**Production and Semi-Automated Processing of <sup>89</sup>Zr Using a Commercially Available TRASIS MiniAiO Module**

#### **Vijay Gaja 1,2, Jacqueline Cawthray <sup>3</sup> , Clarence R. Geyer <sup>4</sup> and Humphrey Fonge 1,5,\***


Academic Editors: Alessandra Boschi and Petra Martini Received: 5 May 2020; Accepted: 3 June 2020; Published: 5 June 2020

**Abstract:** The increased interest in <sup>89</sup>Zr-labelled immunoPET imaging probes for use in preclinical and clinical studies has led to a rising demand for the isotope. The highly penetrating 511 and 909 keV photons emitted by <sup>89</sup>Zr deliver an undesirably high radiation dose, which makes it difficult to produce large amounts manually. Additionally, there is a growing demand for Good Manufacturing Practices (GMP)-grade radionuclides for clinical applications. In this study, we have adopted the commercially available TRASIS mini AllinOne (miniAiO) automated synthesis unit to achieve efficient and reproducible batches of <sup>89</sup>Zr. This automated module is used for the target dissolution and separation of <sup>89</sup>Zr from the yttrium target material. The <sup>89</sup>Zr is eluted with a very small volume of oxalic acid (1.5 mL) directly over the sterile filter into the final vial. Using this sophisticated automated purification method, we obtained satisfactory amount of <sup>89</sup>Zr in high radionuclidic and radiochemical purities in excess of 99.99%. The specific activity of three production batches were calculated and was found to be in the range of 1351–2323 MBq/µmol. ICP-MS analysis of final solutions showed impurity levels always below 1 ppm.

**Keywords:** Zirconium-89; automation; radiolabelling
