A no-carrier-added⁷²Se/⁷²As radionuclide generator based on solid phase extraction

Abstract

Summary 72 As-labelled radiopharmaceuticals could be a valuable resource for Positron Emission Tomography (PET). In particular, the long half-life of 72 As ( T 1/2 = 26 h) facilitates the observation of long-term physiological or metabolic processes, such as the enrichment and distribution of antibodies in tumor tissue. This work describes the primary radiochemical separation of no-carrier-added (nca) 72 Se from cyclotron irradiated germanium targets and the development of a polystyrene type solid-phase extraction based 72 Se/ 72 As radionuclide generator, avoiding the addition of any selenium carrier. The irradiated germanium target is dissolved in HF conc and selenium is reduced with hydrazine dihydrochloride. The nca 72 Se (0) is adsorbed on a solid-phase extraction cartridge, representing the generator column. The 72 As is eluted using various aqueous solvents with 40–60% yield and < 0.1% 72 Se content. To be able to study the radiopharmaceutical arsenic chemistry, subsequent chemical modification of the nca 72 As eluates to nca [ 72 As]AsI 3 provides a versatile radioarsenic labelling synthon.