Electrochemistry of the synthetic tryptamine 5-MeO-MiPT at glassy carbon and screen-printed electrodes: A rapid and simple screening method for application in forensic analysis

Abstract

5-Methoxy-N-methyl-N-isopropyltryptamine (5-MeO-MiPT), also known as moxy, is a synthetic tryptamine analogue used recreationally as a hallucinogenic drug. This work investigates the electrochemical behaviour of 5-MeO-MiPT using carbon electrodes for the first time. Although 5-MeO-MiPT showed only one irreversible oxidation process at a glassy carbon electrode, many electrochemical processes were exhibited on a graphite screen-printed electrode (SPE-Gr). The oxidation reaction of 5-MeO-MiPT on both carbon electrode surfaces involves an adsorption-controlled process with the loss of one electron and one proton. A voltammetric screening method for 5-MeO-MiPT was performed in 0.1 mol L−1 phosphate buffer solution at pH 7.0 on the SPE-Gr using differential pulse adsorptive stripping voltammetry (DPAdSV). The proposed method showed a wide linear range (0.05–30.0 µmol L−1) and a sufficiently low limit of detection (0.015 µmol L−1) for application to seized forensic samples containing 5-MeO-MiPT. Good stability of the electrochemical responses for 5-MeO-MiPT detection on SPE-Gr was obtained, using the same or different electrodes (N = 3) with a relative standard deviation of less than 4.0%. Interference studies with other drugs demonstrated that the proposed sensor is selective for electrochemical screening of 5-MeO-MiPT. In addition, 5-MeO-MiPT was identified in a biological sample of synthetic urine and in real seized samples by the proposed method and confirmed by GC-MS. The analytical performance of SPE-Gr with DPAdSV for 5-MeO-MiPT detection shows great potential as a simple, fast, and selective screening method in forensic scenarios.