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.

Simple Strategy for Selective Determination of Levamisole in Seized Cocaine and Pharmaceutical Samples Using Disposable Screen‐printed Electrodes

“…However, adulterants and diluents promote false positive or negative results in color tests . Electrochemical techniques overcome these problems and they have been explored as an alternative for the determination of cocaine in seized street samples, as these techniques are fast and sensitive and enables on‐site analyses .…”

Voltammetric Determination of LSD with a Schiff Base – Chemically Modified Electrode in Aqueous Solution

“…complexes with Schiff bases of the Salen type can efficiently detect cocaine and have potential application in the forensic context [34][35][36] 38 , and its structure can be seen in Figure 1. All the voltammetric measurements were performed in triplicates in a room under incandescent light, at a fixed temperature of 24 °C.…”

“…(w/w) graphite:paraffin) didn´t show any oxidative process for the drug, as well as the carbon paste modified with the Schiff base. Because of this absence, and the previous works of the group using the uranyl complexes whit Schiff base for cocaine detection [34][35][36] , the modification of the electrode with [UO 2 (Ac-ophen)]•H 2 O was applied.…”

Electrochemical detection of fentanyl using screen-printed carbon electrodes with confirmatory analysis of fentanyl and its analogs in oral fluid using liquid chromatography-tandem mass spectrometry

“…The use of electrochemical methods for the analysis of drugs has been the topic of considerable interest to exploit the abovementioned qualities. The detection of drugs such as cannabis, 13 lysergic acid diethylamide (LSD), 14 cocaine, [15][16][17] synthetic cathinones, 18 codeine, 19 and heroin 20 have been suggested. As such, electrochemical analysis offers a versatile platform that is currently not used to its full potential for detecting a wide array of substances.…”

“…This approach utilized methoxy-substituted N,N'-ethylene-bis(salcylideneiminato)uranyl(VI) complexes to modify a carbon paste electrode along with cyclic voltammetry. The authors reported a working range of 1.0 x 10 -7 M to 1.3 x 10 -6 M 16. Finally, Asturias-Arribas et al reported cytochrome P450 2B4 based electrochemical biosensor for the detection of cocaine with an SPCE.…”