A Simple Method to Screen for Radiostrontium in Water by Ion Exchange Chromatography

摘要

Radiostrontium isotopes (Sr-85, Sr-89, and Sr-90) are major fission by-products in nuclear reactors, in radiological events, and in environmental radioactive contamination. A method to analyze Sr-89 and Sr-90 in water has been developed using gradient elution with dilute hydrochloric acid and cation exchange resin, followed by carbonate precipitation. Counting was done on a gas proportional counter. The sample was recounted a second time after 2 to 3 wk to permit Y-90, a progeny of Sr-90, to achieve secular equilibrium and to allow Sr-89 and Sr-90 to be determined. This method was found to be simple, exhibiting high recovery, reduced use of hazardous chemicals, and lower cost compared to other current methods. An extensive comparison of the performance of the cation exchange method vs. a method using strong nitric acid (US Environmental Protection Agency Method 905.0) and a method using a specific strontium resin was conducted on performance test samples containing Sr-90 (in a number of matrices) from the US Department of Energy's Mixed Analyte Performance Evaluation Program and mixed Sr-89- and Sr-90-containing water samples from the Environmental Resource Associates quality assurance program. The method described here is shown to yield comparable results to others.