Carbon 13 labeled carbonate and one-step method for its preparation

Abstract

The application belongs to the technical field of stable isotope labeled compound preparation, and specifically discloses a carbon 13 labeled carbonate and a one-step preparation method thereof. Under an inert atmosphere, carbon 13 urea is mixed with water to obtain a carbon 13 urea solution; metal hydroxide is mixed with water to obtain a metal hydroxide dispersion; then under the inert atmosphere, the carbon 13 urea solution is added dropwise into the metal hydroxide dispersion to perform a reaction, and a slurry containing carbon 13 labeled carbonate is obtained; after post-treatment, the carbon 13 labeled carbonate is obtained. The application can be widely adapted to various metal hydroxide raw materials, realize the large-scale preparation of a series of carbon 13 labeled carbonate products, and efficiently realize the high-value utilization of low-abundance unqualified carbon 13 urea, effectively solving the industry pain points such as large carbon 13 abundance loss, complicated preparation steps, serious equipment corrosion and easy pollution by environmental CO2 in the existing process.

Description

Technical Field

[0001] This invention relates to the field of stable isotope-labeled compound preparation technology, and in particular to a carbon-13 labeled carbonate and its one-step preparation method. Background Technology

[0002] C13-labeled carbonates, as core functional materials in the stable isotope industry chain, are widely used in several key fields, including clinical medical diagnosis, biological metabolism tracing, geochronological research, environmental pollutant tracing, isotope-labeled organic synthesis, and nuclear industry analysis and calibration, due to their excellent stability and specificity. Among them, C13 calcium carbonate is a core raw material for tracer reagents used in non-invasive diagnosis of Helicobacter pylori, and its purity and abundance directly affect the accuracy of diagnostic results. C13 sodium carbonate and barium carbonate are key starting intermediates for synthesizing various C13-labeled organic compounds, with wide applications in drug development and biomedical research. With the rapid development of related fields, the market demand for C13-labeled carbonate products is steadily increasing, and the requirements for product purity and abundance are constantly rising.

[0003] Currently, the mainstream industrial preparation of C13-labeled carbonates uses a process route that involves purchasing C13 carbon dioxide from cylinders and reacting it in an alkaline solution. This route suffers from several intractable industry challenges: C13 carbon dioxide is a high-pressure hazardous gas, posing a risk of leakage and jeopardizing production safety throughout the storage, transportation, transfer, and reaction processes. Furthermore, it is easily contaminated by naturally occurring carbon dioxide in the ambient air, leading to an irreversible decrease in the abundance of the target product's C13 isotope. The industry generally achieves an abundance recovery rate of less than 97%, failing to meet the demands of medical, high-end scientific research, and other fields for high-abundance products. Simultaneously, purchasing high-purity C13 carbon dioxide is costly, and the gas-liquid contact efficiency during the reaction is difficult to precisely control, resulting in poor batch-to-batch product stability, purity fluctuations, and uneven particle size. This makes industrial-scale production difficult and limits the widespread application of this route.

[0004] Another existing technology involves acid-catalyzed hydrolysis of C13 urea to first recover C13 carbon dioxide, and then reacting it with alkaline solution to prepare carbonates. While this route can solve the cost problem of purchasing C13 carbon dioxide feedstock, it still has significant drawbacks: the acidic hydrolysis system requires concentrated sulfuric acid as a catalyst, which is highly corrosive and severely corrodes production equipment. Actual measurements show that the annual corrosion rate of 316L stainless steel in this system exceeds 0.8 mm, leading to shortened equipment lifespan and high maintenance costs. Simultaneously, side reactions such as urea condensation and carbonization easily occur during acid-catalyzed hydrolysis, with an incidence exceeding 8%. This not only results in the effective loss of C13 isotopes but also introduces difficult-to-remove organic impurities, affecting product purity. Furthermore, this route requires complex equipment such as a high-vacuum system, distillation columns, multi-stage dehydration and purification, and cryogenic cold traps for collection. The process is cumbersome and difficult to operate, with continuous loss of C13 isotopes during multiple material transfer stages. The highest abundance recovery rate can only reach about 98%, and the target carbonate product cannot be obtained directly in one step, resulting in low production efficiency.

