MDMA electrochemical determination in aqueous media containing illicit drugs and validation of a voltammetric methodology

Abstract

MDMA is the abbreviation for 3,4-methylenedioxymethamphetamine, which is commonly found in “ecstasy” pills. The psychoactive and euphoric effects that MDMA causes make this substance an illicit drug that is constantly seized by police forces. We describe a low-cost and fast voltammetric methodology that requires a carbon paste electrode (working electrode) in aqueous solution containing 0.1 mol L^-1 LiClO₄ as the supporting electrolyte. We conducted cyclic and square wave voltammetry and obtained limits of detection of 0.33 μg mL^-1 and 0.36 μg mL^-1, respectively, as others figures of merit for a complete validation. It includes the analysis main interfering substances, and results for seized samples were compared to those obtained by chromatography, which were close. An extended study of robustness were carried out by Youden’s test, that is inedited to electrochemical techniques when applied to forensic analysis. This test contributes to complete methodology validation and study of electrode cost and efficiency during electrochemical measurements involving a carbon paste electrode. In the end, this work presents a full validated methodology able to be applied in forensic laboratories.