LIQUID CHROMATOGRAPHIC ENANTIOMER SEPARATION OF AMINO ACID ESTERS AS 9-ANTHRALDIMINE SCHIFF BASES USING POLYSACCHARIDE-DERIVED CHIRAL STATIONARY PHASES

The liquid chromatographic enantiomer separation of several amino acid methyl esters as 9-anthraldehyde Schiff base derivatives on coating and covalently bonded polysaccharide-derived chiral stationary phases (CSPs) is described. The 9-anthraldehyde imine derivatives of amino acid esters were readily prepared by stirring 9-anthraldehyde with the amino acid ester hydrochloride salts. The performance of Chiralcel OD among all examined CSPs was superior to that of the other CSPs for resolution of 9-anthraldimine derivatives of amino acid methyl esters. The enantiomers of all examined amino acid methyl esters as the 9-anthraldimine derivatives were base-line resolved on Chiralcel OD. The L-enantiomers of all analytes are preferentially retained on Chiralcel OD. The chromatographic methods developed in this study were applied in the determination of enantiomeric purity of some commercially available D- or L-amino acid methyl esters.