Solid phase extraction separation method and kit for separating actinides from each other

Abstract

The present application relates to a solid phase extraction separation method and kit for separating actinides from each other. The actinides are U, Np and / or Pu, and at least one element X selected from Am or Cm. The method comprises: (1) passing a test solution containing the actinides from one side of separation column 1 through a cascade column sequentially connected by separation column 1 and separation column 2, separation column 1 being packed with resin 1, resin 1 comprising a porous base resin 1 and a complexing agent 1 supported thereon for complexing U, Np and / or Pu, separation column 2 being packed with resin 2, resin 2 comprising a porous base resin 2 and a complexing agent 2 supported thereon for complexing element X; (2) eluting separation column 1 with Np eluent containing AHA and nitric acid, Pu eluent containing oxalic acid and ascorbic acid, and / or U eluent containing ammonium carbonate, respectively, and eluting separation column 2 with element X eluent containing AHA and hydrochloric acid. The kit comprises the cascade column and the eluents described above.

Description

Technical Field

[0001] This invention relates to a solid-phase extraction separation method and kit for separating U (uranium), Np (neptunium) and / or Pu (plutonium) from at least one element X selected from Am (americium) or Cm (curium), belonging to the technical field of radionuclide separation. Background Technology

[0002] In the field of radioactive analysis, especially in the area of ​​radioactive analysis related to uranium-fueled nuclear activities, actinide elements U, Np, Pu, and the Am / Cm ratio are often the focus of attention. The analysis of these actinide elements typically employs spectroscopic, radiometric, or mass spectrometric methods. Regardless of the method used, element separation is often an essential step for accurate quantification. (Here and below, "Am / Cm" refers to at least one element selected from Am and Cm; that is, Am and Cm are not separated, and the ratio of their radioactivity can be obtained through alpha spectroscopy.)

[0003] For the separation of actinide elements such as U, Np, Pu, Am / Cm, etc., liquid-liquid extraction and solid-phase extraction are often used. Since the latter has advantages over the former, such as less organic waste liquid generation, no emulsification problem, and easier automation, the method of separating actinide elements by solid-phase extraction is increasingly favored by researchers.

[0004] Numerous reports in the literature describe the use of commercial resins such as TRU, TEVA, UTEVA, DGA, and TK200 to separate actinides. However, the target elements are mostly relatively singular, and in particular, techniques that simultaneously include U, Np, Pu, and Am / Cm in the target element are rarely reported. Generally, the more elements to be separated, the greater the technical difficulty becomes.

[0005] For example, Snow et al. used one TEVA column and two anion exchange columns to separate U / Am, Np, and Pu. However, U and Am were not separated, and the process involved precipitation and evaporation between the three columns, making it complex (Journal of Environmental Radioactivity, 2017, 172: 89-95). Engel et al. used three TEVA columns and one DGA column to separate Np, Pu, and Am from a U matrix. The sample solution needed to be remixed before entering the third TEVA column, resulting in a discontinuous separation process, which was not conducive to the automation of the column separation process, and the Np recovery rate was only 62% (Journal of Radioanalytical and Nuclear Chemistry, 2023, 332: 3205-3214). Xing et al. used one TK200 column and one DGA column to separate Np / Pu and Am / Cm, but Np and Pu were not separated and U was not considered in the analysis (Analytical Chemistry, 2023, 95: 3647-3655).

[0006] Therefore, there is a need in the prior art for a separation method that can simultaneously separate multiple actinide elements, such as U, Np, and / or Pu with Am / Cm, and can be operated continuously and easily automated. Summary of the Invention

[0007] <Problem to be solved by the invention>

[0008] In view of the above, the inventors conducted an in-depth study on mixed samples containing U, Np and / or Pu and Am / Cm, and found that the main difficulty in separating these elements is to achieve the following three points at the same time: (1) Np and Pu can not only be separated, but the separation of Np and Pu should not affect the recovery rate of U and Am / Cm; (2) The salt content in the eluent of each element after column separation should be as low as possible so as to concentrate the sample and / or prepare an α surface source (for α energy spectrum measurement) if necessary, and the recovery rate of each element from its eluent can even be higher than 95%; (3) The column separation process should be continuous, without intermediate material adjustment, and without precipitation, evaporation or other operations, so as to automate the column separation process.

[0009] Therefore, the purpose of this invention is to provide a solid-phase extraction method that can simultaneously separate actinide elements (U, Np and / or Pu, and Am and / or Cm) from each other. This method can easily achieve rapid separation of various actinide elements (even rapidly separating U, Np, Pu, Am / Cm), with good separation effect, recovery rate of each element in its respective eluent exceeding 95%, and very low salt content in each eluent. The entire column separation process can be operated continuously, the operation process is very simple, easy to automate, has a wide range of applications, and is suitable for large-scale industrial production.

[0010] The present invention also aims to provide a solid-phase extraction kit capable of simultaneously separating actinide elements (U, Np and / or Pu, and Am and / or Cm) from each other. This kit can be used to achieve rapid separation of various actinide elements in an easy manner (even rapid separation of U, Np, Pu, Am / Cm), with good separation effect, recovery rate of each element in its respective eluent exceeding 95%, and very low salt content in each eluent. The entire column separation process can be operated continuously, the operation process is very simple, easy to automate, has a wide range of applications, and is suitable for large-scale industrial production.

