Voltammetric detection of 3,4-methylenedioxymethamphetamine (mdma) in saliva in low cost systems

Abstract

The consumption of ecstasy has increased in recent years due to the psychostimulating effects of MDMA (3,4-methylenedioxymethamphetamine), its main active ingredient. With that, there is a great concern on the part of the authorities, mainly for the control of drivers who drive under the influence of drugs. The verification of the drug use is usually made by the presence of its metabolites in blood or urine, but alternative matrices such as oral fluid, sweat and hair have been investigated over past decades. For the oral fluid the collection is simple, noninvasive, and less susceptible to adulteration and can be used to show recent use of the drug. Portable equipment such as Drugwipe®, Cozart RapiScan, and Ora-Check are routinely used because they easy and simple to operate and give the result quickly. Another technique that features portability and easy handling is electrochemistry. This work demonstrates that it is possible to identify MDMA in oral fluid using the carbon paste electrode, as working and auxiliary electrodes, and the screen printed carbon electrode (SPCE) with cyclic and square wave voltammetry. The presence of the drug could also be identified in real saliva, mixed with 0.1 mol L−1 LiClO4 as supporting electrolyte, in a concentration of 2.53 µg mL−1, demonstrating that it can be applied to identify the recent use of the drug, as well as the rapid tests already commercialized. Also, SPCE was used for the detection and quantification of MDMA in seized samples, using aqueous solution of 0.1 mol L−1 LiClO4, with limits of detection and quantification of 1.75 and 5.82 µg mL−1, respectively, and a linear range of 1.75 – 19.98 µg mL−1. These results support the use of these procedures in forensic laboratories as simple, rapid, and alternative methods for detecting MDMA in saliva and for analyzing seized drugs.