title: Cesium ion-selective electrodes based on 1,3-alternate thiacalix[4]biscrown-6,6.
abstract: Four thiacalix[4]biscrown ethers with 1,3-alternate conformation were examined for the potentiometric responses in poly(vinyl chloride) membrane electrodes. Their potentiometric selectivities toward potassium and cesium ions over other alkali, alkaline earth, and transition metal ions were measured by the fixed interference method (FIM). Among the ionophores, 1,3-alternate thiacalix[4]biscrown-6,6 showed a high selectivity for cesium over potassium ion and so was optimized as a Cs(+)-selective electrode. The electrode exhibited a linear response with a near Nernstian slope of 57.6mV per decade in the concentration range of 1.0x10(-6) to 3.2x10(-2)M. It was suitable for use in aqueous solution in a wide range of pH 2.5-12.5 and had a fast response time of ca. 5s. On the basis of 1,3-alternate thiacalix[4]biscrown-6,6, the electrode has a wide linear range and selectivity for cesium ion over potassium ion ( log K (Cs (+ ),K (+))=- 3.7 ) better than those previously reported with other ionophores.
authors.affiliation: School of Chemistry, Seoul National University, Seoul 151-747, South Korea.
authors.forename: Youngsun
authors.initials: Y
authors.lastname: Choi
authors.forename: Hasuck
authors.initials: H
authors.lastname: Kim
authors.forename: Jae Kwang
authors.initials: JK
authors.lastname: Lee
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Heung Bin
authors.initials: HB
authors.lastname: Lim
authors.forename: Jong Seung
authors.initials: JS
authors.lastname: Kim