Electrochemical determination of carbendazim in juice samples using carbon composite electrode modified with ion-exchange resin

This work describes a carbon composite modified electrode (CCME) easily prepared using a simple mixture of a commercial cation exchange resin (Amberlite IR 120H) as modifier, graphite powder and paraffin, which was successfully used for spontaneous preconcentration and voltametric determination of carbendazim (CBZ) in juice samples. Parameters such as amount of resin used in the composition of the electrode, pH and preconcentration time as well as instrumental parameters of differential pulse voltammetry (DPV) were studied. Under optimized conditions, the proposed sensor shows to be able to preconcentrate CBZ at an open circuit potential (OCP) condition and presented the highest analytical response in comparison to the unmodified electrode. An analytical curve was obtained for the CBZ determination employing the proposed CCME and showed a linear dynamic range (LDR) between 80.0 nmol L⁻¹ to 2.0 μmol L⁻¹, with a LOD of 19 nmol L⁻¹ and LOQ of 65 nmol L⁻¹. The effect of concomitants on the voltametric response was evaluated by addition and recovery study and a good selectivity was found. The proposed sensor was successfully applied for the determination of CBZ in spiked mango juice samples without any pretreatment.