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.