Electrochemiluminescence and voltammetry of tris(2,2′-bipyridine)ruthenium (II) with amphetamine-type stimulants as coreactants: an application to the discrimination of methamphetamine

Abstract

We have tried to establish an electrochemical detection method for screening of the stimulants in the forensic samples using electrochemiluminescence (ECL) and voltammetric techniques. Amphetamine-type stimulants (ATSs), such as methamphetamine (MA), amphetamine (AM), dimethylamphetamine (DMA), and methoxyphenamine (MP) have been studied as coreactants in the [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) ECL system. There were two specific ECL peaks located at + 1.1 and + 1.4 V for MP, whereas there was only one ECL peak at + 1.1 V for MA and DMA, and no ECL response for AM. Different reaction mechanisms were proposed to understand the generation of ECL by the [Ru(bpy)3]2+/ATS system. Because the voltammetric responses of these ATSs at a glassy carbon electrode were also different, it was possible to detect MA without a separation process based on the characteristic ECL and cyclic voltammetric signals. By a combination of ECL and voltammetric measurements, a simple and rapid screening method for MA could be proposed, and was applied in the determination of MA in human urine samples with sufficient sensitivity. The present electrochemical approach seems to provide a new way for primary screening of MA in forensic application.