Lead ion-selective electrode prepared by sol–gel and PVC membrane techniques

Abstract

Sol–gel electrode and coated-wire ion-selective electrode (CWISE) based on Schiff base as a neutral carrier, was successfully developed for detection of Pb(II) in aqueous solution. The sol–gel and CWISE exhibited linear response with Nernstian slope of 29.1 and 28.9 mV/decade, respectively, within the concentration ranges of 5.0 × 10 −6 to 1.0 × 10 −1 mol L −1 lead ion for sol–gel and coated. The sol–gel and CWISE has shown detection limits of 3.0 × 10 −6 and 5.0 × 10 −6 M, respectively. The electrodes exhibited good selectivities over a number of alkali, alkaline earth, transition and heavy metal ions. Those sensors yielded steady potential within 10–20 s at linear dynamic range. The electrodes are suitable for use in aqueous solutions in a wide pH range of 4.0–8.2. Applications of those electrodes for determination of lead in real samples and as indicator electrode for potentiometric titration of Pb 2+ ion using K 2CrO 4 are reported.