A Comparison of Separation and Purification Strategies for 51/52Mn cyclotron production

The aim of the ongoing project METRICS (acronym for Multimodal pET/mRI imaging with Cyclotron-produced 51/52Mn iSotopes), funded by the INFN CSN5, is to develop all the technology needed to obtain a cyclotron-driven production of 52/51Mn radionuclide, aimed at achieving a perfect molecular matching between PET and MRI imaging procedures, by taking advantage of both paramagnetic and radioactive properties shown by some manganese isotopes to afford an unprecedented type of PET/MRI hybrid imaging. Manganese-52/51 indeed may be produced starting from natural chromium target, with medium-low energy protons (10-20 MeV) mainly by the 52Cr(p,n)52m/gMn and 53Cr (p,2n)52m/gMn nuclear reaction routes. The radiochemical separation of manganese from the chromium target is a key step to isolate the desired product in a form suitable for its intended application. The adoption of target processing is not only mandatory for medical applications but it is also advantageous for nuclear data research, such as cross-section studies, preliminary investigation on reactions yields, characterization of reaction products, etc. In this context, different radiochemical separation strategies can be adopted aiming at finding the most efficient, fastest, cheapest, safest procedure. Ion exchange chromatography is the most popular separation strategy described in literature to perform Cr/Mn separation. However, because of former experience gained in INFN CSN5-funded research past projects APOTEMA and TECHNOSP about the cyclotron driven 99mTc, it has been also assessed the possible use of solvent extraction technique as a potential alternative. The evaluation of different Cr/Mn separation strategies based on both column chromatography and solvent extraction have been the focus of the radiochemical research of the last year.