From our mentor-by-literature Neal Anderson comes talk of using activated charcoal in your process (from "Practical Process Research and Development", page 215.):
Polar impurities can be removed by stirring a solution of the product with 1-2 wt% of activated carbon relative to the solute, adsorbing these impurities to the finely divided solid. Impurities are trapped in the pores of the activated carbon by van der Waals attractive forces. There are three categories of pore sizes: macroporous (1000 - 100,000 Å), mesoporous (100-1000 Å) and microporous (<100 Å)...Yeah, I hate the stuff. You can't clean it off from anything, and you're always sure it's in there somewhere. Celite does well at getting most of it; I haven't used any of the in-line filters, so I can't speak to those. But when I think about it, I think to myself, "NO." (I'm probably too harsh -- it is useful stuff.)
Activated carbon treatment can cause difficulties in cleaning equipment, as the finely divided solid is moderately electrostatic and tend to adhere to almost every surface it contacts. No solvent effectively dissolves charcoal, although vessels may be cleaned by boiling out with aqueous NaOH. For this reason, activated charcoal treated on large scale is often limited to dedicated vessels. Solution may also be passed through in-line filters containing granular, spherical, or pelletized activated carbon; these filters retain the activated carbon and avoid many of the cleaning issues.
- Adsorption of a molecule to activated carbon may change the pH of the resulting filtrate.
- Adsorption to activated carbon is based on equilibria. Short contact times decrease the efficiency of impurity adsorption.
- Performance of activated carbons can vary greatly.