[0005] In addition, the industry generates a large amount of substandard C13 urea with an abundance of 85% to 95% every year. Because the C13 abundance of such products does not meet the standards, they cannot be used in the production of high-end fields such as medical reagents. The current treatment method is mainly incineration. This treatment method not only causes a complete waste of scarce C13 isotope resources, which does not meet the requirements of industrial policies for resource recycling, but also has a processing cost of up to 20,000 yuan per ton, causing significant economic losses to enterprises. At the same time, the incineration process also produces harmful gases, causing environmental pollution.

[0006] Therefore, developing a method that is simple in steps, mild in reaction conditions, free from isotope fractionation, has high abundance recovery rate, no equipment corrosion, can prepare C13-labeled carbonates in one step, and can realize the high-value utilization of substandard C13 urea, solves many pain points of existing processes, and meets the market demand for high-purity, high-abundance C13-labeled carbonate products is a core technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] In view of this, the present invention provides a one-step preparation method for C13-labeled carbonates, which achieves efficient preparation of high-abundance and high-purity C13-labeled carbonates, while realizing the high-value recycling of substandard C13 urea, reducing production costs, reducing environmental pollution, and promoting technological progress in this field.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A one-step method for preparing carbon-13 labeled carbonates includes the following steps: 1) Under an inert atmosphere, C13 urea is mixed with water to obtain a C13 urea solution; metal hydroxide is mixed with water to obtain a metal hydroxide dispersion. 2) Under an inert atmosphere, a C13 urea solution is added dropwise to a metal hydroxide dispersion to react and obtain a slurry containing C13-labeled carbonates. 3) The slurry containing C13-labeled carbonates is post-processed to obtain C13-labeled carbonates.

[0009] Preferably, the mass fraction of the C13 urea solution is 5-40%; The mass fraction of the metal hydroxide dispersion is 5-40%.

[0010] Preferably, the abundance of the C13 urea is ≥85%; The metal hydroxide includes one or more of calcium hydroxide, sodium hydroxide, barium hydroxide, potassium hydroxide, magnesium hydroxide, and strontium hydroxide; The purity of the metal hydroxide is ≥98%.

[0011] Preferably, the molar ratio of C13 urea to hydroxide in metal hydroxide in step 2) is 1:2~2.5.

[0012] Preferably, the reaction temperature in step 2) is 80~100℃, and the reaction time is 1~6h; the reaction is carried out under stirring conditions, and the stirring rate is 200~500rpm.

[0013] Preferably, the dropping rate of the C13 urea solution in step 2) is 8~30 mL / min.

[0014] Preferably, the inert atmosphere described in steps 1) and 2) independently includes nitrogen and / or argon, and the purity of both nitrogen and argon is ≥99.99%.

[0015] Preferably, the post-processing in step 3) includes sequential gradient cooling, solid-liquid separation, purification washing, and drying.

[0016] Preferably, the reaction described in step 2) produces ammonia gas, which is absorbed by a dilute acid solution to obtain an ammonium salt byproduct.

[0017] Another object of the present invention is to provide a carbon-13 labeled carbonate prepared by the preparation method described above.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: 1. This invention pioneers a one-step process for preparing C13-labeled carbonates, significantly simplifying the production process and reducing costs. Using C13 urea and metal hydroxides as raw materials, this invention directly prepares C13-labeled carbonate products through a one-step isothermal reaction in an alkaline aqueous solution. This eliminates the need for a multi-step process involving hydrolysis, collection, purification, and secondary reactions, thus avoiding the loss and contamination of C13 isotopes during the material transfer process. The number of production steps is reduced by more than 60%, equipment investment is only 1 / 10 of that of the acid hydrolysis process, and raw material costs are reduced by more than 40% compared to the external carbon dioxide purchase process. Furthermore, the simplified operation process reduces operational difficulty, improves production efficiency, and facilitates large-scale industrial production.

