Aminoethyl cellulose (AEC) was thiolated with S-acetylmercaptosuccinic anhydride. The S-acetyl protective groups were removed at pH 11.5 to yield thiolated aminoethyl cellulose (TAEC) preparations with 0.077 to 0.109 × 10−3 mole SH per g TAEC. TAEC bound approximately 0.1 × 10−3 mole of p-mercuribenzoate/g.
Mercury was removed from fish protein by stirring solubilized tuna fish protein concentrate with TAEC at pH values from 6 to 11. The fish protein was solubilized by either a high temperature, high pH process, or by succinylation. The amount of mercury removed was pH dependent, being maximal at pH values 6.4 and 9. Under reducing conditions, that is, TAEC treated with dithiothreitol, and the mercury removed under nitrogen, 80% removal from a 2% protein solution at pH 7 was achieved. Srafion NMRR, a commercial chelator for dissolved organic and inorganic mercuric salts, was ineffective in removing mercury from soluble fish protein concentrate.