RAPID DETERMINATION OF STRONTIUM-90 IN TISSUE, FOOD, BIOTA, AND OTHER ENVIRONMENTAL MEDIA BY TRIBUTYL PHOSPHATE

In a rapid method for the determination of strontium-90 by tributyl phosphate extraction strontium-90 is determined by separation and analysis of its daughter product yttrium-90. The method is applicable to human tissue, food, biota, and other environmental media. For these types of samples, strontium-90 and its daughter, yttrium-90, are usually known to be in equilibrium. The method is sensitive to less than 1 pCi per sample of tissue or food ash. The samples are prepared by either dry-or wet-ashing techniques. The sample prepared for analysis is solubilized in nitric acid. The yttrium-90 daughter is extracted into equilibrated tributyl phosphate. The separated yttrium-90 is further purified by selective stripping and fluoride precipitation to remove the remaining contaminants which may have been carried over. Strontium-89 can also be determined in the same sample by precipitation of strontium prior to the yttrium-90 extraction. © 1969, American Chemical Society. All rights reserved.