Author/Authors :
Ouafy, Hayat EL Department of Chemistry and Environment - Laboratory of Chemical Processes and Applied Materials - Sultan Moulay Slimane University - Faculty of Science and Technology - Beni Mellal, Morocco , EL Ouafy, Tarik Department of Chemistry and Physics - Sultan Moulay Slimane University - Polydisciplinary Faculty - Khouribga, Morocco , Oubenali, Mustapha Department of Chemistry and Environment - Laboratory of Chemical Processes and Applied Materials - Sultan Moulay Slimane University - Faculty of Science and Technology - Beni Mellal, Morocco , EL Idrissi, Mohammed Department of Chemistry - Laboratory of Chemical Processes and Applied Materials - Sultan Moulay Slimane University - Polydisciplinary Faculty - Beni Mellal, Morocco , Echajia, Malika Department of Chemistry and Environment - Laboratory of Chemical Processes and Applied Materials - Sultan Moulay Slimane University - Faculty of Science and Technology - Beni Mellal, Morocco , EL Haimouti, Aziz Department of Chemistry and Physics - Sultan Moulay Slimane University - Polydisciplinary Faculty - Khouribga, Morocco , Mbarki, Mohamed Department of Chemistry and Environment - Laboratory of Chemical Processes and Applied Materials - Sultan Moulay Slimane University - Faculty of Science and Technology - Beni Mellal, Morocco , Oulfajrite, Hassan Department of Chemistry and Environment - Molecular Electrochemistry and Inorganic Materials team - Sultan Moulay Slimane University - Faculty of Science and Technology - Beni Mellal, Morocco
Abstract :
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.
Keywords :
Electroanalysis , N, N’-ethylene-2,2’-bipyridinium , Clay , Cyclic voltammetry , Electrochemical impedance spectroscopy
