A proficiency testing biological ash sample preparation method for radionuclide analysis

Abstract

The present application relates to a kind of for radionuclide analysis proficiency testing biological ash sample preparation method.Belong to the technical field of radiation environment monitoring, according to the weight of biological ash sample to be prepared, select biological ash sample preparation process type;Biological ash sample preparation process corresponding to the biological ash sample preparation process selected by biological ash sample preparation process type is used to prepare biological ash sample, biological ash sample preparation process: prepare first biological ash matrix and second biological ash matrix;Radionuclide standard solution is dropped to the predetermined area of first biological ash matrix, and radionuclide standard solution does not contact with the inner wall of first container;First biological ash matrix is dried;First biological ash matrix after drying is transferred to second container, and second biological ash matrix is transferred to second container by first container, and is mixed, to obtain biological ash sample.The method provided by the present application can make radionuclide and biological ash more uniform, improve the uniformity of proficiency testing sample.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radiation environment monitoring, in particular to a method for preparing a proficiency testing biological ash sample for radionuclide analysis. BACKGROUND

[0002] Proficiency testing biological ash samples are key tools for ensuring the accuracy and reliability of laboratory analysis. These samples are not only used for quality control, helping laboratories monitor consistency and stability during the analysis process, but also verifying the effectiveness of analysis methods, including detection limit, sensitivity and repeatability parameters. In addition, by using standardized biological ash samples, laboratories can compare results and ensure the comparability of data between different laboratories, which is crucial for scientific research and regulatory compliance. In addition, proficiency testing helps laboratories identify potential problems, thereby promoting technical improvement and improving overall analysis capabilities.

[0003] There is a lack of radionuclide standard materials in biological ash, and in internal quality control of laboratories, interlaboratory comparison and proficiency testing, the analysis of radionuclides in biological ash samples will be prepared by spiking method. However, due to the lack of solid standard materials for some radionuclides, when mixing radionuclide standard solution with biological ash sample, the following problems exist:

[0004] The preparation of proficiency testing samples (biological ash samples) for evaluating the proficiency of laboratories in analyzing radionuclides in biological ash by spiking method cannot guarantee uniform mixing of biological ash matrix and radionuclide solution, resulting in low uniformity of proficiency testing samples. During the preparation of biological ash samples, the radionuclide solution may be lost on the wall, which affects the evaluation accuracy. In addition, biological ash is prone to moisture, which can affect the activity concentration value of radionuclides in biological ash samples. Therefore, the present application provides a method for preparing proficiency testing biological ash samples for radionuclide analysis.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] In view of the defects in the prior art, the purpose of the present application is to provide a method for preparing proficiency testing biological ash samples for radionuclide analysis, which can improve the uniformity and evaluation accuracy of proficiency testing samples and ensure that the activity concentration value is not affected.

[0007] To achieve the above object, the technical scheme adopted by the present application is: a method for preparing a biological ash sample for proficiency testing of radionuclide analysis, the method comprising the following steps: selecting a biological ash sample preparation process type according to the weight of a biological ash sample to be prepared; and preparing the biological ash sample by using a biological ash sample preparation process corresponding to the selected biological ash sample preparation process type, wherein the biological ash sample preparation process is as follows:

[0008] preparing a first biological ash substrate and a second biological ash substrate for a spiking operation, the first biological ash substrate being contained in a first container; dropping a radionuclide standard solution into a predetermined area of the first biological ash substrate, the radionuclide standard solution not being in contact with the inner wall of the first container; drying the first biological ash substrate with the radionuclide standard solution dropped thereon until the first biological ash substrate assumes a loose, powdery form; transferring the dried first biological ash substrate to a second container, and transferring the second biological ash substrate to the second container through the first container; and mixing the first biological ash substrate and the second biological ash substrate in the second container to obtain a biological ash sample.

[0009] In the mixing mechanism sample case, the second container is a mixing barrel; and in the pulverizer mechanism sample case, the second container is a pulverizing barrel of a pulverizer.

[0010] Preferably, the step of selecting a biological ash sample preparation process type according to the weight of a biological ash sample to be prepared comprises: in the case where the weight of the biological ash sample to be prepared is greater than a weight threshold, determining that the biological ash sample preparation process type is the mixing mechanism sample; and in the case where the weight of the biological ash sample to be prepared is less than or equal to the weight threshold, determining that the biological ash sample preparation process type is the pulverizer mechanism sample.

[0011] Preferably, before the step of preparing a first biological ash substrate and a second biological ash substrate for a spiking operation, the first biological ash substrate being contained in a first container, the method further comprises: preparing a biological sample; performing first drying treatment on the biological sample; crushing the first-dried biological sample and performing carbonization treatment until the biological sample assumes a clumped, coke-like form; pulverizing the carbonized biological sample and performing heating treatment until the biological sample is completely carbonized to obtain a carbonized sample; performing ashing treatment on the carbonized sample until the carbonized sample assumes a loose, granular form of white or off-white color to obtain an ashed sample; performing second drying treatment on the ashed sample until a constant weight is reached; performing grinding treatment on the second-dried ashed sample; and performing screening treatment on the ground ashed sample to obtain the biological ash substrate, the first biological ash substrate and the second biological ash substrate both being the biological ash substrate.

