beerwiz - 13-11-2018 at 22:21
I read this gem online:
"I once heard of a grad student who had compounds that could be visualized right on the column (similar to the standard undergrad
ferrocene/acetylferrocene separation.) He would do a partial separation on the column but instead of wasting time eluting, he then blew the whole plug
of silica back out of the top and sliced it like a sausage to collect the desired compounds for extraction from the gel."
This sounds much easier than eluting the compound off the column, plus you save on eluent. Any idea how he extruded/pushed out the wet silica from the
column in one piece like a sausage so he can just cut the piece that he needs with the compound for later extraction? What is the best technique?
[Edited on 14-11-2018 by beerwiz]
[Edited on 14-11-2018 by beerwiz]
Metacelsus - 13-11-2018 at 23:45
He probably just applied compressed air to the bottom of the column instead of the top.
However, in cases where this method is possible, you could just use a shorter silica column and elute normally. It's not "wasting time eluting" when
you consider the time it would take to extract the compound from the gel.
Ubya - 13-11-2018 at 23:52
i don't think this could work if the silica is immersed in solvent (not just wet) as it should be, if you first remove the eluent the phases would
smear and move, not good, but if you blew the silica plug while full of eluent it would first push away the eluent ans then maybe the now useless
plug.
i don't think this is a great technique