Abstract
The analytical characterization of a novel chromogenic calix[4]arene derivative based sodium selective, direct optode membranes has been investigated in detail. The dynamic concentration range, ion-selectivity, response time and reproducibility are discussed. The effect of the nature of the membrane matrix on the dynamic concentration range and the operation pH of the relevant optode membranes are explained. The sodium ion response is interpreted on the basis of the ion-exchange theory, which is underlined by the results of calixarene mediated ion-transport experiments.
