Radiochemical purification of no-carrier-added scandium-47 for radioimmunotherapy

A procedure, adaptable to large-scale remote operation, was developed to purify no-carrier-added (NCA) 47Sc from irradiated Ti targets. Methods based on extraction chromatography and cation-exchange chromatography were compared. Results of this comparison led to the development of an optimized procedure based on cation-exchange with Dowex AG 50W-X4 and 47Sc elution with HCl/HF. This method gave 90–97% overall 47Sc recovery, with a Ti separation factor greater than 2.4×10−5, and specific activities ≥0.9 GBq μg−1. Use of the 47Sc product, for labeling monoclonal antibodies, resulted in consistent labeling yields of ≥90%.