Preconcentration and Analysis of Strontium-90 and Technetium-99 from Hanford Groundwater Using Solid Phase Extraction

Abstract

Solid-phase extraction disks produced by 3M and Eichrom were evaluated for routine use in supporting the Hanford Groundwater Monitoring Project. Both disk formats contain Sr- or Tc-selective extractants, bound in a filter support, that act to preconcentrate and isolate the isotope of interest. The 3M Empore™ Sr Rad Disks and Tc Rad Disks were tested with respect to precision, accuracy, radiochemical yields, interferences, and volume-load variation. The Empore™ and Eichrom solid-phase extraction disks were applied to the ⁹⁰Sr and/or ⁹⁹Tc determination in representative Hanford groundwater samples with varying chemical and isotopic compositions. Results were compared to standard analytical methods. Both the Empore™ and Eichrom Tc extraction disks produced consistently higher radiochemical yields, lower detection limits, and greater accuracy than the standard analysis method. The Empore™ Sr extraction disks produced comparable radiochemical yields, detection limit, and accuracy relative to the standard method; however, total uncertainties were lower.