Patent ID: 6852296

Claim:
A method for producing a solution of trivalent bismuth-213 daughter radionuclide ions that is substantially free of divalent radium-225 and trivalent actinium-225 parent and other daughter radionuclide ion impurities comprising the steps of: (a) contacting an aqueous acidic parent-daughter radionuclide ion solution containing trivalent bismuth-213 daughter radionuclide ions with a separation medium having a high affinity for the bismuth-213 daughter radionuclide and a low affinity for the parent and other daughter radionuclides, said separation medium comprising a phosphorus-containing extractant having a phosphoryl bond and the remaining bonds from phosphorus are to one or more of (i) a carbon atom of a C 1 -C 10 alkyl group, a benzyl group, a carboxamido C 1 -C 6 alkyl group whose amido nitrogen atom has the formula —NR 1 R 2 and a phenyl group, (ii) a polymer backbone, (iii) an O—R 1 group wherein R 1 is a hydrido group, a C 1 -C 10 alkyl group, a phenyl group or a benzyl group, (iv) a —NR 1 R 2 group, and (v) a divalent radical selected from the group consisting of an imino group, a C 1 -C 10 cyclic or acyclic hydrocarbylene group, a phenylene group and a xylylene group, where each of the R 1 and R 2 groups is the same or different and is as defined for R 1 , and maintaining that contact for a time period sufficient for said bismuth-213 ions to be bound by the separation medium to form bismuth-213-laden separation medium and a daughter-depleted parent-daughter solution; (b) removing the daughter-depleted parent-daughter solution from the separation medium; and (c) stripping the daughter radionuclide from the daughter-laden separation medium with an aqueous solution to form an aqueous solution of trivalent bismuth-213 daughter radionuclide ions that is substantially free of divalent radium-225 and trivalent actinium-225 parent and other daughter radionuclide ion impurities.