Mercury-Free Analysis of Lead in Drinking Water by Anodic Stripping Square Wave Voltammetry

The analysis of drinking water for lead, which has well-known adverse health effects, provides an instructive example of the use of analytical chemistry to monitor a common hazard of everyday life. Techniques previously utilized for the electrochemical quantitative analysis of lead in tap water have relied on either elemental mercury or a mercury salt to deposit a mercury–lead amalgam on an electrode surface. Modern analytical teaching labs, however, no longer feature mercury setups and avoid most mercuric compounds owing to the toxicity of mercury. We report a mercury-free analytical method for the analysis of lead in drinking water using square wave anodic stripping voltammetry. Concepts required to successfully complete the experiment include: ppm–ppb concentrations, preparation of standard solutions by serial dilution, construction of a calibration curve, determination of an unknown sample by the standard addition method, and sample matrix effects.