Bioanalysis and enantioseparation of dl-carnitine in human plasma by the derivatization approach.

L-carnitine is an over the counter drug, used to treat disorders like cardiomyopathy, skeletal myopathy, hypoglycemia and hyperammonemia. Preparations containing D-carnitine should be avoided by dialysis patients because it has toxic influence on biochemical processes by inhibiting the carnitine acetyltransferase. Therefore, it is of utmost importance to assess and control the content of D-carnitine. A HPLC method was developed and validated for determination and enantiomeric resolution of DL-carnitine in human plasma by derivatization approach. (S)-Naproxen-based three derivatizing reagents were synthesized and applied. The limit of detection values were found to be 1.26 and 1.35 ng ml(-1) for the two isomers. The method is simple, reproducible, and can be used for routine analysis in laboratories for control of enantiomeric purity of carnitine.