Evaluation of a Wet Chemistry Method for Isolation of Cyclotron Produced [211At]Astatine

Applied Sciences

Ethan R. Balkin²  Donald K. Hamlin²  Katherine Gagnon¹  Ming-Kuan Chyan²  Sujit Pal¹  Shigeki Watanabe¹ 

[1] Radiochemistry Division, Department of Radiation Oncology, University of Washington, 616 N.E. Northlake Place, Seattle, WA 98105, USA;

关键词: astatine-211;    wet chemistry isolation;    radioHPLC;    reductive distillation;    bismuth attenuation factor;   

DOI  :  10.3390/app3030636

来源: mdpi

【 摘 要 】

A “wet chemistry” approach for isolation of ²¹¹At from an irradiated bismuth target is described. The approach involves five steps: (1) dissolution of bismuth target in conc. HNO₃; (2) removal of the HNO₃ by distillation; (3) dissolution of residue in 8 M HCl; (4) extraction of ²¹¹At from 8 M HCl into DIPE; and (5) extraction of ²¹¹At from DIPE into NaOH. Results from 55 “optimized” ²¹¹At isolation runs gave recovery yields of approximately 78% after decay and attenuation corrections. An attenuation-corrected average of 26 ± 3 mCi in the target provided isolated (actual) yields of 16 ± 3 mCi of ²¹¹At. A sixth step, used for purification of ²¹¹At from trace metals, was evaluated in seven runs. In those runs, isolated ²¹¹At was distilled under reductive conditions to provide an average 71 ± 8% recovery. RadioHPLC analyses of the isolated ²¹¹At solutions, both initial and after distillation, were obtained to examine the ²¹¹At species present. The primary species of ²¹¹At present was astatide, but astatate and unidentified species were also observed. Studies to determine the effect of bismuth attenuation on ²¹¹At were conducted to estimate an attenuation factor (~1.33) for adjustment of ²¹¹At readings in the bismuth target.

【 授权许可】

CC BY   
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