[0011] <Solutions for solving the problem>

[0012] After in-depth research, the inventors discovered that the following implementation scheme can be used to solve the above-mentioned technical problems.

[0013] [1]. A solid-phase extraction separation method for separating actinide elements, wherein the actinide elements are U, Np and / or Pu and element X, wherein element X is at least one selected from Am or Cm, the method comprising:

[0014] (1) A test solution containing the actinides is passed through a cascade column consisting of separation column 1 and separation column 2 connected in series, and the test solution enters the cascade column from the separation column 1 side.

[0015] The separation column 1 is filled with resin 1, which includes a porous base resin 1 and a complexing agent 1 supported on the porous base resin 1.

[0016] The complexing agent 1 is represented by the following formula (1):

[0017] (1)

[0018] In formula (1), each R1 is an alkyl group;

[0019] The separation column 2 is filled with resin 2, which includes a porous base resin 2 and a complexing agent 2 supported on the porous base resin 2.

[0020] The complexing agent 2 is represented by the following formula (2):

[0021] (2)

[0022] In formula (2), each of R2 is an alkyl group;

[0023] (2) Elute the separation column 1 with Np eluent and collect the eluent containing Np; elute the separation column 1 with Pu eluent and collect the eluent containing Pu; and / or elute the separation column 1 with U eluent and collect the eluent containing U; and elute the separation column 2 with element X eluent and collect the eluent containing element X.

[0024] The Np eluent is a mixed solution containing acetylhydroxamic acid (AHA) and nitric acid;

[0025] The Pu eluent is a mixed solution containing oxalic acid and ascorbic acid;

[0026] The U-eluting agent is a solution containing ammonium carbonate;

[0027] The eluent for element X is a mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid.

[0028] [2]. According to the solid phase extraction separation method described in [1], in the test solution, U is +6, Np is +6, Pu is +4, and element X is +3.

[0029] [3]. According to the solid-phase extraction separation method described in [2], the test solution is obtained by adding nitric acid and ammonium vanadate to the solution to be treated containing the actinides for acidity adjustment and oxidation pretreatment.

[0030] [4]. According to the solid-phase extraction separation method described in [1], wherein in formula (1), R1 is each independently a C4-12 straight-chain or branched alkyl group; and / or

[0031] In formula (2), R2 is each independently a C4-20 straight-chain or branched alkyl group.

[0032] [5]. According to the solid-phase extraction separation method described in [1], wherein the porous base resin 1 and the porous base resin 2 are each independently selected from at least one of (meth)acrylate porous resins and styrene porous resins; and / or

[0033] The loading of complexing agent 1 in resin 1 is 5-50% by mass; and / or

[0034] The loading of complexing agent 2 in resin 2 is 5-50% by mass.

[0035] [6]. According to the solid-phase extraction separation method described in [1], wherein the separation column 1 is obtained by filling the chromatographic column with the resin 1, and / or

[0036] The separation column 2 is obtained by filling the chromatographic column with the resin 2.

[0037] [7]. According to the solid-phase extraction separation method described in [1], wherein the concentration of acetylhydroxamic acid (AHA) in the mixed solution containing acetylhydroxamic acid (AHA) is 0.05–1 mol / L and the concentration of nitric acid is 0.1–4 mol / L; and / or

[0038] In the mixed solution containing oxalic acid and ascorbic acid, the concentration of oxalic acid is 0.05–1.0 mol / L, and the concentration of ascorbic acid is 0.02–0.8 mol / L; and / or

[0039] The concentration of ammonium carbonate in the solution is 0.05–1.5 mol / L; and / or

[0040] The mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid has a concentration of 0.01–1 mol / L and a concentration of 0.01–0.5 mol / L.

[0041] [8]. According to the solid phase extraction separation method described in [1], the flow rate of the test solution and each of the eluents is 0.05 to 5 mL / min.

[0042] [9]. According to the solid phase extraction separation method described in [1], in step (1), after the test solution is passed through the tandem column, a carrier agent that does not contain U, Np, Pu and element X is passed through the tandem column.

[0043]

[10] . A solid-phase extraction kit for separating actinide elements, wherein the actinide elements are U, Np and / or Pu and element X, wherein element X is at least one selected from Am or Cm, the kit comprising: a cascade column consisting of separation column 1 and separation column 2 connected in series, and an eluent for eluting the cascade column.

[0044] The cascade column has an inlet for injecting test solution on one side of the separation column 1.

[0045] The eluent is Np eluent for elution column 1, Pu eluent for elution column 1 and / or U eluent for elution column 1, and element X eluent for elution column 2.

[0046] The separation column 1 is filled with resin 1, which includes a porous base resin 1 and a complexing agent 1 supported on the porous base resin 1.

[0047] The complexing agent 1 is represented by the following formula (1):

[0048] (1)

[0049] In formula (1), each R1 is an alkyl group;

[0050] The separation column 2 is filled with resin 2, which includes a porous base resin 2 and a complexing agent 2 supported on the porous base resin 2.

[0051] The complexing agent 2 is represented by the following formula (2):

[0052] (2)

[0053] In formula (2), each of R2 is an alkyl group;

[0054] The Np eluent is a mixed solution containing acetylhydroxamic acid (AHA) and nitric acid;

[0055] The Pu eluent is a mixed solution containing oxalic acid and ascorbic acid;

[0056] The U-eluting agent is a solution containing ammonium carbonate;

[0057] The eluent for element X is a mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid.

