TRANSPORT EXTRACTION FOR TRACE-ELEMENT SEPARATION AND PRECONCENTRATION .3. POLYURETHANE FOAM SORBENT SUPPORTED TRANSPORT EXTRACTION

A new method of sorbent supported transport extraction based on the us e of open-cell polyurethane foam sorbents in solvent sublation separat ion has been developed. The method has been shown to be effective for the separation and preconcentration of radioiodine and/or stable iodin e from 41 of deionized, drinking (tap) and surface (river) waters usin g N-cetylpyridinium chloride as the cationic surfactant and N-2 carrie r gas as the bubbling medium. A transport extraction efficiency of abo ut 94% was obtained in 60 to 90 min; a 300-fold preconcentration was f ound for radioiodine as measured by direct radioactivity counting. Bot h radioiodine and stable iodine can be back-extracted from the polyure thane foam support (e. g. into acetone with an efficiency of almost 95 %).