Chromatography Forum

Just a question regarding pH control in HILIC.

If you are running an isocratic HILIC method with a very high organic content (approx. 95%) is the pH of the buffered aqueous mobile phase as important (in terms of analyte ionisation) as in reverse-phase, and how efficiently does the buffer control pH when it is present in such a small percentage within the mobile phase?

Thanks.

Probably less of a problem than you might think, because the high % organic will keep your analyte from ionizing. For a thorough discussion of the whole topic, see these LC-GC articles by Bill Tindall:
http://www.lcgcmag.com/lcgc/data/articl ... rticle.pdf
http://www.lcgcmag.com/lcgc/data/articl ... rticle.pdf
http://www.lcgcmag.com/lcgc/data/articl ... rticle.pdf