Potentiometric determination of Cd(II) ions using PVC-based polyaniline Sn(IV) silicate composite cation-exchanger ion-selective membrane electrode

Polyaniline Sn(IV) silicate composite cation-exchanger membranes were fabricated by using solution casting method and used for the preparation of ion-selective membrane electrode (ISME). The membrane electrode showed a linear response of potential for cadmium ions in the concentration range from 1 x 10(-1) to 1 x 1 x 10(-7) M with Nernstian response (28.53 mV decade(-1) of activity) in pH range from 3.5 to 6.5 with a detection limit of 1 x 10(-7) M and fast response time of 10 s. The potentiometric selectivity determined by mixed solution method suggested excellent selectivity for cadmium ions over alkali and alkaline metal interfering ions. The ISME is also applied for the potentiometric titration of cadmium ions using ethylenediamine tetraacetic acid, disodium salt.