Dermatan sulfate as useful chiral selector in capillary electrophoresis

Dermatan sulfate (DS), a complex, polydispersed, sulfated polysaccharide was investigated as a useful chiral selector in capillary electrophoresis for the enantioresolution of a variety of drugs. Analysis was carried out in a fused-silica capillary column of 48.5 cm length (40 cm to detector window) x 50 mu m I.D., and the separation buffer consisted of citric acid-Tris containing DS; the applied voltage was 15 kV and the detection wavelength was 220 nm. The effects of buffer pH, the dermatan concentration and run temperature on the enantioseparation and migration were examined. The method was applied to the enantioresolution of a representative set of twenty basic drugs. At all pH values used (3.0, 4.5 and 6.5) the addition of DS resulted in an increased migration time due to analyte-DS interaction. Using DS concentration of 2% (w/w), at pH 4.5, enantiomeric separations could be obtained for more than 50% of the examined drugs; resorcinic moiety was found to be a very favourable structural feature for obtaining high enantioresolution values. (C) 1998 Elsevier Science B.V. All rights reserved.