[0019] 2. This invention achieves 100% directional transfer of carbon-13 atoms without isotope fractionation, and its abundance recovery rate is at an industry-leading level. By precisely controlling key reaction parameters (such as reaction temperature, raw material ratio, and stirring speed), this invention perfectly matches the urea hydrolysis rate with the carbonate nucleation rate. Carbon-13 atoms in carbon-13 urea can be quantitatively transferred 100% to the carbonate lattice. The reaction process involves no isotope fractionation or carbon loss, and the carbon-13 abundance recovery rate consistently reaches over 99%, with a maximum of 99.8%, far exceeding the 97%~98% of existing processes. Simultaneously, it can directly utilize substandard carbon-13 urea with an abundance of 85%~95% as raw material to prepare products of different abundances, achieving high-value recycling of scarce isotope resources, reducing resource waste, and lowering raw material costs.

[0020] 3. This invention features mild reaction conditions, no highly corrosive system, no side reactions, and high product purity. The reaction is carried out at normal pressure in a mild aqueous solution, eliminating the need for harsh conditions such as high pressure, high vacuum, and high temperature. The mild reaction conditions result in low energy consumption and facilitate industrial scale-up. By eliminating the use of highly corrosive raw materials such as concentrated sulfuric acid, it completely solves the problem of severe equipment corrosion in existing acid hydrolysis processes, reducing equipment maintenance costs by over 90% and extending equipment lifespan. The reaction system avoids side reactions such as urea condensation and carbonization; the only byproduct is ammonia, which can be completely absorbed by dilute acid to produce ammonium salt byproducts. No organic impurities are introduced, and the product, after simple purification and washing, can stably achieve a purity of over 99.0%, with medical-grade products reaching 99.9% purity. This eliminates the need for complex distillation and purification equipment, further reducing production costs.

[0021] 4. The process described in this invention is highly versatile and can cover a full range of C13-labeled carbonate products. The process route of this invention is adaptable to the preparation of more than ten kinds of carbonate products, including C13-labeled sodium carbonate, potassium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, and strontium carbonate, covering application needs in all scenarios such as medical, geological, environmental protection, synthesis, and nuclear industries. The process has extremely high adaptability and scalability, allowing for flexible adjustment of product types according to market demand, and possesses excellent market adaptability.

[0022] 5. This invention utilizes a fully inert atmosphere for protection, completely avoiding environmental CO2 pollution and ensuring excellent batch-to-batch product stability. By employing a fully inert atmosphere and closed-loop reaction process, this invention strictly controls the sealing of the reaction system, fundamentally eliminating the contamination of the product by naturally occurring CO2 in the ambient air. This solves the problems of large fluctuations in product abundance and poor batch-to-batch stability in existing processes. Multiple experiments have verified that the isotope abundance deviation of the product can be controlled within ±0.1%, ensuring stable product quality. It is suitable for applications ranging from small-scale laboratory trials to continuous industrial production, meeting the stringent quality requirements of various fields.

[0023] 6. The entire process is green and environmentally friendly, with no emissions of waste gas, wastewater, or solid waste. The ammonia gas, a byproduct of the reaction, can be completely recovered to prepare ammonium salt byproducts, realizing the resource utilization of byproducts; the washing water can be recycled after simple treatment, reducing water waste; the entire reaction process generates no waste gas, wastewater, or solid hazardous waste, fully complying with national environmental protection requirements. It is a green and low-carbon production process with good environmental benefits. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the one-step preparation apparatus for carbon-13 labeled carbonates according to the present invention. Among them, 1-magnetic stirring and temperature control mechanism, 2-sealed reaction vessel, 3-constant pressure dropping funnel, 4-condensation reflux pipe, 5-inert gas supply unit, 6-ammonia absorption unit, and 7-drying oven. Detailed Implementation

[0026] This invention provides a one-step method for preparing carbon-13 labeled carbonates, comprising the following steps: 1) Under an inert atmosphere, C13 urea is mixed with water to obtain a C13 urea solution; metal hydroxide is mixed with water to obtain a metal hydroxide dispersion. 2) Under an inert atmosphere, a C13 urea solution is added dropwise to a metal hydroxide dispersion to react and obtain a slurry containing C13-labeled carbonates. 3) The slurry containing C13-labeled carbonates is post-processed to obtain C13-labeled carbonates.

