Construction and performance characteristics of polymeric membrane electrode based on (Pr2Ph)-Pr-i-DAD for the selective determination of Fe3+ ion

摘要

A new PVC membrane potentiometric sensor for Fe(III) ions was prepared using N,N-bis(2,6-diisopropylphenyl)-1,4-diaza-1,3-butadiene) ((Pr2Ph)-Pr-i-DAD) as a suitable carrier. The best performance was observed for the membrane composition including 33.0% PVC, 66.0% DOS, and 1.0% ionophore. The electrode displayed a linear potential response over a concentration range from 1.0x10(-6) to 1.0x10(-2)M with a detection limit of 4.5x10(-7)M and a Nernstian slope of 19.9 +/- 0.3mV/decade. The sensor response is pH independent in the range of 2.1-6.0 and has a fast response time of 7s. It also shows good selectivity to Fe(III) ion over many alkali, alkaline earth, transition, and heavy metal ions. The lifetime of the electrode was twomonths. It has been observed that the developed sensor satisfactorily works in partially non-aqueous media up to 10% (v/v) content of methanol, ethanol, and acetone. The proposed electrode could be used to quantify Fe3+ ion in some different synthetic and real samples with satisfactory results. It can also be used as an indicator electrode in potentiometric titration of Fe3+ ion with EDTA.