The Chronopotentiometric Stripping Analysis of Lead Based on Abrasively Immobilized Multi-walled Carbon Nanotubes Bismuth Film Electrode

摘要

A novel mercury free carbon nanotubes-Bi film electrodes was fabricated based on abrasiveimmobilized MWCNTs and in-situ plated Bi film on graphite electrode. Scanning electron microscope(SEM) analysis indicated that the surface of graphite electrode was firmer and homogeneously coatedby MWCNTs via abrasive immobilizing. The constant current chronopotentiometric stripping methodfor the determination of Pb was developed based on the abrasive immobilized MWCNTs Bi filmgraphite electrode. The factors that influence the stripping peak height (dt/dE) of Pb were investigatedin detail. Well-defined peaks along with low background current were obtained in pH 4.6 acetatebuffer with the stripping current of 5.0 A and the Bi (III) concentration of 0.4 mg/L. Under theoptimal conditions, the proposed method exhibited linear ranges from 10.0 g/L to 100.0 g/L withdetection limit of 1.0 g/L at the deposition time of 120 s. The assay results of Pb in soil exampleswith the proposed method were in acceptable agreement with ICP-AES with good accuracy andrecovery when the interference caused by Cu (II) was alleviated by the addition of ferrocyanid.