Tetrabutylammonium Chloride Modified Carbon Paste Electrode for Rapid and Highly Sensitive Voltammetric Determination of Carbendazim

Abstract

The voltammetric characterization and determination of fungicide carbendazim (methyl-1H-benzimidazol-2-yl-carbamate, CBZ) were performed using simple and highly sensitive electrochemical sensor based on tetrabutylammonium chloride (TBACl) ionic liquid as modifier of carbon paste electrode (CPE) and compared to conventional CPE in aqueous Britton-Robinson buffer solution as supporting electrolyte (pH 2.0–11.98). Cyclic voltammetric (CV) studies suggested that electrode reaction is mixed diffusion-adsorption controlled. Also, the square wave voltammetric (SWV) and square-wave adsorptive stripping voltammetric (SW-AdSV) methods were optimized for quantitation of CBZ. In the model solutions of pH 5.0, the linear calibration curves were obtained in CBZ concentration ranges from 2.5 to 280.0 ng ml−1 by SWV and from 1.5 to 40.0 ng ml−1 by SW-AdSV method (Eacc = −0.25 V, tacc = 180 s) with relative standard deviation lower than 2.0%. A great improvement in terms of CBZ electrochemical oxidation with low detection limit as 0.45 ng ml−1 was achieved using proposed highly sensitive SW-AdSV method. TBACl-CPE in combination with the optimized SWV and SW-AdSV methods was successfully applied for trace level determination of CBZ in spiked fruit juice and river water samples, respectively, with good recovery and reproducibility, demonstrating the reliability and accuracy of the developed methods.