Thallium(I) Ion-Selective Electrode Based on Polythiamacrocycles

Abstract

Thallium ion-selective electrodes based on PVC and five kinds of thiaethers are described. Although a PVC membrane electrode containing 5.1 w/w% 1,4,8,11-tetrathiacyclotetradecane (TTCT) plasticized by DOP (61.5 w/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 (KTpC1PB), in the membrane with respect to Tl+ selectivity was also observed.

Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 2. Ionophores for Potentiometric and Optical Sensors

“…Interference of Ag + would not be surprising as rather similar thioethers have also been used for Ag + -selective electrodes with appreciable discrimination of Cu 2+ . Note also that recently a very similar compound was reported as ionophore for Tl + -selective ISEs with a considerable discrimination of Cu 2+ ( Tl + -4, see section II.20) . On the other hand, a macrocyclic dithioether ( Cu 2+ -2 ) resulted in a quite unsatisfactory selectivity for Cu 2+ (log (MSM): Cd 2+ , −1.2; K + , +1.1; oNPOE, KTpClPB) …”

Thallium(Ⅰ)-Selective Membrane Potentiometric Sensor Based on Dibenzyldiaza-18-Crown-6

“…It can be seen from these values that the electrode is characterized by a high selectivity towards thallium ions with respect to alkali, alkaline earth, transition and heavy metal ions. 5,10,11,31…”

Novel Thallium(I)-Selective Membrane Electrode Based on a Podal Ligand

“…As can be seen, the proposed electrode in terms of selectivity coefficient is superior to all of the thallium ionselective electrodes reported in the literature. [7][8][9][10] The proposed thallium ion-selective electrode was found to work well under laboratory conditions. This electrode was used as an indicator electrode in the titration of thallium(I) with K 2 S, and the resulting titration curve is shown in Figure 6.…”

“…Crown ether and calix [4]aren derivatives have been tested as thallium(I)-neutral carriers for ion-selective electrodes, [3][4][5][6][7][8][9][10][11][12] and the resulting thallium(I)-selective electrodes gave good results. However, since crown ethers and calix [4]arens generally have a high affinity for alkali-metal ions and in some cases silver, these thallium(I) electrodes suffer from severe interference by Na In the present study, we wish to introduce a novel thallium(I) electrode by incorporation of a podal ligand as a suitable neutral ionophore for fast monitoring of thallium ion.…”