Variability of selectivity coefficients of solid-state ion-selective electrodes

The generalized model for the selectivity mechanism of solid-state ion-selective electrodes has been experimentally verified. The experimental parameters investigated were the concentration of interfering ion, temperature and stirring. Among the systems studied were electrodes sensitive to chloride (bromide, iodide), bromide (chloride, iodide), iodide (chloride, bromide), silver (copper, lead), copper (silver, lead) and lead (silver, copper), the species given in brackets being considered as the interferents. The model has been confirmed except for cases where the concentration of ions formed at the electrode surface by metathesis is too small to be the factor that dictates the electrode potential.