Separation and purification method for preparing lead-212 and actinide-225 by photo-nuclear reaction method

Abstract

The invention relates to the technical field of radionuclide separation and purification, and particularly discloses a separation and purification method for preparing lead-212 and actinide 225 by a photo-nuclear reaction method. The method comprises the following steps that a radium target dissolving solution sequentially passes through a lead resin column and a DGA resin column, and a recovery solution is obtained; leaching the lead resin column by using a first leacheate to obtain a lead-212 primary purified solution; leaching the DGA resin column with a second leacheate to obtain an actinide 225 primary purified solution; introducing the lead-212 primary purified liquid into a first LN resin column, leaching the first LN resin column by using a third leacheate, and introducing the third desorption liquid into the first LN resin column to obtain a lead-212 secondary purified liquid; and introducing the actinide 225 primary purification liquid into a second LN resin column, leaching the second LN resin column with a fourth leacheate, and introducing the fourth desorption liquid into the second LN resin column to obtain an actinide 225 secondary purification product solution. According to the method, tedious operation steps such as medium conversion are effectively avoided, and the separation and purification efficiency of the lead 212 and the actinide 225 in the radium target is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive nuclide separation and purification, and particularly relates to a separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method. Background Art

[0002] Targeted alpha therapy is a tumor treatment method that uses alpha radionuclides combined with macromolecules to form radionuclide conjugate drugs. By specifically recognizing cancer cell tissues, the radiation generated by the radioactive isotope acts concentratedly on the tumor tissue. The alpha particles emitted by alpha radionuclides have the characteristics of higher energy and shorter radiation penetration, causing less damage to normal healthy tissues and attracting much attention in tumor treatment. Among alpha radionuclides, actinium-225 has attracted much attention due to its suitable half-life, unique decay properties and other factors. However, the large-scale production of actinium-225 and its separation and purification technology are still in the experimental research stage, and the global production is limited. For the field of targeted alpha therapy, there is a significant supply gap.

[0003] Actinium-225 can be prepared by the photonuclear reaction method of irradiating radium-226 with an accelerator. The accelerated electrons bombard the tantalum or tungsten conversion target, and the high-energy gamma rays generated by bremsstrahlung irradiate radium-226. Radium-226 reacts to generate radium-225, and radium-225 undergoes beta decay to obtain actinium-225. In addition, radium-224 generated by irradiating radium-226 decays to produce lead-212. That is to say, irradiating the radium-226 target with high-energy gamma rays can generate radium-225 and radium-224. Radium-225 undergoes beta decay to obtain actinium-225, and radium-224 undergoes 4 alpha decays to obtain lead-212. In order to be able to extract lead-212 and actinium-225 generated in the irradiated target separately, it is necessary to separate and purify a single nuclide of lead-212 or actinium-225. If the existing technology is directly adopted, the conversion of the medium is required, generally involving operations such as evaporation to dryness and dissolution, and the process is relatively cumbersome and not easy to automate. In addition, the existing technology generally aims at the separation of radium in the order of hundreds of milligrams and cannot be directly applied to the separation and purification of lead-212 and actinium-225 in radium targets above the gram level, affecting the separation and purification efficiency of lead-212 and actinium-225 in radium targets. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a separation and purification method and its preparation method for preparing lead-212 and actinium-225 by the photonuclear reaction method, so as to improve the recovery rate and decontamination factor of lead-212 and actinium-225.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method, comprising the following steps:

[0007] S1. Pass the radium target dissolution solution through a lead resin column and a DGA resin column in sequence to obtain a recovery solution;

[0008] S2. Wash the lead resin column with a first eluent to obtain a primary purified solution of lead-212;

[0009] S3. Wash the DGA resin column with a second eluent to obtain a primary purified solution of actinium-225;

[0010] S4. Introduce the primary purified solution of lead-212 into a first LN resin column, wash the first LN resin column with a third eluent to obtain a first waste liquid, and then introduce a third desorbing solution into the first LN resin column to obtain a secondary purified solution of lead-212;

[0011] S5. Introduce the primary purified solution of actinium-225 into a second LN resin column, wash the second LN resin column with a fourth eluent to obtain a second waste liquid, and then introduce a fourth desorbing solution into the second LN resin column to obtain a secondary purified product solution of actinium-225.

