ELECTROCHEMICAL MEASURING DEVICE AND METHOD OF COPPER ION

PROBLEM TO BE SOLVED: To provide a device and method for electrochemically detecting and measuring the concentration of a copper ion in a sample solution in which ammonia or hydrogen peroxide coexist.SOLUTION: An electrochemical measuring device comprises a cell 5 incorporating a working electrode composed of a counter electrode 3 and a conductive diamond electrode 2, acid adding means for adding an acid to a sample solution and acidic buffer supply means for supplying an acidic buffer into the cell. The electrochemical measuring device comprises means for supplying the potential for electrodeposition of copper on the working electrode surface in a state where the working electrode is brought into contact with the sample solution to which an acid is added and potential varying means for supplying the potential for eluting copper electrodeposited on the working electrode surface in a state where the working electrode on the surface of which copper is electrodeposited is brought into contact with the acidic buffer. The electrochemical measuring device comprises current detection means for detecting the current change between the working electrode and the counter electrode and an information processor 8 for calculating the concentration of a copper ion from the detected current change.