A method for extracting Pb-212 from radium solution
By using a TK100 resin column and an extraction method with specific acidity control, the problem of high Ra impurity content in the extraction of Pb-212 from radium solution was solved, achieving the separation and recovery of high-purity Pb-212 and improving the effect of drug ligand labeling.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- STATE POWER INVESTMENT NUCLIDES TONGCHUANG (CHONGQING) TECH CO LTD
- Filing Date
- 2024-10-16
- Publication Date
- 2026-05-26
AI Technical Summary
Existing techniques for extracting Pb-212 from radium solutions suffer from high Ra impurity content and low purity, leading to reduced ligand labeling rates and potential damage to human tissues.
Extraction was performed using a TK100 resin column loaded with di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl)phosphate extractants. Ra and Pb-212 were separated by combining different acidities and washing conditions. Effective separation was achieved by adjusting the concentration and flow rate of nitric acid and hydrochloric acid.
This improved the purity and recovery rate of Pb-212, reduced the leakage rate of Ra, and ensured the high radionuclear purity of Pb-212 products, which is beneficial for labeling experiments of drug ligands.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of Pb-212 preparation technology, specifically relating to a method for extracting Pb-212 from radium solution. Background Technology
[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.
[0003] Pb-212 has significant advantages in cancer treatment and, along with Ac-225 (actinium-225), has become one of the two most watched targeted therapeutic alpha nuclides in recent years. Its high energy transfer efficiency helps achieve more effective radiopharmaceutical dosage delivery. Moreover, compared to Ac-225, it does not have a complex decay chain, resulting in less off-target toxicity from daughter nucleus recoil and less toxicity caused by daughter nucleus dispersal. The design of chelates is also relatively simple. Pb-212 can be obtained through methods such as isolation and purification from natural thorium series nuclei, nuclear fuel irradiated by reactors, isolation and purification from U-232 decay daughter nuclei, and accelerator production.
[0004] During the production of Ac-225 from a proton-irradiated thorium target, not only is Ra-223 (radium-223) produced as a byproduct, but also large quantities of Th-228 (thorium-228) and Ra-224 (radium-224), both of which can be used as precursors for Pb-212 production. In the separation of Ac from the irradiated thorium target, Th, which constitutes over 99.9% by mass, is first separated from other trace elements, yielding a large matrix thorium solution containing Th-228 and trace elements containing radium and actinium. Raum and actinium are then separated to obtain crude radium and crude actinium products. Further purification of the crude radium product by removing other impurities such as Ba, Sr, Pb, Pd, and Rb yields a Ra product with higher purity. Then wait for Ra-224 to decay into Pb-212 to obtain Pb-212 with high radionuclear purity. During the separation process, it is necessary to reduce the leakage rate of Ra, otherwise the Ra impurity content in the Pb product will increase, the purity of the Pb-212 product will decrease, and the subsequent ligand labeling rate of the nuclide will decrease. In addition, Ra contains a certain proportion of Ra-225, and the β rays it emits will cause unnecessary damage to human tissues. Summary of the Invention
[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for extracting Pb-212 from radium solution.
[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:
[0007] A method for extracting Pb-212 from a radium solution includes the following steps:
[0008] The matrix thorium and actinium in the proton-irradiated thorium target were removed sequentially to obtain a crude radium product solution.
[0009] After removing impurity elements from the crude radium product solution, the Ra product solution is obtained.
[0010] The Ra product solution was left to stand for a set time to allow the activity of its daughter product Pb-212 to reach the required level.
[0011] The nitric acid concentration of the Ra product solution was adjusted to 0.001-0.01 mol / L;
[0012] The diluted solution was passed through a TK100 resin column loaded with di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl)phosphate extractants.
[0013] The TK100 resin column was washed with nitric acid at a concentration of 0.001-0.01 mol / L for a washing volume of 3-5 column volumes; then the TK100 resin column was washed with hydrochloric acid at a concentration of 5.5-6.5 mol / L for a washing volume of 3-5 column volumes.