[0027] In this invention, the mass fraction of the C13 urea solution is 5-40%, specifically 10%, 15%, 20%, 25%, 30%, or 35%; the mass fraction of the metal hydroxide dispersion is 5-40%, specifically 8%, 10%, 15%, 20%, 25%, 30%, or 35%. The concentration range disclosed in this invention balances reaction efficiency and product dispersibility, avoiding product agglomeration due to excessively high concentrations or affecting the reaction rate due to excessively low concentrations.

[0028] In this invention, the abundance of the C13 urea is ≥85%, specifically 86%, 88%, 90%, 91.2%, 92%, 92.5%, 94%, 95%, 96%, 98%, and 99%. Among them, C13 urea with an abundance of 85% to 95% is unqualified C13 urea, which can also be processed by this invention to obtain C13-labeled carbonates with excellent properties.

[0029] In this invention, the metal hydroxide includes one or more of calcium hydroxide, sodium hydroxide, barium hydroxide, potassium hydroxide, magnesium hydroxide, and strontium hydroxide; the purity of the metal hydroxide is ≥98%, specifically 98.2%, 98.5%, 98.8%, 98.9%, 99%, 99.2%, 99.5%, 99.8%, and 99.9%; it is free of obvious impurities, ensuring the purity of the reaction and the quality of the product.

[0030] In this invention, the molar ratio of C13 urea to hydroxide ions in metal hydroxide in step 2) is 1:2 to 2.5, preferably 1:2.2 to 2.4, and more preferably 1:2.3; this molar ratio range can ensure an excess of metal hydroxide and guarantee complete hydrolysis of urea.

[0031] In this invention, the reaction temperature in step 2) is 80~100℃, specifically 82℃, 84℃, 85℃, 86℃, 88℃, 90℃, 92℃, 94℃, 95℃, 96℃, or 98℃; the reaction time is 1~6h, specifically 2h, 3h, 4h, or 5h; the reaction is carried out under stirring conditions at a stirring rate of 200~500rpm, specifically 250rpm, 300rpm, 350rpm, 400rpm, or 450rpm. This invention, by controlling the stirring rate, ensures uniform mixing of the reaction system, improving the reaction rate and product uniformity.

[0032] In this invention, the dropping rate of the C13 urea solution in step 2) is 8~30 mL / min, specifically 10 mL / min, 12 mL / min, 15 mL / min, 18 mL / min, 20 mL / min, 22 mL / min, 25 mL / min, or 28 mL / min.

[0033] In this invention, the inert atmosphere described in steps 1) and 2) independently includes nitrogen and / or argon, both of which have a purity of ≥99.99%. Preferably, the inert atmosphere is constructed by purging with inert gas at least three times to ensure that no air remains in the system after purging, thus ensuring that the reaction proceeds in an oxygen-free and carbon dioxide-free environment.

[0034] In this invention, the water used is preferably carbon dioxide-free deionized water.

[0035] In this invention, the post-processing in step 3) includes sequential gradient cooling, solid-liquid separation, purification washing and drying.

[0036] In this invention, purification washing is preferably carried out using carbon dioxide-free deionized water at 40~80℃ in a suspension washing manner, and the washing is performed no less than 3 times. The washing endpoint is when no color reaction occurs after adding phenolphthalein indicator to the washing solution, ensuring the removal of impurities and unreacted raw materials remaining on the surface of the product.

