Cupric ISE are potentiometric devices used for the rapid determination of free cupric ions in samples, and as a detector for the titration of cupric with EDTA. Cupric sensors are “electrodes of the third kind” because they detect cations, which also form low-solubility salts with sulfide anions and silver. The electrode functions as a sensor or ionic conductor. The mixed cupric sulfide/silver sulfide solid-state membrane produces a potential change due to changes in the sample’s cupric ion activity. When the ionic strength of the sample is fixed by the addition of ISA, the voltage is proportional to the concentration of cupric ions in solution and the electrode follows the Nernst equation.
The cupric ISE is available as a combination version with both indicating half cell and reference half cell or available as an indicating half cell that will be used with a separate reference half cell.