1994 Volume 10 Issue 3 Pages 491-495
Thallium ion-selective electrodes based on PVC and five kinds of thiaethers are described. Although a PVC membrane electrode containing 5.1w/w% 1, 4, 8, 11-tetrathiacyclotetradecane (TTCT) plasticized by DOP (61.5w/w%) showed good performance for Tl+ sensitivity, potassium ion did not interfer. However, electrode containing other macrocyclic thiaethers do not show a Nernstian response to thallium activity. The size of the macrocyclic ring and a hydrophilic group introduced into the macrocyclic thiaether influenced the Nernstian slope as well as the linear activity range of the emf response. The additive effect of a lipophilic salt, potassium tetrakis(p-chlorophenyl)borate (KTpCLPB), in the membrane with respect to Tl+ selectivity was also observed.
