Reagentless Dissolution and Quantification of Particulate Lead in Tap Water via Membrane Electrolysis

The presence of particulate Pb in tap water has been a limiting factor in the design of accurate and portable platforms for quantifying this toxic metal. Convenient and affordable electrochemical techniques are blind toward particulate species and thus require addition of reagents and additional chemical processing such as sample acidification. This study describes the fundamentals and the first use of membrane electrolysis for the reagentless sample preparation of tap water for the detection of particulate Pb contaminants. Membrane electrolysis allows for the in-situ generation of nitric acid, which, in combination with anodic stripping voltammetry, provides a powerful tool for the accurate and reagent-free detection of Pb2+. The configuration of the setup allows for its semi-autonomous operation and requires minimal attention, making electrochemical methods more suitable and accessible for continuous measurements of particulate contaminants in tap-water. The voltammetric response is linear in the range of 24.1-398 nM of Pb, which covers the action level of 48 nM suggested by the World Health Organization.