[0037] The drying method is to dry at 100~110℃ under normal pressure for 1~4 hours, or at 60~80℃ under vacuum for 2~4 hours, until the product reaches constant weight, ensuring that the product moisture content is less than 0.5% and improving product stability.

[0038] In this invention, the reaction described in step 2) produces ammonia gas, which is absorbed by a dilute acid solution to obtain an ammonium salt byproduct.

[0039] The present invention also provides a carbon-13 labeled carbonate prepared by the above preparation method, which has a purity of ≥99.0%, a carbon-13 isotope abundance recovery rate of ≥99.0%, uniform particle size, and no obvious impurities, and can meet the application needs of multiple fields such as medical treatment, scientific research, and industry.

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1

[0042] use Figure 1 The apparatus shown is used for a one-step preparation of carbon-13 labeled carbonates.

[0043] Preparation of raw material solutions: Under a nitrogen atmosphere (nitrogen purity 99.99%), 60.06 g (1.0 mol) of substandard C13 urea with a C13 isotope abundance of 92.5% was taken. This C13 urea has a purity of 98.5% and contains a small amount of impurities. Using carbon dioxide-free deionized water that has been pre-boiled for 15 min and cooled to room temperature in a sealed environment, 240.24 g of C13 urea solution with a mass fraction of 25% was precisely prepared. After stirring evenly, it was placed in a constant pressure dropping funnel for later use. 88.92 g (1.2 mol) of calcium hydroxide with a purity of 98.5% was taken and prepared into a calcium hydroxide suspension with a mass fraction of 10% using the same batch of carbon dioxide-free deionized water. After stirring evenly, it was added to a 10 L closed jacketed reactor.

[0044] Inert atmosphere replacement: The reactor and all pipelines were evacuated and purged with nitrogen three times using a high-purity nitrogen cylinder (nitrogen purity 99.99%). Each replacement lasted 8 minutes, and the nitrogen introduction rate was 80 mL / min. Finally, a slightly positive pressure nitrogen atmosphere was maintained in the reactor, with the pressure controlled at 0.108 MPa, to ensure that there was no residual air or carbon dioxide in the system.

[0045] Isothermal reaction: The magnetic stirrer was turned on and the speed was set to 300 rpm. The system was heated to 98°C under normal pressure reflux at a rate of 8°C / min through the jacket heat transfer oil. After stabilizing for 30 min, C13 urea solution was added dropwise at a rate of 25 mL / min. After the addition was completed, the reaction was maintained at 98°C for 3.5 h. The residual amount of urea was detected by high performance liquid chromatography to confirm that the urea was completely hydrolyzed, and a uniformly dispersed reaction slurry containing C13-labeled calcium carbonate was obtained.

[0046] Gradient cooling and post-treatment: After the reaction, maintain the temperature at 98℃ and stir for 30 min, then gradually cool down to 60℃ at a rate of 1℃ / min and stir for 20 min, and then let it cool naturally to room temperature; let the reaction slurry stand and settle for 30 min, decant to remove the supernatant, and use 60℃ carbon dioxide-free deionized water to perform three suspension washings on the precipitate, with the amount of water used for each washing being 8 times the mass of the precipitate, until no color reaction occurs after adding phenolphthalein indicator to the washing liquid, and then filter through atmospheric pressure to obtain a wet filter cake.

[0047] Drying the finished product: The wet filter cake is placed in a 105℃ forced-air drying oven and dried for 2.5 hours until constant weight. The entire process is carried out in the absence of air, and the final product of carbon-13 labeled calcium carbonate is obtained.

[0048] The carbon-13 labeled calcium carbonate product obtained in this embodiment has a purity of 99.6%, a carbon-13 isotope abundance of 92%, a carbon-13 abundance recovery rate of 99.7%, uniform particle size, and a water content of 0.3%. It can be used for research on tumor metabolism, mitochondrial function, nutritional metabolism, and aging.

