Method for producing thorium-226
Disclosed herein are embodiments of a method for producing thorium-226. The method comprises separating thorium-226 from uranium-230 to produce a solution of thorium-226 in a solvent, such as a chelating buffer, suitable for direct labeling by a chelate. The thorium-226 may be separated from the uranium-230 using extraction chromatography. The extraction may be repeated multiple times as additional thorium-226 is produced by uranium-230 decay.
1. A method, comprising:
forming a first solution comprising uranium-230 and thorium-226;
contacting a first resin with the first solution such that the uranium-230 and the thorium-226 bind to the first resin, wherein the first resin is a diglycolamide resin, a monoamide resin, a malonamide resin, or a multi-podant DGA ligand,
eluting the thorium-226 from the first resin with a carboxylic acid-based chelating buffer to form a second solution comprising the thorium-226 and the carboxylic acid-based chelating buffer.
2. The method of claim 1 , wherein the first solution comprises a first mineral acid having a first acid concentration of from greater than 2 M to 12 M.
3. The method of claim 2 , wherein the first mineral acid is hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydriodic acid sulfuric acid, nitric acid, phosphoric acid, or a combination thereof.
4. The method of claim 1 , wherein the first resin is N,N,N′,N′-tetra-n-octyldiglycolamide, or N,N,N′,N′-tetrakis-2-ethylhexyldiglycolamide.
5. The method of claim 1 , wherein prior to eluting the thorium-226 the method comprises eluting the uranium-230 from the first resin with a second mineral acid to form a third solution.
6. The method of claim 5 , wherein the second mineral acid is nitric acid.
7. The method of claim 5 , wherein the second mineral acid has a second acid concentration of from greater than zero to less than 6M.
8. The method of claim 5 , further comprising:
allowing the third solution to stand for a time period sufficient for a portion of the uranium-230 in the third solution to decay to form additional thorium-226;
adding the third solution to the first resin; and
eluting the additional thorium-226 with an additional amount of the chelating buffer.
9. The method of claim 8 , wherein the time period is from 30 to 360 minutes.
10. A method, comprising:
forming a first solution comprising uranium-230 and thorium-226;
contacting a first resin selected from a phosphonic acid resin, a phosphine oxide resin, or a phosphine sulfide resin with the first solution such that the uranium-230 and the thorium-226 bind to the first resin;
eluting the thorium-226 from the first resin with a mineral acid to form a second solution, the mineral acid having an acid concentration of from 0.5 M to 4 M;
contacting a cation exchange resin with the second solution; and
eluting the thorium-226 from the cation exchange resin with the chelating buffer to form a third solution.
11. The method of claim 10 , further comprising allowing the first resin and uranium-230 to stand for a time period sufficient for a portion of the uranium-230 on the first resin to decay to form additional thorium-226, and eluting the additional thorium-226 from the first resin with an additional amount of the mineral acid.
12. The method of claim 11 , wherein the time period is from 30 to 360 minutes.
13. The method of claim 1 , wherein the chelating buffer comprises a carboxylic acid, a hydroxyl group, or a combination thereof.
14. The method of claim 13 , wherein the chelating buffer comprises glycolic acid, citric acid, tartaric acid, malonic acid, oxalic acid, succinic acid, glutaric acid, adipic acid, isocitric acid, aconitric acid, propane-1,2,3-tricarboxylic acid, malic acid, maleic acid, lactic acid, or a combination thereof.
15. The method of claim 13 , wherein the chelating buffer has a pH of from 0 to 8.
16. A method, comprising:
forming a first solution comprising uranium-230 and thorium-226 in 6M hydrochloric acid;
contacting a diglycolamide resin with the first solution to bind the uranium-230 and thorium-226 to the resin;
eluting the uranium-230 from the resin with nitric acid having a nitric acid concentration of from 0.01 M to 0.25 M, to form a second solution comprising uranium-230;
eluting the thorium-226 from the resin with a chelating buffer to form a third solution comprising thorium-226, the chelating buffer comprising a carboxylic acid and having a pH of from 2 to 6.
17. The method of claim 16 , wherein the chelating buffer comprises citric acid.
18. The method of claim 10 , comprising:
forming the first solution comprising uranium-230 and thorium-226 in 6M hydrochloric acid;
contacting the first resin with the first solution to bind the uranium-230 and thorium-226 to the first resin;
eluting the thorium-226 from the first resin with a first portion of hydrochloric acid having an acid concentration of from 0.5 M to 4 M to form the second solution;
contacting the cation exchange resin with the second solution; and
eluting the thorium-226 from the cation exchange resin with the chelating buffer to form the third solution comprising thorium-226, wherein the chelating buffer comprises a carboxylic acid and has a pH of from 4 to 6.
19. The method of claim 18 , wherein the chelating buffer comprises citric acid.