Cesium-selective membrane electrode based on a recently synthesized 16-membered macrocyclic diamide

A PVC membrane sensor for the Cs+ ion based on 1, 5-diaza-2,3,4-naphthyl-8,11,14-trioxacyclohexadecane-6,16-dione (L) has been prepared. The sensor has a linear dynamic range of 5.0x10(-1)-6.9x10(-6) mol L-1, a Nernstian slope of 59.5+/-0.8 mV decade(-1), and a detection limit of 4.7x10(-6) mol L-1. It has a fast response time of <15 s and can be used for at least 8 weeks without any considerable divergence in potentials. The selectivity of the proposed electrode relative to alkali, alkaline earth, and transition metal ions was comparatively good. The electrode could be used in the pH range 4.5-11.0.