INFLUENCE OF BORATE COMPLEXATION ON THE ELECTROPHORETIC BEHAVIOR OF CARBOHYDRATES IN CAPILLARY ELECTROPHORESIS

The influence of different borate buffers as background electrolytes on the electrophoretic mobilities of underivatized mono- and oligosaccharides as well as glycosylated peptides in capillary electrophoresis is investigated. Electrophoretic mobilities of various carbohydrates are calculated, and some structural characteristics of sugar-borate complexes are deduced. Due to the fact that the addition of borate to aqueous solutions of mono- and oligosaccharides results in an increase of absorbance at 195 nm, the sugars can be detected without derivatization. Additionally, resolution and efficiency were dramatically improved by performing electrophoresis at elevated temperatures up to 60-degrees-C. CE experiments of a hexapeptide and its glycosylated form confirm that not only does glucose complex with borate in the open-chain form but, under conditions of very high borate concentrations, the pyranose form also complexes with borate.