Separation of carnitine enantiomers as the 9-anthroylnitrile derivatives and high-performance liquid chromatographic analysis on an ovomucoid-conjugated column.

9-Anthroylnitrile was used as an achiral reagent for the derivatization of carnitine. The reagent forms UV-absorbing derivatives with the hydroxyl groups of carnitine enantiomers under very mild conditions. The derivatives were separated by high-performance liquid chromatography on an ovomucoid-conjugated column with a mobile phase of acetonitrile-20 mM KH2PO4 (adjusted to pH 4.5 with phosphoric acid) (17:83, v/v). The separation factor (alpha) and resolution (Rs) of the enantiomers were 1.44 and 5.05, respectively. The calibration plots indicated good linearity over a sample concentration ranging from 0.2 to 1.0 mg ml-1, and the detection limit at 254 nm was 0.05 mg ml-1 for each carnitine enantiomer. The reproducibility in the analysis of 1 mg ml-1 of each enantiomer was within 2.0%. The method was applied successfully to the determination of carnitine enantiomers in pharmaceutical preparations.