Thorium / lead generator from natural thorium salt and method for lead-212 production

Abstract

The application discloses a natural thorium salt thorium / lead generator which is composed of a liquid storage system, a collection system, an adsorption system and a power system, wherein the liquid storage system is used for storing mother liquor, acid washing liquid, water washing liquid and elution liquid; the collection system is used for collecting tail liquid; the adsorption system is used for adsorbing 212 Pb; and the power system is used for providing power for the liquid storage system. A lead 212 preparation method based on the natural thorium salt thorium / lead generator comprises the following steps: 1, preparation of raw materials; 2, separation of lead 212; 3, acid washing of a resin column; 4, water washing of the resin column; 5, elution of the resin column; 6, recovery of the resin column; and 7, post-treatment of a collection bottle. 212 The preparation method can separate more than 90% of lead 212 from the natural thorium source, and the adsorption 212 The elution efficiency of the adsorbed lead 212 is more than 99%, and the obtained 212 The radioactivity purity of the obtained lead 212 is more than 99%.

Description

Technical Field

[0001] This invention belongs to the field of medical radioisotope production technology, specifically relating to a thorium / lead generator for natural thorium salts and a method for preparing lead-212. Background Technology

[0002] Targeted alpha therapy has the advantage of high anti-tumor efficacy and can be applied to melanoma, prostate cancer, and pancreatic cancer. However, the production of targeted alpha therapy radiopharmaceuticals requires high-purity alpha nuclides. 212 Bi is a commonly used nuclide for preparing targeted alpha therapy radiopharmaceuticals. Its preparation principle involves using lead-212 (… 212 Pb)(t 1 / 2 =10.64 h) After β decay, it produces the daughter nuclide bismuth-212 ( =10.64 h) 212 Bi)(t 1 / 2 =60.55 min). However, 212 Bi has a short half-life, which is not conducive to the preservation and preparation of targeted alpha nucleotherapy. Therefore, it can be improved through preparation and preservation... 212 Pb, then through 212 Pb / 212 Bi body generator obtained 212 Bi.

[0003] Because China possesses the advantage of high thorium reserves, therefore, in order to obtain... 212 Pb can be obtained from natural thorium (Pb). 232 Th) produced in the radioactive decay chain 212 Pb is obtained through separation. For example, existing literature 1 (Chinese Chemical Letters 33 (2022) 3474–3477) uses a resin separation method to achieve an average adsorption efficiency of 83% and a elution efficiency of 95%. Clearly, this technical solution has limitations. 212 The low efficiency of Pb separation directly leads to 212 Waste of Pb. Summary of the Invention

[0004] The purpose of this invention is to provide a thorium / lead generator for natural thorium salts and a method for preparing lead-212. Specifically, it uses a natural thorium source as raw material and a crown ether resin, which has specific separation properties for lead, as the separation material to obtain high-purity lead. 212 Pb, while achieving high yield, is suitable for preparing radiopharmaceuticals for nuclear medicine, and is particularly suitable for targeted alpha therapy for cancer.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A thorium / lead generator for natural thorium salts comprises a liquid storage system, a collection system, an adsorption system, and a power system, wherein...

[0007] The liquid storage system is used to store mother liquor, pickling solution, washing solution, and rinsing solution. The liquid storage system consists of a mother liquor bottle, a pickling bottle, a washing bottle, and a rinsing bottle, as well as corresponding valves. The mother liquor bottle is used to store a natural thorium source aqueous solution, the pickling bottle is used to store an inorganic acid aqueous solution, the washing bottle is used to store water, and the rinsing bottle is used to store the rinsing solution aqueous solution.

[0008] The collection system is used to collect tail liquid; the collection system consists of a mother liquor tail liquid collection bottle, an acid washing collection bottle, a water washing collection bottle, and a rinsing collection bottle, as well as corresponding valves. The mother liquor tail liquid collection bottle is used to collect mother liquor tail liquid, the acid washing collection bottle is used to collect acid washing tail liquid, the water washing collection bottle is used to collect water washing tail liquid, and the rinsing collection bottle is used to collect rinsing tail liquid.

[0009] Adsorption system is used for adsorption 212 Pb; The adsorption system consists of crown ether resin columns;

[0010] The power system is used to provide power to the liquid storage system; the power system consists of a peristaltic pump and corresponding valves.

