Reusing Silica in column chromatography

[Ganoderma]

title says it all. can i just rinse the silica with various solvents and wash it to reuse? or do i need to chuck it when im done.....kind of expensive and i need to pay for it all myself (not a student or a professional :smilingsun:)

 

 

also, if i may ask.....is $85/kg an ok price for 230–400 Mesh?

[Mercedes Benzene]

I suppose it's possible to cleanse it yourself and reuse it. How sensitive is your application? I would never reuse it in the lab because I wouldn't want any chance of contamination.

 

That price sounds about right for technical grade silica gel. Higher purity is more expensive.

[Ganoderma]

thanks! I see you r point. I suppose i could jsut use it for non important things like getting dyes out of crude extracts. use new for things i am studying.

[UncleAl]

In principle you could ramp up to very polar solvent to rip off everything adsorbed then ramp down back to your solvent system. This makes sense in a small volume HPLC system but not in a column. 1) Solvents cost money - so does disposal, 2) polar solvents degas silica - the column cracks, 3) You will be introducing trace water into the column, deactivating the silica from the top down.

 

I've seen folks pack a column tapped to density, add some fine sand atop, then put a silica layer above that. The idea is that irreversible muck is trapped in the leading plug that can be removed and replaced while the column itself says clean. That was no doubt invented by somebody who told others what to do.