Determination of Zn2+ and Cd2+ by glassy carbon electrode modified with Perilla frutescens activated carbon

Abstract

A Perilla frutescens (L.) Britton activated carbon that had high specific surface area (HSAPFAC) was modified on the surface of the glassy carbon electrode (GCE) for preparing a HSAPFAC/GCE, and on this basis, a differential pulse voltammetry (DPV) method for the simultaneous determination of zinc and cadmium ions (Zn2+ and Cd2+) was developed by using HSAPFAC/GCE. The determination conditions such as the film thickness, deposition potential, deposition time, and electrolyte acidity were investigated. The amperometric determination was carried out in a NaAc–HAc buffer solution (0.1 mol L−1, pH 5.5) after enriching for 550 s at –1.3 V. The oxidation peaks appear at –1.160 V and –0.845 V for Zn2+ and Cd2+, respectively. The oxidation peak currents of Zn2+ and Cd2+ are proportional to their concentrations in the ranges of 0.5 ∼ 20 μg L−1 and 0.25 ∼ 10 μg L−1, with the detection limits of 0.15 μg L−1 and 0.01 μg L−1 (signal/noise (S/N) = 3). The proposed method was applied to the determination of Zn2+ and Cd2+ in tap water samples. The recoveries were 101.6%∼103.0% and 84.0%∼88.8%, respectively.