Separation system for preparing Ra-223, separation method, application and preparation method thereof

Abstract

The present invention discloses a separation system for preparing Ra-223 and a separation method, application and preparation method thereof. The separation system for preparing Ra-223 comprises a first separation column and a second separation column; the filler of the first separation column is a 507 solid phase extractant, which is used to separate the Ra-223 from the solid phase extractant. 227 Th and 228Th The second separation column is filled with P204 solid phase extractant, which is used to extract the eluent from the first separation column. 227 Th and 227 Ac is retained in the second separation column, and the second separation column is flushed multiple times to make only 223 Ra and its decay daughters flow out with the eluent; the eluents of the first separation column and the second separation column are both hydrochloric acid. 223 In Ra 227 Ac and 227 Th, and the operation is simple, and high concentration nitric acid is not used, which is conducive to the preparation of radioactive drugs.

Description

Technical Field

[0001] The present invention relates to the technical field of radioisotope preparation, and in particular to a separation system for preparing Ra-223, a separation method thereof, and an application and a preparation method thereof. Background Art

[0002] 223 Ra is an α-radioactive nuclide with a physical half-life of 11.4 days. It only emits α rays. When it enters the human body as a radioactive drug, its energy is absorbed locally and causes less radiation damage to normal tissues. Therefore, it has obvious advantages in the treatment of tumor bone metastasis and is a therapeutic nuclide with important application value.

[0003] 223 Ra has a half-life of 11.4 days, which allows it to integrate deeper into the matrix of the bone surface before decaying, making it an ideal radioactive drug for bone exploration. 223 Ra emits alpha particles with a short range (less than 10 cell diameters), which can minimize damage to surrounding normal tissues. Ra has similar properties to Ca and can selectively target bones, especially bone metastasis areas, by forming a complex with hydroxyapatite (HAP) in bones. 223 The high linear energy transfer (LET) rays (80 keV / μm) emitted by Ra can induce high-frequency double-strand DNA breaks in adjacent tumor cells, thereby producing a potent cytotoxic effect and further producing an anti-tumor effect on bone metastasis.

[0004] 223 The preparation principle of Ra, such as Figure 1 As shown: 226 Ra is used as the target material, and the reactor is irradiated by reaction 226 Ra(n,γ) 227 Ra generated 227 Ra decays to 227 Ac, 227 Ac decays to 227 Th, 227 Th undergoes α decay to 223 Ra.

[0005] Reactor irradiation produces 223 Ra contains 227 Ac and 227 Th, therefore, needs to be separated 223 In Ra 227 Ac and 227 Th. Existing separation methods mainly include solvent extraction and column chromatography.

[0006] The extraction method uses CCD and polyethylene glycol dissolved in carbon tetrachloride to extract radium from hydrochloric acid or nitric acid solution, and then uses TBP plus nitric acid for back extraction. The recovery rate of radium is greater than 95%. 227 Ac and 227 The separation factor of Th is greater than 10 6 This method is completed in two steps 223 The extraction and separation of Ra is simple, the separation system is a nitric acid system, and an organic solvent is used, which does not meet the requirements of medical nuclides. 223 Ra's needs and requires a lot of manual steps.

[0007] The existing column chromatography method requires many operation steps due to the filler problem of the separation column, and is not suitable for expansion or automation; for example, the use of f-zone characteristic silica gel actinide resin with P, P'-dioctyl methane diphosphate functional group; or the combination of anion exchange resin and cation exchange resin, using a mixed system of nitric acid and methanol, can achieve 227 Ac and 223 The separation of Ra and the removal of methanol are considered at the end, which increases the operation steps. The existing column chromatography method also uses a nitric acid system for purification, which has simple separation steps, but the system used is a high concentration of nitric acid, which is not conducive to the preparation of radioactive drugs. Summary of the invention

[0008] The purpose of the present invention is to provide a separation system and a separation method for preparing Ra-223, which can not only realize separation and extraction 227 Ac and 227 Th 223 Ra, and the operation is simple, and high concentration nitric acid is not used, which is conducive to the preparation of radioactive drugs.

[0009] In addition, the present invention also provides the application of the separation system and the preparation method of Ra-223.

