HAIR ANALYSIS FOR DRUGS OF ABUSE .18. 3,4-METHYLENEDIOXYMETHAMPHETAMINE (MDMA) DISPOSITION IN HAIR ROOTS AND USE IN IDENTIFICATION OF ACUTEMDMA POISONING

Disposition of 3,4-methylenedioxymethamphetamine (MDMA) in hair roots was studied using rats and the hair root samples were evaluated to pro ve acute MDMA poisoning. The back hair of male pigmented hairy rats (n =6) mas shaved and 5d later the animals mere intraperitoneally adminis tered with acute poisonous doses (20, 40, 60, 80 and 100 mg/kg) of MDM A. Roots of the hairs mere then plucked out with a hair nipper 5 min a nd, 0.5, 1, 2, 6 and 24h after injection. The hair root samples mere, directly or after being washed with detergent, extracted with methanol -5 N HCl (20: 1) under ultrasonication in ice-cold mater for 4h. After filtration and evaporation, the residue was derivatized with pentaflu oropropionic anhydride and analyzed by GC/MS. From all samples includi ng the 5 min sample, MDMA was detected at high concentrations (up to 1 56 ng/mg) accompanied by 3,4-methylenedioxyamphetamine (MDA). Some of the animals died within 2h after administration, but in the surviving rats the MDMA concentrations in the hair roots increased up to 6h and then slowly decreased until 24h. The remaining MDMA after washing appa rently increased from 13-31% at 0.5h to 51-83% at 24h in the surviving rats. These facts show that most of drugs in the hair roots are not y et immobilized in the early stage and are thereafter gradually incorpo rated into the hair shaft. Increase of the MDMA concentration stopped soon after death of the animal, probably due to the cessation of hair growth. Although the ratios of MDA/MDMA steadily increased over time, those after death plateaued, probably due to the cessation of metaboli sm after death. It was clearly shown that MDMA is more quickly incorpo rated into and more firmly retained in hair than methamphetamine (MA) by comparing their disposition in hair roots.