Chromatography Forum

Hello,

How can I remove DBAA from a C18 column?

Previously, I wanted to remove TBAhydrogensulfate from a column and the advice was: try to flush it with the same buffer, but without IP agent.

When I apply the same theory in this case, I should flush the column with pure water? (the column I am tying to regenerate now is Synergi Hydro C18, Phenomenex, 250x2.0 mm 4um particle size). We were using 10 mM DBAA pH=7.

I want the IP agent removed, because after several runs, slight loss of retention was observed but the main problem is loss of separation.

Any suggestions? Thanks, PHOBIUS

Removal of basic ion-pair reagents can be more problematic because as cations they are likely to stick to any ionized silanols. The general strategy would be the same, but possibly with the addition of a low level of low-pH buffer. Even then, no guarantees.

Thanks for your advice, it has helped. After flushing the column with water during the whole weekend at half flow rate, perfect separation was achieved again. At least something works as it ought to