Ultra trace level determination of fenoxanil by highly sensitive square wave adsorptive stripping voltammetry in real samples with a renewable silver amalgam film electrode

A new, simple, and highly sensitive voltammetric method for the determination of low concentrations of a novel fungicide, fenoxanil (Fen), was developed using square wave voltammetry (SWV) and square wave adsorptive stripping voltammetry (SWAdSV) on a renewable silver amalgam film electrode (Hg(Ag)FE). The electrochemical reduction of Fen at the Hg(Ag)FE in Britton-Robinson (B-R) buffer at pH 6.8 was studied for the first time. The effect of the supporting electrolyte, pH, conditioning potential and conditioning time, frequency, amplitude, step potential, and accumulation potential and accumulation time were studied to select the optimum experimental conditions. The developed method can determine Fen in the concentration range of 5 x 10(-7)-4 x 10(-6) mol L-1 for SWV and 1 x 10(-10)-9 x 10(-10) mol L-1 for SWAdSV. Validation of the method was carried out. The method was successfully applied for trace level determination of Fen in spiked Warta River water and spiked rice samples by the standard addition method. The interference of common agents and metal ions was also examined. Fen adsorption at the mercury electrode was studied. (C) 2014 Elsevier B.V. All rights reserved.