DOI: 10.1002/elan.201400249 Electrochemical Degradation of the Pesticide Dimethenamid-P at Gold, DSA Platinum and Ruthenium Oxide Electrodes in Different Electrolytes O. S. Glavasˇki, [a] S. D. Petrovic´, [b] D. Z ˇ . Mijin, [b] M. B. Jovanovic´, [b] A. M. Dugandzˇic´, [b] T. M. Zeremski, [a] and M. L. Avramov Ivic´* [c] Industrial chemicals, pesticides, dyes and pharmaceuticals are persistent organic pollutants (POPs) and due to their high stability, to sunlight irradiation and resistance to mi- crobial attack and temperature, have been detected in ground, surface and drinking waters [1]. In order to im- prove removal of pesticides from waters, a large variety of advanced oxidation processes (AOPs) was recently de- veloped [1–3]. Electrochemical oxidation of pollutants can occur directly at anodes through the generation of physically adsorbed “active oxygen” (adsorbed hydroxyl radicals or chemisorbed “active oxygen” (oxygen in the oxide lattice) [4]. When indirect oxidation is concerned, anodically generated active chlorine can be used to oxi- dize pollutants [5]. The dimethenamid-P (2-chloro-N-(2,4-dimethyl-3- thienyl)-N-(2-methoxy-1-methylethyl)acetamide) belongs to the group of chloroacetamides. Together with other members of acetamide herbicides, it is an important tool in the plants protection against broadleaf weeds and annual grasses in row crops [6]. Dimethenamid-P molecu- lar structure is shown in Figure 1. Among acetamide herbicides, dimethenamid-P has a great application in the United States and in Europe for control of weeds in different crops. Although U.S. Envi- ronmental Protection Agency)s registered dimethenamid- P under Reduced-Risk Initiative (in 2000), there was an evidence of detected residues of these herbicides in ground and surface waters [7–11]. The relatively high sol- ubility in water (1449 mg dm À3 ) of this compound makes it mobile in the environment [12]. In Reference [13], the review with 132 references is fo- cused on the electroanalytical behavior of pesticides relat- ed to their structure on various electrodes. Dimethena- mid-P is not mentioned and is not published until now as well. The aim of this work is to test, for the first time, the degradation ability of dimethenamid-P on Au, DSA Ti/ PtOx and DSA Ti/RuO 2 electrodes with the two different electrochemical methods. The direct electrochemical deg- radation of dimethenamid-P using long term potential cy- cling at gold electrode in 0.05 M NaHCO 3 was performed by cyclic voltammetry. The degradation of pesticide by the reaction of indirect electrolysis with electrochemically [a] O. S. Glavasˇki, T. M. Zeremski Institute of Field and Vegetable Crops Maksima Gorkog 30, 21000 Novi Sad, Serbia [b] S. D. Petrovic´, D. Z ˇ . Mijin, M. B. Jovanovic´, A. M. Dugandzˇic´ Faculty of Technology and Metallurgy, Belgrade University Karnegijeva 4, 11120 Belgrade, Serbia [c] M. L. A. Ivic´ ICTM – Institute of Electrochemistry, University of Belgrade Njegosˇeva 12, 11000, Belgrade, Serbia *e-mail: milka@tmf.bg.ac.rs Supporting Information for this article is available on the WWW under http://dx.doi.org/10.1002/elan.201400249. Abstract : For the first time the electrochemical degrada- tion of the pesticide dimethenamid-P was studied. Its direct electrochemical degradation, using potential cy- cling at a gold electrode, was performed by cyclic voltam- metry and HPLC analysis of electrolyte after 72 h showed 56.8 % of degradation. HPLC-MS indicates the formation of degradation products through the elimination of chlor- ine atom and CÀN bond cleavage. By indirect electrolysis using DSA Ti/PtOx and DSA Ti/RuO 2 electrodes during 30 minutes 87.2 % and 88.3 % of dimethenamid-P was de- gradated, respectively. The high percentage of degrada- tion of dimethenamid-P was achieved with non time con- suming, simple and cheap electrochemical processes. Keywords: Cyclic voltammetry · Liquid chromatography · Electrolysis · Liquid mass spectroscopy Fig. 1. Structural formula of dimethenamid-P. www.electroanalysis.wiley-vch.de # 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Electroanalysis 2014, 26, 1877 – 1880 1877 Short Communication