New and Effective Analytical Reagent of 5-(4-Aminophenyl)-1,3,4-Oxadiazole-2-thiol in The Determination of Copper and Lead

Copper(II) and lead(II) are hazardous ions in environmental samples. Determining these ions from the samples is an important issue in analytical chemistry. Currently, various methods with analytical reagents are used in the determination of Cu(II) and Pb(II) ions, however, these methods and analytical reagents are expensive, hazardous, time-consuming, and non-recyclable. In this research, it is recommended new analytical reagent named 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thiol in the determination of copper(II) and lead(II) by the amperometric titration method. It is found that this analytical reagent effectively determines the Cu(II) and Pb(II) ions from environmental samples by amperometric titration, which is time-saving and low-cost. This reagent is also recyclable. It was found: (i) the detection limit for lead(II) and copper(II) ions were 2.08 and 3 ppm, respectively; (ii) the complex of 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thiol with lead(II) and copper(II) ions have a sharp angle at 0.5 V and 0.75 V, respectively, indicating that these ions are determined at one solution with this reagent; (iii) it was found that the half-wave potential of 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thiol was 0.55 V, confirming that the reagent is a reducing agent. The selectivity of this reagent is very high. In the future, this reagent should be widely used in the analytical determination of Cu(II) and Pb(II) ions.