The determination of strontium-90 in environmental and biological materials using DI-(2-ethylhexyl) phosphoric acid.

Abstract

A method is described in which strontium-90 is determined by solvent extraction of the yttrium-90 daughter. After a preliminary extraction of a hydrochloric acid solution of the sample by di-(2-ethylhexyl) phosphoric acid, yttrium-90 is allowed to return to equilibrium in the presence of yttrium carrier. A second extraction quantitatively separates the yttrium-90 which is subsequently stripped into concentrated hydrochloric acid. An extraction with Aliquat 336 is used to remove interfering radionuclides before the yttrium is finally precipitated and counted as the oxalate. Typical recovery is 85-90 per cent.