Cadmium(II)-selective membrane electrode based on a synthesized tetrol compound

A new PVC membrane electrode for Cd2+ ions based on [1,1'-bicyclohexyl]-1,1',2,2'-tetrol as membrane carrier was prepared. The electrode exhibits a Nernstian response for Cd2+ over a wide concentration range (1.0 x 10(-1)-1.0 x 10(-5) M) with a slope of 27.8 mV decade(-1). The limit of detection is 9.0 x 10(-6) M (1.0 mu g ml(-1)). The electrode has a response time of <15 s and a useful working pH range of 4.0-7.0. The proposed membrane sensor shows excellent discriminating ability towards Cd2+ ion with regard to several alkali, alkaline earth, transition and heavy metal ions. It was successfully applied for the direct determination of Cd2+ in solution and, as an indicator electrode, in potentiometric titrations of cadmium ion. (C) 2000 Elsevier Science B.V. All rights reserved.