Cobalt(II)-Selective Membrane Electrode Based on a Recently Synthesized Benzo-Substituted Macrocyclic Diamide

Abstract

A PVC-membrane electrode based on a recently synthesized 18-membered macrocyclic diamide is presented. The electrode reveals a Nernstian potentiometric response for Co²⁺ over a wide concentration range (2.0 × 10^-6 - 1.0 × 10^-2 M). The electrode has a response time of about 10 s and can be used for at least 2 months without any divergence. The proposed sensor revealed very good selectivities for Co²⁺ over a wide variety of other metal ions, and could be used over a wide pH range (3.0 - 8.0). The detection limit of the sensor is 6.0 × 10^-7 M. It was successfully applied to the direct determination and potentiometric titration of cobalt ion.