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

The paper describes solvent polymeric membrane anion selective electrodes b ased 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 d emonstrates anti-Hofmeister behavior, and the selectivity sequence observed is: thiocyanate > benzoate > perchlorate > iodide > nitrite > nitrate > ac etate > 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 thio cyanate deteriorate to some extent. The electrode based on tribenzyltin p-n itrophenolate has a fast response time, fair stability and reproducibility and could be used for the detection of thiocyanate in actual samples with s atisfactory results.