[0058] <The Effects of the Invention>

[0059] In this invention, by sequentially passing a test solution containing the elements to be separated through separation columns 1 and 2 respectively filled with specific porous resins, and eluting separation columns 1 and 2 with various eluents of specific components, it is possible to separate U, Np and / or Pu from Am and / or Cm, or even separate U, Np, Pu and Am / Cm, with good separation effect.

[0060] Furthermore, the recovery rates of each element in their respective eluents can reach very high levels (e.g., all exceeding 95%). Moreover, the salt content in the resulting eluents is very low, and after concentration, transformation, and sample preparation, they can be analyzed using spectroscopic methods, radiometric methods (including liquid scintillation, alpha spectroscopy, gamma spectroscopy, etc.), or mass spectrometry. In some cases, the eluents can even be directly prepared for measurement using liquid scintillation and / or alpha spectroscopy and / or gamma spectroscopy without concentration or transformation.

[0061] Moreover, since it uses a series column as the separation device, the entire column separation process can be operated continuously, which is very simple, easy to automate, and has a wide range of applications. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the process for simultaneously separating U, Np, Pu, and element X in this invention.

[0063] Figure 2 The separation effect diagram of Embodiment 1 provided by the present invention. Detailed Implementation

[0064] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0065] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0066] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0067] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0068] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0069] In this specification, the numerical range referred to as "value A to value B" refers to the range including endpoint values ​​A and B. The numerical range referred to as "above" and "below" refers to the range including endpoint values. The numerical range referred to as "greater than" and "less than" refers to the range excluding endpoint values.

[0070] In this specification, "optional" or "optionally" means that the event or situation described below may or may not occur, and the description includes both the scenario in which the event occurs and the scenario in which the event does not occur.

[0071] Solid-phase extraction separation method

[0072] The solid-phase extraction separation method of the present invention is used to separate actinide elements, wherein the actinide elements are U, Np and / or Pu and element X, wherein element X is at least one selected from Am or Cm.

[0073] In some preferred embodiments, it is preferably adapted to separate at least two of U, Np or Pu from element X, or even to separate all four of U, Np, Pu from element X.

[0074] In this invention, "separating U, Np and / or Pu from each of at least one element X selected from Am or Cm" means that when at least one of U, Np and / or Pu and element X are present in the test solution, each of the aforementioned actinide elements present in the test solution can be separated.

[0075] In this invention, the solid-phase extraction separation method is implemented by employing cascade column solid-phase extraction technology.

[0076] For ease of understanding, Figure 1 The diagram above illustrates a specific embodiment of the solid-phase extraction separation method of the present invention.

[0077] In this invention, the solid-phase extraction separation method includes the step (1) of passing the test solution through a cascade column.

[0078] Specifically, in step (1), the test solution containing the actinide elements (i.e., U, Np and / or Pu and element X) is passed through a cascade column consisting of separation column 1 and separation column 2 connected in series. Moreover, the test solution enters the cascade column from the separation column 1 side; in other words, the test solution passes through separation columns 1 and 2 in sequence.

[0079] In this invention, the order in which the test solution passes through the separation column in the cascade column is crucial. If the order of the separation column is changed, the purpose of this invention cannot be achieved.

[0080] There are no particular restrictions on the flow rate of the test solution, which can be adjusted appropriately according to actual needs. In some preferred embodiments, in order to enable more complete adsorption by the separation column, the flow rate of the test solution is 0.05 to 5 mL / min, more preferably 0.2 to 3 mL / min.

[0081] In this invention, there is no particular limitation on the number of separation columns 1 and 2 connected in series; each can be either a single column or multiple columns.

[0082] In this invention, when the test solution contains both Am and Cm, Am and Cm are not separated. Furthermore, for at least one element X selected from Am or Cm, this invention sometimes designates it as "Am and / or Cm" or "Am / Cm".

[0083] In step (1), the separation column 1 is filled with resin 1, which includes a porous base resin 1 and a complexing agent 1 loaded on the porous base resin 1. The complexing agent 1 is capable of complexing with U, Np and Pu. The complexing agent 1 is represented by the following formula (1).

[0084] (1)

[0085] In formula (1), each R1 is an alkyl group. Each R1 may be the same or different.

[0086] In some preferred embodiments, each of R1 is independently a C4-12 straight-chain or branched alkyl group, more preferably, each of R1 is independently a C6-10 straight-chain or branched alkyl group.

[0087] Examples of complexing agents 1, without limitation, include: tripentylphosphine oxychloride, trihexylphosphine oxychloride, triheptylphosphine oxychloride, trioctylphosphine oxychloride, trinonylphosphine oxychloride, tridecylphosphine oxychloride, tri(undecyl)phosphine oxychloride, methyldipentylphosphine oxychloride, ethyldipentylphosphine oxychloride, butyldioctylphosphine oxychloride, etc. These compounds can be used alone or in combination of two or more.

[0088] In some particularly preferred embodiments, from the viewpoint of further improving the separation effect, the complexing agent 1 is trioctylphosphine (TOPO).

[0089] In step (1), the separation column 2 is filled with resin 2, which includes a porous base resin 2 and a complexing agent 2 loaded on the porous base resin 2. The complexing agent 2 is capable of complexing with the element X. The complexing agent 2 is represented by the following formula (2).

