A cesium-selective electrode prepared from a crystalline synthetic zeolite of the mordenite type

Cesium-selective electrodes were prepared from a synthetic zeolite molecular sieve of the mordenite type. The membrane was made from zeolite crystals embedded in an epoxy resin. The response towards cesium ions -was linear from about 3 × 10^-5 to at least 0.1 mol l^-1, with almost Nernstian slope. The usable pH range was 3.5–9 for 0.01 mol l^-1 cesium solutions. The selectivity order was Cs > Ag, K > Na > Li for univalent ions. The response for divalent ions was not Nernstian, Cs > Ba > Ca > Cu. About two weeks after the hydration, there was a degradation of electrode performance indicated by increased detection limit and decreased slope.