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. HNO
3; (2) removal of the HNO
3 by distillation; (3) dissolution of residue
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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. HNO
3; (2) removal of the HNO
3 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.
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