[0014] After Ra is left to stand for several days, the activity of the daughter product Pb-212 is at its maximum. However, Ra still dominates the mass ratio in the mixed solution, with only a small amount of Pb-212. The mass ratios of the two elements are vastly different, and many separation methods can easily cause Ra to leak through during separation, resulting in a high Ra impurity content in the Pb-212 product.
[0015] In this invention, the acidity of the solution is adjusted to low acidity, and the solution is passed through a TK100 resin column. The extractant loaded on the TK100 resin column is a mixture of di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate. The particle size of the resin particles is 100-150 μm, the loading rate of the solution is 0.5-1 mL / min, Ra is adsorbed on the column, and Pb-212 flows out with the solution.
[0016] Specifically, the nitric acid concentration of the Ra product solution is adjusted to 0.001-0.01 mol / L. Passing the solution through a TK100 resin column within this acidity range allows for relatively complete adsorption of Ra, while most impurities remain in the effluent. Excessive or insufficient nitric acid concentration in the Ra product solution reduces its adsorption capacity for Ra to varying degrees.
[0017] Next, the column was washed with 0.001-0.01 mol / L nitric acid at a rate of 1 mL / min for 2-3 column volumes to remove any remaining impurities. Then, elution was performed with 5.5-6.5 mol / L hydrochloric acid. Within this acidity range, the column's adsorption capacity for Pb-212 is weak, making desorption easier. Elution was performed at a rate of 0.5-1.5 mL / min for 3-5 column volumes to completely elute the Pb-212 from the column, yielding a high-purity Pb-212 product.
[0018] In some embodiments, the diluent is fed onto the TK100 resin column at a rate of 0.5-1 mL / min.
[0019] In some embodiments, the extractant loaded on the TK100 resin column is a mixture of di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate.
[0020] Preferably, the particle size of TK100 resin is 100-150μm.
[0021] Methods for preparing Ra product solution include cation exchange resin column purification, TK101 purification, and TK102 purification.
[0022] In some embodiments, the method for preparing Ra product solution by removing impurity elements from the crude radium product solution is as follows:
[0023] The concentration of nitric acid in the crude radium product solution was adjusted to 0.4-0.6 mol / L to ensure that all elements could be loaded onto the column. Then, it was passed through a cation exchange resin column. The resin of the cation exchange resin column was made of styrene-divinylbenzene crosslinked with sulfonate groups.
[0024] Then, the cation exchange resin column was eluted with 0.2-0.4 mol / L citric acid. Sr, Pb, La and Pd were eluted first, followed by Ba, and finally Ra, thus completing the separation of Ra from other elements.
[0025] Ra has similar chemical properties to elements in the same group, making separation somewhat difficult. This invention utilizes the different complexing abilities of complexing agents for different alkaline earth metals to achieve separation from other elements.
[0026] Preferably, the cationic resin is of type DOWEX50-X8, AG50W-X8 or AGMP-50.
[0027] Preferably, the particle size of the cationic resin is 200-400 mesh.
[0028] Preferably, the citric acid has a pH value of 3-6.
[0029] In some embodiments, the method for preparing Ra product solution by removing impurity elements from the crude radium product solution is as follows:
[0030] The concentration of nitric acid in the crude radium product solution was adjusted to 0.04-0.06 mol / L, and then it was passed through a TK101 resin column.
[0031] The TK101 resin column was washed with 0.04-0.06 mol / L nitric acid for a wash volume of 2 column volumes.
[0032] Then, the TK101 resin column was eluted with 2.5-3.5 mol / L nitric acid for 6-8 column volumes to obtain the Ra product solution.
[0033] The TK101 resin column was washed with 0.04-0.06 mol / L nitric acid to elute off elements such as Ba, Sr, Pb, and La adsorbed on the TK101 resin column.
[0034] Then, the TK101 resin column is eluted with 2.5-3.5 mol / L nitric acid for 6-8 column volumes to elute Ra and obtain a pure Ra product solution.
[0035] Ba was eluted with 6-8 mol / L nitric acid at a volume of 4-5 column volumes and a elution rate of 0.5-1 mL / min.
