Application of differential pulse anodic stripping voltammetry to the determination of heavy metals in environmental samples.

A reliable procedure for the determination of the trace metals Cd, Cu, Ni, Pb and Zn in liquid and solid environmental samples by an advanced voltammetric method has been developed. A convenient method of sample pretreatment is wet digestion in a HNO3/HClO4 mixture. The simultaneous voltammetric determination of Cd, Cu, Pb and Zn is made at pH 2 by differential pulse anodic stripping voltammetry (DPASV); the simultaneous determination of Ni and Co at pH 9 after adsorptive accumulation of the respective complex with dimethylglyoxime at the electrode is made by adsorption differential pulse voltammetry (ADPV). The particular advantages of the voltametric approach in food control for heavy metals are high sensitivity, good precision and accuracy, the possibilities for the simultaneous determination of groups of metals and low cost instrumentation.