[0090] (2)

[0091] In formula (2), each R2 is an alkyl group. Each R2 may be the same or different.

[0092] In some preferred embodiments, each of R2 is independently a C4-20 straight-chain or branched alkyl group, more preferably, each of R2 is independently a C6-12 straight-chain or branched alkyl group.

[0093] Examples of complexing agents 2 include, without limitation, TEHDGA and TODGA.

[0094] In some particularly preferred embodiments, from the viewpoint of further improving the separation effect, the complexing agent 2 is at least one selected from TEHDGA and TODGA.

[0095] In this invention, the desired separation effect can be achieved by including complexing agent 1 in separation column 1 and complexing agent 2 in separation column 2.

[0096] In this invention, there are no particular restrictions on the materials of porous base resins 1 and 2, as long as they do not participate in the reaction during solid-state extraction (i.e., they are inert to the separation process).

[0097] In some preferred embodiments, from the viewpoint of reducing costs, achieving higher recovery rates of the target element, and improving separation performance, porous base resin 1 and porous base resin 2 are each independently selected from at least one of (meth)acrylate porous resins and styrene porous resins.

[0098] In this invention, the term "(meth)acrylate porous resin" refers to a porous resin formed using polymers with units based on (meth)acrylate monomers as the main component. The term "styrene porous resin" refers to a porous resin formed using polymers with units based on styrene monomers as the main component.

[0099] In this invention, there are no particular restrictions on the specific structure of the porous base resin, which can be appropriately adjusted according to actual needs (such as test solution composition, equipment scale, test solution flow rate, etc.).

[0100] In some specific embodiments, porous base resins 1 and 2 are each in particulate form. In this case, the average particle size of porous base resins 1 and 2 can be 100 nm to 1 mm, preferably 2 μm to 800 μm, and more preferably 20 μm to 200 μm.

[0101] In some other specific embodiments, the pore sizes of the porous base resins 1 and 2 can be 2 nm to 0.1 mm, preferably 2 nm to 100 nm, and more preferably 5 nm to 15 nm.

[0102] In addition, porous base resins 1 and 2 may be the same or different; preferably, they are the same.

[0103] In this invention, there is no particular limitation on the loading amount of complexing agent in resin 1 or 2, which can be appropriately adjusted according to actual needs (e.g., composition of the test solution, scale of equipment, flow rate of the test solution, etc.).

[0104] In some specific implementations, from the viewpoint of balancing cost and desired separation effect, the loading of complexing agent 1 in resin 1 can be 5 to 50% by mass (relative to 100% of the total mass of resin 1), preferably 20 to 40% by mass.

[0105] In other specific embodiments, from the viewpoint of balancing cost and desired separation effect, the loading of complexing agent 2 in resin 2 can be 5 to 50% by mass (relative to 100% of the total mass of resin 2), preferably 20 to 40% by mass.

[0106] In this invention, there are no particular limitations on the method of loading the complexing agent onto the porous base resin, and various methods known in the art can be used.

[0107] In some specific embodiments, the porous base resin (porous base resin 1 or 2) can be washed, then mixed with a complexing agent (complexing agent 1 or 2) in a solvent, and then the solvent can be removed (e.g., by vacuum distillation) to obtain resin 1 or 2.

[0108] Furthermore, there are no particular restrictions on the form in which the separation columns are used. In some specific embodiments, separation column 1 can be obtained by filling the chromatographic column with the resin 1, and separation column 2 can be obtained by filling the chromatographic column with the resin 2.

[0109] When using a chromatographic column, to better avoid radionuclide residue and wall adhesion, it is preferable that the column be made of stainless steel or a polymer material.

[0110] Furthermore, there are no particular restrictions on the size of the chromatographic column, which can usually be adjusted appropriately according to factors such as the scale of the application. In some specific implementations, the length of the chromatographic column can be 2 cm to 1 meter, for example, 5 cm, 7 cm, 9 cm, 15 cm, 20 cm, 25 cm, 30 cm, 40 cm, 45 cm, 50 cm, 55 cm, 60 cm, 65 cm, 70 cm, 75 cm, 80 cm, 85 cm, and 90 cm. In some cases, it can be 2 to 10 cm, in some cases it can be greater than 10 cm but less than 50 cm, and in some cases it can be greater than 50 cm but less than 1 meter.

[0111] In some specific implementations, the inner diameter of the chromatographic column is 1 mm to 5 cm, for example, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 18 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, and 50 mm. In some cases, it can be 1 mm to 15 mm; in others, it can be greater than 15 mm but less than 30 mm; and in still others, it can be greater than 30 mm but less than 50 mm.

[0112] In this invention, there are no particular limitations on the source of the test solution containing the actinide elements (i.e., U, Np and / or Pu and element X). The test solution can be the original solution to be treated (the solution to be treated) or a treated solution that has already been treated.

[0113] In some preferred embodiments, in order to more fully separate the nuclides (i.e., the various elements to be separated mentioned above), the test solution contains U with a +6 valence, Np with a +6 valence, Pu with a +4 valence, and element X with a +3 valence. Under these preferred valence conditions, it is easier to achieve: (1) almost all of U, Np, and / or Pu are adsorbed by separation column 1; (2) almost all of Am and / or Cm are adsorbed by separation column 2.

