Nickel Ion-Selective Coated Graphite PVC-Membrane Electrode Based on Benzylbis(thiosemicarbazone)

Abstract

A highly sensitive and selective membrane electrode for the determination of ultra trace amount of nickel was prepared. The PVC membrane electrode based on benzylbis(thiosemicarbazone) which was directly coated on graphite, displays a Nernstian response for Ni2+ ions over a wide concentration range (1.0×10−2−1.0×10−7 M) with a limit of detection of 4.0×10−8 M (ca. 2.4 ppb). It has a fast response time of ca. 15 s and can be used for at least 3 months without observing any major deviation. The electrode revealed a very good selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions. It was used as an indicator electrode in potentiometric titration of nickel ions and direct determination of nickel in edible oil and wastewater of nickel electroplating samples.