Copper(II)-selective membrane electrode based on a recently synthesized macrocyclic diamide

A recently synthesized 23-member macrocyclic diamide was used as a membrane -active component to prepare a new Cu2+-selective polymeric membrane electr ode. The electrode exhibits a Nernstian response for copper(II) ions over a wide concentration range (1.0 X 10(-1) to 3.2 X 10(-5) M), with a limit of detection of 1.2 X 10(-5) M (0.77 ppm). It has a response time <20 s and c an be used for at least 3 months without any considerable divergence in pot entials. The proposed membrane sensor revealed very good selectivities for Cu2+ over a wide variety of other metal ions and could be used in the pH ra nge 3.5-6.0. It was used as an indicator electrode in potentiometric titrat ion of copper ions with EDTA. (C) 1999 Academic Press.