Voltammetric Determination of Cocaine in Confiscated Samples Using a Carbon Paste Electrode Modified with Different [UO2(X-MeOsalen)(H2O)]center dot H2O Complexes

Author(s)

de Oliveira, Laura Siqueira ^[1] ; dos Santos Poles, Ana Paula ^[1] ; Balbino, Marco Antonio ^[1] ; Teles de Menezes, Matheus Manoel ^[1] ; de Andrade, Jose Fernando ^[1] ; Dockal, Edward Ralph ^[2] ; Tristao, Heloisa Maria ^[3] ; de Oliveira, Marcelo Firmino ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Quim, Ctr Ciencias Exatas & Tecnol, BR-13565905 Sao Carlos, SP - Brazil

^[3] Superintendencia Policia Tecn Cient Estado Sao Pa, Nucleo Pericias Criminalist Ribeirao Preto, BR-14015040 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: SENSORS; v. 13, n. 6, p. 7668-7679, JUN 2013.
• Web of Science Citations: 16

Abstract

A fast and non-destructive voltammetric method to detect cocaine in confiscated samples based on carbon paste electrode modified with methoxy-substituted N,N'-ethylene-bis(salcylideneiminato)uranyl(VI)complexes, {[}UO2(X-MeOSalen)(H2O)]center dot H2O, where X corresponds to the positions 3, 4 or 5 of the methoxy group on the aromatic ring, is described. The electrochemical behavior of the modified electrode and the electrochemical detection of cocaine were investigated using cyclic voltammetry. Using 0.1 mol.L-1 KCl as supporting-electrolyte, a concentration-dependent, well-defined peak current for cocaine at 0.62 V, with an amperometric sensitivity of 6.25 x 10(4) mu A.mol.L-1 for cocaine concentrations ranging between 1.0 x 10(-7) and 1.3 x 10(-6) mol.L-1 was obtained. Chemical interference studies using lidocaine and procaine were performed. The position of the methoxy group affects the results, with the 3-methoxy derivative being the most sensitive. (AU)

• FAPESP's process: 12/00084-7 - Development of chemically modified electrodes for the voltammetric determination of cocaine, MDMA, LSD, and D-9-tetrahydrocannabinol in samples of forensic interest
• Grantee: Marcelo Firmino de Oliveira
• Support Opportunities: Regular Research Grants