SEPARATION AND QUANTIFICATION BY ION-ASSOCIATION CAPILLARY-ZONE-ELECTROPHORESIS OF UNSATURATED DISACCHARIDE UNITS OF CHONDROITIN SULFATES AND OLIGOSACCHARIDES DERIVED FROM HYALURONAN

An analytical method has been developed for assay of unsaturated disac charides of chondroitin sulfates and of oligosaccharides (tetra- and h exasaccharides) of hyaluronan, using ion-association capillary zone el ectrophoresis. Samples were applied at the anode (the usual polarity), using a berate buffer modified by an ion-pairing reagent, tetrabutyla mmonium (TBA) phosphate, and the effect of the concentration of the io n-pairing reagent on various electrophoretic parameters (electroosmoti c flow, electrophoretic mobility of products, capacity factors) was ob served, Increasing concentrations of the reagent led to a decrease of zeta potential, probably due to specific adsorption of the quaternary ammonium ion onto the capillary wall. The authors propose a mechanism of separation, in which anionic berate complexes are formed and intera ct with TEA ion inside the capillary tube. The capillary electrophoret ic system described is potentially a powerful method for specific meas urement of the concentrations in joint tissues of chondroitin 4-sulfat e, chondroitin 6-sulfate, and hyaluronan, whose relative abundances ma y vary in various diseases or after local treatments with, for example , antiinflammatory drugs, chondroprotective agents, or orthopedic impl ants.