APPLICATION OF HEPARIN TO CHIRAL SEPARATIONS OF ANTIHISTAMINES BY CAPILLARY-ELECTROPHORESIS

A study of the chiral separations of antihistamines, including phenira mine, chlorpheniramine, brompheniramine, carbinoxamine and doxylamine in capillary electrophoresis (CE) was accomplished using heparin as a chiral additive (CA) and phosphate buffer as the background electrolyt e. Several factors were shown to affect both the selectivity and the m igration time, including concentration of heparin, concentration of bu ffer, and the pH. A dual mechanism involving both inclusion complexati on and ionic interactions with heparin is thought to be responsible fo r the chiral recognition. In the pH range of 2.6-3.5 and reversed pola rity, baseline resolutions were obtained using a wide range of buffer and heparin concentrations. Typically, chiral resolution was obtained within 50 min.