Simultaneous Determination of Copper, Lead, and Cadmium at Hexagonal Mesoporous Silica Immobilized Quercetin Modified Carbon Paste Electrode

Fangquan Xia,Zhen Liu,Xin Zhang,Danzi Sun,Changli Zhou,Yanmin Dong

doi:10.1155/2010/824197

Abstract

A new method was developed for simultaneous determination of copper, lead, and cadmium, based on their voltammetric response at a carbon paste electrode modified with hexagonal mesoporous silica (HMS) immobilized quercetin (HMS-Qu/CPE). Compared with quercetin modified carbon paste electrode (Qu/CPE) and quercetin ionic liquid modified carbon paste electrode (Qu-IL/CPE), the HMS-Qu/CPE exhibited improved selectivity and high sensitivity toward the detection of copper, lead, and cadmium. The properties of the HMS-Qu/CPE in 0.1 M HCOONa-HCl buffer solution (pH4.7) were investigated by adsorptive stripping voltammetry (ASV) and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of copper, lead, and cadmium at the modified electrodes and factors affecting the preconcentration procedures were also investigated. Detection limits of 5.0, 0.8, 1.0 nM for copper, lead, and cadmium were obtained, respectively. The method is simple, fast, sensitive, and selective, and is successfully applied to soil sample.

Highlights

Heavy metal contamination in the environment is a major concern worldwide because of the toxicity of these metals and their potential threat to human health
Yantasee [22,23,24,25,26,27] and coworkers have reported on simultaneous determination of copper, lead, and cadmium using a carbon paste electrode modified with mesoporous silica
The results show that hexagonal mesoporous silica (HMS)-quercetin modified carbon paste electrode (Qu/carbon paste electrode (CPE)) as a working electrode exhibits higher sensitivity and selectivity toward the detection of copper, lead and cadmium than Qu/CPE, and Qu-Ionic liquids (IL)/CPE

Summary

Introduction

Heavy metal contamination in the environment is a major concern worldwide because of the toxicity of these metals and their potential threat to human health. There are no reports about simultaneous determination of copper, lead, and cadmium by using Qu modified electrode. Yantasee [22,23,24,25,26,27] and coworkers have reported on simultaneous determination of copper, lead, and cadmium using a carbon paste electrode modified with mesoporous silica. We developed a more simple and sensitive electrochemical method for simultaneous determination of copper, lead and cadmium utilizing the excellent properties of HMS and Qu. In this work, a new quercetin modified carbon paste electrode (Qu/CPE), quercetin ionic liquid modified carbon paste electrode (Qu-IL/CPE), and an HMS immobilized quercetin carbon paste electrode (HMSQu/CPE) were fabricated, respectively. A novel electrochemical method is developed for simultaneous determination of copper, lead, and cadmium, and applied to the analysis of soil samples with satisfying results

Experimental

Results and Discussion

Conclusion