[0011] A method for preparing lead-212 in a thorium / lead generator based on natural thorium salts includes the following steps:

[0012] Step 1, preparation of raw materials: the mother liquor bottle contains mother liquor obtained by dissolving natural thorium source in an inorganic acid aqueous solution; the acid washing bottle contains an inorganic acid aqueous solution; the water washing bottle contains water; the rinsing bottle contains an rinsing solution aqueous solution; and the resin column contains crown ether resin.

[0013] (The corresponding content below should be consistent with the claims after modification.)

[0014] The natural thorium source is one of thorium nitrate, thorium chloride, thorium sulfate, metallic thorium, thorium dioxide, or thorium fluoride, and has been stored for more than 3 years. The mass fraction of the natural thorium source is greater than 0.2 g / mL, and the volume of the mother liquor is 0.02-1000 L. When the natural thorium source is insoluble, it is dissolved in an inorganic acid to become soluble.

[0015] The mother liquor and the pickling bottle contain the same type and concentration of inorganic acid; the inorganic acid is one of hydrochloric acid, nitric acid or sulfuric acid, and the concentration of the inorganic acid is 0.05-3 mol / L.

[0016] The eluent is one of ammonium citrate, ammonium oxalate, ammonium acetate, and ethylenediamine oxalic acid, and the concentration of the eluent is 0.05-1 mol / L;

[0017] The crown ether resin is loaded with one of 18 crown 6 ether, TK102 resin, Pb resin or Sr resin. The crown ether resin has a mesh size of 100-300 mesh, a volume of 2-100 mL, and a quantity of 1-30 pieces.

[0018] The volume ratio of the mother liquor, inorganic acid, water, rinsing solution, and resin is (5-1000):(1-6):(1-6):(0.5-5):1.

[0019] Step 2, lead-212 separation: First, open the valve and turn on the peristaltic pump. Then, pass the mother liquor through the resin column. 212 Pb separation and adsorption were performed, and the mother liquor tail liquid was collected in a mother liquor tail liquid collection bottle. Finally, after all the mother liquor had passed through the resin column, the valve was closed and the peristaltic pump was stopped.

[0020] The flow rates of the mother liquor through the resin column, the inorganic acid through the resin, and the water through the resin are all the same, ranging from 0.6 to 100 mL / min, while the flow rate of the eluent through the resin is 0.3 to 100 mL / min.

[0021] Step 3, acid washing of the resin column: First, open the valve and restart the peristaltic pump. Then, use the inorganic acid in the acid bottle to wash the adsorbent. 212 Pb is acid-washed with a resin column, and the acid wash tail liquid is collected with an acid wash collection bottle. Finally, the peristaltic pump is turned off and the valve is closed.

[0022] Step 4, water washing of the resin column: First, open the valve and turn on the power of the peristaltic pump. Then, use the water in the washing bottle to wash the resin column and collect the washing tail liquid in the washing collection bottle. Finally, close the valve and stop the peristaltic pump.

[0023] Step 5, rinsing the resin column: First, open the valve and restart the peristaltic pump. Then, use the eluent from the eluent bottle to rinse the resin column. Collect the eluent residue using the eluent collection bottle, thus completing the collection process. 212 For the Pb solution, finally, close the valve and stop the peristaltic pump;

[0024] Step 6, Resin Column Restoration: First, open the valve and restart the peristaltic pump. Then, use water from the wash bottle to wash the resin column and collect the wash tail liquid in the wash collection bottle, thus restoring the resin column to its initial state. Finally, close the valve and turn off the peristaltic pump.

[0025] Step 7, post-processing of the collection bottles: The mother liquor tail liquid collected in the mother liquor tail liquid collection bottle is poured into the mother liquor bottle; the tail liquid collected in the acid washing collection bottle and the water washing collection bottle are transferred to specific tail liquid treatment containers respectively; the rinsing collection bottle is replaced with an empty bottle, and the rinsing tail liquid in the original rinsing collection bottle, i.e. 212 The Pb solution was allowed to stand to achieve... 212 Pb reaches equilibrium;

[0026] In step 7, the settling time is 48 hours.

[0027] The preparation method of this invention is effective for natural thorium sources. 212 Pb separation efficiency exceeds 90%, adsorption 212 The leaching efficiency of Pb exceeds 99%, and the obtained 212 The radioactive purity of Pb exceeds 99%.

[0028] The technical effect of this invention, as demonstrated by radioactivity testing, is that it is effective against natural thorium sources. 212 Pb separation efficiency exceeds 90%, adsorption 212 The leaching efficiency of Pb exceeds 99%, and the obtained 212 The radioactive purity of Pb exceeds 99%.

