Lead(II)-selective Polymeric Electrode Using a Schiff Base Complex of N,N'-Bis-thiophene-2-ylmethylene-ethane-1,2-diamine as an Ion Carrier

Abstract

We prepared lead ion-selective PVC membranes that were based on N,N'-bis-thiophene-2-ylmethylene-ethane-1,2-diamine as a membrane carrier. The membrane electrode has a linear dynamic range between 1.0 <TEX>${\times}$</TEX> <TEX>$10^{-5}$</TEX> and 1.0 <TEX>${\times}$</TEX> <TEX>$10^{-1}$</TEX> M with a Nernstian slope of 29.79 mV per decade, and its detection limit was 2.04 <TEX>${\times}$</TEX> <TEX>$10^{-6}$</TEX> M at room temperature. The potentiometric response is independent of the pH of the solution in the pH range of 5-7. The proposed electrode revealed good selectivity and response for <TEX>$Pb^{2+}$</TEX> over a wide variety of other metal ions in pH 5.0 buffer solutions, and there was good reproducibility of the base line on the subsequent measurements. The membrane electrode has a relatively fast response time, satisfactory reproducibility and a relatively long life time.