Determination of Carbendazim by an Ionic Liquid-Modified Carbon Paste Electrode

Abstract

A new method for the electroanalytical determination of carbendazim is reported using a novel ionic liquid-based carbon paste electrode. 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 1-butyl-1-methylpyrrolidinium bis(trifluoromethyl-sulfonyl)imide were used as additives in the paste for electrode fabrication. The electrodes were characterized by cyclic voltammetry of the couple and scanning electron microscopy. The carbon paste electrode containing 19% 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide was selected for the electrochemical determination of carbendazim by differential pulse adsorptive stripping voltammetry. The influence of electrolyte pH, accumulation potential and time, and the presence of selected pesticides on electrochemical behavior of carbendazim were characterized. The optimal conditions for differential pulse adsorptive stripping voltammetry of carbendazim were determined to be a pH 5.0 Britton–Robinson buffer, an accumulation potential of −0.05 V, an accumulation time of 120 s, a start potential of −0.10 V vs. the reference; an end potential of +1.30 V, and a scan rate of 0.050 V s−1. The linear dynamic range of the method was from 0.010 to 0.247 mg L−1 with a correlation coefficient of 0.9995. The recovery was 104.1% in fortified tap water, demonstrating its suitability for the analysis of water.