Determination of Ag(I) Ion at a Modified Carbon Paste Electrode Containing N,N′-Diphenyl Oxamide

Abstract

New approach for the determination of Ag(I) ion was performed by using a carbon paste electrode (CPE) containing N,N′-Diphenyl oxamide (DPO) with anodic stripping voltammetry. The CMEs have been prepared by making carbon paste mixtures containing an appropriate amount of DPO salt coated onto graphite particles to analyze trace metal ions via complexation followed by stripping voltammetry. Various experimental parameters affecting the response, such as pH, deposition time, temperature, and electrode composition, were carefully optimized. Using differential pulse anodic stripping voltammetry, the logarithmic linear response range for the Ag(I) ion was 1.0 × 10 -7 - 5.0 × 10-9 M at the deposition time of 10 min, with the detection limit was 7.0 × 10-10 M. The detection limit adopted from anodic stripping differential pulse voltammetry was 7.0 × 10-10 M for silver and the relative standard deviation was ± 3.2% at a 5.0 × 10-8 M of Ag(I) ion (n = 7). The proposed electrode shows a very good selectivity for Ag(I) in a standard solution containing several metals at optimized conditions.