Study of the redox process of the molecules of MDMA, MDA and MDEA on surface of a chemically modify electrode with Schiff Bases: development of a voltammetric sensor for forensic interest

• Grant number: 19/04439-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2019
• End date: August 31, 2020
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Marcelo Firmino de Oliveira
• Grantee: Gustavo Murilo Alves
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 19/19796-6 - Fentanyl analysis at carbon paste electrodes modified with Schiff base complexes and screen-printed electrodes coupled to characterization of seized amphetamine samples employing SERS: contributions to public healthcare policies, BE.EP.IC

Abstract

According to ONU reports, the use of illicit drugs has increased, as well as the need for sensitive instrumental analytical techniques for the detection of these substances. Therefore, the present research project aims to study the oxidation-reduction of MDMA and its derivates on the surface of chemically carbon paste electrodes modified with 4 Schiff-type complexes: [Co (salen)], [Cu (salcn)], [Mn (salen)] and [VO (salen)], and evaluate the potential of these electrodes for use in voltammetric sensors capable of quantifying seized MDMA samples. For this, will be used a cell containing three electrodes: reference electrode, Ag / AgCl Metrohm®; electrode, platinum spiral and, as a working electrode, the chemically modified carbon paste electrode with Schiff base-type complexes, using as electrolyte KCl and PBS pH = 7, both 0.1 mol L-1. Initially, it is intended to perform the thermal stability analysis through TGA and DSC, and the study of morphology through SEM-EDS analysis, to later perform the electrochemical analysis, through cyclic voltammetry, differential pulse, square wave and of linear sweep in the potential range of -1 to 1.5 V, using a Metrohm® AUTOLAB 128N potentio stat model coupled to a computer. Together with the tests for MDMA determination in seized samples, studies will be carried out with possible interferents such as MDA and MDEA, where the results will be identified, classified and separated using PCA through the Pirouette program. The validation of the developed method will be done with the tests of repeatability, reproducibility and comparison with a methodology using high-performance liquid chromatography described in the literature, using phosphate buffer pH = 3 and acetonitrile (95: 5 /v ) and C-18 column with isocratic flow at 1 mL per minute, the wavelength being between 288 and 324 nm.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MURILO ALVES, GUSTAVO; SOARES CASTRO, ALEX; MCCORD, BRUCE ROYSTON; DE OLIVEIRA, MARCELO FIRMINO. MDMA Electrochemical Determination and Behavior at Carbon Screen-printed Electrodes: Cheap Tools for Forensic Applications. Electroanalysis, v. 33, n. 3, NOV 2020. (19/04439-3, 19/19796-6, 16/23825-3)