High sensitivity simultaneous determination in hair of the major constituents of ecstasy (3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxyethylamphetamine) by high-performance liquid chromatography with direct fluorescence detection

A simple, but sensitive and specific high-performance liquid chromatographi c assay for the simultaneous determination of the major constituents of ''e cstasy'' [i.e. 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxy amphetemine (MDA), 3,4-methylenedioxyethylamphetamine (MDE)] with direct fl uorimetric detection, particularly intended for the routine analysis of hai r, is described. Hair samples (100 mg) were overnight incubated in 1 ml of 0.25 M HCl at 45 degrees C and extracted with a commercial liquid-liquid me thod. The dried residue reconstituted with 500 mu l of 0.05 M NaH2PO4 pH 5. 2 was injected. Isocratic reversed-phase liquid chromatography was carried out on a column (250X4.6 mm I.D.) packed with spherical 5-mu m poly(styrene -divinylbenzene) particles; the mobile phase was composed of 0.1 M potassiu m phosphate (pH 3)-acetonitrile (82:18). The excitation and the emission wa velengths were set to 285 and 320 nm, respectively. Under the described con ditions, MDA, MDMA and MDE eluted in symmetric peaks with an analysis time of 30 min. The limit of detection was lower than 1 ng/ml, with a signal-to- noise ratio of 5, for each compound in solution, allowing a cut-off of 0.1 ng/mg in the hair matrix to be established. The intra-day precision (n=6) o f the assay was characterised by RSDs between 1.0 and 3.0% and between 0.52 and 0.88% for concentrations of 10 and 100 ng/ml, respectively; in day-to- day precision tests (n=6), RSDs ranged between 5.12 and 11.12%, respectivel y, for the same concentrations. Interferences from as many as 92 therapeuti c and/or abused drugs currently in use in the population were excluded, inc luding N-methyl-1-(3,4-methylenedioxyphenyl)-2 butanamine (MBDB). (C) 1999 Elsevier Science B.V. All rights reserved.