Analysis of monosaccharide composition by capillary electrophoresis

The monosaccharide composition analysis described in this paper employs capillary electrophoretic separation of sugar monomers liberated from glycoproteins or oligosaccharides, by high temperature acidic hydrolysis. Trifluoroacetic acid was used for sialo- and neutral-sugar hydrolysis, and hydrochloric acid was used for amino-sugar hydrolysis. The neutral- and amino-sugars in the hydrolyzates were then labeled with a charged fluorophore, 8-aminopyrene-1,3,6-trisulfonate, while sialic acids were labeled with 9-aminoacridone. The stoichiometry of labeling was such that only one fluorophore molecule was attached to each monosaccharide molecule. The labeled monosaccharides were then separated by high-performance capillary electrophoresis with laser induced fluorescence detection. The acidic hydrolysis and fluorophore labeling conditions described in this paper are suitable for monosaccharide composition analysis of a wide variety of complex carbohydrates from glycoprotein and/or oligosaccharide samples using capillary electrophoresis.