Analytical and Bioanalytical Electrochemistry is an international scientific journal published online by the Center of Excellence in Electrochemistry at the University of Tehran, Tehran, Iran. The journal was published quarterly from 2009 to 2011, bimonthly from 2011 to 2018, and has been published in at least eight issues per year since 2018. Analytical and Bioanalytical Electrochemistry - 12 2 2020 02 01 Electroanalysis of the Herbicide Diquat by Electrochemical Detector Containing Particles of Clay in Environmental Water 168 179 38584 EN Hayat EL Ouafy Department of Chemistry and Environment, Laboratory of Chemical Processes and Applied Materials, Sultan Moulay Slimane University, Faculty of Science and Technology, Beni Mellal, Morocco Tarik EL Ouafy Department of Chemistry and Physics, Sultan Moulay Slimane University, Polydisciplinary Faculty, Khouribga, Morocco Mustapha Oubenali Department of Chemistry and Environment, Laboratory of Chemical Processes and Applied Materials, Sultan Moulay Slimane University, Faculty of Science and Technology, Beni Mellal, Morocco Mohammed EL Idrissi Department of Chemistry, Laboratory of Chemical Processes and Applied Materials, Sultan Moulay Slimane University, Polydisciplinary Faculty, Beni Mellal, Morocco Malika Echajia Department of Chemistry and Environment, Laboratory of Chemical Processes and Applied Materials, Sultan Moulay Slimane University, Faculty of Science and Technology, Beni Mellal, Morocco Aziz EL Haimouti Department of Chemistry and Physics, Sultan Moulay Slimane University, Polydisciplinary Faculty, Khouribga, Morocco Mohamed Mbarki Department of Chemistry and Environment, Laboratory of Chemical Processes and Applied Materials, Sultan Moulay Slimane University, Faculty of Science and Technology, Beni Mellal, Morocco Hassan Oulfajrite Department of Chemistry and Environment, Molecular Electrochemistry and Inorganic Materials team, Sultan Moulay Slimane University, Faculty of Science and Technology, Beni Mellal, Morocco Journal Article 2019 11 19 Clay modified carbon paste electrode (CPE-C) its applicability for electroanalysis of N, N’-ethylene-2,2’-bipyridinium (diquat) has been described in the present work. Electrochemical modification was performed by electronic impedance spectroscopy (EIS) and cyclic voltammetry (CV) in the range of -0.6 V to 1.2 V in 0.1 M K2SO4 (pH 3). The voltammetric method behavior of DQ is suggested where an anodic and cathodic peak appeared at Epa=0.55 V and Epc=0.1 V, successively. These peaks obtained from the reversible redox of DQ at the CPE-C surface. The optimal preconcentration time and percentage of clay insert were 10 min and 20% respectively. The proposed method exhibits certainly an electro-catalytic success toward DQ redox. The peaks current recorded using cyclic voltammetry has been linearly dependent on the DQ concentration ranging from 1×10-5 to 5×10-5 molL-1. The detection limit (DL) calculated for the anodic peak is 5.33×10-8 molL-1. Then relative standard deviation for 2×10-5 molL-1 diquat has been 4.3% for nine repetitions. The proposed detector has been successfully applied for DQ electroanalysis in a river water sample with a DL of 8.17×10-8 molL-1. https://www.abechem.com/article_38584_3d12d2874b4f02d7725c726942cc8b7e.pdf