A new PVC-membrane electrode based on a thia-substituted macrocyclic diamide for selective potentiometric determination of silver ion

Abstract

A new PVC-membrane electrode for Ag+ ion based on a thia-substituted macrocyclic diamide has been prepared. The electrode exhibited a Nernstian response for Ag+ over a wide concentration range (1.7 × 10-6-1.0 × 10-1 M). It has a response time <15 s and can be used for at least 3 months without divergence. The proposed membrane sensor revealed good selectivities for Ag+ over a variety of metal ions and can be used in a pH range 3,0-7,5. It has been used successfully for direct determination of Ag+ in different real samples and, as an indicator electrode, in the titration of silver ion.