Production and performance of a ¹⁷²Hf/¹⁷²Lu generator

A ¹⁷²Hf/¹⁷²Lu radionuclide generator system to produce ¹⁷²Lu for laboratory scale applications in lutetium-based radiochemistry development was established and evaluated. The parent ¹⁷²Hf radionuclide was produced through 35.2 MeV proton irradiation of natural lutetium metal foil at the Brookhaven Linac Isotope Producer. Four resins were investigated for ¹⁷²Hf separation from bulk Lu target material: LN resin, ZR resin, in-house synthesized hydroxamate, and methyl-substituted hydroxamate resins, all with comparable performance. Separated ¹⁷²Hf was consolidated and used to create a ZR resin-based 4.9(3) MBq ¹⁷²Hf/¹⁷²Lu generator which was eluted 49 times over two years with no observed breakthrough of ¹⁷²Hf, and an average elution efficiency of 98(1)%. The eluted ¹⁷²Lu was used to radiolabel the macrocyclic chelator DOTA with an apparent molar activity of 8(2)x10² kBq/nmol.