De Novo Approaches to the Solid-Phase Separation of Titanium(IV) and Scandium(III): Translating Speciation Data to Selective On-Bead Chelation toward Applications in Nuclear Medicine.

The solution chemistry of the hydrolytic, early-transition-metal ions Ti and Sc represents a coordination chemistry challenge with important real-world implications, specifically in the context of Ti/Sc and Ti/Sc radiochemical separations. Unclear speciation of the solid and solution phases and tertiary mixtures of mineral acid, organic chelators, and solid supports are common confounds, necessitating tedious screening of multiple variables. Herein we describe how thermodynamic speciation data in solution informs the design of new solid-phase chelation approaches enabling separations of Ti and Sc.

Accelerator Production of Scandium Radioisotopes: Sc-43, Sc-44, and Sc-47.

Scandium radioisotopes are increasingly considered viable radiolabels for targeted molecular imaging (Sc-43, Sc-44) and therapy (Sc-47). Significant technological advances have increased the quantity and quality of available radioscandium in the past decade, motivated in part by the chemical similarity of scandium to therapeutic radionuclides like Lu-177. The production and radiochemical isolation techniques applied to scandium radioisotopes are reviewed, focusing on charged particle and electron linac initiated reactions and using calcium and titanium as starting materials.

A Review of Accelerator-Produced Ga-68 with Solid Targets.

Gallium-68 is a positron-emitting nuclide that has recently achieved clinical acceptance as the diagnostic radionuclide in PET tracers used for theranostic studies of lutetium-177 labeled therapeutic drugs due to the ease of access provided by germanium-68/gallium-68 generators. An alternative method of production currently being explored uses accelerators to form gallium-68 directly. This review of gallium-68 production strategies discusses available accelerator targetry at a range of beam energies and intensities, the many radiochemical separation techniques available to isolate Ga-68 from irradiated targets, isotopically enriched target material recovery, and the implications of these techniques for downstream radiolabeling applications.