Cyclotron Production and Purification of 83Sr as a 90Sr Substitute for Positron Emission Tomography (PET)

Radioactive contaminations in soil, which originate from nuclear power production, nuclear weapon testing, or uncontrolled release, are of great environmental concern. One of the major fission product contaminants is 90Sr, whose high mobility demands a method to track contamination pathways and remediation processes. Positron emission tomography (PET) is a valuable tool for the required studies. As a β−/γ-emitter, 90Sr is not suitable for PET, which requires β+-emitters. As an alternative, 83Sr, with a 12% intensity of β+-emission and a half-life of 32.4 h, is an appropriate PET substitute for 90Sr. We produced 83Sr with an enriched target of [85Rb]RbCl in a 85Rb(p,3n)83Sr reaction. The target material was bombarded with 36.22 MeV protons (ø 1.78 µA, 315 min), at a solid target station at the cyclotron U-120M (NPI CAS). The irradiated target (1.5 GBq) was dissolved in water, evaporated to dryness, redissolved in nitric acid, and transferred onto a Sr-selective cartridge (Sr-SpecTM, TRISKEM, France). Following target material wash out, 83Sr elution with water, solvent evaporation, and reformulation (in dilute nitric acid) yielded 1.2 GBq (82% radiochemical extraction efficiency, non-decay-corrected) of an 83Sr-solution. The easy and fast method is able to produce non-carrier-added 83Sr with high radionuclidic purity.