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

Abstract

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 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%.