Ga2O for target, solvent extraction for radiochemical separation and SnO2for the preparation of a68Ge/68Ga generator

Summary The target for the production of⁶⁸Geconsists of a disc of gallium suboxide, Ga₂O, with a 19 mm diameter. The suboxide was primarily prepared by repeatedly mixing metallic Ga and Ga₂O₃at 700 °C. The target (2.4 g) was quite stable under a long-time irradiation with a 34 MeV proton beam at a current of ~80<span lang=EN-ZA style='font-size:12.0pt; font-family:Symbol;mso-bidi-font-family:Symbol;mso-ansi-language:EN-ZA'>mA. The dissolution of the target was performed using 12M sulphuric acid solution, assisted with the dropwise addition of 30% H₂O₂solution, and took less than 4 hours. A solvent extraction method, using a 9M H₂SO₄-0.3M HCl/CCl₄system, was employed for the radiochemical separation of⁶⁸Ge from Ga and Zn radionuclides, while 0.05M HCl was used for the back extraction of⁶⁸Ge from the organic phase. The⁶⁸Ge obtained in the dilute HCl was directly loaded onto a column containing either a hydrous tin dioxide or a crystalline tin dioxide, obtained by calcinations of the hydrous oxide at 450, 700, and 900 °C. The calcinated hydrous tin dioxide at 900 °C showed the highest crystallinity and highest⁶⁸Ga elution yield and was selected for use in the generator. The⁶⁸Ga elution from the column generator packed with 2 g of tin dioxide, using 3 ml of 1M HCl, and yielded an average of 65%. The breakthrough of⁶⁸Ge was 6.1^. 10^-4%.