N′, N″ , N″-tris(2-pyridyloxymethyl) ethane as ionophore in potentiometric sensor for Pb(II) ions

Abstract

N′, N″ , N″-tris (2-pyridyloxymethyl) ethane (TPOME) has been used as an ionophore in a polyvinylchloride (PVC)-based membrane. Membrane electrode with a composition 30:5:62:3 (PVC:TPOME: o-NPOE:NaTPB) exhibits Nernstian response towards Pb(II) ions with a slope of 30mV/decade, over a concentration range of 1 ×10?5 M to 1 ×10?1 M. Potential response remains almost unchanged over pH range of 3.7-6.4. The electrode shows fast response time of 15 ±2 s and a lifetime of four months. It shows good selectivity for Pb(II) ions over other mono-, di- and trivalent cations. Electrode response is satisfactory in mixed solvent media up to 30% (v/v) non-aqueous contents. Selectivity of the ionophore for Pb(II) ions was determined by spectrophotometric method. The electrode can also be used as an indicator electrode in potentiometric titration of Pb(II) ions with standard chromate solution and its determination in real-life samples. Surface morphology of membrane electrode at different stages of its development and use is also discussed. © Indian Academy of Sciences.