Determination of trace Pb（II）, Cd（II） and Zn（II） using differential pulse stripping voltammetry without Hg modification

In this work, we reported a simultaneous determination approach for Pb（II）, Cd（II） and Zn（II） at μg L^-1 concentration levels using differential pulse stripping voltammetry on a bismuth film electrode （BiFE）. The BiFE could be prepared in situ when the sample solution contained a suitable amount of Bi（NO）3, and its analytical performance was evaluated for the simultaneous determination of Pb（II）, Cd（II） and Zn（II） in solutions. The determination limits were found to be 0.19 μg L^-1 for Zn（II）, and 0.28 μg L^-1 for Pb（II） and Cd（II）, with a preconcentration time of 300 s. The BiFE approach was successfully applied to determine Pb（II）, Cd（II） and Zn（II） in tea leaf and infusion samples, and the results were in agreement with those obtained using an atomic absorption spectrometry approach. Without Hg usage, the in situ preparation for BiFE supplied a green and acceptability sensitive method for the determination of the heavy metal ions.