Electrolytical microcell for on-line preconcentration of trace metals in flow systems

Summary The separation of trace metals from solutions of electrolytes by electrodeposition in a 30 l electrolytical flow-through cell was studied. The working electrode of the flow cell was made from powdered spectral or glassy carbon. The electrodeposition is complete for Cu²⁺, Cd²⁺, Mn²⁺ and Pb²⁺, partial for Zn²⁺, Fe³⁺ and Ni²⁺. Mn²⁺ and Pb²⁺ can also be deposited by anodic oxidation on the working electrode. The deposition is complete up to sample flow rates of 3–4 ml/min. The deposited elements are dissolved by short-circuiting the electrodes and flushing the cell with diluted acid. The dissolved elements are determined on-line by flame AAS. Data evaluation through peak area measurement is discussed.