Salicylate anion-selective electrodes based on cyclic organotin complexes as carriers

Two new cyclic pentacoordinative organotin (IV) complexes, 2,4-dihydroxyacetophenone tribenzyltin (HAPTBT) and 2,4-dihydroxyacetophenone triphenyltin(HAPTPT) were synthesized and used as anion ionophore for PVC membrane electrode. The new electrodes exhibit specificity selectivity for salicylate. The electrode based on HAPTBT as a neutral carrier displays a highly potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in the following order: Sal(-) > SCN- > I- > NO2- > Br- > Cl- > CIO4-,> NO3- > SO42-. The electrode has the advantages of fast response, stability and reproducibility, simplicity. The response mechanism is discussed in view of UV spectroscopy technique. The results show that there are close relationship between the potentiometric response characteristics and structure of organotin(IV) complexes. The electrode was applied to medicine analysis with satisfactory results.