[0012] Optionally, in step S2, after washing the lead resin column with the first eluent, introduce a first desorbing solution into the lead resin column.

[0013] Optionally, in step S3, after washing the DGA resin column with the second eluent, introduce a second desorbing solution into the DGA resin column.

[0014] Optionally, before step S1, pass 20 - 40 mL of 0.5 - 3.0 mol / L HNO3 solution through the lead resin column and the DGA resin column in sequence to obtain a first washing solution.

[0015] Optionally, the volume of the lead resin in the lead resin column is 1 mL; the first eluent is 50 - 70 mL of 0.1 - 1.0 mol / L HNO3 solution, the volume of the DGA resin in the DGA resin column is 5 mL; the second eluent is 50 - 120 mL of 0.5 - 3.0 mol / L HNO3 solution.

[0016] Optionally, the first desorbing solution is 20 - 40 mL of 0.0001 - 0.001 mol / L HNO3 solution;

[0017] The second desorbing solution is 20 - 40 mL of 0.001 - 0.01 mol / L HNO3 solution.

[0018] Optionally, the volume of the LN resin in the first LN resin column is 5 mL. Before step S4, 20 - 40 mL of 0.005 - 0.01 mol / L HNO3 solution is passed through the first LN resin column to obtain a second washing solution; the third eluent is 20 - 40 mL of 0.005 - 0.01 mol / L HNO3 solution, and the third desorbent is 10 - 40 mL of 0.5 - 1.0 mol / L HNO3 solution.

[0019] Optionally, the volume of the LN resin in the second LN resin column is 5 mL. Before step S5, 20 - 40 mL of 0.01 - 0.05 mol / L HNO3 solution is passed through the second LN resin column to obtain a third washing solution; the fourth eluent is 50 - 70 mL of 0.01 - 0.05 mol / L HNO3 solution, and the fourth desorbent is 10 - 40 mL of 0.5 - 1.0 mol / L HNO3 solution.

[0020] Optionally, the volume of the lead - 212 primary purification solution is 20 - 40 mL; in step S5, the volume of the actinium - 225 primary purification solution is 20 - 40 mL.

[0021] The beneficial effects of the present invention are as follows: The method for separating and purifying lead - 212 and actinium - 225 in the irradiated radium target involved in this application not only has the advantages of simple operation and easy automation implementation, but also performs excellently in terms of improving efficiency and purity. Utilizing the adsorption and desorption characteristics of different resins for radium - 226, lead - 212, and actinium - 225, the present invention provides a method for directly separating and purifying lead - 212 and actinium - 225 from the radium target dissolution solution without medium conversion. This breakthrough method not only simplifies the operation steps but also significantly improves the efficiency and reliability of separation and purification. In addition, the process of directly performing secondary purification from the primary purification desorbent further ensures the high purity of the final product.

[0022] The present invention realizes the precise matching of adsorption and desorption conditions between various separation and purification steps, effectively avoiding cumbersome operation steps such as medium conversion, thereby greatly reducing the operation time and cost and improving the separation and purification efficiency of lead - 212 and actinium - 225 in the radium target. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Embodiment

[0025] Example 1

[0026] Use wet packing for a 1 mL lead resin column and a 5 mL DGA resin column, and connect the two resin columns in series in sequence. Place the lead resin column above and the DGA resin column below. Use a pipette manually or an injection pump or a peristaltic pump to make 20 mL of 0.5 mol / L HNO3 solution pass through the lead resin column and the DGA resin column in sequence at a flow rate of 0.5 - 0.8 mL / min to obtain the first washing solution; then use a pipette or an injection pump or a peristaltic pump to make 20 mL of irradiated radium target analog solution pass through the lead resin column and the DGA resin column in sequence at a flow rate of 0.5 mL / min. The effluent can be used for further separation and purification of the analog Pb of lead-212 and the analog La of actinium-225, or used as a recovery solution for recovering the analog Ba of radium-226. Then separate the lead resin column and the DGA resin column, and perform primary separation and purification of the analog Pb of lead-212 and the analog La of actinium-225 respectively;

