: Unknown peak co eluting with main peak ( pka 2.0)
Posted: Thu Jul 23, 2015 5:39 pm
by Vlad Orlovsky