Patent ID: 7973157

Claim:
A method for the purification of a crude D-1-deoxygalactonojirimycin contaminated with an alkali- or alkali earth metal-containing compound comprising: (a) admixing D-1-deoxygalactonojirimycin with a solution having at least 35% hydrochloric acid or with hydrogen chloride gas to saturation to form a chloride salt of the alkali- or alkali earth metal-containing compound; (b) forming the chloride salt of the alkali- or alkali earth metal-containing compound; (c) removing the chloride salt of the alkali- or alkali earth metal-containing compound wherein the chloride salt is a solid; and (d) crystallizing D-1-deoxygalactonojirimycin by addition of a solvent miscible with hydrochloric acid.