PVC-membrane potentiometric sensors based on a recently synthesized Schiff base for Fe(III) ion

Abstract

A potentiometric iron sensor based on the use 3-(2-diethylamino-ethylimino) -1,3-dihydro-indol- 2-one (DEDIO) as an ionophore in poly(vinyl chloride) (PVC) matrix, is reported. The plasticized membrane sensor exhibits a Nernstian response for Fe(III) ions over a wide concentration range (2.0 × 10-6 - 5.0 × 10-2 M) with a super Nernstian slope of 26(±1) mV per decade. It has a fast response time of < 12 s and can be used for ten weeks without any considerable divergences in its potentials .the electrode can be used in the pH range 4.5-8.0. The proposed sensor shows fairly good discriminating ability towards Fe(III) ion in comparison with a large number of alkali, alkaline earth, transition and heavy metal ions. The sensor was used as indicator electrode in potentiometric titration of Fe(III) ions vs. EDTA. © 2012 Chemical Society of Ethiopia.