[0010] The present invention is achieved through the following technical solutions:

[0011] A separation system for preparing Ra-223, comprising a first separation column and a second separation column;

[0012] The filler of the first separation column is a separation material containing an acidic phosphorus extractant, which is used to separate 227 Th and 228 Th is retained in the first separation column, so that the eluate of the first separation column contains 226 Ra, 224 Ra, 223 Ra, 227 Ac and its decay daughters ( 226 Ra, 224 Ra, 223 Ra, 227Four types of decay daughters of Ac);

[0013] The filler of the second separation column is another acidic phosphorus extractant, which is used to extract the eluent from the first separation column. 227 Th and 227 Ac is retained in the second separation column, and the second separation column is flushed multiple times to continuously generate Ac in the second separation column. 223 Ra and its decay daughters flow out with the eluent;

[0014] The eluents of the first separation column and the second separation column are both hydrochloric acid.

[0015] The separation material containing acidic phosphorus extractant of the present invention comprises P507 solid phase extractant and P507 leaching resin; another acidic phosphorus extractant comprises P204 solid phase extractant and P204 leaching resin, that is, the second separation column and the first separation column use different acidic phosphorus extractants.

[0016] Among them, P507 leaching resin and P204 leaching resin are commercially available substances; 507 solid phase extractant and P204 solid phase extractant are both homemade solid phase extractants, and homemade solid phase extractants are preferred, which have the advantages of strong mechanical properties and good radiation resistance, and can be better applied to the separation of nuclear radioactive materials.

[0017] The preparation method of the homemade P204 solid phase extraction agent comprises the following steps:

[0018] S1, subjecting di(2-ethylhexyl)phosphate to chlorination treatment to obtain chlorinated di(2-ethylhexyl)phosphate;

[0019] Mixing di(2-ethylhexyl) phosphate with thionyl chloride and pyridine, then adding the mixture into an organic solvent and heating under reflux to obtain chlorinated di(2-ethylhexyl) phosphate;

[0020] S2, grafting the inorganic material with a silane coupling agent to obtain an inorganic material grafted with the coupling agent, wherein the inorganic material is an inorganic material with hydroxyl groups on the surface;

[0021] S3, grafting the chlorinated di(2-ethylhexyl) phosphate obtained in step S1 onto the inorganic material of the graft coupling agent obtained in step S2 to obtain a solid phase extractant.

[0022] The preparation method of the homemade P507 solid phase extraction agent comprises the following steps:

[0023] S1, chlorination treatment of 2-ethylhexyl phosphate mono-2-ethylhexyl ester to obtain chlorinated 2-ethylhexyl phosphate mono-2-ethylhexyl ester;

[0024] The mixture of 2-ethylhexyl phosphate mono-2-ethylhexyl ester and sodium metal is added to an organic solvent and heated under reflux to obtain saponified 2-ethylhexyl phosphate mono-2-ethylhexyl ester, and then SOCl2 and pyridine are added and refluxed to obtain chlorinated 2-ethylhexyl phosphate mono-2-ethylhexyl ester;

[0025] S2, grafting the inorganic material with a silane coupling agent to obtain an inorganic material grafted with the coupling agent, wherein the inorganic material is an inorganic material with hydroxyl groups on the surface;

[0026] S3. Grafting the 2-ethylhexyl phosphate mono-2-ethylhexyl ester obtained in step S1 onto the inorganic material of the graft coupling agent obtained in step S2 to obtain a solid phase extractant.

[0027] The silane coupling agent includes 3-aminopropyltriethoxysilane; and the inorganic material includes silicon dioxide, zirconium dioxide, aluminum oxide or titanium dioxide.

[0028] Compared with the existing column chromatography method, the separation system of the present invention adopts an acidic phosphorus extractant, and fills the two separation columns with P507 solid phase extractant and P204 solid phase extractant respectively, which can not only realize separation and extraction 227 Ac and 227 Th 223 Ra, and the operation is simple, and the eluent is hydrochloric acid, without using high concentration nitric acid, which is conducive to the preparation of radioactive drugs.

[0029] Furthermore, the flushing liquids of the first separation column and the second separation column are both medical hydrochloric acid with a concentration of 0.01-6 mol / L.

