Enantiomeric separation of promethazine and D,L-alpha-amino-beta-[4-(1,2-dihydro-2-oxo-quinoline)] propionic acid drugs by capillary zone electrophoresis using albumin as chiral selectors

The enantiomeric separation of promethazine and D,L-alpha-amino-beta-[4-(1, 2-dihydro-2-oxo-quinonline)] propionic acid (AOQ) drugs using albumin as ch iral selector by capillary zone electrophoresis (CZE) was developed. Severa l influencing factors, the capillaries pretreatment, electrolyte type, pH i n background electrolyte (BGE), proteins or organic solvents as chiral addi tives, were optimized. Direct baseline separation of chiral promethazine wa s successfully achieved within 13 min by using 50 mM phosphate buffer solut ion of pH 7.6 which contains 50 mu M bovine serum albumin (RSA) without any organic modifiers. It was found that the BSA has the ability of enantio-se lectivity to promethazine only when it is in a negatively charged state. AO Q showed varied migration patterns in different coated capillaries. Baselin e separation of AOQ was obtained only in polyacrylamide-coated capillary us ing the electrolyte of pH 7.4, SO mM phosphate buffer solution containing 5 0 mu M human serum albumin (HSA). Alternatively nearly baseline separation of AOQ can be obtained in the HSA-coated capillary under the same condition s. The numbers of theoretical plates for the separation of AOQ in HSA-coate d capillary and polyacrylamide-coated capillary were 23172 and 18723, respe ctively. (C) 1999 Elsevier Science B.V. All rights reserved.