Determination of Methylamphetamine in Urine by Differential Pulse Polarography

A new electroanalytical method for detecting methylamphetamine as a stimulant drug in human urine has been proposed for forensic purposes. Although methylamphetamine itself has no remarkable voltammetric waves at any electrode in various electrolytes, we have found that the copper complex of methylamphetamine obtained by the method of Feigl showed a well-defined peak at–0.56 V (vs. SCE) at a mercury electrode by differential pulse polarography (DPP) in an aqueous ethanol solution containing 0.25 M ammonium acetate. The peak height was linear as a function of the methyl-amphetamine concentration in the original test solutions in the region of at least 0–50 µg/ml. The concentrations of methylamphetamine determined by the present method for eight abusers’ urine samples were in excellent agreement with those obtained by the conventional methods (GC-MS analysis) so far used. The proposed method is rather simple in procedure, rapid and selective with a satisfactory detection limit (<0.125 mg/ml) for analysis of methylamphetamine, and would also be applicable for field use.