[0027] Use a pipette or an injection pump or a peristaltic pump to make 50 mL of 0.5 mol / L HNO3 solution pass through the lead resin column at a flow rate of 0.5 mL / min to obtain the first effluent; then use a pipette or an injection pump or a peristaltic pump to make 40 mL of 0.001 mol / L HNO3 solution pass through the lead resin column at a flow rate of 0.5 mL / min to obtain the primary purification solution of the analog Pb of lead-212;

[0028] Use a pipette or an injection pump or a peristaltic pump to make 100 mL of 0.5 mol / L HNO3 solution pass through the DGA resin column at a flow rate of 0.5 mL / min to obtain the second effluent; then use a pipette or an injection pump or a peristaltic pump to make 40 mL of 0.01 mol / L HNO3 solution pass through the DGA resin column at a flow rate of 0.5 mL / min to obtain the primary purification solution of the analog La of actinium-225;

[0029] Use wet packing for a 5 mL first LN resin column. Use a pipette manually or an injection pump or a peristaltic pump to make 20 mL of 0.01 mol / L HNO3 solution pass through the first LN resin column at a flow rate of 0.5 - 0.8 mL / min to obtain the first washing solution; then use a pipette or an injection pump or a peristaltic pump to make 40 mL of the primary purification product solution of the analog Pb of lead-212 pass through the first LN resin column at a flow rate of 0.5 mL / min, and then use a pipette or an injection pump or a peristaltic pump to make 50 mL of 0.01 mol / L HNO3 solution pass through the first LN resin column at a flow rate of 0.5 mL / min to obtain the first waste liquid; finally use a pipette or an injection pump or a peristaltic pump to make 20 mL of 0.5 mol / L HNO3 solution pass through the first LN resin column at a flow rate of 0.5 mL / min to obtain the secondary purification product solution of the analog Pb of lead-212;

[0030] The second LN resin column was filled with 5 mL of resin by the wet method. A pipette, syringe pump or peristaltic pump was used to pass 20 mL of 0.05 mol / L HNO3 solution through the second LN resin column at a flow rate of 0.5 mL / min to obtain the second washing solution. Then, a pipette, syringe pump or peristaltic pump was used to pass 40 mL of the primary purification product solution of the actinium-225 analog La through the second LN resin column at a flow rate of 0.5 mL / min. After that, a pipette, syringe pump or peristaltic pump was used to pass 50 mL of 0.05 mol / L HNO3 solution through the second LN resin column at a flow rate of 0.5 mL / min to obtain the second waste liquid. Finally, a pipette, syringe pump or peristaltic pump was used to pass 20 mL of 0.5 mol / L HNO3 solution through the second LN resin column at a flow rate of 0.5 mL / min to obtain the secondary purification product solution of actinium-225.

[0031] Example 2

[0032] A separation and purification method for the preparation of lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the first eluent is 30 mL of 0.1 mol / L HNO3 solution.

[0033] Example 3

[0034] A separation and purification method for the preparation of lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the first eluent is 50 mL of 0.1 mol / L HNO3 solution.

[0035] Example 4

[0036] A separation and purification method for the preparation of lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the first eluent is 30 mL of 0.5 mol / L HNO3 solution.

[0037] Example 5

[0038] A separation and purification method for the preparation of lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the first eluent is 50 mL of 0.5 mol / L HNO3 solution.

[0039] Example 6

[0040] A separation and purification method for the preparation of lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the volume of the DGA resin is 2 mL and the second eluent is 10 mL of 0.5 mol / L HNO3 solution.

[0041] Example 7

[0042] A separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the volume of the DGA resin is 5 mL, and the second eluent is 50 mL of 1.0 mol / L HNO3 solution.

[0043] Example 8

[0044] A separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the volume of the DGA resin is 5 mL, and the second eluent is 120 mL of 1.0 mol / L HNO3 solution.

[0045] Example 9

[0046] A separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the volume of the DGA resin is 5 mL, and the second eluent is 10 mL of 0.5 mol / L HNO3 and 40 mL of 3.0 mol / L HNO3 solution for elution in sequence.

