Ultrarapid Purification of Manganese-52 from Chromium-52 Targets via Potentiostatic Anodic Dissolution and Chelation Ion Chromatography

Manganese-52 (52 Mn, t1/2 = 5.6 days) is an attractive positron-emitting isotope for integrated positron emission tomography and magnetic resonance imaging. Its availability, however, is constrained by the challenge of achieving rapid, high-purity separation from cyclotron-irradiated chromium-52 (52Cr) targets. This study presents an ultrarapid, two-step purification strategy that couples potentiostatic anodic dissolution with single-column chelation ion chromatography. Electrochemical analysis indicates that the Mn target undergoes rapid oxidation and is dissolved as ammine complexes in an ammonium/ammonium chloride buffer (pH 8) at 0.7 V (vs Hg/HgO), whereas the Cr target remained almost passivated and trace Cr leached was precipitated on the target surface as Cr(OH)3 under identical conditions. The sharp decrease in anodic current density, induced by the distinct dissolution behavior of Mn/Cr targets, provides a convenient real-time endpoint for assessing complete Mn dissolution. The resulting analyte was then loaded directly onto iminodiacetate resins (Diaion CR11) and eluted with HCl, converting the ammine complexes to hydrated Mn2+. Simulated experiments achieved a Mn chromatographic recovery of 98.65% with >99.99% purity within 30 min. This integrated approach offers significant advantages in processing speed and recovery yield over conventional methods, demonstrating high potential for the production of clinical 52 Mn.