Voltammetric MDMA Analysis of Seized Ecstasy Samples

Abstract

(1) Background: 3,4-Methylenedioxymethamphetamine (MDMA) is an illicit drug that is sold as ecstasy. We aimed to develop a voltammetric method based on a chemically modified electrode (CME) to analyze MDMA. (2) Methods: The CME was evaluated with respect to the percentage of modifier, pre-concentration time, electroanalytical parameters, and selectivity. Then, the performance of the new voltammetric method was compared to the performance of color tests and chromatographic analyses (GC-MS and UPLC-MS) during the analysis of 11 seized ecstasy batches. (3) Results: The modifier percentage (v/v) of 1.5% provided the best CME. The electroanalytical parameters were in a linear range from 4.06 to 25.42 µmol L−1, SD = 0.018 µA, m = 84.0 × 103 µA L mol−1, r = 0.999, LD = 0.64 µmol L−1, and LQ = 2.17 µmol L−1. The CME was selective for MDMA. The MDMA concentration in the analyzed ecstasy lots ranged from 0 (without MDMA) to 63% (w/w). The voltammetric method developed for quantifying MDMA in ecstasy lots proved feasible and accurate (with a relative percentage error of ≤ ±13.2%). (4) Conclusions: The CME developed herein showed greater sensitivity (m) and lower LD and LQ for quantifying MDMA traces, paving the way for the use of voltammetric methods during forensic investigations.