Cation exchange separation of 61Cu2+ from natCo targets and preparation of 61Cu–DOTA–HSA as a blood pool agent

An improved method for isolation of 61Cu2+ from a natCo target using cation exchange was developed. 61Cu2+ was eluted from a cation exchange resin column by 0.2 M HCl with 90% acetone, while Co2+ remained on the column. The whole separation process was completed within 50 min at more than 72% yield. The Co2+ impurity level in 61Cu2+ solution was reduced to less than 0.1 ppm. Highly pure 61Cu2+ solution was then applied to prepare 61Cu–1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)–human serum albumin (HSA) which showed good blood pool imaging properties.