Poly(vinyl chloride) membrane cesium ion-selective electrodes based on lipophilic calix[6]arene tetraester derivatives

New lipophilic tetraesters of calix[6]arene and calix[6]diquinone are investigated as cesium ion-selective ionophores in poly(vinyl chloride) membrane electrodes. For an ion-selective electrode based on calix[6]arene tetraester I, the linear response is 1×10−6–1×10−1 M of Cs+ concentrations. The selectivity coefficients for cesium ion over alkali, alkaline earth and ammonium ions are determined. The detection limit (log aCs+=−6.31) and the selectivity coefficient (log kCs+,Rb+pot=−1.88) are obtained for polymeric membrane electrode containing calix[6]arene tetraester I.