SUB-MINUTE SEPARATIONS OF ORGANIC AND INORGANIC ANIONS WITH CO-ELECTROOSMOTIC CAPILLARY ELECTROPHORESIS

Fast capillary electrophoretic separations of various classes of anion ic compounds are performed by using very short effective separation le ngths in addition to a similarly directed movement of the electroosmot ic flow and the inherent electrophoretic mobilities of the analytes. A polycationic surfactant (hexadimethrine bromide) is added to the elec trolyte, which dynamically coats the inner surface of the capillary an d causes a fast anodic electroosmotic flow. Selective separations in t he sub-minute range combined with high separation efficiencies of seve ral hundred thousand theoretical plates per meter effective separation length can be achieved if organic solvents or mixtures thereof are ad ded to the electrolytes. The methods are used for the high-speed separ ation of various anionic analytes, such as carbohydrates, carboxylic a cids, phenolic compounds and inorganic anions. (C) 1997 Elsevier Scien ce B.V.