[0030] The separation method based on the above separation system comprises the following steps:

[0031] S1, respectively loading an acidic phosphorus-containing extractant and another acidic phosphorus-containing extractant into a first separation column and a second separation column;

[0032] S2, the first separation column and the second separation column are pre-treated and rinsed with injection water and inorganic acid in sequence;

[0033] S3, transferring the target material solution into the first separation column, allowing the target material solution to contact with the acidic phosphorus extractant for a contact time of not less than 0.1h, adding hydrochloric acid to elute the first separation column, 228 Th and 227 Th is retained in the first separation column, and the eluate in the first separation column contains 226 Ra, 224 Ra, 223 Ra, 227 Ac and its decay products ( 226 Ra, 224 Ra,223 Ra, 227 Ac four decay forms);

[0034] S4, transferring the eluate obtained in step S3 to a second separation column, allowing the target material solution to contact with an acidic phosphorus extractant for a contact time of not less than 0.1 h, adding hydrochloric acid to elute the second separation column, and the eluate containing Ra-226 and 223 Ra, Done 226 Recovery of Ra; let it stand for a while, rinse with hydrochloric acid, and you can get the Ra content in cycles. 223 The eluent of Ra.

[0035] It can be obtained by cycle:

[0036] Depending on the amount of Ac-227 loaded, the elution time here can be 1 day / time, 1 week / time, or n days / time, and Ra-223 can be obtained in all cases, but the amount obtained before equilibrium is different.

[0037] Furthermore, in step S2, the flow rates of the water for injection and the inorganic acid are both 0.01 mL / min to 5 mL / min.

[0038] Furthermore, in step S2, the inorganic acid includes nitric acid, hydrochloric acid or medical hydrochloric acid.

[0039] Furthermore, in step S3 and step S4, the concentration of hydrochloric acid is 0.01 mol / L to 6 mol / L.

[0040] Applications of separation systems, including for reactor irradiation preparation 223 Ra, 224 Ra and 226 Ra (for 227 Ac or 227 Th 223 Ra, used for 228 Th 224 Ra, etc.), directly use the second separation column to 227 Ac, 227 Th, 223 Separation of Ra and direct preparation using a second separation column 227 Ac- 223 Ra generator, directly use the second separation column 227 Th, 223 Separation and preparation of Ra 227 Th- 223 Ra generator, directly use the first separation column for 228 Th, 224 Ra separation and direct use of the first separation column for preparation 228 Th-224 Ra generator.

[0041] The application of the separation system in achieving the mutual separation of Ac, Th and Ra can achieve the mutual separation of Ac, Th and Ra according to the use order and use conditions of the separation materials in the first separation column and the second separation column.

[0042] A method for preparing Ra-223 comprises the following steps:

[0043] Step 1: Prepare a target using radium salt and irradiate the target to obtain the irradiated 226 Ra target material;

[0044] Step 2: After irradiation 226 The Ra target material is heated and dissolved using an inorganic acid, the solution is evaporated to near dryness, and then dissolved using hydrochloric acid to obtain a target material solution;

[0045] Step 3: Separate the target material solution obtained in step 2 using the separation method described in any one of claims 3 to 7, and complete the following steps: 226 Ra, 223 Recovery of Ra.

[0046] Furthermore, the process of step one is:

[0047] The radium salt is placed in a quartz tube and sealed by melting, and the target is placed in the quartz tube and sealed by welding. The thermal neutron injection rate of the irradiation channel is >1×10 14 n cm -2 s -1 The irradiation time is 1 to 2 months, and the cooling time is not less than 10 days.

[0048] Furthermore, the inorganic acid used in step 2 includes nitric acid, hydrochloric acid or medical hydrochloric acid.

[0049] Furthermore, the inorganic acid used in step 2 is hydrochloric acid or medical hydrochloric acid, and the concentration of hydrochloric acid is 0.01-2 mol / L.

[0050] Furthermore, the radium salt in step 1 at least includes radium sulfate ( 226 RaSO4), radium nitrate ( 226 Ra(NO3)2), radium chloride ( 226 RaCl2), radium bromide ( 226 RaBr2) and radium carbonate ( 226 RaCO3).

[0051] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0052] 1. The separation system and separation method of the present invention can not only achieve separation 223 In Ra227 Ac and 227 The operation is simple and does not require high concentration of nitric acid, which is beneficial for the preparation of radioactive drugs.

