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

A novel mercury free carbon nanotubes-Bi film electrodes was fabricated based on abrasive immobilized 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 coated by MWCNTs via abrasive immobilizing. The constant current chronopotentiometric stripping method for the determination of Pb was developed based on the abrasive immobilized MWCNTs Bi film graphite electrode. The factors that influence the stripping peak height (dt/dE) of Pb were investigated in detail. Well-defined peaks along with low background current were obtained in pH 4.6 acetate buffer with the stripping current of 5.0 μA and the Bi (III) concentration of 0.4 mg/L. Under the optimal conditions, the proposed method exhibited linear ranges from 10.0 μg/L to 100.0 μg/L with detection limit of 1.0 μg/L at the deposition time of 120 s. The assay results of Pb in soil examples with the proposed method were in acceptable agreement with ICP-AES with good accuracy and recovery when the interference caused by Cu (II) was alleviated by the addition of ferrocyanid