Enantioselective high-performance liquid chromatographic method for the determination of methadone and its main metabolite in urine using an AGP and a C-8 column coupled serially

A simple and sensitive method for the enantioselective high-performance Liq uid chromatographic determination of methadone and its main metabolite, EDD P, in human urine is described. (-)-(R)-Methadone, (+)-(S)-methadone, (+)-( R)-EDDP, (-)-(S)-EDDP and imipramine as an internal standard are detected b y ultraviolet detection at 200 nn. The enantiomers of methadone and EDDP we re extracted from human urine by a simple Liquid-Liquid extraction procedur e. The extracted sample was reconstructed in mobile phase and the enantiome rs of methadone and EDDP were quantitatively separated by HPLC on a short a nalytical LiChrospher RPs column coupled in series with a chiral AGP column . Determination of all four enantiomers was possible in the range of 0.03 t o 2.5 mu M. The recoveries of methadone enantiomers and EDDP enantiomers ad ded to human urine were about 90% and 80%, respectively. The method was app licable for determination of methadone enantiomers and the enantiomers of i ts main metabolite in urine samples from methadone maintenance patients and patients suffering from severe chronic pain. (C) 1999 Elsevier Science B.V . All rights reserved.