Patent ID: 7087206

Claim:
A method for producing a solution of actinium and optionally present radium daughter radionuclide ions that is substantially free of thorium parental radionuclide ion impurities comprising the steps of: (a) contacting an aqueous parent-daughter radionuclide ion solution having a pH value of about 8 or less that contains sulfate ions as well as thorium parental radionuclide ions and actinium and optionally present radium desired daughter radionuclide ions with a first solid phase separation medium having a high affinity for the desired daughter radionuclide ions and a low affinity for the parent radionuclide ions, and maintaining that contact for a time period sufficient for said actinium and optionally present radium ions to be bound to form a desired daughter ion-laden first separation medium and a thorium ion-containing, desired daughter-depleted parent-daughter solution; (b) separating the thorium ion-containing desired daughter-depleted parent-daughter solution from the solid phase desired daughter ion-laden first separation medium; (c) stripping the desired daughter radionuclide from the desired daughter-laden first separation medium with an aqueous nitric or hydrochloric acid solution to form an aqueous nitric or hydrochloric acid solution of actinium and optionally present radium desired daughter radionuclide ions that may contain trace amounts of parental thorium ion impurities; (d) contacting said aqueous nitric or hydrochloric acid solution of actinium and optionally present radium desired daughter radionuclide ions that may contain trace amounts of parental thorium ion impurities of step (c) with a second solid phase separation medium that has a high affinity for the parent thorium radionuclide ions and a low affinity for the actinium and optionally present radium desired daughter radionuclide, and maintaining that contact for a time period sufficient for the parent thorium radionuclide to be bound by the second solid phase separation medium to form a solution of actinium and optionally present radium desired daughter radionuclide ions that is highly purified and is substantially free of thorium parental radionuclide ion impurities; and (e) separating the solid and solution phases to provide a solution of actinium and optionally present radium desired daughter radionuclide ions that is highly purified and is substantially free of thorium parental radionuclide ion impurities.