RAPID-DETERMINATION OF METHADONE AND ITS MAJOR METABOLITE IN BIOLOGICAL-FLUIDS BY GAS-LIQUID-CHROMATOGRAPHY WITH THERMIONIC DETECTION FOR MAINTENANCE TREATMENT OF OPIATE ADDICTS

A rapid gas-liquid chromatographic assay is developed for the quantifi cation of methadone (Mtd) and its major metabolite, 2-ethylidene-1,5-d imethyl-3,3-diphenylpyrrolidine (EDDP), in biological fluids of opiate addicts. After alkaline extraction from samples with lidocaine hydroc hloride as internal standard, Mtd and EDDP are separated on SP-2250 co lumn at 220 degrees C and detected with a thermionic detector. The chr omatographic time is about 6 min. The relative standard deviations (R. S.D.) of Mtd and EDDP standards are between 1.5 and 5.5%. Most drugs o f abuse (morphine, codeine, narcotine, cocaine, benzoylecgonine, cocae thylene, dextropropoxyphene etc) are shown not to interfere with this technique. The method has been applied to study the levels of Mtd and EDDP metabolite in serum, saliva and urine of patients under maintenan ce treatment for opiate dependence. EDDP levels were found higher than those of Mtd in urine samples from four treated patients, but lower i n serum and undetectable in saliva. However, Mtd concentrations were h igher in saliva than in serum. (C) 1998 Elsevier Science B.V. All righ ts reserved.