[0114] If the valence state of the nuclide in the solution to be treated does not satisfy the above-mentioned preferred valence state, there are no particular limitations on the method for maintaining the valence state of the nuclide as the above-mentioned preferred valence state. For example, the test solution is obtained by adding nitric acid and ammonium vanadate to the solution to be treated containing the actinide elements (i.e., U, Np and / or Pu and element X) for acidity adjustment and oxidation pretreatment.

[0115] In some preferred embodiments, in order to adjust the acidity to a more suitable level for more complete separation of the nuclides, the concentration of nitric acid in the test solution is preferably 0.5 to 10.0 mol / L, more preferably 3 to 5 mol / L.

[0116] In some preferred embodiments, the concentration of ammonium vanadate in the test solution is preferably 0.01–0.5 mol / L, more preferably 0.05–0.2 mol / L.

[0117] The oxidation pretreatment is carried out by adding nitric acid and ammonium vanadate to the solution to be treated and stirring for a specified time.

[0118] In some preferred embodiments, the oxidation pretreatment time is preferably 5 to 60 minutes, more preferably 10 to 20 minutes.

[0119] In addition, the test solution of the present invention may also contain various other elements, which vary depending on the source of the solution to be treated.

[0120] Furthermore, in this invention, after the test solution passes through the cascade column, a carrier agent free of U, Np, Pu, and element X can be passed through the cascade column again. This process allows the test solution to pass through the cascade column more thoroughly. In some specific embodiments, the carrier agent can be a nitric acid solution.

[0121] The concentration of the nitric acid solution used as a carrier can be 0.5–10.0 mol / L, preferably 3–5 mol / L. Further, the concentration of the nitric acid solution used as a carrier is more preferably the same as the concentration of nitric acid in the test solution.

[0122] There are no particular restrictions on the flow rate of the carrier, which can be adjusted appropriately according to actual needs. In some preferred embodiments, in order to enable more complete adsorption on the separation column, the flow rate of the carrier is 0.05 to 5 mL / min, more preferably 0.2 to 3 mL / min.

[0123] In this invention, the solid phase extraction separation method includes the step (2) of eluting separation column 1 and separation column 2 with a specific eluent and collecting the corresponding eluent.

[0124] Specifically, in step (2), the Np-containing eluent is used to elute the separation column 1, and the eluent containing Np is collected; the Pu-containing eluent is used to elute the separation column 1, and the Pu-containing eluent is collected; and / or the U-containing eluent is used to elute the separation column 1, and the U-containing eluent is collected; and the element X-containing eluent is used to elute the separation column 2, and the element X-containing eluent is collected.

[0125] There are no particular restrictions on the order in which the eluents are added, and they can be adjusted appropriately according to actual needs. For example, elution can be performed first in separation column 1 and then in separation column 2, or vice versa. Furthermore, in some particularly preferred embodiments, when Np, Pu, and U are present simultaneously, it is preferable to elute separation column 1 with Np eluent, Pu eluent, and U eluent in that order.

[0126] There are no particular restrictions on the flow rate of each eluent, which can be adjusted appropriately according to actual needs. In some preferred embodiments, in order to achieve more complete desorption of the separation column, the flow rate of each eluent is preferably 0.05 to 5 mL / min, more preferably 0.2 to 3 mL / min.

[0127] In this invention, the use of the following specific eluents can not only achieve the separation of the target element, but also achieve a high recovery rate of the target element and a low salt content.

[0128] In this invention, the Np eluent is a mixed solution containing acetylhydroxamic acid (AHA) and nitric acid. Preferably, an AHA-nitric acid aqueous solution is used (i.e., an aqueous solution using AHA and nitric acid as solutes).

[0129] The structural formula of acetylhydroxamic acid (AHA) is shown in formula (3).

[0130] (3)

[0131] In some preferred embodiments, the concentration of AHA in the mixed solution containing AHA and nitric acid is preferably 0.05 to 1 mol / L, more preferably 0.2 to 0.8 mol / L.

[0132] In some preferred embodiments, the concentration of nitric acid in the mixed solution containing AHA and nitric acid is preferably 0.1 to 4 mol / L, more preferably 0.2 to 2 mol / L.

[0133] In this invention, the Pu eluent is a mixed solution containing oxalic acid and ascorbic acid. Preferably, an aqueous solution of oxalic acid and ascorbic acid (i.e., an aqueous solution using oxalic acid and ascorbic acid as solutes) is used.

[0134] In some preferred embodiments, the concentration of oxalic acid in the mixed solution containing oxalic acid and ascorbic acid is 0.05 to 1.0 mol / L, more preferably 0.3 to 0.8 mol / L.

[0135] In some preferred embodiments, the concentration of ascorbic acid in the mixed solution containing oxalic acid and ascorbic acid is 0.02 to 0.8 mol / L, more preferably 0.05 to 0.4 mol / L.

[0136] In this invention, the eluent U is a solution containing ammonium carbonate. Preferably, an aqueous solution of ammonium carbonate is used.

[0137] In some preferred embodiments, the concentration of ammonium carbonate in the solution is 0.05–1.5 mol / L, more preferably 0.2–0.8 mol / L.

[0138] In this invention, the eluent for element X is a mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid (HCl). Preferably, an aqueous solution of AHA and hydrochloric acid (i.e., an aqueous solution using AHA and HCl as solutes) is used.

