Electro Generating Cu+2 Ions Based on Electrochemically Modified CPE for The Determination of Malathion Pesticide using Valid SW-ASV Method

Abstract

Abstract This work investigates the validation of SW-ASV method for the determination of malathion organophosphorus pesticide based on electrochemically modified CPE with copper metal. The surface of the modified CPE was constructed by electrodepositing copper layer at the accumulation step in 1mM CuSO4.5H2O, PBS at pH 6.6, E accumulation: -0.8 V, and T accumulation 240 s. The determining step was performed by adding different concentrations of malathion pesticide and applied the potential towards more positive potential at (-0.8 - +1.4 V) to enhance the oxidation of Cu0 metal. It was noticed that the malathion concentrations gradient enhances the oxidation peak current of copper at + 0.03V gradually. This was the paradigm for developing SW-ASV method and investigation of the method validation. SW-ASV method validation was performed in PBS at pH 6.6, potential window (-0.8 - +1.4 V), E accumulation: -0.8 V, T accumulation 240 s, and linearity range of malathion concentrations confined in (0–10µM). The calibration curve was constructed and R2 was equal to 0.99995 with good fitted linear relationship. LOD and LOQ were calculated to be 0.0247, and 0.08236 µM respectively. the raggedness of the test method was verified towards the deliberate variations for the CuSO4.5H2O concentration which closely varied to be (0.9, 1, and 1.1 mM) in accumulation step. Insignificant differences were observed between taken and measured concentration values of malathion. ANOVA for two sets of measurements using the standard GLC method and the suggested SW-ASV electroanalytical method was demonstrated via the calculations of F-value and t-value. F and t- values were calculated to be 1.698 and 0.289 respectively which not exceeded the tabulated F and t- values at degree of freedom equal to 4, resulting in the great similarity of results and ensuring the reliability of the suggested test method. The suggested SW-ASV method was used to perform the quality control routine analysis of the technical grade (95% - TC) and the pesticide formulation (57% - EC) of the malathion. Valid results were achieved with satisfactory limits of accuracy and precision.