Direct and simultaneous determinations of Zn,Cd, Pb,Cu, Sb and Bi dissolved in sea water by differential pulse anodic stripping voltammetry with a hanging mercury drop electrode

Differential pulse anodic stripping voltammetry with a hanging mercury drop electrode is used for the direct and simultaneous determination of Zn, Cd, Pb, Cu, Sb and Bi at their natural levels in sea water after adjustment to pH 1 and to a 2 M chloride concentration. The optimal instrumental parameters are described. With a plating time of 60 min, the detection limits are about 0.1 ppb for Zn and Cu, 0.01 ppb for Cd and Pb, and 0.05 ppb for Sb and Bi. Relative standard deviations are about 10—15%. Simultaneous determinations of the six metals take about 2 h.