Evaluation of hair roots for detection of methamphetamine and 3,4-methylenedioxymethamphetamine abuse by use of an HPLC-chemiluminescence method.
We describe the use of hair roots as a matrix for detection of methamphetamine (MP) and 3,4-methylenedioxymethamphetamine (MDMA) abuse. The concentration of drugs was determined in rat hair roots, hair shafts, and plasma after a single administration of MP or MDMA, by use of an HPLC-peroxyoxalate chemiluminescence (PO-CL) method involving column switching. Plasma and hair roots and shafts were collected from male Wistar rats before and after administration of MP (10 mg kg(-1), i.p.). In addition, the roots and shafts of pigmented and non-pigmented hair of male Lister hooded rats were collected after administration of MDMA (10 mg kg(-1), i.p.). The concentrations of MP and MDMA in plasma and hair were determined by use of the HPLC-PO-CL method, with satisfactory sensitivity and reproducibility. The concentration of MP in hair roots 1-14 days after administration ranged from 0.038 to 0.115 ng mg(-1) (n 3). By use of the HPLC-PO-CL method, MP could be detected in hair roots for longer (up to 14 days) than it could be detected in conventional biological specimens, for example plasma (1 day), and MDMA was detected in hair roots from 1 to 10 days after administration. The AUC(1-10) (ng day mg(-1)) for MDMA in roots of non-pigmented and pigmented hair was comparable (4.93 ± 2.09 vs. 6.67 ± 1.28, n 3), whereas AUC(1-14) for hair shafts differed significantly (1.86 ± 0.93 vs. 4.58 ± 0.63, P < 0.05, n 3). The window for detecting MP (or MDMA) in hair roots under our conditions was 1-14 (or 1-10) days.