[0012] Preferably, the first drying treatment is performed in an oven, and the drying temperature is 108-112°C; the carbonization treatment is performed at a temperature less than or equal to 450°C; the ashing treatment is performed in a muffle furnace, and the ashing temperature is less than or equal to 450°C; the second drying treatment is performed in an oven, and the drying temperature is 105°C, and the drying time is greater than or equal to 24 hours; and the ashed sample is sieved through a 100-mesh sieve.

[0013] Preferably, the radionuclide standard solution is dropped onto a predetermined region of the first bio-ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, including at least one of the following: dropping the radionuclide standard solution onto the central region of the surface of the first bio-ash matrix contained in the first container, and the radionuclide standard solution does not contact the inner wall of the first container; or dropping the radionuclide standard solution onto the geometric center region of the first bio-ash matrix contained in the first container, and the radionuclide standard solution does not contact the inner wall of the first container; or dropping the radionuclide standard solution onto the geometric center region of the first container, and the radionuclide standard solution does not contact the inner wall of the first container.

[0014] Preferably, the radionuclide standard solution is dropped onto a predetermined region of the first bio-ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, including: using a pipette to draw the radionuclide standard solution, and dropping the radionuclide standard solution onto the predetermined region of the first bio-ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

[0015] Preferably, the first bio-ash matrix and the second bio-ash matrix prepared for the spiking operation include: weighing a first weight value of bio-ash matrix into the second container; transferring a second weight value of the first bio-ash matrix from the second container to the first container, and weighing a third weight value of the second bio-ash matrix for standby.

[0016] Preferably, in the case of using the sample mixing mechanism, the mixing treatment of the first bio-ash matrix and the second bio-ash matrix in the second container to obtain a bio-ash sample includes: adding a plurality of mixing balls to the mixing barrel, the plurality of mixing balls at least including a first mixing ball and a second mixing ball, the first mixing ball and the second mixing ball having different masses; fixing the mixing barrel on the mixing machine for mixing treatment to obtain a bio-ash sample; wherein the mixing time is greater than 100 hours, and the mixing balls are stainless steel balls.

[0017] Preferably, when using the pulverizer to sample, the step of mixing the first and second bioash substrates in the second container to obtain a bioash sample includes: turning on the pulverizer, mixing the first and second bioash substrates in the pulverizing bucket, and pulverizing the sample 4-10 times, with each pulverization lasting 0.5-2 minutes.

[0018] Preferably, an annular inner gasket is provided between the lid and the body of the mixing container, and the annular inner gasket is installed on the lid of the mixing container; an annular inner gasket is provided between the lid and the body of the pulverizing container, and the annular inner gasket is installed on the lid of the pulverizing container.

[0019] Preferably, the first container is a beaker; wherein, drying the first bioash matrix containing the radionuclide standard solution includes: placing the beaker containing the first bioash matrix in an oven for drying, wherein the first bioash matrix in the beaker contains the radionuclide standard solution, and wherein the drying temperature of the oven is any value between 100℃ and 110℃.

[0020] Preferably, the beaker is a polytetrafluoroethylene (PTFE) beaker.

[0021] The beneficial effects of this disclosure are as follows: Using the proficiency testing bioash sample preparation method for radionuclide analysis provided by this disclosure, the bioash sample preparation process type is selected according to the weight of the bioash sample to be prepared; the bioash sample is prepared using the bioash sample preparation process corresponding to the selected bioash sample preparation process type. The bioash sample preparation process is as follows: A first bioash matrix and a second bioash matrix are prepared for standard doping, with the first bioash matrix placed in a first container; a radionuclide standard solution is dropped onto a predetermined area of ​​the first bioash matrix, ensuring that the radionuclide standard solution does not contact the inner wall of the first container; the first bioash matrix with the dropped radionuclide standard solution is dried until it becomes a loose, fine powder; the dried first bioash matrix is ​​transferred to a second container, and the second bioash matrix is ​​transferred from the first container to the second container; the first and second bioash matrices in the second container are mixed to obtain a bioash sample; wherein, the bioash sample preparation process type includes a mixing mechanism sample preparation and a pulverizing mechanism sample preparation. In the case of a mixing mechanism sample preparation, the second container is a mixing bucket; in the case of a pulverizing mechanism sample preparation, the second container is the pulverizing bucket of a pulverizer.

[0022] This disclosure selects a suitable biological ash sample preparation process based on the weight of the biological ash sample to be prepared, thereby improving the uniformity of mixing and preparation efficiency, and reducing the loss of biological ash sample.