[0047] Example 10

[0048] A separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method, which is different from Example 1 in that the volume of the DGA resin is 5 mL, and the second eluent is 10 mL of 0.5 mol / L HNO3 and 90 mL of 3.0 mol / L HNO3 solution for elution in sequence.

[0049] Example 11

[0050] Use wet packing for a 1 mL lead resin column and a 5 mL DGA resin column, and connect the two resin columns in series in sequence. Use a pipette manually or an injection pump or a peristaltic pump to make 20 mL of 0.5 mol / L HNO3 solution pass through the lead resin column and the DGA resin column at a flow rate of 0.5 mL / min in sequence to obtain the first washing solution; then use a pipette or an injection pump or a peristaltic pump to make 20 mL of the simulated irradiated target dissolution solution pass through the lead resin column and the DGA resin column at a flow rate of 0.5 mL / min in sequence. The effluent can be used for further separation and purification of the lead-212 analog Pb and the actinium-225 analog La, or used as a recovery solution for recovering radium-226. Then separate the lead resin column and the DGA resin column, and perform primary separation and purification of the lead-212 analog Pb and the actinium-225 analog La respectively.

[0051] Use a pipette, syringe pump, or peristaltic pump to pass 50 mL of 0.1 mol / L HNO3 solution through a lead resin column at a flow rate of 0.5 mL / min to obtain a first effluent; then use a pipette, syringe pump, or peristaltic pump to pass 20 mL of 0.0001 mol / L HNO3 solution through the lead resin column at a flow rate of 0.5 mL / min to obtain a primary purified solution of lead-212 analog Pb;

[0052] Use a pipette, syringe pump, or peristaltic pump to pass 50 mL of 0.5 mol / L HNO3 solution through a DGA resin column at a flow rate of 0.5 mL / min to obtain a second effluent; then use a pipette, syringe pump, or peristaltic pump to pass 20 mL of 0.001 mol / L HNO3 solution through the DGA resin column at a flow rate of 0.5 mL / min to obtain a primary purified solution of actinium-225 analog La;

[0053] Use wet packing to fill a 5 mL first LN resin column, and use a pipette manually, syringe pump, or peristaltic pump to pass 20 mL of 0.005 mol / L HNO3 solution through the first LN resin column at a flow rate of 0.5 mL / min to obtain a first washing solution; then use a pipette, syringe pump, or peristaltic pump to pass 20 mL of the primary purified product solution of lead-212 analog Pb through the first LN resin column at a flow rate of 0.5 mL / min, and then use a pipette, syringe pump, or peristaltic pump to pass 50 mL of 0.005 mol / L HNO3 solution through the first LN resin column at a flow rate of 0.5 mL / min to obtain a first waste liquid; finally, use a pipette, syringe pump, or peristaltic pump to pass 10 mL of 0.5 mol / L HNO3 solution through the first LN resin column at a flow rate of 0.5 mL / min to obtain a secondary purified product solution of lead-212 analog Pb;

[0054] Use wet packing to fill a 5 mL second LN resin column, and use a pipette manually, syringe pump, or peristaltic pump to pass 20 mL of 0.01 - 0.05 mol / L HNO3 solution through the second LN resin column at a flow rate of 0.5 mL / min to obtain a second washing solution; then use a pipette, syringe pump, or peristaltic pump to pass 20 mL of the primary purified product solution of actinium-225 analog La through the second LN resin column at a flow rate of 0.5 mL / min, and then use a pipette, syringe pump, or peristaltic pump to pass 50 mL of 0.01 mol / L HNO3 solution through the second LN resin column at a flow rate of 0.5 mL / min to obtain a second waste liquid; finally, use a pipette, syringe pump, or peristaltic pump to pass 10 mL of 0.5 mol / L HNO3 solution through the second LN resin column at a flow rate of 0.5 mL / min to obtain a secondary purified product solution of actinium-225 analog La.

