Determination of strontium-89 and -90 in soil with total sample decomposition

Abstract

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, and set aside for ' OY Ingrowth. After ingrowth the strontium sulfate is reprecipitated, and the '"Y is extracted from the supernate Into bis( 2-ethyhexyl)phosphorlc acid. When both ''Sr and "Sr 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 ''Si plus "Sr. Yttrium-90 Is counted on yttrium oxalate to determine %r, and *'Sr is determined by difference. Precision, accuracy, sensitivity, and the effects of interferences are discussed.