title: Voltammetric determination of cocaine in confiscated samples using a carbon paste electrode modified with different [UO2(X-MeOsalen)(H2O)] · H2O complexes.
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)] · 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 × 104 μA · mol · L(-1) for cocaine concentrations ranging between 1.0 × 10(-7) and 1.3 × 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.
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, São Paulo, Brasil. lauraolliver@yahoo.com.br
authors.forename: Laura Siqueira
authors.initials: LS
authors.lastname: de Oliveira
authors.forename: Ana Paula dos Santos
authors.initials: AP
authors.lastname: Poles
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Balbino
authors.forename: Matheus Manoel Teles
authors.initials: MM
authors.lastname: de Menezes
authors.forename: José Fernando
authors.initials: JF
authors.lastname: de Andrade
authors.forename: Edward Ralph
authors.initials: ER
authors.lastname: Dockal
authors.forename: Heloísa Maria
authors.initials: HM
authors.lastname: Tristão
authors.forename: Marcelo Firmino
authors.initials: MF
authors.lastname: de Oliveira
mesh_terms: D002244:Carbon / Q000737:chemistry; D003042:Cocaine / Q000032:analysis*; D056831:Coordination Complexes / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D044707:Forensic Sciences; D012545:Schiff Bases / Q000737:chemistry; D014501:Uranium / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D004573:Electrolytes; D012545:Schiff Bases; D014501:Uranium; D002244:Carbon; D003042:Cocaine