Determinação voltamétrica de metais em meio aquoso e etanólico, empregando eletrodos de diamante dopado com boro /

Abstract

The presence of toxic potentially metals in aquatic bodies and biofuels has been increasing considerably in recent years, and several harmful aspects have been reported in the literature due to their presence in these matrices. The detection of these contaminants with adequate selectivity, sensitivity and reproducibility is essential for reliable methodologies in the determination of these metal ions. Stripping Voltammetry are important electrochemical techniques in trace metal analysis. This work sought to carry out a complete study about the Anodic Stripping Voltammetry (ASV) Technique, in the determination of metals in aqueous and ethanoic environments, using the BDD electrode as the working electrode. In this way, a study of the optimization of the parameters of the ASV technique coupled to square wave voltammetry (SWASV) was performed: Accumulation Time (Tacc), Accumulation Potential (Eacc), Frequency (f) and amplitude (a), using BDD electrodes with level of 5000 and 8000 ppm doping in the determination of the Fe3+, Cu2+, Zn2+, Pb2+ and Cd2+ species in aqueous and ethanoic environments. After parameter optimization, the simultaneous determination of these metallic species was performed for the first time using the DDB electrode in aqueous and ethanolic media. Analytical curves were developed to estimate detection and quantification limits, reaching detection limit values (LD) of less than 2 μg / L for all species under study. The optimized methodology was applied to real fuel ethanol samples and optimal recovery values were found. Through these results it is possible to infer that the BDD electrode can be used for the determination of these metal species in aqueous and ethanoic environments.