[0049] Example 2

[0050] Preparation of raw material solutions: Under a nitrogen atmosphere (nitrogen purity 99.99%), 30.03 g (0.5 mol) of C13 urea with a C13 isotope abundance of 99.0% and a purity of 99.5% was taken. 100.1 g of a 30% C13 urea solution was precisely prepared using deionized water that had been boiled for 12 min in advance, sealed in an airtight container, and cooled to room temperature. The solution was stirred thoroughly and then placed in a constant pressure dropping funnel for later use. 44.02 g (1.1 mol) of sodium hydroxide with a purity of 99.0% was prepared using the same batch of deionized water to prepare 176.08 g of a 25% sodium hydroxide solution. The solution was stirred thoroughly and then added to a 5 L sealed three-necked flask.

[0051] Inert atmosphere replacement: The reaction system was replaced three times using a high-purity argon gas cylinder (argon purity 99.99%), with each replacement lasting 6 minutes and the argon gas introduction rate being 60 mL / min. Finally, a slightly positive pressure argon atmosphere was maintained in the system, with the pressure controlled at 0.106 MPa to ensure that there was no residual air or carbon dioxide.

[0052] Isothermal reaction: Turn on the magnetic stirrer and set the speed to 300 rpm. Heat the system to 95°C under isothermal reflux at a rate of 7°C / min. After stabilizing for 20 min, add C13 urea solution dropwise at a rate of 15 mL / min. After the addition is complete, maintain the reaction at 95°C for 4 h. Detect the residual amount of urea by high performance liquid chromatography to confirm that the urea is completely hydrolyzed and obtain a reaction solution containing C13 labeled sodium carbonate.

[0053] Gradient cooling and post-treatment: After the reaction is completed, maintain 95℃ and stir for 30 min, then cool naturally to room temperature; transfer the reaction solution to a rotary evaporator and concentrate it at 60℃ and 0.08MPa until crystals precipitate. After cooling and crystallization for 2 h, filter and wash the crude crystals twice with anhydrous ethanol, using 5 times the mass of the crude crystals each time to remove residual impurities.

[0054] Drying the finished product: The washed crystals were placed in an 80℃ vacuum drying oven and dried at 0.09MPa for 3 hours until constant weight was obtained, finally yielding the carbon-13 labeled sodium carbonate product.

[0055] The carbon-13 labeled sodium carbonate product obtained in this embodiment has a purity of 99.2%, a carbon-13 isotope abundance of 98.95%, a carbon-13 abundance recovery rate of 99.95%, uniform particle size, and a water content of 0.2%, and can be used for the synthesis of carbon-13 labeled organic compounds.

[0056] Example 3

[0057] Preparation of raw material solutions: Under a nitrogen atmosphere (nitrogen purity 99.99%), take 30.03g (0.5mol) of substandard C13 urea with a C13 isotope abundance of 91.2% and containing 5% NaCl impurities. The purity of this C13 urea is 98.0%. Use carbon dioxide-free deionized water that has been boiled for 10 minutes in advance, sealed and cooled to room temperature to prepare 150.15g of C13 urea solution with a mass fraction of 20%. After stirring evenly, put it into a constant pressure dropping funnel for later use. Take 94.40g (0.55mol) of barium hydroxide with a purity of 98.0%. Use carbon dioxide-free deionized water from the same batch to prepare 1180g of barium hydroxide solution with a mass fraction of 8%. After stirring evenly, add it to a 5L sealed three-necked flask.

[0058] Inert atmosphere replacement: The reaction system was replaced three times using a high-purity nitrogen cylinder (nitrogen purity 99.99%), with each replacement lasting 10 minutes and the nitrogen introduction rate being 70 mL / min. Finally, a slightly positive pressure nitrogen atmosphere was maintained in the system, with the pressure controlled at 0.107 MPa to ensure that there was no residual air or carbon dioxide.

