DEVELOPMENT OF METHOD FOR THE PREPARATION OF HIGHLY PURIFIED Y-90

The extraction of Y3+ from Sr2+ has been carried out with a new type o f extractant, sym-dibenzo-16-crown-5-oxyacetic acid, in chloroform usi ng Sr-87m and Y-90m as tracers. The extraction efficiency of Y3+ depen ds strongly on the pH of aqueous phase, whereas the extraction of Sr2 is negligible at pH < 6.5. The dependence of the concentration of sym -dibenzo-16-crown-5-oxyacetic acid on the distribution ratio of Y3+ is linear and has a slope of about 2. This suggests that Y3+ appears to form a 1:2 complex with ligand. The new method for preparing highly pu rified Y-90 by solvent extraction from equilibrium Sr-90-Y-90 has been developed. The radionuclide purity of Y-90 obtained is estimated to b e 10(-8) and the recovery rate of Y-90 is about 99%. (C) 1995 Academic Press, Inc.