2 m hcl

⁸⁹Zr was produced in house by the ⁸⁹Y(p,n) ⁸⁹Zr reaction via an adaptation of the methods of Walther et al. [42 (link)] and Dabkowskiet al. [43 (link)]. Briefly, a disk of natural abundance ⁸⁹Y foil (300 µm thick, Goodfellow, Huntingdon, UK) in a custom made aluminium holder was loaded into a COSTIS Solid Target System (STS) fitted to an IBA Cyclone (18/9) cyclotron (Brussels, Belgium) equipped with a 400 µm thick niobium beam degrader. The disk was irradiated for 4 h with a beam of energy of 40 µA. The irradiated disk was left in the cyclotron for 12 h to allow any short lived ^89mZr to decay to ⁸⁹Zr before removal for purification (activity 1.5-2 GBq). The disk was then dissolved in 2 M HCl (Fisher Scientific, Loughborough, UK) with stirring and heat and the ⁸⁹Zr was isolated by flowing over a hydroxymate functionalized ion exchange resin column (freshly prepared in house for each separation). The column was rinsed with 2 M HCl and water to remove ⁸⁹Y before the ⁸⁹Zr was eluted with 1 M oxalic acid (Fisher Scientific, Loughborough, UK) and collected in 3 fractions of 1 mL. The most concentrated fraction contained 800–1000 MBq, which equates to a specific activity of 8.9–11.1 MBq/mg of oxalic acid (800–1000 MBq/mmol).