Extractive scintillating resin for 99Tc quantification in aqueous solutions

Abstract

A method utilizing extractive scintillating resin for 99Tcmonitoring in aqueous solutions is presented. These extractive scintillatorscombine analyte selective uptake and scintillating properties to produce dualfunctionality analytical resins. These resins were produced by (1) co-locatedextraction chromatographic resin and plastic scintillating beads, (2) immobilizingfluors in macroporous polystyrene supports to which chains of monomethylatedpolyethylene glycol have been grafted and (3) co-immobilizing organic scintillatingfluors and a quaternary ammonium extractant (Aliquat-336) within macroporousacrylic and polystyrene supports. The first and third resins selectively extractpertechnetate ions from dilute acid whereas the second resin selectively extractspertechnetate ions from high ionic strength solutions. These resins were utilizedin ~0.20 ml pore volume columns while 99Tc was continually monitoredwith commercially available scintillation detection systems. Manual and automatedmicrofluidics were used to deliver sample and reagent solution for loadingand elution of the 99Tc. The detection efficiencies were determinedto be 45 and 70% for acrylic and polystyrene based resins, respectively, andindependent of extractant. Minimum detectable 99Tc concentrationusing the Aliquat-336/acrylic-based resin was 6.2 Bq . l –1 for a 50-mlsample and 30-minute count time. The new methodology was applied towards analysisof contaminated groundwater samples and nuclear waste simulants.