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 Ne
rnstian 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 sh
ows excellent discriminating ability towards Cd2+ ion with regard to severa
l alkali, alkaline earth, transition and heavy metal ions. It was successfu
lly applied for the direct determination of Cd2+ in solution and, as an ind
icator electrode, in potentiometric titrations of cadmium ion. (C) 2000 Els
evier Science B.V. All rights reserved.