Determination of Cu(II), Pb(II) and Cd(II) ions in water by differential pulse anodic stripping voltammetry

Abstract

For direct simultaneous determination of Cu (II), Pb(II) and Cd(II) ions in tap water and untreated drinking water by differential pulse anodic stripping voltammetry (DPASV) with a hanging mercury drop electrode (HMDE), the effect of supporting electrolytes and deposition time on metal currents were studied. Chloride ion affects peak potentials and peak heights of Cu(II) and Pb(II). Except for potassium chloride, nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid and perchloric acid are suitable supporting electrolytes for water samples including a few colloidal particles consisting of Fe and Mn. Long deposition time is not always effective for increasing the DPASV peak currents of Cd(II) and causes the increase in blank peak currents of Pb(II). After nitric acid or hydrochloric acid was added to the 6 ml of water samples, DPASV of them with deposition time of 30 s were measured. The detection limits of Cu(II), Pb(II) and Cd(II) were 1.1, 0.8, 0.9 ng/ml, respectively. The present analysis requires only about 10 min.