Enantiomeric separation of underivatized small amines in conventional and on‐chip capillary electrophoresis with contactless conductivity detection

Abstract

The determination of the enantiomers of small non‐UV‐absorbing amines which otherwise can only be achieved with difficulty was possible by using a combination of the chiral crown ether (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid (18C₆H₄) and dimethyl‐β‐CD as selectors in CE and contactless conductivity measurement for detection. Alkylamines without any other functional group, amino alcohols, species with ether or ester groups and with a cyclic moiety were investigated. The detection limits were found to be about 1.0 μM and the determination is possible up to at least 1.0 mM. The determination of enantiomeric ratios of up to 99.5:0.5 was also found feasible.