Production of 61Cu by the natZn(p,α) reaction: improved separation and specific activity determination by titration with three chelators

Abstract

The cyclotron-based production of positron-emitting 61Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched 64Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate 61Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified 61Cu determined using ICP-MS analysis ranged from 143.3 ± 14.3(SD) to 506.2 ± 50.6 MBq/µg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7 ± 0.2–412.5 ± 15.3 MBq/µg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods are significantly affected by the presence of trace-metal contaminants.