Field-based heavy metal analyser for the simultaneous determination of multiple cations on-site

Abstract

A hand-held, battery-powered electroanalytical instrument utilizing anodic stripping voltammetry was designed to determine simultaneously solution concentrations of Cu²⁺, Pb²⁺ and Cd²⁺ in environmental samples down to 10 µg l^–1, with an overall analysis time of 180 s. The instrument utilizes baseline and peak correction, a glassy carbon working electrode, in situ plating and forced convection to achieve low detection limits. Analysis is undertaken by pre-treatment of the sample with 1 ml of a solution of matrix-modifying electrolyte containing a mixture of hydrochloric acid and mercury(II) salt. The instrument and its application to the determination of heavy metals in rivers, lakes and tap water are described.