The application of poorly crystalline silicotitanate in production of 225Ac

摘要

Actinium-225 (²²⁵Ac) can be produced from a Thorium-229/Radium-225 (²²⁹Th/²²⁵Ra) generator, from high/low energy proton irradiated natural Thorium or Radium-226 target. Titanium based ion exchanger were evaluated for purification of ²²⁵Ac. Poorly crystalline silicotitanate (PCST) ion exchanger had high selectivity for Ba, Ag and Th. ²²⁵Ac was received with trace amounts of ²²⁷Ac, ²²⁷Th and ²²³Ra, and the solution was used to evaluate the retention of the isotopes on PCST ion exchanger. Over 90% of the ²²⁵Ac was recovered from PCST, and the radiopurity was >99% (calculated based on ²²⁵Ac, ²²⁷Th, and ²²³Ra). The capacity of the PCST inorganic ion exchange for Barium and ²³²Th was determined to be 24.19 mg/mL for Barium and 5.05 mg/mL for Thorium. PCST ion exchanger could separate ²²⁵Ac from isotopes of Ra and Th, and the process represents an interesting one step separation that could be used in an ²²⁵Ac generator from ²²⁵Ra and/or ²²⁹Th. Capacity studies indicated PCST could be used to separate ²²⁵Ac produced on small ²²⁶Ra targets (0.3–1 g), but PCST did not have a high enough capacity for production scale Th targets (50–100 g).