CESIUM-SELECTIVE POLY (VINYLCHLORIDE) MEMBRANE ELECTRODE BASED ON A NEW CALIX[4]ARENE DERIVATIVE IN THE 1,3-ALTERNATE CONFORMATION

ABSTRACT

A new calix[4]arene derivative [25-(3-bromo-propyloxy)-5,11,-17,23-tetrakis(tert-butyl)-26,27,28-tris(1-propyloxy) calix[4]arene] (BTC) in the 1,3-alternate conformation was tested as a cesium-selective ionophore plasticized PVC membrane electrode. The resulting electrode showed a Nernstian behavior for Cs⁺ ion over a wide concentration range (1.0 × 10⁻⁶–1.0 × 10⁻¹ M). The selectivity coefficients for cesium with respect to alkali, alkaline earth, ammonium and some transition metal ions, were determined. A relatively high Cs⁺/Rb⁺ selectivity was observed, the selectivity coefficient being ca. 10⁻². Effects of membrane composition and pH of test solution on the potential response of the electrode were also discussed. The proposed electrode revealed a lower limit of detection (2.1 × 10⁻⁷ M) and improved Cs⁺/Rb⁺ selectivity in comparison with the previously reported Cs⁺ ion selective electrodes.

Keywords:

• Cesium-selective electrode
• PVC membrane
• 25-(3-Bromo-propyloxy)-5,11,17,23-tetrakis(tert-butyl)-26,27,28-tris(1-propyloxy) calix[4]arene
• 1,3-Alternate conformation

Acknowledgments