DETERMINATION OF SR-89 AND SR-90 IN SOIL WITH TOTAL SAMPLE DECOMPOSITION

Potassium fluoride and pyrosulfate fusions of soil guarantee strontium Is In the ionic state. After dissolving the fusion cake, strontium sulfate is coprecipitated with lead and calcium which are preferentially dissolved into EDTA and discarded. Subsequently, strontium sulfate is dissolved in EDTA and hydrolytic elements are separated on ferric hydroxide. Strontium sulfate is precipitated from EDTA at a lower pH, dissolved in DTPA, set aside for 90Y ingrowth. After ingrowth the strontium sulfate is reprecipitated, the 90Y is extracted from the supernate into bis(2-ethyhexyl)phosphoric acid. When both 89Sr and 90Sr are being determined, barium chromate is separated from a DTPA solution of strontium. Strontium sulfate is precipitated from the barium chromate supernate and counted for 89Sr plus 90Sr. Yttrium-90 is counted on yttrium oxalate to determine 90Sr, 89Sr is determined by difference. Precision, accuracy, sensitivity, the effects of interferences are discussed. © 1979, American Chemical Society. All rights reserved.