New electrochemical sensors used for potentiometric determination of copper and nickel

Faculty ofChemistry, University ofCraiova, A. I. Cuza 13, Romania

E-mail : adychem@yahoo.com Fax : 40-51-1 97048

Manuscript received 17 July 2001, revised 17 May 2002, accepted 12 June 2002

The paper presents the experimental and theoretical data regarding the preparation, characterization and analytical applications of four liquid-membrane electrodes. The active substances whose solutions in nitrobenzene have constituted the membranes on graphite rod, are mixed complex combinations of Cu^II and Ni^II ions with two Schiff base ligands N-[2- thienylmethylidenc]-2-propanolamine (TNAHP) and N-[-2-thienylmethylidene]aminopropane (TNAP). The Cu^II-selective and Ni^II -selective electrodes have been used to determine Cu and Ni ions in aqueous solutions, both by direct potentiometry and potentiometric titration with EDTA. They have also been used for determining Cu^II and Ni^II ions in industrial water by direct potentiometry.