An Experimental Generator for Production of High-Purity212Pb for Use in Radiopharmaceuticals

The feasibility, performance, and radiation safety of an experimental generator were evaluated to efficiently produce 212Pb intended for radiopharmaceuticals. Methods: The generator consisted of a flask with a removable cap containing a source of 224Ra or 228Th absorbed on quartz wool. Gaseous 220Rn emanated from the decaying source, which subsequently decayed to 212Pb, which was adsorbed on the flask's interior surface. The 212Pb was collected by washing the flask with 0.5-1 mL of 0.1 M HCl. Results: The generator collector flask trapped 62%-68% of the 212Pb, of which more than 87% (tested up to 26 MBq) could be harvested. The obtained 212Pb solution had a high purity (>99.98%) and could be used for the preparation of radioconjugates with more than 97% radiochemical purity. Future designs of the generator should aim to further reduce the risk of radon and γ-energy exposure to operators. Conclusion: The presented technology is a promising method for easy and convenient 212Pb production.