Thiocyanate-selective PVC membrane electrodes based on organotin(IV) compounds as neutral carriers

The paper describes solvent polymeric membrane anion selective electrodes based on tribenzyltin phenolates as neutral carriers. The electrode based on tribenzyltin p-nitrophenolate possesses excellent potentiometric response characteristics and selectivity towards thiocyanate, the linear range is (0. 1 similar to 2 46) X 10(-5) mol/L with a slope of -56. 8. The electrode demonstrates anti-Hofmeister behavior, and the selectivity sequence observed is: thiocyanate > benzoate > perchlorate > iodide > nitrite > nitrate > acetate > bromide > chloride. The potentiometric response characteristics and selectivity have a close relationship with the structure of the carriers, as the substitute in phenol ring changes from nitro- to hydrogen, then to t-butyl, the potentiometric response characteristics and selectivity to thiocyanate deteriorate to some extent. The electrode based on tribenzyltin p-nitrophenolate has a fast response time, fair stability and reproducibility and could be used for the detection of thiocyanate in actual samples with satisfactory results.