[0036] Preferably, the particle size of TK101 resin is 100-150μm.
[0037] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows:
[0038] (1) TK100 resin was used for the first time to separate Ra and Pb, with a Pb-212 recovery rate of nearly 97% and a decontamination coefficient >10. 3 This effectively removes Ra contamination from Pb.
[0039] (2) In the Ra purification stage and Ra / Pb separation stage, cation exchange resin / TK101 / TK102+TK100 was used to complete the purification of crude radium and the extraction of Pb. This effectively reduced the elemental proportion of the parent element Ra in the Pb-212 product solution, which will improve the radionuclear purity of Pb-212 and is more conducive to the labeling experiment of drug ligands. Detailed Implementation
[0040] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0041] The method for removing matrix thorium from a proton-irradiated thorium target is as follows:
[0042] A large amount of matrix thorium was removed using an anion exchange resin column method. Specifically, under high-concentration nitric acid conditions, thorium, uranium, protactinium, and other elements formed complex anions with nitrate ions and were adsorbed onto the column, while radium, actinium, and other impurity elements eluted with the effluent. The thorium solution concentration decreased from 100 g / L to 10 g / L. -5 g / L, with a decontamination factor of approximately 10 for thorium. 7 .
[0043] The anion exchange resin used in the thorium removal process is either DOWEX1-X8 or AGMP-1M, with a resin particle size of 100-200 mesh or 200-400 mesh, and the resin exchange ion is nitrate. The acidity of the thorium solution loaded onto the column is 7-7.5 mol / L or 7.5-8 mol / L nitric acid, with a flow rate of approximately 0.4-0.8 mL / min. The separation column is then washed with 2-4 column volumes of nitric acid solution at an acidity of 7-7.5 mol / L or 7.5-8 mol / L nitric acid, with a flow rate of approximately 0.4-0.8 mL / min. Finally, the elements on the column are eluted with 0.01 mol / L-0.1 mol / L nitric acid.
[0044] The method for removing actinium is as follows:
[0045] One method involves adjusting the acid concentration of a solution containing radium, actinium, and other impurity elements to 0.5 mol / L. The solution is then passed through a cation exchange resin column at a flow rate of 0.1-0.2 mol / L. The cation exchange resin used is DOWEX50-X8, AG50W-X8, or AGMP-50, or other strongly basic cation exchange resins with similar functions. The resin is cross-linked styrene-divinylbenzene, with sulfonic acid ions as the exchange groups and hydrogen ions as the exchange ions. The resin particle size is 100-200 mesh.
[0046] The separation column was then washed with 2-3 mol / L nitric acid to separate divalent elements such as radium from trivalent elements such as actinium, with a washing volume of 12-18 column volumes. Divalent elements such as radium were eluted first, followed by trivalent elements such as actinium. Thorium remained on the separation column and could be eluted with 4-5.5 mol / L nitric acid at a flow rate of 0.5-1 mL / min.
[0047] Method two involves adjusting the acid concentration of the radium, actinium, and other impurity element solutions to 2 mol / L. The resin material, column loading rate, and washing flow rate are the same as in Method one. The washing volume is 10-15 column volumes. The washing behavior of the elements remains unchanged: divalent elements are eluted first, followed by trivalent elements. Thorium remains on the column and can be eluted subsequently with 4-5.5 mol / L nitric acid at a flow rate of 0.5-1 mL / min.
[0048] After the above methods are completed, a crude radium product solution is obtained, which is a mixed solution of radium and impurity elements such as barium, strontium, lead, palladium, and tin.
[0049] The present invention will be further described below with reference to the embodiments.
[0050] Example 1
[0051] Simulated solutions of crude radium product were prepared using Ba (simulating Ra), Sr, Pb, and La (simulating Ac) with concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, and La-12ppm, respectively. The solutions had an acidity of 0.5mol / L nitric acid and a volume of 10mL.
[0052] The solution was passed through AG50W-X8 resin with a particle size of 200-400 mesh, a resin volume of 1 mL, and a column loading speed of 0.3 mL / min.
