Nickel(II) selective membrane potentiometric sensor using a recently synthesized mercapto compound as neutral carrier

A PVC membrane electrode for Ni2+ ions based on a recently synthesized mercapto compound, as an ionophore was prepared. The electrode exhibits a Nernstian slope of 28-30 mV per concentration decade at wide concentration range of (1.0 X 10(-2)-1.0 X 10(-7) M). It has a fast response time of < 15 s and can be used for at least 4 weeks. The potentiometric response is independent of the pH of the test solution in the pH range 5-8.5. The proposed electrode revealed good selectivities over a wide variety of other cations including alkali, alkaline earth, transition and heavy metal ions. It was successfully applied to the direct determination and potentiometric titration of nickel ion with EDTA. (C) 2002 Elsevier Science B.V. All rights reserved.