Separating Strontium and Barium with Eichrom Technologies’ Sr Resin Using Chelating Eluent Solutions

Year
2017
Author(s)
Alicia Surrao - Nuclear Engineering Division, Argonne National Laboratory, Department of Chemistry, University of Cincinnati
Skyler W. Smith - Department of Chemistry, University of Cincinnati
Emma Foerster - Department of Chemistry and Physics, University of South Carolina Aiken
Henry B. Spitz - Department of Nuclear and Radiological Engineering, University of Cincinnati
Donald G. Graczyk - Nuclear Engineering Division, Argonne National Laboratory
Julio A. Landero-Figueroa - Department of Chemistry, University of Cincinnati
William B. Connick - Department of Chemistry, University of Cincinnati
Jennifer L. Steeb - Nuclear Engineering Division, Argonne National Laboratory
Abstract
Age dating radioactive 137Cs and 90Sr sources, which are a potential concern in radiation dispersal devices (RDD), can provide evidence for attribution in a nuclear forensic investigation. Precise measurement of the 137Cs-137Ba or 90Sr-90Zr isotope ratio by ICP-MS in tandem with non-linearity and mass-bias data manipulation dramatically increases precision and decreases uncertainty, leaving inadequate chemical separation efficiencies as the lead contributor to uncertainty in age determination. To improve the separation of these isobars before ICP-MS analysis, we evaluated eluents containing EDTA and DTPA chelating agents against previously studied eluents for their ability to achieve complete removal of Sr and Ba from Eichrom Technologies’ Sr resin. Barium separation efficiencies using 0.05M EDTA, pH-adjusted 0.05M EDTA, and pH-adjusted 0.05M DTPA were found to be 100.9 ± 2.2%, 99.4 ± 0.8%, and 99.3 ± 1.2%, respectively. Strontium separation efficiences using 0.05M disodium EDTA and 0.05M potassium EDTA were determined to be 100.14 ± 0.53% and 100.19 ± 0.97% respectively. These results demonstrate that eluents containing chelating agents out-perform previously studied eluent solutions at removing barium and strontium from Sr resin.