[0139] In some preferred embodiments, the concentration of AHA in the mixed solution containing AHA and HCl is 0.01 to 1 mol / L, more preferably 0.05 to 0.5 mol / L.

[0140] In some preferred embodiments, the concentration of hydrochloric acid (HCl) in the mixed solution containing AHA and HCl is 0.01–0.5 mol / L.

[0141] In this invention, each eluent contains other components besides the solutes mentioned above, such as NaCl, and other unavoidable impurities.

[0142] In this invention, the recovery rate of each element from the sample solution can reach a very high level through solid-phase extraction, for example, above 95%.

[0143] In radiochemical separation, the recovery rate is the ratio of the mass (or activity) of the target element recovered after separation to the mass (or activity) of the target element in the original sample before separation, usually expressed as a percentage.

[0144] Furthermore, the solid-phase extraction separation method of the present invention may also include other steps, such as concentrating or diluting the eluents, or extracting corresponding elements from the eluents.

[0145] These other steps can be performed using methods known in the art.

[0146] <Supply kits for solid phase extraction>

[0147] The solid-phase extraction kit of the present invention is used to separate actinide elements, wherein the actinide elements are U, Np and / or Pu and element X, wherein element X is at least one selected from Am or Cm.

[0148] In some preferred embodiments, the solid-phase extraction kit of the present invention is preferably adapted to separate at least two selected from U, Np or Pu from element X, or even to separate all four of U, Np, Pu from element X.

[0149] The solid-phase extraction kit of the present invention includes a cascade column consisting of a separation column 1 and a separation column 2 connected in series, and an eluent for eluting the cascade column. The cascade column has an inlet for injecting a test solution on the separation column 1 side. It is understood that the cascade column has an outlet for the test solution to flow out on the separation column 2 side.

[0150] The eluent is an Np eluent for eluting separation column 1, a Pu eluent for eluting separation column 1, and / or a U eluent for eluting separation column 1, and an element X eluent for eluting separation column 2.

[0151] In this invention, depending on the type of actinide element contained in the test solution to be treated, the eluent can be at least one selected from Np eluent, Pu eluent and U eluent, as well as element X eluent.

[0152] The separation column 1 is filled with resin 1, which includes a porous base resin 1 and a complexing agent 1 loaded on the porous base resin 1.

[0153] The complexing agent 1 is represented by the following formula (1).

[0154] (1)

[0155] In formula (1), R1 is an alkyl group.

[0156] The separation column 2 is filled with resin 2, which includes a porous base resin 2 and a complexing agent 2 loaded on the porous base resin 2.

[0157] The complexing agent 2 is represented by the following formula (2).

[0158] (2)

[0159] In formula (2), R2 is an alkyl group independently.

[0160] The Np eluent is a mixed solution containing acetylhydroxamic acid (AHA) and nitric acid; the Pu eluent is a mixed solution containing oxalic acid and ascorbic acid; the U eluent is a solution containing ammonium carbonate; and the element X eluent is a mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid.

[0161] In other words, the kit of the present invention includes a combination of the above-described cascade column and the above-described eluent.

[0162] In addition, the kit of the present invention may optionally include other components, such as a carrier agent.

[0163] In this invention, the details of separation columns 1 and 2, resins 1 and 2, porous base resins 1 and 2, complexing agents 1 and 2, each eluent, and carrier are as described in the previous text <Solid Phase Extraction Separation Method>, and will not be repeated here.

[0164] Example

[0165] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0166] <Example 1: Separation of Actinide Elements from Feed Liquid in Simulated Environment>

[0167] (a) Preparation of test solutions, carriers, and various eluents

[0168] (1) Preparation of test solution: Take an appropriate amount 233 U、 237 Np, 238-241 Pu and 241 Am tracer Am is placed in 50 mL test tube A. A certain amount of solid ammonium metavanadate (the amount is such that its final concentration in the test solution is 0.05 mol / L) is weighed into 50 mL test tube B, and 20 mL of simulated environmental solution is added to test tube B and stirred to dissolve.

[0169] The detailed composition of the simulated environment feed solution is as follows. The medium is 4 mol / L nitric acid, and the metal element composition (unit: mg / L) is: Al, 4200; Ca, 4000; Fe, 7000; K, 2000; Mn, 80; Na, 1000; Ni, 200; Pb, 700; Ti, 300.

[0170] Transfer all the solution in test tube B to test tube A, stir and oxidize for 10 minutes. The resulting liquid is referred to as the test solution.

[0171] (2) The carrier is a 4 mol / L nitric acid solution.

[0172] (3) The eluent for Np is an AHA-nitric acid aqueous solution, specifically 0.5 mol / L AHA + 1.5 mol / L nitric acid. The eluent for Pu is an oxalic acid-ascorbic acid aqueous solution, specifically 0.6 mol / L oxalic acid + 0.1 mol / L ascorbic acid. The eluent for U is a 0.5 mol / L ammonium carbonate aqueous solution. The eluent for element X (i.e., Am) is an AHA-hydrochloric acid aqueous solution, specifically 0.02 mol / L AHA + 0.1 mol / L hydrochloric acid.

[0173] (II) Separation Process

[0174] Start the separation process at a flow rate of 0.5 mL / min. The test solution flows sequentially through separation column 1 (containing resin 1 loaded with TOPO) and separation column 2 (containing resin 2 loaded with TEHDGA). After all the test solution in the test bottle has entered the separation column, switch to the carrier medium, using 20 mL of carrier medium.

