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 × 10−6 to 1.0 × 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 KA,BPot 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.