A Super-Sensitive Voltammetric Procedure for the Determination of Pb(II) Ions in Natural Waters Using an Environmentally Friendly Microelectrode

A versatile voltammetric procedure for quantitative determination of Pb(II) directly in environmental water samples has been proposed. Differential pulse technique in the variant of anodic stripping voltammetry was applied to study Pb(II) at a solid bismuth microelectrode (SBiµE). The proposed procedure was tested using model solutions containing 0.1 mol L^-1 acetate buffer (pH = 3.4) and 5 × 10^-9 mol L^-1 Pb(II). Under optimized measurement conditions, i.e., activation potential and time -2.5 V and 30 s, respectively, and accumulation potential and time -1.4 V and 30 s, respectively, a linearity range of 1 × 10^-10-3 × 10^-8 mol L^-1, a detection limit of 3.4 × 10^-11 mol L^-1 and a relative standard deviation of 3.1% were obtained. The applicability of the developed procedure was confirmed by direct analysis of environmental waters, such as water from the Bystrzyca River and water from the Baltic Sea.