SEPARATION OF ENANTIOMERS AND ISOMERS OF AMINO-COMPOUNDS BY CAPILLARYELECTROPHORESIS AND HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY UTILIZING CROWN-ETHERS

Separation of enantiomers and isomers of a wide variety of primary ami nes by capillary electrophoresis (CE) was investigated employing charg ed and uncharged crown ethers. Enantiomer separation of primary amines by CE was successful through the addition of a chiral crown ether, 18 -crown-6 tetracarboxylic acid (18C6H(4)). Thirteen out of 17 enantiome rs tested were separated by CE with 18C6H(4). Low pH values (pH 1.9-2. 1) and relatively high Tris concentration (20 mM) were effective for t he fast enantiomer separation. Enantiomer separation of the same prima ry amines was also investigated by high-performance liquid chromatogra phy (HPLC) with a chiral Crownpak CR(+) column, although different chi ral crown ether moieties were employed in CE and HPLC. Other than enan tiomers, separation of positional isomers of aromatic amino compounds such as aminophenols, aminocresols was investigated by both CE with th ree kinds of 18-membered crown ethers and HPLC with a Crownpak CR(+) c olumn. The use of crown ethers for the separation of amino compounds i s discussed in viewpoint of practical applications. The optical purity testing of amino compounds is also demonstrated.