Simultaneous radionuclide determination using PSresin: 2in2 and 2in1 tandem configuration

Abstract

Background: Analyzing mixtures of radionuclides is a complex task. Two situations are the mixtures of 89Sr with 90Sr and 90Sr with plutonium isotopes. The challenge arises in emergency scenarios resulting from accidents where the activity of 89Sr is over 20 times higher than that of 90Sr, complicating its quantification and requiring delayed measurements. In scenarios involving accidents, both 90Sr and plutonium isotopes, may be present within various matrices. Given their distinct elemental properties, separation is typically achieved using different methods, followed by a measurement post-elution through alpha spectrometry and scintillation techniques. Therefore, methods which allow the fast and reliable determination of those mixtures are still required in routine laboratories. Results: A novel method for the simultaneous determination of radionuclide mixtures using PSresin is introduced. This innovative approach utilizes PSresins in tandem and has been applied to the analysis of 89Sr and 90Sr, as well as mixtures of 90Sr and plutonium isotopes. Two strategies were investigated: using two PSresin in two cartridges and two measurements (2in2); and using two PSresin in a single cartridge and one measurement employing α/β discrimination (2in1). The methods were validated with standard solutions and applied to river water samples, achieving quantification errors below 10 % for both strategies within 5 and 8 h, respectively, from sample reception. Significance: This represents a great improvement for 89Sr and 90Sr quantification which is achieved in less than 5 h since sample reception reducing the 30 days required by conventional methods. Additionally, the simultaneous measurement of 90Sr and plutonium isotopes reduce the number of required analysis to half, reducing the overall time and cost of the analysis.