[0053] The AG50W-X8 resin column was then eluted with 0.25 mol / L citric acid solution at pH 5 at a rate of 0.5 mL / min, yielding 10 mL of eluent 1 (containing La, Sr, and Pb), 10 mL of eluent 2 (containing Ba), and 15 mL of eluent 3 (corresponding to Ra solution). The detergency coefficients of Ba for Sr, Pb, and La were 5600, 2000, and 6000, respectively.
[0054] Ba and Ra have very similar chemical properties. To simulate the properties of Ra, a simulated solution of Ra-224 and Pb-212 after equilibrium was prepared: Ba concentration was 28 ppm, Pb-212 concentration was 3 ppm, solution acidity was 0.005 mol / L nitric acid, and volume was 10 mL.
[0055] The simulated solution was passed through TK100 resin with a particle size of 100 μm at a loading rate of 0.75 mL / min, and Ba was adsorbed onto the column. The column was then washed with 0.005 mol / L nitric acid at a rate of 1 mL / min for a washing volume of 2 column volumes to remove other trace impurities contained in the Ba. Finally, the Pb adsorbed on the resin column was eluted with 6 mol / L hydrochloric acid at a rate of 1 mL / min for a elution volume of 5 column volumes.
[0056] The final decontamination factor of Pb for Ba was 1800. The decontamination factors of Ba for Sr, Pb, and La were 2400, 1100, and 2000, respectively. The elemental purity of Pb was 99.98%, and the recovery rate was 98.2%.
[0057] Example 2
[0058] Simulated solutions of radium crude product were prepared using Ba (simulating Ra), Sr, Pb, and La (simulating Ac) at concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, and La-12ppm, respectively. The acidity was adjusted to 0.05mol / L nitric acid, and a total of 10mL was prepared. The solutions were then passed through TK101 resin with a particle size of 100-150 micrometers, a resin volume of 0.5mL, and a loading rate of 0.7mL / min.
[0059] The separation column was then eluted with 0.05 mol / L nitric acid solution at a rate of 0.5 mL / min for 10 column volumes, yielding a total of 15 mL of La, Sr, Pb, and Pd eluent. The column was then eluted again with 3 mol / L nitric acid to obtain 15 mL of Ba eluent at a rate of 0.5 mL / min.
[0060] Ba and Ra have very similar chemical properties. To simulate the properties of Ra, a simulated solution of Ra-224 and Pb-212 after equilibrium was prepared. The concentration of Ba was 28 ppm, the concentration of Pb was 3 ppm, the acidity of the solution was 0.008 mol / L nitric acid, and the volume was 10 mL.
[0061] The simulated solution was passed through TK100 resin with a particle size of 100 μm at a loading rate of 0.75 mL / min, and Ba was adsorbed onto the column. The column was then washed with 0.008 mol / L nitric acid at a rate of 1 mL / min for a washing volume of 2 column volumes to remove other trace impurities contained in the Ba. Finally, the Pb adsorbed on the resin column was eluted with 5.5 mol / L hydrochloric acid at a rate of 1 mL / min for a elution volume of 5 column volumes.
[0062] The final decontamination factor of Pb against Ba was 1800, the elemental purity of Pb was 99.97%, and the recovery rate was 96.5%.
[0063] Example 3
[0064] Compared to Example 2, the acidity of the simulated Ba, Sr, Pb, La, and Pd solutions was adjusted to 0.05 mol / L, totaling 10 mL. The solutions were then passed through DOWEX 50-X8 resin with a particle size of 200 mesh, a resin volume of 1 mL, and a loading speed of 0.2 mL / min.
[0065] The separation column was then eluted with 0.25 mol / L citric acid solution at pH 5 at a rate of 0.2 mL / min, yielding 10 mL of eluent 1 (containing La, Sr, Pb, and Pd), 10 mL of eluent 2 (containing Ba), and 15 mL of eluent 3 (corresponding to Ra solution). The decontamination coefficients of Ba for Sr, Pb, and La were 2400, 800, and 3000, respectively.
