Electro-oxidative polymerization of Schiff-base of 1,8-diaminonaphthaline and 3-acetylthiophene. I. Preparation and study the redox behaviour of the resulting polymer

Voltammetric determination of cocaine in confiscated samples using a carbon paste electrode modified with different [UO2(X-MeOsalen)(H2O)] · H2O complexes

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.