Use of Chiral Crown Ethers in Capillary Electrophoresis

Chiral crown ethers are known to include stereoselectively compounds containing primary amino groups. This principle has successfully been applied in liquid chromatography (LC) using crown ether-based stationary phases (1 –10 ). Kuhn et al. (11 ) transferred this basic principle to capillary electrophoresis (CE) using (+)?18-crown-6-tetracarboxylic acid (Fig. 1 ) as a chiral selector added to the electrolyte for the chiral separation of amino acids. This crown ether was shown to be applicable also to the chiral separation of dipeptides (12 ,13 ) (Fig. 2 ), sympathomimetics (14 ) (Fig. 3 ), and various other drugs containing primary amino groups (15 ) by CE.