Nickel(II) Selective PVC‐Based Membrane Sensor Using a Schiff Base

Abstract

A polyvinylchloride (PVC) membrane optode was prepared by using 1,2‐di( o ‐salicylaldiminophenylthio)ethane (H 2 DSALPTE) as a chelating reagent for selective determination of Ni(II) ions. The optimized membranes incorporating H 2 DSALPTE as an ionophore, sodium tetraphenylborate (NaTPB) as an anion excluder, and tributyl phosphate (TBP) as a solvent mediator were prepared and applied for determination of Ni(II) ions. The membrane responded to Ni(II) ion by changing the color from yellow to green in an acetate buffer solution at pH 6.0. The best performance was observed when the membrane having a composition of 3.17% ligand, 31.64% PVC, 63.29% TBP, and 1.90% NaTPB. The membrane can be worked well over a wide concentration range from 1.0 × 10 −5 to 5.0 × 10 −3 M. The membrane exhibited a detection limit of 8.51 × 10 −6 M, and the response time of the membrane was within 7–12 min depending on the concentration of Ni(II) ions. The selectivity of the probe towards nickel determination was found to be very good. Experimental results showed that the probe could be used as an effective tool in analyzing the Ni(II) content of water samples.