by
dblux_ » Tue Jul 24, 2012 5:41 pm
lmh wrote:
hplcconsult: on an Agilent 1100 (and 1200) system if you don't have a manual column bypass and realise you really don't want the injection that's about to happen to land up on your column, you can also quickly open the purge valve so there's no solvent flow into the column. Once the injection is safely out of the way, stop the pump, remove the column, run for a few minutes to waste, and then replace the column.
Bad idea IMHO.
Opening purge valve will abruptly reduce high pressure to zero and column packing will expand. I doubt column might resist such abuse - void volumes will form inside packing. And typical, "doubled" peaks (snake tongue like) will tell of sad end of column life. Monolitic columns are much more forgiving and probably might survive.
disclaimer - I'm not aware whether 1100 or 1200 is somehow secured against pressure drop when purge valve is opened. Dionex LPG 680 pump certainly is not.