Abstract

A new capillary zone electrophoretic method has been developed for the enantiomeric separation and quantification of enantiomers of carnitine. D- and L-carnitine were derivatized with 9-fluorenylmethyl chloroformate in a flow system, working on-line with the capillary electrophoretic equipment. The separation was performed using a selective chiral buffer containing 2,6-dimethyl-beta-cyclodextrin (heptakis). Triethanolamine was used as electroosmotic modifier and the separation was carried out in a uncoated capillary. Under the optimal conditions the resolution between D- and L-carnitine was 1.2 and the limits of detection for both isomers were about 5.0 mu M. The proposed method was applied to the determination of D-carnitine in excess of L-carnitine in synthetic samples, and the results demonstrated that the maximal D-:L-carnitine ratio determined was approximate to 1:100. (C) 1999 Elsevier Science B.V. All rights reserved.