High-performance capillary electrophoresis of O-glycosidically linked sialic acid-containing oligosaccharides in glycoproteins as their alditol derivatives with low-wavelength UV monitoring.

Several O-glycosidically linked monosialooligosaccharides from glycoproteins were separated as their alditol derivatives in ca. 10 min in borate buffer (pH 9.6) containing sodium dodecyl sulfate (SDS), and sensitively detected at the 10(-4) M level by measuring absorption at 185 nm. Oligosaccharides having higher degree of polymerizations migrated faster, and N-acetyl- and N-glycolylneuraminic acid-containing oligosaccharide analogues could be resolved from each other under the conditions employed. Good linearity was demonstrated between 0.9 and 20 mM concentrations for relative response of N-acetylneuraminyllactose as a model compound to lactobionic acid as an internal standard. The detection limit was 0.2 mM, which corresponded to 0.80 pmol as the injected amount. The relative standard deviation of relative response at 9 mM was 1.97% (n = 7). The established system was successfully applied to microanalysis of sialooligosaccharides in bovine submaxillary mucin and swallow nest material.