[0053] 2. The preparation method of the present invention is used to dissolve, separate and prepare the irradiated 226 Ra target material can be processed to achieve 223 Separation and extraction of Ra, preparation 223 RaCl2; using this preparation method 223 Preparation of RaCl2 solution, separation preparation conditions are the same system, simplifying the operation process, solution preparation conditions are suitable for medical hydrochloric acid system, easy to 223 Subsequent use of RaCl2 solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0055] Figure 1 For the present invention 226 Schematic diagram of Ra irradiation products and decay;

[0056] Figure 2 For the present invention 226 Ra Extraction and Preparation 223 Schematic diagram of RaCl2 solution;

[0057] Figure 3 is a SEM image of the P204 solid phase extractant prepared in Example 1;

[0058] Figure 4 This is the SEM image of the P507 solid phase extractant prepared in Example 1.

[0059] Marks and corresponding parts names in the attached drawings:

[0060] 1-first separation column; 2-second separation column. DETAILED DESCRIPTION

[0061] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0062] Embodiment 1:

[0063] like Figure 2 As shown, a separation system for preparing Ra-223 comprises a first separation column 1 and a second separation column 2;

[0064] The filler of the first separation column 1 is a separation material containing an acidic phosphorus extractant (such as P507 solid phase extractant), which is used to separate 227 Th and 228Th Retained in the first separation column 1, the eluate of the first separation column 1 contains 226 Ra, 224 Ra, 223 Ra, 227 Ac and its decay daughters;

[0065] The filler of the second separation column 2 is a separation material containing another acidic phosphorus extractant (such as P204 solid phase extractant), which is used to separate the eluent of the first separation column 1 from the 227 Th and 227 Ac is retained in the second separation column 2. The second separation column 2 is eluted periodically so that only 223 Ra and its decay daughters flow out with the eluent;

[0066] The eluents of the first separation column 1 and the second separation column 2 are both hydrochloric acid.

[0067] Preferably, the flushing liquids of the first separation column 1 and the second separation column 2 are both medical hydrochloric acid with a concentration of 0.01-6 mol / L.

[0068] The separation method based on the separation system described in this embodiment includes the following steps:

[0069] S1. respectively load P507 solid phase extractant and P204 solid phase extractant into the first separation column 1 and the second separation column 2.

[0070] S2, the first separation column 1 and the second separation column 2 are pre-treated and rinsed with injection water and inorganic acid in sequence;

[0071] Specifically: the inorganic acid includes nitric acid, hydrochloric acid or medical hydrochloric acid, preferably hydrochloric acid or medical hydrochloric acid, more preferably medical hydrochloric acid, and the concentration of hydrochloric acid is 0.01-6 mol / L.

[0072] During pretreatment flushing, the flow rates of injection water and inorganic acid are both 0.01 mL / min to 5 mL / min.

[0073] S3, transfer the target material solution into the first separation column 1, and after the target material solution is in contact with the 507 solid phase extractant for not less than 0.1h, add hydrochloric acid to elute the first separation column 1, 228 Th and 227 Th is retained in the first separation column 1. The eluate in the first separation column 1 contains 226 Ra, 224 Ra, 223 Ra, 227Ac and its decay products;

[0074] S4, the eluate obtained in step S3 is transferred to the second separation column 2, and after the target material solution is in contact with the P204 solid phase extractant for not less than 0.1h, hydrochloric acid is added to elute the second separation column 2, and the eluate contains Ra-226 and 223 Ra, Done 226 Recovery of Ra; let it stand for a while, rinse with hydrochloric acid to obtain 223 The eluent of Ra.

[0075] In this embodiment, the P507 solid phase extractant and the P204 solid phase extractant can be homemade, or commercially available P507 leaching resin and P204 leaching resin can be used.

