Sensitive voltammetric approach for selective determination of a new generation fungicides mefentrifluconazole and fluxapyroxad

Abstract

Electrochemical behaviour of fungicides mefentrifluconazole and fluxapyroxad was investigated for the first time. Moreover, sensitive voltammetric methods for their determination, based on the oxidation, were developed. The proposed approaches allowed their simultaneous determination in mixtures. The determination was carried out by differential pulse voltammetry in combination with a boron -doped diamond working electrode in Britton-Robinson buffer (pH 9) in the presence of 33% acetonitrile. Low limits of quantification were achieved, namely 49.1 nmol L-1 for mefentrifluconazole and 70.2 nmol L-1 for fluxapyroxad. These methods were successfully applied to analysis of four real plant protection products containing both of the following analytes. Based on LC-MS analysis of the preparative electrolysis products, plausible compounds formed during the electrochemical oxidation of analytes were proposed and the obtained results were supported with HOMO spatial distribution calculations.