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Chromatography of Zwitterionic Buffers (MES, MOPS, etc.)

Posted: Tue Jul 08, 2008 8:18 pm
by Nalizer
Hello:

I am looking for a simple method to analyze zwitterionic buffers, like MOPS and HEPES

http://en.wikipedia.org/wiki/MOPS

What are my choices? I have no retention on RP column even at very low organic (various pH)

Posted: Tue Jul 08, 2008 8:41 pm
by tom jupille
That would be a classic application for ion-pair chromatography, or else one of the "mixed-mode) packings with embedded ion-exchange groups. Or, you could use good old ion-exchange (just run at a pH that suppresses one of your charged sites).

Posted: Tue Jul 08, 2008 10:05 pm
by Uwe Neue
I would consider HILIC as well.

Residual HEPES by LC-MS

Posted: Thu Dec 11, 2008 10:26 am
by depstein
I found this article:

Analytical Chimica Acta 583 (2007) pp 124-127 where HEPES is the internal standard and they used an amide-80 column.

If you found any other solutions, I'd be interested in hearing about them.

Posted: Thu Dec 11, 2008 4:41 pm
by Vlad Orlovsky
Here are few methods for several zwitter-ionic buffers:

http://www.sielc.com/compound_256.html

regards,

Vlad