Method of separating and purifying cesium-131 from barium carbonate
The present invention provides a method of separating and purifying Cesium-131 (Cs-131) from Barium (Ba). Uses of the Cs-131 purified by the method include cancer research and treatment, such as for the use in brachytherapy. Cs-131 is particularly useful in the treatment of faster growing tumors.
1. A method for purifying Cs-131, comprising the steps of:
(a) dissolving neutron-irradiated barium comprising barium and Cs-131, in a first solution comprising an acid, whereby the barium and Cs-131 are dissolved in the first solution;
(b) adding the first solution to a second solution comprising carbonate, under conditions of rate of addition and mixing sufficient to precipitate the barium as a solid, whereby the Cs-131 remains dissolved in the combined solution of the first and second solutions; and
(c) separating solids from the combined solution containing the Cs-131, thereby purifying the Cs-131.
2. The method according to claim 1 wherein the acid in step (a) is acetic acid.
3. The method according to claim 1 wherein the neutron-irradiated barium in step (a) is barium carbonate.
4. The method according to claim 1 wherein the carbonate in step (b) is ammonium carbonate.
5. The method according to claim 1 wherein the separated solids of step (c) are subjected to the steps of:
(i) storing the solids to allow additional Cs-131 to form from decay of Ba-131; and
(ii) repeating steps (a), (b) and (c) of claim 1 .
6. The method according to any one of claims 1 - 5 having additional step (d), comprising (d) contacting the combined solution containing the Cs-131 of step (c) with a resin that removes barium, thereby removing trace barium if present from the Cs-131.
7. The method according to any one of claims 1 - 5 having additional steps (d) and (e), comprising (d) evaporating the combined solution containing the Cs-131 to incipient dryness; and (e) contacting the purified Cs-131 with a solution.
8. The method according to claim 6 having additional steps (e) and (f), comprising (e) evaporating the combined solution containing the purified Cs-131 of step (d) to incipient dryness; and (f) contacting the purified Cs-131 with a solution.
9. The method according to any one of claims 1 - 5 having additional step (d), comprising (d) evaporating the combined solution containing the Cs-131 to incipient dryness to leave a residue containing the Cs-131.
10. The method according to claim 9 whereby steps (a), (b), and (c) of claim 1 are repeated beginning with the residue of step (d).
11. The method according to claim 9 having additional steps (e) and (f), comprising (e) contacting the residue with at least 90-wt % HNO 3 whereby Cs-131 is dissolved in the acid solution and barium is precipitated as a solid; and (f) separating solids from the acid solution containing the Cs-131, thereby removing trace barium from the Cs-131.