Electrochemical and spectroscopic insights of interactions between alizarin red S and arsenite ions

摘要

Interferences of arsenite ions on electrocatalytic oxidation of alizarin red S (ARS) was studied using Pt and ITO electrodes. A Pt electrode can oxidize both arsenite ions and ARS molecules simultaneously. The oxidation wave of ARS exceeds that of arsenite until the [AsO2 (-)]/[ARS] ratio surpasses 0.07. Meanwhile, an ITO electrode can oxidize only ARS molecules. It was seen that the diffusion coefficient of ARS molecules decreased from 4.3 x 10(-6) cm(2) s(-1) to 1.68 x 10(-7) cm(2) s(-1) in the presence of arsenite ions. The electrokinetic investigation shows that ARS oxidation was a two-electron transfer consecutive process. The EIS studies showed that charge transfer resistance was increased in the presence of arsenite ions during ARS oxidation.