Automated, cassette-based isolation and formulation of high-purity [61Cu]CuCl2 from solid Ni targets

Abstract

Abstract Background A need for improved, cassette-based automation of 61 Cu separation from irradiated Ni targets was identified given the growing interest in theranostics, and generally lengthy separation chemistries for 64 Cu/ 64 Ni, upon which 61 Cu chemistry is often based. Methods A method for separating 61 Cu from irradiated nat Ni targets was therefore developed, with provision for target recycling. Following deuteron irradiation, electroplated nat Ni targets were remotely transferred from the cyclotron and dissolved in acid. The dissolved target solution was then transferred to an automated FASTlab chemistry module, where sequential TBP and TK201 (Triskem) resins isolated the [ 61 Cu]CuCl 2 , removed Ni, Co, and Fe, and concentrated the product into a formulation suitable for anticipated radiolabelling reactions. Results 61 Cu saturation yields of 190 ± 33 MBq/μA from energetically thick nat Ni targets were measured. The average, decay-corrected, activity-based dissolution efficiency was 97.5 ± 1.4% with an average radiochemical yield of 90.4 ± 3.2% ( N = 5). The isolated activity was collected approximately 65 min post end of bombardment in ~ 2 mL of 0.06 M HCl (HCl concentration was verified by titration). Quality control of the isolated [ 61 Cu]CuCl 2 ( N = 5) measured 58 Co content of (8.3 ± 0.6) × 10 − 5 % vs. 61 Cu by activity, Ni separation factors ≥ (2.2 ± 1.8) × 10 6 , EoB molar activities 85 ± 23 GBq/μmol and NOTA-based EoB apparent molar activities of 31 ± 8 MBq/nmol and 201 MBq/nmol for the 30 min and 3.3 h ( N = 1) irradiations, respectively. Conclusion High purity 61 Cu was produced with the developed automated method using a single-use, cassette-based approach. It was also applicable for 64 Cu, as demonstrated with a single proof-of-concept 64 Ni target production run.

Topics & Concepts