[0066] Ba and Ra have very similar chemical properties. To simulate the properties of Ra, a simulated solution of Ra-224 and Pb-212 after equilibrium was prepared. The concentration of Ba was 28 ppm, the concentration of Pb was 3 ppm, the acidity of the solution was 0.002 mol / L nitric acid, and the volume was 10 mL.
[0067] The simulated solution was passed through TK100 resin with a particle size of 100 μm at a loading rate of 0.75 mL / min, and Ba was adsorbed onto the column. The column was then washed with 0.002 mol / L nitric acid at a rate of 1 mL / min for a washing volume of 2 column volumes to remove other trace impurities contained in the Ba. Finally, the Pb adsorbed on the resin column was eluted with 6.5 mol / L hydrochloric acid at a rate of 1 mL / min for a elution volume of 5 column volumes.
[0068] The elemental purity of Pb is 99.98%, and the recovery rate is 98.1%.
[0069] Comparative Example 1
[0070] Simulated solutions of crude radium product were prepared using Ba (simulating Ra), Sr, Pb, and La (simulating Ac) at concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, and La-12ppm, respectively. The solution acidity was 0.5mol / L nitric acid, and the solution volume was 10mL. Same as Example 1.
[0071] Compared to Example 1, the pre-purification step using AG50W-X8 resin was omitted, and the column was directly fed through TK100 resin at a loading rate of 0.75 mL / min, with some Ba eluting with the solution. The column was washed with 0.005 mol / L mol / L nitric acid at a rate of 1 mL / min for a washing volume of 5 column volumes, eluting off all the Ba. Finally, Pb adsorbed on the resin column was eluted with 6 mol / L hydrochloric acid at a rate of 1 mL / min for a elution volume of 5 column volumes. The experimental results showed that Pb could not be effectively separated from other elements.
[0072] Comparative Example 2
[0073] Simulated solutions of crude radium product were prepared using Ba (simulating Ra), Sr, Pb, and La (simulating Ac) with concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, and La-12ppm, respectively. The solution acidity was 0.5mol / L nitric acid, and the solution volume was 10mL, as in Example 1.
[0074] The solution was passed through DOWEX 50-X8 resin with a particle size of 200 mesh, a resin volume of 1 mL, and a column loading speed of 0.3 mL / min.
[0075] The separation column was then eluted with 0.25 mol / L citric acid solution at pH 5 at a rate of 0.5 mL / min, yielding 10 mL of eluent 1 (containing La, Sr, and Pb), 10 mL of eluent 2 (containing Ba), and 15 mL of eluent 3 (which should be a Ra solution). The decontamination coefficients of Ba for Sr, Pb, and La were 2400, 800, and 3000, respectively.
[0076] Ba and Ra have very similar chemical properties. To simulate the properties of Ra, a simulated solution of Ra-224 and Pb-212 after equilibrium was prepared. The concentration of Ba was 28 ppm, the concentration of Pb was 3 ppm, the acidity of the solution was 0.1 mol / L nitric acid, and the volume was 10 mL.
[0077] The simulated solution was passed through DOWEX 50-X8 resin with a particle size of 200 mesh, a resin volume of 1 mL, and a loading rate of 0.5 mL / min. The column was then eluted with 0.25 mol / L citric acid solution (pH 5) at a rate of 0.5 mL / min, yielding 10 mL of Pb eluent and 15 mL of Ba eluent. The decontamination factor of Pb for Ba was 200, and the final elemental purity of Pb was 99.5%, with a recovery rate of 98%.
[0078] Comparative Example 3
[0079] The difference from Example 1 is that the simulated solution was passed through TK100 resin with a particle size of 100 micrometers at a loading rate of 0.75 mL / min, and Ba was adsorbed onto the column. The column was washed with 0.011 mol / L nitric acid at a rate of 1 mL / min for a washing volume of 2 column volumes to remove other trace impurities contained in Ba. Finally, the Pb adsorbed on the resin column was eluted with 6 mol / L hydrochloric acid at a rate of 1 mL / min for a elution volume of 5 column volumes.
