DIRECT CHIRAL SEPARATION OF AMINO-ACIDS DERIVATIZED WITH 2-(9-ANTHRYL)ETHYL CHLOROFORMATE BY CAPILLARY ELECTROPHORESIS USING CYCLODEXTRINS AS CHIRAL SELECTORS - EFFECT OF ORGANIC MODIFIERS ON RESOLUTION AND ENANTIOMERIC ELUTION ORDER

Direct chiral separation of amino acids derivatized by 2-(9-anthryl)et hyl chloroformate (AEOC) has been performed by capillary electrophores is in capillary zone electrophoretic (CZE) mode and micellar electroki netic (MEKC) mode using cyclodextrins (CDs) as chiral selectors. The c oncentrations of chiral selector, surfactant and organic modifier were optimized. Application of beta- and gamma-CD as chiral selectors in M EKC, resulted in D/L separation of 12 and 13 amino acids, respectively . In CZE, chiral separation was obtained only with gamma-CD, 8 amino a cids were chirally separated in this mode. Separation in the MEKC mode resulted in higher resolutions of the enantiomers than in the CZE mod e. Addition of 2-propanol to the buffer caused reversal of the enantio meric elution order for some amino acids in MEKC mode.