Anion buffering in the internal electrolyte resulting in extended durability of phosphate-selective electrodes

The decomposition of the ionophore uranyl salophene in a polymeric membrane is the main source of the deterioration of phosphate-selective electrodes in time. Due to the efficient buffering of both phosphate and uranyl ions in the internal electrolyte solution, a significant decrease of the rate of decomposition of uranyl salophene in the membrane was observed, improving the lifetime of phosphate-selective electrodes. The most efficient buffering of such ions, resulting in the best sensor durability, was obtained using the internal electrolyte solution containing barium-uranyl phosphate mineral, meta-uranocircite II.