CESIUM-SELECTIVE OPTODE MEMBRANE-BASED ON THE LIPOPHILIC CALIX[4]BISCROWN IN THE 1,3-ALTERNATE CONFORMATION

One type of lipophilic calix[4]biscrowns in the 1,3-alternate conforma tion which are highly selective complexant for cesium has been used to construct cesium poly(vinyl chloride) (PVC) membrane optode. The reve rsible sensing system has been formed by incorporating the lipophilic neutral H+-selective chromoionophore ETH5294 in the plasticized PVC me mbrane with 1,3-calix[4]bisnaphtyl-crown-6. The measuring range of ces ium ions can be conditioned by buffering different pH in the cesium so lutions. At pH 7.0, the measuring range of the optode membrane for ces ium ions is from 1 x 10(-6) to 1 x 10(-2) M. The response behavior of optode membrane including response time, selectivity, reproducibility and lifetime, has been described in detail. (C) 1998 Elsevier Science B.V. All rights reserved.