Chloride ion selective electrode using polyurethane polymer matrix

For the purpose of developing an ion selective electrode for the measurement of chloride ion in blood, chloride ion selective liquid ion exchanger was trapped in polyurethane membrane to prepare a chloride ion selective electrode. The electrode showed linear response to chloride ion activity between 100M and 10-4 M and the average potential changes against decade change of chloride ion activity were 61.3, 59.0, 56.6 and 53.9 mV at 35, 25, 15 and 5 °C, respectively. The optimum amount of the ion exchanger, tridodecylmethylammonium chloride, was found to be about 40% in the membrane. The electrode exhibited steady potential within several seconds after its immersion in the chloride solution. The electrode showed constant potential in the pH range of 4.0 to 7.5. Selectivity coefficients of the electrode for various anions were determined with the mixed solution method and the continuous variation method proposed by Hiiro et al. The durability of the electrode was examined with 10010-6 M aqueous chloride solutions. The electrode exhibited constant response for at least 260 h.