[0059] Isothermal reaction: Turn on the magnetic stirrer and set the speed to 250 rpm. Heat the system to 90℃ at a rate of 6℃ / min and keep it stable for 25 min. Then, add C13 urea solution dropwise at a rate of 10 mL / min. After the addition is complete, maintain the reaction at 90℃ for 3 h. The residual amount of urea is detected by high performance liquid chromatography to confirm that the urea is completely hydrolyzed and a uniformly dispersed reaction slurry containing C13-labeled barium carbonate is obtained.

[0060] Gradient cooling and post-treatment: After the reaction is completed, maintain the temperature at 90℃ and stir for 30 min. Then, gradually cool the temperature to room temperature at a rate of 1℃ / min. Let the reaction slurry stand and settle for 20 min. Decant the supernatant to remove the supernatant. Use 50℃ carbon dioxide-free deionized water to perform three suspension washings on the precipitate. The amount of water used for each washing is 7 times the mass of the precipitate. Continue until no color reaction occurs after adding phenolphthalein indicator to the washing liquid. Then, filter to obtain a wet filter cake.

[0061] Drying the finished product: The wet filter cake is placed in a 105℃ forced-air drying oven and dried for 3 hours to constant weight, with air isolated throughout the process, to finally obtain the carbon-13 labeled barium carbonate product.

[0062] The carbon-13 labeled barium carbonate product obtained in this embodiment has a purity of 99.5%, a carbon-13 isotope abundance of 90.9%, a carbon-13 abundance recovery rate of 99.2%, uniform particle size, and a water content of 0.4%, and can be used in the field of nuclear industry analysis and calibration.

[0063] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A one-step method for preparing carbon-13 labeled carbonates, characterized in that, Includes the following steps: 1) Under an inert atmosphere, C13 urea is mixed with water to obtain a C13 urea solution; metal hydroxide is mixed with water to obtain a metal hydroxide dispersion. 2) Under an inert atmosphere, a C13 urea solution is added dropwise to a metal hydroxide dispersion to react and obtain a slurry containing C13-labeled carbonates. 3) The slurry containing C13-labeled carbonates is post-processed to obtain C13-labeled carbonates.

2. The one-step preparation method of C13-labeled carbonates according to claim 1, characterized in that, The mass fraction of the C13 urea solution is 5-40%; The mass fraction of the metal hydroxide dispersion is 5-40%.

3. The one-step preparation method of C13-labeled carbonates according to claim 2, characterized in that, The abundance of the C13 urea is ≥85%; The metal hydroxide includes one or more of calcium hydroxide, sodium hydroxide, barium hydroxide, potassium hydroxide, magnesium hydroxide, and strontium hydroxide; The purity of the metal hydroxide is ≥98%.

4. A one-step preparation method for C13-labeled carbonates according to any one of claims 1 to 3, characterized in that, The molar ratio of C13 urea to hydroxide in metal hydroxide in step 2) is 1:2~2.

5.

5. The one-step preparation method of C13-labeled carbonate according to claim 4, characterized in that, The reaction temperature in step 2) is 80~100℃, and the reaction time is 1~6h; the reaction is carried out under stirring conditions, and the stirring rate is 200~500rpm.

6. The one-step preparation method of C13-labeled carbonate according to claim 5, characterized in that, The dropping rate of the C13 urea solution in step 2) is 8~30 mL / min.

7. A one-step preparation method for C13-labeled carbonates according to claim 5 or 6, characterized in that, The inert atmosphere described in steps 1) and 2) independently includes nitrogen and / or argon, both of which have a purity of ≥99.99%.

8. The one-step preparation method of C13-labeled carbonate according to claim 7, characterized in that, The post-processing described in step 3) includes sequential gradient cooling, solid-liquid separation, purification washing, and drying.

9. The one-step preparation method of C13-labeled carbonate according to claim 8, characterized in that, The reaction described in step 2) will produce ammonia gas, which is absorbed by a dilute acid solution to obtain an ammonium salt byproduct.

10. The carbon-13 labeled carbonate prepared by the preparation method according to any one of claims 1 to 9.

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