Development of a method for cyclic voltametric determination of copper (II) ions in the composition of technological objects

The use of heteroatom organic reagents, such as ۵-(o-aminophenyl)-۱,۳,۴-oxadiazole-۲-thione, is important in developing selective and sensitive methods for the detection of Cu۲+ ions. For this purpose, the use of cyclic voltammetric analysis, one of the electrochemical analysis methods, leads to high selectivity. Optimal conditions for CV determination of Cu۲+ ion with ۵-(o-aminophenyl)-۱,۳,۴-oxadiazole-۲-thione reagent: found that the linear dependence of the analytical signal on the metal ion concentration at an electrode scanning speed of ۵۰ mV/s in ethyl alcohol solvent is ۱.۱۲-۹.۴ ppm/l. It has been proven that the formation of a complex between an organic reagent and a metal ion on the electrode surface occurs within ۶ seconds using chronoamperometric and integral pulse amperometric methods. The half-wave potential of the organic reagent was found to be ۰.۴۸ V, and that of the complex formed by the Cu²⁺ ion was ۰.۶۵ V, with the potential shifting to the positive side proving the formation of a complex. From the CV of the complex, it was determined that the anodic and cathodic diffusion coefficients were Dox=۲.۵۹*۱۰-۶sm۲/s; Dred=۲,۳۵۴*۱۰-۱۰sm۲/s. The fact that the determination of copper(II) ion is not interfered with by Cd(II), Zn(II), and Pb(II) cations in a ۱:۱ ratio indicates that the developed method has a high selectivity. The developed method found a lower detection limit of copper(II) ion of ۱.۱۲ μg/ml. The accuracy of the method was compared with the atomic absorption method, and the calculated Student's coefficient of ۲.۴۳ and Fisher's value of ۶.۳۷, which are smaller than the values in the table, prove that the accuracy of the method is high. The developed CV method for determining Cu۲+ ions was applied to the analysis of process water at the Almalyk Mining and Metallurgical Combine, and the relative standard deviation not exceeding ۰.۰۱۴۵ indicates the high accuracy of the method.

Keywords:

Cu (II) ions , chronoamperometry , Student' s coefficient , half-wave potential , cyclic voltammetry , analytical reagent , amperometric titration , manual potentiostat