Methadone and EDDP in hair from human subjects following a maintenance program: results of a pilot study

A specific method has been developed for the quantitative determination of methadone (MTD) and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-dip henylpyrrolidine (EDDP), in hair. An amount of 50 mg hair samples were incubated in 0.01 M HCl overnight at 6 0 C and deuterated internal standards of MTD and EDDP were added before ext raction. Hydrolyzed solutions were extracted by automated solid-phase extra ction procedure and analyzed on a gas chromatography (GC) coupled to a ion trap mass spectrometer (MS). Positive chemical ionization was used with ace tonitrile as liquid reagent. The different validation parameters, linearity , repeatability, recovery and detection limits are presented. A relative st andard deviation (R.S.D.) of 12 and 11% was obtained for the repeatability of MTD and EDDP. respectively. The limits of quantification (LOQ) was 0.05 ng/mg for MTD and 0.2 ng/mg for EDDP. A number of 26 hair samples from human subjects following a long-term MTD t herapy were analyzed by this method. Blood samples of these subjects were a nalyzed with a routine method using a liquid-liquid extraction and GC/nitro gen phosphorus detector (NPD). MTD was quantified in blood and hair samples and EDDP found in 50% of the hair sample. A comparison was made between the concentrations found in blood or in hair and the dose administrated. This study could demonstrate that there is no r elation between the administrated dose and MTD or EDDP concentrations in ha ir. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.