Abstract
Yttrium including yttrium 91 is first removed from a sea water sample by precipitation of ferric hydroxide. Then, leave the filtrate aside for two weeks to make strontium 90 in radioactive equilibrium with yttrium 90, which is separated and determined. Solvent extraction procedure using a 100% tri-n-butyl phosphate (T. B. P.)-14M nitric acid system can be applied to the separation of yttrium from other nuclides. The results of this method agreed with those of the conventional method.
