Process for the purification of ruthenium with respect to technetium and metal impurities in an aqueous nitric acid solution
OwnerEugen ANDREIADIS, Ella MOREAUinventors
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Abstract
A process for purifying ruthenium from an aqueous nitric acid solution which is present together with technetium and metal impurities, at a concentration at least 10 times lower than that of the technetium. A process for producing ruthenium-97 from a technetium-99 target which has been proton-irradiated beforehand, including implementation of the purification process. The processes herein can be used for production of ruthenium-97-based radiopharmaceuticals used in nuclear medicine for the diagnosis of cancer by imaging and the treatment thereof by targeted radiotherapy.
Claims20
A process for purifying ruthenium from an aqueous solution A1 of nitric acid comprising, in addition to the ruthenium at a concentration C1, technetium at a concentration C2 at least 10 times higher than C1, and metallic impurities, which comprises at least the following successive steps:
- a) extracting the ruthenium from the aqueous solution A1 by means of a cation-exchange resin which retains the ruthenium selectively with respect to the technetium when ruthenium and technetium are in an aqueous solution of nitric acid with a molarity comprised between a first value M1 and a second value M2 higher than M1, the extraction comprising contacting, in a chromatography column, the cation-exchange resin with the aqueous solution A1, the molarity of the aqueous solution A1 being comprised between M1 and M2;
- b) washing at least once the cation-exchange resin with an aqueous solution A2 of nitric acid with a molarity comprised between M1 and M2;
- and
- c) eluting the ruthenium from the cation-exchange resin with an aqueous solution A3 of nitric or hydrochloric acid with a molarity higher than M2 or an aqueous solution A4 of nitric or hydrochloric acid with a molarity at most equal to M2 and comprising a metal nitrate or chloride, whereby an aqueous solution A5 containing the ruthenium is obtained.
A process for producing ruthenium-97 from a technetium-99 target having been irradiated with protons, comprising at least the following successive steps:
- preparing an aqueous solution A1 of nitric acid comprising ruthenium-97 at a concentration C1, technetium at a concentration C2 at least 10 times higher than C1, and metal impurities by dissolving the target in the nitric acid;
- purifying the ruthenium-97 present in the aqueous solution A1, the purification comprising the following successive steps:
- a) extracting the ruthenium-97 from the aqueous solution A1 by means of a cation-exchange resin which retains the ruthenium selectively with respect to the technetium when ruthenium and technetium are in an aqueous solution of nitric acid with a molarity comprised between a first value M1 and a second value M2 higher than M1, the extraction comprising contacting, in a chromatography column, the cation-exchange resin with the aqueous solution A1, the molarity of the aqueous solution A1 being comprised between M1 and M2;
- b) washing at least once the cation-exchange resin with an aqueous solution A2 of nitric acid with a molarity comprised between M1 and M2;
- and
- c) eluting the ruthenium-97 from the cation-exchange resin with an aqueous solution A3 of nitric or hydrochloric acid with a molarity higher than M2 or an aqueous solution A4 of nitric or hydrochloric acid with a molarity at most equal to M2 and comprising a metal nitrate or chloride, whereby an aqueous solution A5 containing the ruthenium-97 is obtained.
Dependencies are inferred from the claim text.