FLOW-THROUGH ANODIC-STRIPPING COULOMETRY AND ANODIC-STRIPPING COULOMETRY WITH COLLECTION FOR THE SIMULTANEOUS ABSOLUTE DETERMINATION OF COPPER, LEAD, CADMIUM AND ZINC

Flow-through electrochemical cells with porous working electrodes made of crushed reticulated vitreous carbon and plated with mercury were used for the absolute determination of copper, lead, cadmium and zinc by anodic stripping coulometry and anodic stripping coulometry with collection in a flow system. The system consisted of a peristaltic pump, pneumatic pulse damper, electrochemical flow-through scrubber to remove impurities and dissolved oxygen from the flowing electrolyte, sample injection port and two serial flow-through cells with porous working electrodes. Trace metals from the injected sample volume were deposited at the working electrode of the first cell, then stripped by scanning the potential to positive values and finally collected at the second cell. Both the stripping and collection currents were registered and integrated. The conditions for a quantitative deposition, Stripping and collection were investigated.