[0080] The final elemental purity of Pb was 99.7%, and the recovery rate was 98.1%.
[0081] Comparative Example 4
[0082] The difference from Example 1 is that the simulated solution was passed through TK100 resin with a particle size of 100 micrometers at a loading rate of 0.75 mL / min, and Ba was adsorbed onto the column. The column was washed with 0.0007 mol / L nitric acid at a rate of 1 mL / min for a washing volume of 2 column volumes to remove other trace impurities contained in Ba. Finally, the Pb adsorbed on the resin column was eluted with 6 mol / L hydrochloric acid at a rate of 1 mL / min for a elution volume of 5 column volumes.
[0083] The final elemental purity of Pb was 99.73%, and the recovery rate was 97.15%.
[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for extracting Pb-212 from a radium solution, characterized in that: Includes the following steps: The matrix thorium and actinium in the proton-irradiated thorium target were removed sequentially to obtain a crude radium product solution. After removing impurity elements from the crude radium product solution, the Ra product solution is obtained. The Ra product solution was left to stand for a set time to allow the activity of its daughter product Pb-212 to reach the required level. The Ra product solution was diluted to obtain a diluted solution, so that the nitric acid concentration in the diluted solution reached 0.001-0.01 mol / L; The diluted solution was passed through a TK100 resin column loaded with di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl)phosphate extractants. The TK100 resin column was washed with nitric acid at a concentration of 0.008-0.01 mol / L for a washing volume of 3-5 column volumes; then the TK100 resin column was washed with hydrochloric acid at a concentration of 5.5-6.5 mol / L for a washing volume of 3-5 column volumes.
2. The method for extracting Pb-212 from radium solution according to claim 1, characterized in that: The diluent was fed onto the TK100 resin column at a rate of 0.5-1 mL / min.
3. The method for extracting Pb-212 from a radium solution according to claim 2, characterized in that: The extractant loaded on the TK100 resin column is a mixture of di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate.
4. The method for extracting Pb-212 from a radium solution according to claim 2, characterized in that: The particle size of TK100 resin is 100-150 μm.
5. The method for extracting Pb-212 from a radium solution according to claim 1, characterized in that: The method for preparing Ra product solution by removing impurity elements from crude radium product solution is as follows: The concentration of nitric acid in the crude radium product solution was adjusted to 0.4-0.6 mol / L, and then it was passed through a cation exchange resin column. The resin of the cation exchange resin column was made of styrene-divinylbenzene crosslinked with sulfonate groups. Then, the cation exchange resin column was eluted with 0.2-0.4 mol / L citric acid. Sr, Pb, La and Pd were eluted first, followed by Ba, and finally Ra, thus completing the separation of Ra from other elements.
6. The method for extracting Pb-212 from a radium solution according to claim 5, characterized in that: The cationic resin is designated as DOWEX50-X8, AG50W-X8, or AGMP-50.
7. The method for extracting Pb-212 from a radium solution according to claim 6, characterized in that: The particle size of the cationic resin is 200-400 mesh.
8. The method for extracting Pb-212 from a radium solution according to claim 5, characterized in that: The citric acid has a pH value of 3-6.
9. The method for extracting Pb-212 from a radium solution according to claim 1, characterized in that: The method for preparing Ra product solution by removing impurity elements from crude radium product solution is as follows: The concentration of nitric acid in the crude radium product solution was adjusted to 0.04-0.06 mol / L, and then it was passed through a TK101 resin column. The TK101 resin column was washed with 0.04-0.06 mol / L nitric acid for a wash volume of 2 column volumes. Then, the TK101 resin column was eluted with 2.5-3.5 mol / L nitric acid for 6-8 column volumes to obtain the Ra product solution.
10. The method for extracting Pb-212 from a radium solution according to claim 9, characterized in that: The extractant loaded on the TK101 resin column is a mixture of di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate.
11. The method for extracting Pb-212 from a radium solution according to claim 9, characterized in that: The particle size of TK101 resin is 100-150 μm.