[0029] Therefore, compared with the prior art, the present invention has the following advantages:

[0030] 1. Automated separation can be achieved using a thorium / lead generator based on natural thorium salts;

[0031] 2. High separation efficiency;

[0032] 3. Income 212 Pb has high radioactive purity. Attached Figure Description

[0033] Figure 1 A schematic diagram of a thorium / lead generator for natural thorium salts;

[0034] Figure 2 The energy spectrum of the mother liquor sample;

[0035] Figure 3 This is the energy spectrum of the adsorption tail liquid;

[0036] Figure 4 This is the energy spectrum of the first rinsing volume sample. Detailed Implementation

[0037] The present invention will be further described in detail through embodiments and with reference to the accompanying drawings, but this is not intended to limit the scope of the invention.

[0038] Example 1

[0039] A thorium / lead generator based on natural thorium salts, structural schematic diagram shown below. Figure 1 As shown, it consists of a liquid storage system, a collection system, an adsorption system, and a power system, wherein,

[0040] The liquid storage system consists of a mother liquor bottle 1, an acid washing bottle 2, a water washing bottle 3, and a rinsing bottle 4, along with corresponding valves 12, 13, 14, and 15.

[0041] The purpose of mother liquor bottle 1 is to store thorium nitrate aqueous solution.

[0042] The purpose of pickling bottle 2 is to store nitric acid solution.

[0043] The purpose of water bottle 3 is to store water.

[0044] The purpose of rinse bottle 4 is to store ammonium citrate aqueous solution;

[0045] The collection system consists of a mother liquor and tail liquor collection bottle 5, an acid washing collection bottle 6, a water washing collection bottle 7, and a rinsing collection bottle 8, along with corresponding valves 18, 19, 20, and 21.

[0046] The function of mother liquor tail liquid collection bottle 5 is to collect the mother liquor tail liquid.

[0047] The function of pickling collection bottle 6 is to collect the pickling tail liquid.

[0048] The function of water washing collection bottle 7 is to collect the water washing tail liquid.

[0049] The function of the rinsing collection bottle 8 is to collect the rinsing tail liquid;

[0050] The adsorption system consists of resin column 9, which serves to store crown ether resin and perform adsorption. 212 The role of Pb;

[0051] The power system consists of peristaltic pumps 10 and 11, and corresponding valves 16 and 17, wherein,

[0052] The function of peristaltic pump 10 is to provide power to mother liquor bottle 1 and pickling bottle 2.

[0053] The function of the peristaltic pump 11 is to provide power for the wash bottle 3 and the rinse bottle 4.

[0054] A method for preparing lead-212 in a thorium / lead generator based on natural thorium salts includes the following steps:

[0055] Step 1, Preparation of raw materials: Mother liquor bottle 1 contains 20g of thorium nitrate stored for 10 years dissolved in 40mL of 0.25mol / L nitric acid aqueous solution; acid washing bottle 2 contains 0.25mol / L nitric acid aqueous solution; water washing bottle 3 contains water; rinsing bottle 4 contains 0.5mol / L ammonium citrate aqueous solution; resin column 9 contains 2mL of crown ether resin.

[0056] Step 2, separation of lead 212: First, open valves 12, 16, and 18, and turn on the power to the peristaltic pump 10. Then, pass the mother liquor through the resin column 9 at a flow rate of 1.5 mL / min. 212 Pb separation and adsorption, and mother liquor tail liquid is collected in mother liquor tail liquid collection bottle 5. Finally, after all the mother liquor has passed through the resin column, valves 12 and 18 are closed, and the peristaltic pump is stopped.

[0057] To prove 212 The separation efficiency of Pb was determined by detecting the radioactivity of the mother liquor before and after treatment using a gamma-ray spectrometer. The detection results were as follows: Figure 2 and Figure 3 As shown, calculations based on the detection results indicate that... 212 The separation efficiency of Pb was 97.2%;

[0058] Step 3, acid washing of resin column 9: First, open valves 13 and 19, and restart peristaltic pump 10. Then, at a flow rate of 1.5 mL / min and a volume ratio of 4.5 times the volume of resin column 9, inject inorganic acid from acid bottle 2 to adsorb the resin column 9. 212 Pb is acid-washed in resin column 9, and the acid washing tail liquid is collected in acid washing collection bottle 6. Finally, peristaltic pump 10 is turned off, and valves 13, 16, and 19 are closed.

