{sup 55}Co separation from proton irradiated metallic nickel

• Main Authors: Valdovinos, H. F., Graves, S., Barnhart, T., Nickles, R. J.
• Format: Conference Proceeding
• Language: English
• Subjects: 07 ISOTOPES AND RADIATION SOURCES; COBALT 55; COBALT COMPLEXES; HYDROCHLORIC ACID; ION EXCHANGE CHROMATOGRAPHY; IRRADIATION; ISOTOPE PRODUCTION; ISOTOPE SEPARATION; LABELLING; MEV RANGE; NICKEL 58; NICKEL 58 TARGET; PHANTOMS; PROTON REACTIONS; REACTIVITY; TEMPERATURE RANGE 0273-0400 K
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4901397

{sup 55}Co with > 97% radionuclidic purity 24 hours after end of bombardment (EoB) was produced from the {sup 58}Ni(p,α) reaction using proton irradiations of 16 MeV on natural nickel. Two-hour irradiations with 25 μA on a 254 μm thick nickel foil generate 0.18 ± 0.01 GBq (n = 3) 24 hours after EoB. The separation of cobalt from the target material and other metallic contaminants present at trace levels is accomplished in HCl medium by two rounds of anion exchange chromatography (AG1-X8) using an automated module driven by a peristaltic pump. 80 ± 5 % (n = 3) of the activity generated at EoB is ready for labeling in 0.1 M HCl one hour after the start of separation. Using 99.999% pure Ni, the reactivity (decay corrected to EoB) with the bifunctional chelator (BFC) DOTA was 8.5 GBq/μmol; enough for radiolabeling BFC conjugated biomolecules at a nmol scale with > 90% yield. Using 99.9% pure Ni the reactivity with DOTA and NOTA was 0.19 +/− 0.09 GBq/μmol and 2.9 +/− 1.7 GBq/μmol (n = 2), respectively. Both cobalt complexes showed 100% in vitro stability in PBS and mouse serum over 41 hours at room temperature. MicroPET images of a miniature Derenzo phantom show excellent resolution where rods of 1.5 mm were separated by two times their diameter.