Voltammetric Detection of the Herbicide Metamitron at a Bismuth Film Electrode in Nondeaerated Solution

Abstract

In this work, we present a novel application of bismuth film electrodes (BiFE) for the direct analysis of the herbicide metamitron (4-amino-3-methyl-6-phenyl-1,2,4-triazin-5one) in nondeaerated solutions by square-wave voltammetry (SWV) and differential pulse amperometry. Bismuth films were plated ex-situ onto carbon paste electrodes (CPE) by 240 s deposition at −0.600 V from a 0.10 M acetate buffer (pH 4.5) containing 0.50 mM bismuth nitrate. Metamitron SWV analytical signals were registered in 0.10 M acetate buffer (pH 4.5) solutions, where the herbicide reduction takes place at −0.675 V. The metamitron signals obtained with BiFE have the double sensitivity and a 50 mV positive potential shift when compared to those obtained with plain CPE. Under these conditions, the dynamic linear range of concentrations is comprised between 10 and 200 μM and the detection limit is 2 μM.