[0175] (III) Washing process

[0176] After the carrier banding process was completed, the elution process began. Each eluent was collected in a test tube, and the tube was replaced every 4 minutes. 2 mL of eluent was collected from each tube. Specifically, column 1 was eluted sequentially with 20 mL each of Np, Pu, and U eluents, and column 2 was eluted with 20 mL of element X eluent. All eluents were collected sequentially in 40 test tubes.

[0177] (iv) Analysis after separation

[0178] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. The U eluent was used to analyze U; the Np eluent to analyze Np; the Pu eluent to analyze Pu; and the element X eluent to analyze Am.

[0179] The analysis results of the eluent in the above 40 test tubes are as follows: Figure 2 As shown in the figure, material balance analysis revealed that the recoveries of U, Np, Pu, and Am in their respective eluents were all above 95%. Combined with alpha energy dispersive spectroscopy analysis, it was found that there was minimal cross-contamination of the target elements in each eluent.

[0180] <Example 2: Separation of Actinide Elements from a Simulated Environmental Feed>

[0181] Except that the resin 2 loaded with TEHDGA in the separation column 2 was replaced with resin 2 loaded with TODGA, the same method as in Example 1 was used for (a) to (b).

[0182] (iv) Analysis after separation

[0183] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. The U eluent was used to analyze U; the Np eluent to analyze Np; the Pu eluent to analyze Pu; and the element X eluent to analyze Am.

[0184] Similar to the results in Example 1, the recovery rates of elements such as U, Np, Pu, and Am in their respective eluents were all higher than 95%, and there was little cross-contamination of the target elements in each eluent.

[0185] <Example 3: Separation of Actinide Elements from Simulated High-Level Radioactive Waste>

[0186] Except that the simulated environmental feed liquid in Example 1 was replaced with simulated high-level radioactive waste liquid, the procedures (I) to (III) were carried out in the same manner as in Example 1. The detailed composition of the simulated high-level radioactive waste liquid is as follows. The medium is 4 mol / L nitric acid, and the metal element composition (unit: mg / L) is: Na, 18300; Fe, 6000; Al, 5700; Ni, 2900; Nd, 1500.

[0187] (iv) Analysis after separation

[0188] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. The U eluent was used to analyze U; the Np eluent to analyze Np; the Pu eluent to analyze Pu; and the element X eluent to analyze Am.

[0189] Similar to the results in Example 1, the recovery rates of elements such as U, Np, Pu, and Am in their respective eluents were all higher than 95%, and there was little cross-contamination of the target elements in each eluent.

[0190] <Example 4: Simulated Separation of Actinide Elements from High-Level Radioactive Waste>

[0191] Except that the TEHDGA-loaded resin 2 in the separation column 2 was replaced with TODGA-loaded resin 2, the same method as in Example 3 was used for (a) to (b).

[0192] (iv) Analysis after separation

[0193] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. The U eluent was used to analyze U; the Np eluent to analyze Np; the Pu eluent to analyze Pu; and the element X eluent to analyze Am.

[0194] Similar to the results in Example 1, the recovery rates of elements such as U, Np, Pu, and Am in their respective eluents were all higher than 95%, and there was little cross-contamination of the target elements in each eluent.

[0195] <Example 5: Separation of Actinide Elements in Pure Nitric Acid Medium>

[0196] Except that the simulated environment solution in Example 1 was replaced with a 4 mol / L nitric acid aqueous solution, the same method as in Example 1 was used for (I) to (III).

[0197] (iv) Analysis after separation

[0198] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. The U eluent was used to analyze U; the Np eluent to analyze Np; the Pu eluent to analyze Pu; and the element X eluent to analyze Am.

[0199] Similar to the results in Example 1, the recovery rates of elements such as U, Np, Pu, and Am in their respective eluents were all higher than 95%, and there was little cross-contamination of the target elements in each eluent.

[0200] <Example 6: Separation of Actinide Elements in Pure Nitric Acid Medium>

[0201] Except that the resin 2 loaded with TEHDGA in the separation column 2 was replaced with resin 2 loaded with TODGA, the same method as in Example 5 was used for (a) to (b).

[0202] (iv) Analysis after separation

[0203] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. The U eluent was used to analyze U; the Np eluent to analyze Np; the Pu eluent to analyze Pu; and the element X eluent to analyze Am.

[0204] Similar to the results in Example 1, the recovery rates of elements such as U, Np, Pu, and Am in their respective eluents were all higher than 95%, and there was little cross-contamination of the target elements in each eluent.

[0205] <Comparative Example 1>

[0206] Except that the TOPO-loaded resin 1 in the separation column 1 was replaced with TEVA-loaded resin 1, the process was carried out in the same manner as in Example 1 (i) to (iii).

[0207] (iv) Analysis after separation

[0208] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. However, more than 80% of U and Np entered the element X eluent, indicating significant cross-contamination of the target element in the eluent.

[0209] <Comparative Example 2>

[0210] Except for replacing the Np eluent with 0.6 mol / L oxalic acid + 0.1 mol / L ascorbic acid and the Pu eluent with 0.5 mol / L AHA + 1.5 mol / L nitric acid, the procedures (i) to (iii) were carried out in the same manner as in Example 1.

