Abstract
A procedure for trace cadmium determination by stripping voltammetry at a lead film electrode is presented. Measurements consist of three steps: simultaneous in situ formation of lead film and a deposition of metallic cadmium at a lead film electrode, oxidation of cadmium for 1 s and in the last step registering the current corresponding to Cd(II) reduction. The calibration graph was linear from 2 × 10−9 to 1 × 10−6 mol L−1 for a deposition time of 300 s. A detection limit for cadmium following deposition time of 300 s was 6 × 10−10 mol L−1. The relative standard deviation at cadmium concentration 2 × 10−8 mol L−1 was 3.6%. The measurements were carried out from undeaerated solutions. The procedure proposed was validated by analysis of rain water certified reference material.