Determination of trace heavy metals in milk using an ionic liquid and bismuth oxide nanoparticles modified carbon paste electrode

JianFeng Ping,Jian Wu,YiBin Ying

doi:10.1007/s11434-012-5115-1

JianFeng Ping, Jian Wu + Show 1 more

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https://doi.org/10.1007/s11434-012-5115-1

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Journal: Science Bulletin	Publication Date: Apr 11, 2012
Citations: 41	License type: CC BY 2.0

Affiliation: Zhejiang University

Abstract

A novel carbon composite electrode modified with bismuth oxide nanoparticles and the ionic liquid n-octylpyridinium hexafluorophosphate was fabricated and used to simultaneously determine cadmium and lead levels using square wave anodic stripping voltammetry. This electrode combines the unique advantages of nanomaterials and ionic liquid with the low cost and easy fabrication of the carbon composite electrode. Compared with the traditional binder based composite electrode, our electrode exhibited well-defined and separate stripping voltammetric peaks for cadmium and lead. Furthermore, the antifouling capacity of the bismuth film electrode was significantly improved by the ionic liquid. Under optimized conditions, the linear range of the composite electrode was from 3.0 to 30.0 μg L−1 for both metal ions with a detection limit of 0.15 μg L−1 for cadmium and 0.21 μg L−1 for lead. Trial milk sample analyses showed that the modified electrode was sensitive, reliable and effective for the determination of trace heavy metals, holding great promise for routine analysis applications.

Highlights

A novel carbon composite electrode modified with bismuth oxide nanoparticles and the ionic liquid n-octylpyridinium hexafluorophosphate was fabricated and used to simultaneously determine cadmium and lead levels using square wave anodic stripping voltammetry
bismuth oxide nanoparticles (BONPs)-Ionic liquids (IL)-carbon paste electrodes (CPEs) recorded in 0.1 mol L−1 KOH solution
In alkaline solution a chemical reaction between bismuth oxide and OH− occurred (eq (1)), whilst the electrochemical reduction of BiO2− occurred at −0.95 V

Summary

Introduction

A novel carbon composite electrode modified with bismuth oxide nanoparticles and the ionic liquid n-octylpyridinium hexafluorophosphate was fabricated and used to simultaneously determine cadmium and lead levels using square wave anodic stripping voltammetry. This electrode combines the unique advantages of nanomaterials and ionic liquid with the low cost and easy fabrication of the carbon composite electrode. The traditional procedure for heavy metal determination is based on spectroscopic methods, such as atomic absorption spectrometry and X-ray fluorescence spectrometry [6,7]. These methods, require complex sample pretreatment processes and expensive instrumentation and are not ideal for routine applications [8]. BiFEs have a serious limitation because of insufficient adhesion of the film to the electrode surface which causes degradation of the electrode [18]

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