A zinc-selective electrode based on N,N′-bis(acetylacetone)ethylenediimine

The potentiometric response characteristics of electrodes based on N,N'-bis(acetylacetone)ethylenediimine (I) in poly(vinyl chloride) (PVC) combined with an anion localizing agent (sodium tetraphenyl borate, NaTPB) and solvent mediators, viz. o-nitrophenyl octyl ether (NPOE), dibutyl (butyl) phosphonate (DBBP), tri-n-butyl phosphate (TBP) and chloronaphthalene (CN) were investigated. The best result for Zn2+-sensing was obtained for the electrode membrane of the composition of I:PVC:NaTPB:NPOE=5:100:6:200, where the electrode had a Nernstian response (30.0 mV/decade of Zn2+ activity) to Zn2+ within the concentration range of 1.0 x 10(-6) to 1.0 x 10(-1) M. The operational pH range of the electrode was 3.2-7.1. Selectivity characteristic of the proposed electrode was also assessed by calculating K-A.B(Pot) with a fixed interference method. The sensor has been successfully used in real sample analysis and also in the potentiometric titration of zinc ions with EDTA. (c) 2005 Elsevier B.V. All rights reserved.