Abstract:
An electrochemical cell for measuring concentrations of metal ions comprises a sampling enclosure including a working electrode, a reference electrode, and a counter electrode. Ports are provided in the sampling enclosure for the introduction and removal of a liquid sample, an auxiliary reagent, and a standard solution. A stirring mechanism maintains a uniform composition of the liquid sample during operation of the cell. The electrochemical cell is operated by introducing the liquid sample into the sampling enclosure, applying a plating voltage between the working electrode and the counter electrode, and measuring the voltage response of the working electrode when the applied voltage is removed. The concentration of metal ions is then calculated from the voltage response. A standard solution is added to the liquid sample, after which the measurement is repeated to calculate the concentration of metal ions relative to the standard solution.