[0211] (iv) Analysis after separation

[0212] After the cascade column separation process, the U eluent, Np eluent, Pu eluent, and element X eluent were measured using a liquid scintillation analyzer and an alpha spectrometer, respectively. However, more than 95% of Np and Pu entered the Np eluent, indicating significant cross-contamination of the target elements in the eluent.

[0213] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0214] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A solid-phase extraction separation method for separating actinide elements, wherein the actinide elements are U, Np, Pu and element X, or Np, Pu and element X, wherein element X is at least one selected from Am or Cm, characterized in that, The method includes: (1) A test solution containing the actinides is passed through a cascade column consisting of separation column 1 and separation column 2 connected in series, and the test solution enters the cascade column from the separation column 1 side. The separation column 1 is filled with resin 1, which includes a porous base resin 1 and a complexing agent 1 supported on the porous base resin 1. The complexing agent 1 is represented by the following formula (1): (1) In formula (1), each R1 is an alkyl group; The separation column 2 is filled with resin 2, which includes a porous base resin 2 and a complexing agent 2 supported on the porous base resin 2. The complexing agent 2 is represented by the following formula (2): (2) In formula (2), each of R2 is an alkyl group; (2) Elute the separation column 1 with Np eluent and collect the eluent containing Np; elute the separation column 1 with Pu eluent and collect the eluent containing Pu; and / or elute the separation column 1 with U eluent and collect the eluent containing U; and elute the separation column 2 with element X eluent and collect the eluent containing element X. The Np eluent is a mixed solution containing acetylhydroxamic acid (AHA) and nitric acid; The Pu eluent is a mixed solution containing oxalic acid and ascorbic acid; The U-eluting agent is a solution containing ammonium carbonate; The eluent for element X is a mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid.

2. The solid-phase extraction separation method according to claim 1, characterized in that, In the test solution, U has a +6 valence, Np has a +6 valence, Pu has a +4 valence, and element X has a +3 valence.

3. The solid-phase extraction separation method according to claim 2, characterized in that, The test solution was obtained by adding nitric acid and ammonium vanadate to the solution containing the actinides for acidity adjustment and oxidation pretreatment.

4. The solid-phase extraction separation method according to claim 1, characterized in that, In formula (1), R1 is each independently a C4-12 straight-chain or branched alkyl group; and / or In formula (2), R2 is each independently a C4-20 straight-chain or branched alkyl group.

5. The solid-phase extraction separation method according to claim 1, characterized in that, The porous base resin 1 and the porous base resin 2 are each independently selected from at least one of (meth)acrylate porous resins and styrene porous resins; and / or The loading of complexing agent 1 in resin 1 is 5-50% by mass; and / or The loading of complexing agent 2 in resin 2 is 5-50% by mass.

6. The solid-phase extraction separation method according to claim 1, characterized in that, The separation column 1 is obtained by filling the chromatographic column with the resin 1, and / or The separation column 2 is obtained by filling the chromatographic column with the resin 2.

7. The solid-phase extraction separation method according to claim 1, characterized in that, The mixed solution containing acetylhydroxamic acid (AHA) and nitric acid has an AHA concentration of 0.05–1 mol / L and a nitric acid concentration of 0.1–4 mol / L; and / or In the mixed solution containing oxalic acid and ascorbic acid, the concentration of oxalic acid is 0.05–1.0 mol / L, and the concentration of ascorbic acid is 0.02–0.8 mol / L; and / or The concentration of ammonium carbonate in the solution is 0.05–1.5 mol / L; and / or The mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid has a concentration of 0.01–1 mol / L and a concentration of 0.01–0.5 mol / L.

8. The solid-phase extraction separation method according to claim 1, characterized in that, The flow rate of each of the test solutions and each of the eluents is 0.05–5 mL / min.

9. The solid-phase extraction separation method according to claim 1, characterized in that, In step (1), after the test solution is passed through the cascade column, a carrier agent that does not contain U, Np, Pu and element X is then passed through the cascade column.

10. A solid-phase extraction kit for separating actinide elements, wherein the actinide elements are U, Np, Pu and element X, or Np, Pu and element X, wherein element X is at least one selected from Am or Cm, characterized in that, The kit includes: a cascade column consisting of separation column 1 and separation column 2 connected in series, and an eluent for eluting the cascade column. The cascade column has an inlet for injecting test solution on one side of the separation column 1. The eluent is Np eluent for elution column 1, Pu eluent for elution column 1 and / or U eluent for elution column 1, and element X eluent for elution column 2. The separation column 1 is filled with resin 1, which includes a porous base resin 1 and a complexing agent 1 supported on the porous base resin 1. The complexing agent 1 is represented by the following formula (1): (1) In formula (1), each R1 is an alkyl group; The separation column 2 is filled with resin 2, which includes a porous base resin 2 and a complexing agent 2 supported on the porous base resin 2. The complexing agent 2 is represented by the following formula (2): (2) In formula (2), each of R2 is an alkyl group; The Np eluent is a mixed solution containing acetylhydroxamic acid (AHA) and nitric acid; The Pu eluent is a mixed solution containing oxalic acid and ascorbic acid; The U-eluting agent is a solution containing ammonium carbonate; The eluent for element X is a mixed solution containing acetylhydroxamic acid (AHA) and hydrochloric acid.

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