[0076] Wherein, the preparation method of the homemade P204 solid phase extraction agent comprises the following steps:

[0077] S1. Take 10 mL of P204 (commercially available) (9.26 mmol), 5.5 mL of SOCl2 (9.26 mmol), and 2.25 mL of pyridine (9.26 mmol), add them to 50 mL of toluene, and heat, stir, and reflux for 24 h;

[0078] S2. Take 5g of activated silica (200-300 mesh), add 5mL of ethanol, 20mL of toluene and 15mL of 3-aminopropyltriethoxysilane, and heat under reflux for 24h under nitrogen protection. After the reaction is completed, filter, wash alternately with 20mL of water and anhydrous ethanol for 3 times, and dry at 90℃;

[0079] S3, take 5g of SiO2 grafted coupling agent and add it to the above reaction solution, heat and continue the reaction for 24h, after the reaction is completed, wash it alternately with 20mL water and anhydrous ethanol for 3 times, and dry it at 90℃ to obtain a solid powder (solid phase extractant); the infrared spectrum of the solid phase extractant: IR, v, cm -1 :2960 (-CH3, -CH2-, -CH- stretching vibration); 1504 (-CH3, -CH2-, -CH- bending vibration); 1640 (-P=O, stretching vibration), the SEM image of P204 solid phase extractant is shown in Figure 3 shown.

[0080] The preparation method of the homemade P507 solid phase extraction agent comprises the following steps:

[0081] S1. Take 9.5 mL of P507 (commercially available) (9.26 mmol), 0.32 g of sodium metal (4.63 mmol), add to 50 mL of toluene and heat under reflux for 4 h, add 5.5 mL of SOCl2 (9.26 mmol), 2.25 ml of pyridine (9.26 mmol) and heat under reflux for 12 h;

[0082] S2. Take 5g of activated silica (200-300 mesh), add 20mL toluene and 10mL 3-aminopropyltriethoxysilane, and heat under reflux for 12h under nitrogen protection. After the reaction is completed, filter, wash with 20mL water and anhydrous ethanol alternately for 3 times, and dry at 50°C;

[0083] S3, take 5g of SiO2 grafted coupling agent and add it to the above reaction solution, heat and continue the reaction for 24h, after the reaction is completed, wash it alternately with 1mol / L HCl, 20mL water and anhydrous ethanol for 3 times respectively, and dry it at 50℃ to obtain a solid powder (solid phase extractant). The infrared spectrum of the solid phase extractant is: IR, v, cm -1 :3430 (-OH stretching vibration); 2920, 2851 (-CH3, -CH2-, -CH- stretching vibration); 1504 (-CH3, -CH2-, -CH- bending vibration); 1620 (-P=O, stretching vibration);, SEM image of P507 solid phase extractant is shown in Figure 4 shown.

[0084] Embodiment 2:

[0085] Application of the separation system as described in Example 1, including for reactor irradiation preparation 223 Ra, used for 227 Ac or 227 Th 223 Ra, used for 228 Th 224 Ra etc. can be achieved by directly using the second separation column 2 227 Ac, 227 Th, 223 Separation of Ra and direct preparation using the second separation column 2 227 Ac- 223 Ra generator, directly use the second separation column 2 227 Th, 223 Separation of Ra and direct preparation using the second separation column 2 227 Th- 223 Ra generator, directly using the first separation column 1 for 228 Th, 224 Ra separation and direct use of the first separation column 1 for preparation 228 Th-224 Ra generator.

[0086] Embodiment 3:

[0087] The separation system described in Example 1 is used to separate Ac, Th and Ra according to the order and conditions of use of separation materials 1 and 2.

[0088] Embodiment 4:

[0089] A method for preparing Ra-223 comprises the following steps:

[0090] Step 1: Prepare a target using radium salt and irradiate the target to obtain the irradiated 226 Ra target material:

[0091] The radium salt is placed in a quartz tube and sealed by melting, and the target is placed in the quartz tube and sealed by welding. The thermal neutron injection rate of the irradiation channel is >1×10 14 n cm -2 s -1 , irradiation time 1 to 2 months, cooling time 1 to 2 months;

[0092] Radium salts include at least radium sulfate ( 226 RaSO4), radium nitrate ( 226 Ra(NO3)2), radium chloride ( 226 RaCl2), radium bromide ( 226 RaBr2) and radium carbonate ( 226 RaCO3).

[0093] Step 2: After irradiation 226 The Ra target material is heated and dissolved using an inorganic acid, the solution is evaporated to near dryness, and then dissolved using hydrochloric acid to obtain a target material solution;

[0094] The inorganic acid used in step 2 includes nitric acid, hydrochloric acid or medical hydrochloric acid, preferably hydrochloric acid or medical hydrochloric acid, and the concentration of hydrochloric acid is 0.01-2 mol / L.

