Ion-selective potentiometric determination of Pb(II) ions using PVC-based carboxymethyl cellulose Sn(IV) phosphate composite membrane electrode

Pb(II) ion-selective electrode membranes were fabricated by using solution casting method using carboxymethyl cellulose Sn(IV) phosphate composite cation-exchange material. The membrane electrode showed response towards Pb(II) ions in the concentration range from 1x10(-1) to 1x10(-6)M with a Nernstian slope of 28.057mV per decade change in Pb2+ ion concentration and can be used for five months without observing any deviation. The membrane electrode exhibited fast response time of 10s studied for 1x10(-2) and 1x10(-3)M of Pb2+ ion concentrations. The membrane electrode was operated successfully at 1x10(-2)M, 1x10(-3)M and 1x10(-4)M concentrations of lead ion over the pH range 2-4. The proposed electrode was found selective for Pb(II) in the presence of alkali and alkaline earth metal ions. It was also employed as an indicator electrode in the potentiometric titration of Pb(II) using ethylenediamine tetraacetic acid, disodium salt (EDTA). The sharp end-point corresponds to the stoichiometry of Pb(II)-EDTA complex.