Separation of cyclotron-produced cobalt-55/58m from iron targets using cation exchange chromatography with non-aqueous solvents and extraction chromatography.

Cobalt-55 and -58m form a theranostic pair that has relevant properties for cancer research. We report a cation exchange chromatography/extraction chromatography method that separates cyclotron-produced 55/58mCo from 54/57Fe in <1.5 h, recovers >85% Co and achieves [55Co]Co-NOTA and -DOTA AMA 89 ± 48 and 35 ± 7 MBq/nmol (EOB), respectively. Cobalt-55 and -58m were quantitatively labeled to functionalized NOTA at 106 and 50 MBq/nmol (EOB), respectively, corroborating measured AMA. This method is faster than previously published methods and achieves better [55/58mCo]Co-NOTA and -DOTA AMA. • [55Co]Co-NOTA/DOTA apparent molar activity 89 ± 48/35 ± 7 MBq/nmol (N=6) at EOB. • 58mCo quantitatively labeled at 50 MBq/nmol to functionalized NOTA (EOB). • 55/58mCo separated from 54/57Fe via cation exchange and extraction chromatography in < 1.5 h. • >85% Co RCY in 1 mL and >99.99% 55Co radionuclidic purity. • >98% 54/57Fe recovery and resulting 54/57Fe can be electrodeposited. [ABSTRACT FROM AUTHOR]