[0095] Step 3: Separate the target material solution obtained in step 2 using the separation method described in Example 1 to Example 3, and complete the following steps: 226 Ra, 223 Recovery of Ra.

[0096] A specific example 1 based on Example 4 is:

[0097] Weigh 1.8 mg of radium nitrate ( 226 Ra(NO3)2), which is loaded into the target tube to make a target. The thermal neutron injection rate in HFETR is 2×10 14 n cm -2 s-1 The irradiation conditions were 28 days, and the material was cut and transferred after cooling for 1 month. 2 g of separation material 1 (P507 solid phase extractant) was weighed and loaded into the first separation column 1. 20 mL of sterile injection water and 20 mL of 0.05 mol / L medical hydrochloric acid were used for pretreatment in sequence, and the separation column was rinsed for pretreatment.

[0098] Take 100 μL of the target material solution and load it into the first separation column 1. Elute with 0.05 mol / L medical hydrochloric acid. The eluent contains only 226 Ra, 227 Ac, 223 Ra and its decay daughters, 227 Th and 228 Th remains in the first separation column 1 .

[0099] Weigh 2 g of separation material 2 (P204 solid phase extractant), load it into the second separation column 2, and use 20 mL of sterile water for injection and 20 mL of 0.05 mol / L medical hydrochloric acid to pretreat it in sequence, and rinse the separation column for pretreatment.

[0100] will contain 226 Ra, 227 Ac, 223 The eluate of Ra and its decay daughters is loaded into the second separation column 2 and eluted with 0.05 mol / L medical hydrochloric acid. 226 Ra, 223 Ra and its decay daughters, 227 Th and 227 Ac is retained in the second separation column, completing 226 Recovery of Ra.

[0101] After the separation column in Case 1 was placed for 1 week, it was eluted with 0.05 mol / L medical hydrochloric acid. 223 Ra and its decay daughters flow out with the eluent. 223 The elution volume of Ra is about 10 mL, and the first 5 mL of eluent 223 The content of Ra was greater than 95% of the total elution amount and was not detected in the eluate. 227 Ac and 227 Th.

[0102] Therefore, the preparation method described in Example 4 can achieve 223 Separation and extraction of Ra, preparation 223 RaCl2. 223 Preparation of RaCl2 solution, separation preparation conditions are the same system, simplifying the operation process, solution preparation conditions are suitable for medical hydrochloric acid system, easy to 223 Subsequent use of RaCl2 solution.

[0103] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A separation system for preparing Ra-223, characterized in that: It comprises a first separation column (1) and a second separation column (2); The filler of the first separation column (1) is a separation material containing an acidic phosphorus extractant, which is used to retain 227Th and 228Th in the first separation column (1), so that the eluent of the first separation column (1) contains 226Ra, 224Ra, 223Ra, 227Ac and their decay daughters; The filler of the second separation column (2) is another separation material containing an acidic phosphorus extractant, which is used to retain 227Th and 227Ac in the eluent of the first separation column (1) in the second separation column (2), and the second separation column (2) is flushed multiple times so that only 223Ra and its decay daughters in the second separation column (2) flow out with the eluent; The eluents of the first separation column (1) and the second separation column (2) are both hydrochloric acid; The preparation method of the acidic phosphorus-containing extractant in the first separation column is: S1. Take P204, SOCl2 and pyridine, add them into toluene, heat and stir to reflux; S2, take the activated silica, add ethanol, toluene and 3-aminopropyltriethoxysilane, and heat to reflux under nitrogen protection; after the reaction is completed, filter, wash alternately with water and anhydrous ethanol, and then dry; S3, take SiO2 grafted coupling agent and add it to the reaction solution, heat and continue the reaction, after the reaction is completed, wash alternately with water and anhydrous ethanol, and then dry to obtain a solid phase extractant; The preparation method of the acidic phosphorus-containing extractant in the second separation column is: S1. Take P507 and sodium metal, add toluene and heat to reflux, add SOCl2 and pyridine, heat and stir to reflux; S2, take the activated silica, add toluene and 3-aminopropyltriethoxysilane, and heat to reflux under nitrogen protection; after the reaction is completed, filter, wash alternately with water and anhydrous ethanol, and then dry; S3, taking SiO2 grafted with coupling agent and adding it into the reaction solution, heating and continuing the reaction, after the reaction is completed, washing alternately with HCl, water and anhydrous ethanol in sequence, and then drying to obtain a solid phase extractant.

