UPTAKE OF METAL-IONS BY A NEW CHELATING ION-EXCHANGE RESIN .7. ALKALINE-EARTH CATIONS

The comparison among the uptake of alkaline earth cations from dilute acidic solutions by the Diphonix(TM) resin, a silica based Diphonix-li ke resin, and a sulfonic type strong acid ion exchange resin has shown that the alkaline earth cations at tracer level concentration are ret ained by the Diphonix resin because they are bound mainly to the dipho sphonic acid groups of the resin. Consequently, a dual-mechanism of ac cess and recognition can be assumed to be operative in the uptake of t he Group IIa cations by the Diphonix resin. A similar conclusion had b een previously reached for the uptake of actinide ions based on the sh ape of their acid dependencies. Infrared spectra of the Diphonix resin and some of its metal salts have shown that the alkaline earth cation s are bound to the diphosphonic acid groups through highly ionic inter actions.