HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND CAPILLARY ELECTROPHORESIS OF L-CARNITINE AND D-CARNITINE BY PRECOLUMN DIASTEREOMERIC DERIVATIZATION

A new method for the simultaneous assay of D- and L-enantiomers of car nitine is described. The method is based on precolumn derivatization w ith (+)-1-(9-fluorenyl)ethyl chloroformate [(+)FLEC] producing a diast ereomeric derivative which can be detected both by UV absorbance and f luorescence detection. Also acyl esters of carnitine can be processed with this method, after alkaline hydrolysis. The D-enantiomer of carni tine and acylcarnitine can be detected at a concentration as low as 0. 2% in the raw material and in pharmaceuticals. Assays can be carried o ut using an autoinjector either by HPLC or capillary electrophoresis ( CE) because the derivative proved to be very stable. Its application i s proposed for the routine assay of the enantiomeric excess of L-carni tine and their acyl esters in pharmaceutical products.