2. The separation system for preparing Ra-223 according to claim 1, characterized in that: The flushing liquids of the first separation column (1) and the second separation column (2) are both medical hydrochloric acid with a concentration of 0.01-6 mol / L.

3. The separation method based on the separation system according to claim 1 or 2, characterized in that: The following steps are involved: S1, respectively loading an acidic phosphorus extractant and another acidic phosphorus extractant into a first separation column (1) and a second separation column (2); S2, the first separation column (1) and the second separation column (2) are pre-treated and rinsed with injection water and inorganic acid in sequence; S3, transferring the target material solution into the first separation column (1), allowing the target material solution to contact with an acidic phosphorus extractant for a contact time of not less than 0.1 h, adding hydrochloric acid to elute the first separation column (1), 228Th and 227Th are retained in the first separation column (1), and the eluate in the first separation column (1) contains 226Ra, 224Ra, 223Ra, 227Ac and their decay daughters; S4. The eluate obtained in step S3 is transferred to a second separation column (2), and the target material solution is contacted with another acidic phosphorus extractant for a contact time of not less than 0.1 h. Hydrochloric acid is added to elute the second separation column (2). The eluate contains Ra-226 and 223Ra, and the recovery of 226Ra is completed. The mixture is allowed to stand for a period of time, and then elutes with hydrochloric acid to obtain an eluate containing 223Ra in a periodic manner.

4. The separation method according to claim 3, characterized in that In step S2, the flow rates of water for injection and inorganic acid are both 0.01 mL / min to 5 mL / min.

5. The separation method according to claim 3, characterized in that In step S2, the inorganic acid includes nitric acid, hydrochloric acid or medical hydrochloric acid.

6. The separation method according to claim 3, characterized in that In step S3 and step S4, the concentration of hydrochloric acid is 0.01 mol / L to 6 mol / L.

7. Use of the separation system according to claim 1 or 2, characterized in that: The invention comprises the steps of preparing 223Ra, 224Ra and 226Ra by reactor irradiation, directly using a second separation column (2) to separate 227Ac, ​​227Th and 223Ra and directly using the second separation column (2) to prepare a 227Ac-223Ra generator, directly using the second separation column (2) to separate 227Th and 223Ra and prepare a 227Th-223Ra generator, and directly using a first separation column (1) to separate 228Th and 224Ra and directly using the first separation column (1) to prepare a 228Th-224Ra generator.

8. Use of the separation system as claimed in claim 1 or 2 in achieving separation of Ac, Th and Ra.

9. A method for preparing Ra-223, characterized in that: The following steps are involved: Step 1: preparing a target by using a radium salt and irradiating the target to obtain an irradiated 226Ra target material; Step 2: The irradiated 226Ra target material is heated and dissolved using an inorganic acid, the solution is evaporated to near dryness, and then dissolved using hydrochloric acid to obtain a target material solution; Step 3: Separate the target material solution obtained in step 2 using the separation method described in any one of claims 3 to 6, and recover 226Ra and 223Ra in turn.

10. The preparation method according to claim 9, characterized in that: The process of step one is: The radium salt is placed in a quartz tube and sealed by melting, the target is placed in the quartz tube and sealed by welding, the thermal neutron injection rate of the irradiation channel is greater than 1×1014n·cm-2s-1, the irradiation time is 1 to 2 months, and the cooling time is not less than 10 days.

11. The preparation method according to claim 9, characterized in that: The inorganic acid used in step 2 includes nitric acid, hydrochloric acid or medical hydrochloric acid.

12. The preparation method according to claim 10, characterized in that: The inorganic acid used in step 2 is hydrochloric acid or medical hydrochloric acid, and the concentration of hydrochloric acid is 0.01-2 mol / L.

13. The preparation method according to any one of claims 11 to 12, characterized in that: The radium salt in step 1 includes at least one of radium sulfate, radium nitrate, radium chloride, radium bromide and radium carbonate.

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