HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF MONOSACCHARIDES AND OLIGOSACCHARIDES ON A GRAPHITIZED CARBON COLUMN

Chromatographic behavior of several mono- and di-saccharides and cyclomaltaoses on Hypercarb, a graphitized carbon column, was investigated. Monosaccharides were weakly retained on this column and were eluted with water within 1.8-3.6 min at 1 mL/min of flow rate and 30-degrees. Nevertheless, each peak of D-xylose, D-glucose, D-galactose, and L-fucose was split into anomer peaks. Disaccharides were adequately eluted with 15:85 methanol-water or 4:96 acetonitrile-water, and each showed two peaks for the anomers. These peaks each coalesced into a single peak upon the addition of mm sodium hydroxide to the eluent. Simultaneous separation of nine glucodisaccharides was achieved on this column by gradient elution with mm sodium hydroxide solution containing 1.5-5.0% acetonitrile. Detection was by a pulsed amperometric detector. Cyclomaltohexaose (alpha-CD). cyclomaltoheptaose (beta-CD), cyclomaltooctaose (gamma-CD), and their glucosyl derivatives (G-alpha-CD, G-beta-CD and G-gamma-CD) were analyzed by using 13-15% aq. acetonitrile as the eluent. Interestingly their retention times were increased with increases in temperature, and the sharpness of their peaks was also shown to be enhanced. Furthermore, positional isomers of glucosyl-inositol and of dimaltosyl-beta-CD, neither of which can be separated on conventional bonded phases, were well resolved on this column.