Organic/Water Interface Electrochemistry for the Direct Detection of a Model Pesticide in Soybean Oil

An electrochemical methodology was applied directly at an organic/water interface to detect a pesticide directly in oil, without the necessity of pre-treatment of the sample. The oil phase was composed of soybean oil contaminated with carbendazim (methyl-2-benzimidazolecarbamate), and the aqueous phase consisted of a conventional BrittonRobinson buffer with a pH of 2. A boron-doped diamond (BDD) electrode was placed directly at the interface of the two immiscible liquids. The ionic strength played an important role in the oxidation of carbendazim in our interfacial studies, as indicated by the oxidation currents varying from zero to 12 µA, depending on the position of the electrode.