[0055] Example 12

[0056] A separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method, comprising the following steps:

[0057] Wet-pack a 1 mL lead resin column and a 5 mL DGA resin column, and connect the two resin columns in series in turn. Use a pipette manually or an injection pump or a peristaltic pump to pass 40 mL of 3.0 mol / L HNO3 solution through the lead resin column and the DGA resin column in turn at a flow rate of 0.8 mL / min to obtain a first washing solution; then use a pipette or an injection pump or a peristaltic pump to pass 40 mL of a simulated irradiated target dissolution solution through the lead resin column and the DGA resin column in turn at a flow rate of 0.8 mL / min. The effluent can be used for further separation and purification of lead-212 analog Pb and actinium-225 analog La, or used as a recovery solution for recovering radium-226. Then separate the lead resin column and the DGA resin column, and perform primary separation and purification of lead-212 analog Pb and actinium-225 analog La respectively;

[0058] Use a pipette or an injection pump or a peristaltic pump to pass 70 mL of 1.0 mol / L HNO3 solution through the lead resin column at a flow rate of 0.8 mL / min to obtain a first effluent; then use a pipette or an injection pump or a peristaltic pump to pass 40 mL of 0.001 mol / L HNO3 solution through the lead resin column at a flow rate of 0.8 mL / min to obtain a primary purification solution of lead-212 analog Pb;

[0059] Use a pipette or an injection pump or a peristaltic pump to pass 120 mL of 3.0 mol / L HNO3 solution through the DGA resin column at a flow rate of 0.8 mL / min to obtain a second effluent; then use a pipette or an injection pump or a peristaltic pump to pass 40 mL of 0.01 mol / L HNO3 solution through the DGA resin column at a flow rate of 0.8 mL / min to obtain a primary purification solution of actinium-225 analog La;

[0060] Wet-pack a 5 mL first LN resin column, use a pipette manually or an injection pump or a peristaltic pump to pass 40 mL of 0.01 mol / L HNO3 solution through the first LN resin column at a flow rate of 0.8 mL / min to obtain a first washing solution; then use a pipette or an injection pump or a peristaltic pump to pass 40 mL of the primary purification product solution of lead-212 analog Pb through the first LN resin column at a flow rate of 0.8 mL / min, and then use a pipette or an injection pump or a peristaltic pump to pass 70 mL of 0.01 mol / L HNO3 solution through the first LN resin column at a flow rate of 0.8 mL / min to obtain a first waste liquid; finally, use a pipette or an injection pump or a peristaltic pump to pass 40 mL of 1.0 mol / L HNO3 solution through the first LN resin column at a flow rate of 0.8 mL / min to obtain a secondary purification product solution of lead-212 analog Pb;

[0061] A 5 mL second LN resin column was filled by wet method. A pipette, syringe pump or peristaltic pump was used to make 40 mL of 0.05 mol / L HNO3 solution pass through the second LN resin column at a flow rate of 0.8 mL / min to obtain a second washing solution. Then, a pipette, syringe pump or peristaltic pump was used to make 40 mL of the actinium-225 analogue La primary purification product solution pass through the second LN resin column at a flow rate of 0.5 mL / min. After that, a pipette, syringe pump or peristaltic pump was used to make 70 mL of 0.05 mol / L HNO3 solution pass through the second LN resin column at a flow rate of 0.8 mL / min to obtain a second waste liquid. Finally, a pipette, syringe pump or peristaltic pump was used to make 40 mL of 1.0 mol / L HNO3 solution pass through the second LN resin column at a flow rate of 0.8 mL / min to obtain a secondary purification product solution of the actinium-225 analogue La.

[0062] Performance detection

[0063] 1. Based on the chemical property similarities between Ba and Ra, and between La and Ac, as well as the adsorption and desorption performance similarities on the separation resin, the present invention uses Ba to simulate Ra and La to simulate Ac, and verifies the feasibility and performance effect of the solution described in the present invention through simulation experiments. The simulated radium target dissolution solution is a mixed solution of Ba, La and Pb. A mixed solution containing 1 g of Ba, 50 μg of Pb and 50 μg of La was prepared, with the medium being 20 mL of 0.5 mol / L HNO3 solution, and this solution was used as the simulated target dissolution solution.

[0064] 2. The secondary purification product solution in the example was collected, and the concentrations of Pb and La in it were measured by ICP-OES. The concentrations of Pb and La were multiplied by the volume of the secondary purification product solution to obtain the total masses of Pb and La in the product solution. The total masses of Pb and La were divided by the total masses of Pb and La in the prepared target dissolution solution to obtain the recovery rates of Pb and La.