[0059] Step 4, water washing of resin column 9: First, open valves 14, 17, and 20, and turn on the power of peristaltic pump 11. Then, at a flow rate of 1.5 mL / min and a volume ratio of 3 times the volume of resin column 9, water from water washing bottle 3 is used to wash resin column 9. The water washing tail liquid is collected in water washing collection bottle 7. Finally, close valves 14 and 20, and stop peristaltic pump 11.

[0060] Step 5, rinsing of resin column 9: First, open valves 15 and 21, and restart peristaltic pump 11. Then, rinse resin column 9 with eluent from eluent bottle 4 at a flow rate of 1 mL / min and a volume four times the volume of resin column 9. Collect the eluent tail liquid using eluent collection bottle 8, thus completing the collection process. 212 For the Pb solution, finally, close valves 15 and 21, and stop the peristaltic pump 11;

[0061] To prove 212 The elution efficiency and sample purity of Pb were determined by detecting the radioactivity of the first resin volume of eluent using gamma-ray spectrometry. The detection results were as follows: Figure 4 As shown, calculations based on the detection results indicate that... 212 The leaching efficiency of Pb is greater than 99%, and the radioactive purity is >99%;

[0062] Step 6, Resin Column Restoration: First, open valves 14 and 20, and restart peristaltic pump 11. Then, wash resin column 9 with water from wash bottle 3 at a flow rate of 1 mL / min and a volume of 6 times that of resin column 9. Collect the wash tail liquid with wash collection bottle 7 to restore resin column to its initial state. Finally, close valves 14, 17, and 20, and turn off peristaltic pump 11.

[0063] Step 7, post-processing of the collection bottles: The mother liquor tail liquid collected in mother liquor tail liquid collection bottle 5 is poured into mother liquor bottle 1; the tail liquids collected in acid washing collection bottle 6 and water washing collection bottle 7 are transferred to specific tail liquid treatment containers respectively; the rinsing collection bottle 8 is replaced with an empty bottle, and after a standing time of 48 hours, the rinsing tail liquid in the original rinsing collection bottle 8, i.e. 212 The Pb solution was allowed to stand to achieve... 212 Pb reaches equilibrium.

[0064] To demonstrate that the resin column is reusable and that the apparatus and method of the present invention are capable of processing large quantities of thorium nitrate, Example 2 is provided.

[0065] Example 2

[0066] A method for preparing lead 212 from a large quantity of thorium nitrate and reusable resin, wherein the steps not specifically described are the same as in Example 1, except that: the resin column 9 uses the resin used in Example 1, and the mass of thorium nitrate in mother liquor bottle 1 is increased to 75g. Due to the increase in the mass of thorium nitrate, the nitric acid aqueous solution is replaced with 150mL of 0.5mol / L, and the concentration of the nitric acid aqueous solution in acid washing bottle 2 is replaced with 0.5mol / L.

[0067] To demonstrate the effects of large amounts of thorium nitrate and recycled resin, 212 The separation efficiency of Pb was determined by detecting the radioactivity of the mother liquor before treatment using a gamma-ray spectrometer. 212 The separation efficiency of Pb was 95.4%, the elution efficiency was greater than 99%, the elution efficiency of the first resin volume was 96.2%, and the radioactivity purity was >99%.

Claims

1. A thorium / lead generator for natural thorium salts, characterized in that: It consists of a liquid storage system, a collection system, an adsorption system, and a power system, among which, The liquid storage system is used to store mother liquor, pickling solution, washing solution and rinsing solution; The collection system is used to collect the tailings liquid; Adsorption system is used for adsorption 212 Pb; The power system is used to provide power to the liquid storage system.

2. The thorium / lead generator according to claim 1, characterized in that: The liquid storage system consists of a mother liquor bottle, an acid washing bottle, a water washing bottle, and a rinsing bottle, as well as corresponding valves. The mother liquor bottle is used to store the natural thorium source aqueous solution, the acid washing bottle is used to store the inorganic acid aqueous solution, the water washing bottle is used to store water, and the rinsing bottle is used to store the rinsing solution aqueous solution. The collection system consists of a mother liquor tail liquid collection bottle, an acid washing collection bottle, a water washing collection bottle, and a rinsing collection bottle, as well as corresponding valves. The mother liquor tail liquid collection bottle is used to collect the mother liquor tail liquid, the acid washing collection bottle is used to collect the acid washing tail liquid, the water washing collection bottle is used to collect the water washing tail liquid, and the rinsing collection bottle is used to collect the rinsing tail liquid. The adsorption system consists of crown ether resin columns; The power system consists of a peristaltic pump and corresponding valves.

