Electrochemical degradation of triketone herbicides and identification of their main degradation products

Abstract

The aim of this paper was the development and optimization of an electrochemical method for the degradation of two triketone herbicides, mesotrione, and sulcotrione, in a two-electrode undivided electrochemical cell equipped with commercially available, non-modified, electrode materials. The electrochemical parameters studied included five different electrode systems (Zr/Pt, Pd/Pt, C/Pt, Nb/Pt, and Ti/Pt), current densities (27.66, 55.33,..., 110.66mA·cm-2) and pH values (3, 7, and 9) in 0.05M sodium sulfate as supporting electrolyte. The electrical energy consumption and chemical oxygen demand were calculated for optimal conditions. The degradation efficiency was determined by high performance liquid chromatography (HPLC) equipped with a diode array detector, while the degradation products for both pesticides were identified and compared by ultra-high performance liquid chromatography (UHPLC)-mass spectrometry. The results could lead to an accurate estimate of their effect on the environment. A real water sample was used to study the influence of organic matter on pesticide degradation. Based on the results obtained the electrochemical treatment could be used for the successful removal of triketone herbicides from contaminated water.