[0065] 3. The concentration of Ba in the secondary purification product solution was measured by ICP-OES. The concentration of Ba was multiplied by the volume of the product solution to obtain the total mass of Ba in the product solution. The total mass of Ba in the prepared target dissolution solution was divided by the total mass of Ba in the product solution to obtain the decontamination factor of Ba.

[0066] Lead recovery rate Ba decontamination factor La recovery rate Ba decontamination factor Example 1 99％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 2 97％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 <!-- 5 -->]]> Example 3 100％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 4 98％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 5 96％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 6 99％ <![CDATA[1×10 7 > 70％ <![CDATA[1×10 7 > Example 7 99％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 8 99％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 9 99％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 10 99％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 11 99％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 > Example 12 99％ <![CDATA[1×10 7 > 100％ <![CDATA[1×10 7 >

[0067] Finally, it should be noted that the above are only the preferred examples of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction, characterized in that: The steps include: S1, passing the radium target dissolved solution through a lead resin column and a DGA resin column in sequence to obtain a recovered solution; S2, using the first eluent to elute the lead resin column to obtain a lead-212 primary purified solution; S3, using a second eluent to elute the DGA resin column to obtain a primary purified actinium-225 solution; S4, introducing the lead-212 primary purified liquid into a first LN resin column, and eluting the first LN resin column with a third eluent to obtain a first waste liquid, and then introducing the third desorption liquid into the first LN resin column to obtain a lead-212 secondary purified liquid; S5, introducing the actinium-225 primary purification solution into a second LN resin column, and eluting the second LN resin column with a fourth eluent to obtain a second waste liquid, and then introducing the fourth desorption solution into the second LN resin column to obtain an actinium-225 secondary purification product solution.

2. The separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction method according to claim 1, characterized in that: In step S2, after the lead resin column is eluted with a first eluent, a first desorption liquid is introduced into the lead resin column.

3. The separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction method according to claim 1, characterized in that: In step S3, the DGA resin column is eluted with a second eluting liquid, and then a second desorption liquid is introduced into the DGA resin column.

4. The separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction method according to claim 1, characterized in that: Before step S1, 20-40 mL of 0.5-3.0 mol / L HNO3 solution is passed through a lead resin column and a DGA resin column in sequence to obtain a first washing solution.

5. The separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction method according to claim 1, characterized in that: The volume of the lead resin in the lead resin column is 1 mL; the first eluent is 50-70 mL of a 0.1-1.0 mol / L HNO3 solution, the volume of the DGA value in the DGA resin column is 5 mL; the second eluent is 50-120 mL of a 0.5-3.0 mol / L HNO3 solution.

6. The separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction method according to claim 1, characterized in that: The first desorption liquid is 20-40 mL of 0.0001-0.001 mol / L HNO3 solution; The second desorption liquid is 20-40 mL of 0.001-0.01 mol / L HNO3 solution.

7. The separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction method according to claim 1, characterized in that: The volume of the LN resin in the first LN resin column is 5 mL. Before step S4, 20 to 40 mL of 0.005 to 0.01 mol / L HNO3 solution is passed through the first LN resin column to obtain a second washing liquid; the third eluent is 20 to 40 mL of 0.005 to 0.01 mol / L HNO3 solution, and the third desorption liquid is 10 to 40 mL of 0.5 to 1.0 mol / L HNO3 solution.

8. The separation and purification method for preparing lead-212 and actinium-225 by photonuclear reaction method according to claim 1, characterized in that: The volume of the LN resin in the second LN resin column is 5 mL. Before step S5, 20 to 40 mL of 0.01 to 0.05 mol / L HNO3 solution is passed through the second LN resin column to obtain a third washing liquid; the fourth eluent is 50 to 70 mL of 0.01 to 0.05 mol / L HNO3 solution, and the fourth desorption liquid is 10 to 40 mL of 0.5 to 1.0 mol / L HNO3 solution.

9. According to the separation and purification method for preparing lead-212 and actinium-225 by the photonuclear reaction method of claim 1, in step S4, the volume of the lead-212 primary purification solution is 20-40 mL; in step S5, the volume of the actinium-225 primary purification solution is 20-40 mL.