3. A method for preparing lead-212 in a thorium / lead generator based on natural thorium salts, characterized in that... Includes the following steps: Step 1, preparation of raw materials: the mother liquor bottle contains mother liquor obtained by dissolving natural thorium source in an inorganic acid aqueous solution; the acid washing bottle contains an inorganic acid aqueous solution; the water washing bottle contains water; the rinsing bottle contains an rinsing solution aqueous solution; and the resin column contains crown ether resin. The natural thorium source is one of thorium nitrate, thorium chloride, thorium sulfate, metallic thorium, thorium dioxide, or thorium fluoride, and has been stored for more than 3 years. The mass fraction of the natural thorium source is greater than 0.2 g / mL, and the volume of the mother liquor is 0.02-1000 L. When the natural thorium source is insoluble, it is dissolved in an inorganic acid to become soluble. The mother liquor and the pickling bottle contain the same type and concentration of inorganic acid; the inorganic acid is one of hydrochloric acid, nitric acid or sulfuric acid, and the concentration of the inorganic acid is 0.05-3 mol / L. The eluent is one of ammonium citrate, ammonium oxalate, ammonium acetate, and ethylenediamine oxalic acid, and the concentration of the eluent is 0.05-1 mol / L; The crown ether resin is loaded with one of 18 crown 6 ether, TK102 resin, Pb resin or Sr resin. The crown ether resin has a mesh size of 100-300 mesh, a volume of 2-100 mL, and a quantity of 1-30 pieces. The volume ratio of the mother liquor, inorganic acid, water, rinsing solution, and resin is (5-1000):(1-6):(1-6):(0.5-5):

1. Step 2, lead-212 separation: First, open the valve and turn on the peristaltic pump. Then, pass the mother liquor through the resin column. 212 Pb separation and adsorption, and the mother liquor tail liquid is collected in the mother liquor tail liquid collection bottle. Finally, after all the mother liquor has passed through the resin column, the valve is closed and the peristaltic pump is stopped. The flow rates of the mother liquor through the resin column, the inorganic acid through the resin, and the water through the resin are all the same, ranging from 0.6 to 100 mL / min, while the flow rate of the eluent through the resin is 0.3 to 100 mL / min. Step 3, acid washing of the resin column: First, open the valve and restart the peristaltic pump. Then, use the inorganic acid in the acid bottle to wash the adsorbent. 212 Pb is acid-washed with a resin column, and the acid wash tail liquid is collected with an acid wash collection bottle. Finally, the peristaltic pump is turned off and the valve is closed. Step 4, water washing of the resin column: First, open the valve and turn on the power of the peristaltic pump. Then, use the water in the washing bottle to wash the resin column and collect the washing tail liquid in the washing collection bottle. Finally, close the valve and stop the peristaltic pump. Step 5, rinsing the resin column: First, open the valve and restart the peristaltic pump. Then, use the eluent from the eluent bottle to rinse the resin column. Collect the eluent residue using the eluent collection bottle, thus completing the collection process. 212 For the Pb solution, finally, close the valve and stop the peristaltic pump; Step 6, Resin Column Restoration: First, open the valve and restart the peristaltic pump. Then, use water from the wash bottle to wash the resin column and collect the wash tail liquid in the wash collection bottle, thus restoring the resin column to its initial state. Finally, close the valve and turn off the peristaltic pump. Step 7, post-processing of the collection bottle: the mother liquor tail liquid collected in the mother liquor tail liquid collection bottle is poured into the mother liquor bottle; The tailings collected in the acid washing and water washing collection bottles are transferred to specific tailings treatment containers, respectively; the rinsing collection bottle is replaced with an empty bottle, and the rinsing tailings in the original rinsing collection bottle are removed. 212 The Pb solution was allowed to stand to achieve... 212 Pb reaches equilibrium; In step 7, the settling time is 48 hours.

4. The preparation method according to claim 3, characterized in that: For natural thorium sources 212 Pb separation efficiency exceeds 90%, adsorption 212 The leaching efficiency of Pb exceeds 99%, and the obtained 212 The radioactive purity of Pb exceeds 99%.

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