Boron-Doped Diamond Electrode as Sensitive and Selective Green Electroanalytical Tool for Heavy Metals Environmental Monitoring: Zinc Detection in Rubber Industry Waste

A simple and sensitive electroanalytical technique for the detection and quantification of zinc has been developed that demonstrates beneficial analytical features of boron-doped diamond electrode. The influence of deposition potential on the stripping peak current of zinc was studied, and optimum value of -1.7 V vs. Ag/AgCl electrode was chosen. Optical and atomic force microscopic studies showed that the mechanism of deposition process is governed by nucleation by which first nanoparticles and then grains of zinc are formed. The detection limit of 4.7×10 mol·l, good repeatability (relative standard deviation of 3.2%) as well as wide linear dynamic range from 5×10 to 5×10 mol·l were obtained in 0.1 mol·l KCl for deposition time of 120 s. Interference from other heavy metals such as Hg, Cu, Pb, and Cd do not significantly influence anodic stripping peak of zinc even in a 100-fold excess. The method was applied in analysis of zinc in environmental rubber industry samples with results in good agreement with those obtained by atomic absorption spectrometry, confirming that the boron-doped diamond electrode is an excellent sensing tool for heavy metals environmental monitoring.