Gas chromatography of neutral and amino sugars in glycoproteins

A gas chromatographic method for determining the neutral and amino sugars commonly found in glycoproteins of animal origin is described. Following mild acid hydrolysis, the solution is neutralized with Dowex 1 HCO₃⁻, and the sugars are reduced to alditols in the cold with sodium borohydride. The solution is lyophilized, and the alditols are acetylated with acetic anhydride in pyridine. Monosaccharides can be determined on as little as 1 mg of a glycoprotein which contains 6% total carbohydrate.