Electrochemical Behavior of Metribuzin on a Glassy Carbon Electrode in an Aqueous Medium including Quantitative Studies by Anodic Stripping Voltammetry

摘要

The electrochemical behavior of the herbicide metribuzin was studied in an aqueous solution on glassy carbon, carbon paste/Nujol oil and carbon paste/castor oil using cyclic voltammetry, square-wave voltammetry, differential pulse voltammetry, controlled-potential coulometry and electrolysis, for quantification and decontamination purposes. The main electrolytic products obtained from the reduction of metribuzin, after consumption of 8.26 mol electron mol(-1), were deaminometribuzin and diketometribuzin. The anodic wave observed after electroreduction is associated with the oxidation of the methylthiolate generated in the electrolytic process. This wave was used to quantitatively determine metribuzin in a commercial sample by anodic stripping voltammetry. The electro-Fenton method was employed to promote decontamination by eliminating the herbicide, resulting in 80% of mineralization of the metribuzin.