Analysis of heavy metals in ecstasy tablets by electrochemical methods

Abstract

Trace amounts of heavy metals have been analysed by electrochemical techniques in ecstasy tablets obtained from different police seizures in Spain. Lead, cadmium, copper and zinc were determined by differential-pulse anodic stripping voltammetry at a hanging mercury drop electrode, whereas nickel and cobalt were determined by adsorptive differential-pulse cathodic stripping voltammetry from their dimethylglyoxime complexes, M(DMG)₂. The performance of the procedure was compared with electrothermal atomic absorption spectrometry. The procedure was applied to the determination of these elements in nine ecstasy samples, finding that Zn is the element present in the highest concentration, ranging from 0.3 to 200 mg kg⁻¹, Ni, Cu appear below 15 mg kg⁻¹ and Pb below 8 mg kg⁻¹, while Cd and Co levels were always lower than 0.51 mg kg⁻¹.

Keywords:

• Ecstasy
• (3,4-methylenedioxymethamphetamine) MDMA
• heavy metals
• stripping voltammetry
• electrothermal atomic absorption spectrometry

Acknowledgements

The authors are grateful to the Junta de Castilla y León (Consejería de Educación y Cultura VA115/04) for the financial support of this study.