I realize that this seems to be a very elementary problem, none-the-less I have had serious purification problems of late trying to get rid of Norit A from material being purified. Celite, very fine filter paper, syringe filter packs have all been tried but still some Norit A or any other type of decolourizing carbon remained. Other than not using this material any suggestions for keeping it out of my product? The colour that I was trying to remove happened to follow my product down a silica column regardless of the solvent system used.