[0023] Furthermore, by dropping the radionuclide standard solution onto a predetermined area of ​​the first bioash matrix without contacting the inner wall of the first container, the loss of the radionuclide standard solution during the preparation of the bioash sample can be reduced, thereby improving the accuracy of the bioash evaluation of the verification sample.

[0024] Furthermore, the first bioash matrix containing the radionuclide standard solution is dried and mixed in a sealed environment to prevent the sample from getting damp, thereby ensuring that the activity concentration value is not affected. Attached Figure Description

[0025] Figure 1 This is a schematic flowchart of a proficiency testing bioash sample preparation method for radionuclide analysis according to an embodiment of the present disclosure.

[0026] Figure 2 This is a schematic flowchart of the method for preparing bio-ash matrix in an embodiment of this disclosure.

[0027] Figure 3 This is a schematic flowchart of a proficiency testing bioash sample preparation method for radionuclide analysis according to another embodiment of this disclosure. Detailed Implementation

[0028] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0029] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0030] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0031] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0032] The following describes the method for preparing bioash samples for proficiency testing of radionuclide analysis.

[0033] Figure 1 This is a schematic flowchart of a proficiency testing bioash sample preparation method for radionuclide analysis according to an embodiment of this disclosure, as shown below. Figure 1 As shown in the embodiment of the present invention, a method for preparing proficiency testing bioash samples for radionuclide analysis is provided, the method comprising the following steps S101 and S102.

[0034] S101. Select the bioash sample preparation process type based on the weight of the bioash sample to be prepared.

[0035] S102, prepare a biological ash sample using a biological ash sample preparation process corresponding to the selected biological ash sample preparation process type. The biological ash sample preparation process includes the following steps S1021 to S1025.

[0036] S1021, a first bioash matrix and a second bioash matrix are prepared for the standard mixing operation, with the first bioash matrix placed in a first container.

[0037] S1022, a radioactive nuclide standard solution is dropped onto a predetermined area of ​​the first biological ash matrix, and the radioactive nuclide standard solution does not come into contact with the inner wall of the first container.

[0038] S1023, the first biological ash matrix containing the radioactive nuclide standard solution is dried until the first biological ash matrix appears as a loose fine powder.

[0039] S1024, the dried first bioash substrate is transferred to the second container, and the second bioash substrate is transferred from the first container to the second container.

[0040] S1025, the first and second bioash substrates in the second container are mixed to obtain a bioash sample.

[0041] Among them, the biological ash sample preparation process types include mixing mechanism sample preparation and pulverizing mechanism sample preparation. In the case of mixing mechanism sample preparation, the second container is a mixing bucket; in the case of pulverizing mechanism sample preparation, the second container is the pulverizing bucket of the pulverizer.

[0042] This disclosure selects a suitable bioash sample preparation process based on the weight of the bioash sample to be prepared, thereby improving the uniformity of mixing and preparation efficiency, and reducing bioash sample loss. A radionuclide standard solution is dropped onto a predetermined area of ​​the first bioash matrix, ensuring that the radionuclide standard solution does not contact the inner wall of the first container. This reduces the loss of the radionuclide standard solution during bioash sample preparation, thereby improving the accuracy of bioash evaluation of the verification sample. The first bioash matrix containing the radionuclide standard solution is dried and mixed in a sealed environment to prevent the sample from becoming damp, thus ensuring that the activity concentration value is not affected.

[0043] The method provided in this disclosure enables more uniform mixing of radionuclides with the bioash matrix, improving the homogeneity of proficiency testing samples. Furthermore, the bioash samples prepared using the method provided in this disclosure can effectively assess the ability to determine radionuclides in bioash, thereby enhancing overall monitoring capabilities and ensuring environmental protection and public safety.

[0044] The evaluation accuracy of bioash samples used for proficiency testing is related to the quality of the bioash matrix. Bioash samples prepared with high-quality bioash matrix have high evaluation accuracy. To improve the evaluation accuracy of bioash samples, this disclosure provides a method for preparing a bioash matrix. The following exemplary embodiments illustrate how to prepare a bioash matrix.

[0045] In an exemplary embodiment, such as Figure 2 As shown, before the first and second bioash substrates for the standardization operation are prepared and the first bioash substrate is placed in the first container, the method may further include S201 to S208.

[0046] S201, Prepare biological samples.

[0047] In this embodiment of the disclosure, the biological sample is a biological sample that meets the analytical requirements. A biological sample that meets the analytical requirements refers to a sample that can be used for analysis after pretreatment of plant or animal samples. For example, for pasture samples, dust, dead leaves, and other debris should be removed; for poultry and livestock, edible parts should be taken, washed, and dried to remove surface moisture.

[0048] S202, the biological sample undergoes its first drying process.

[0049] In this embodiment of the disclosure, the biological sample is placed in an oven for a first drying treatment at a temperature of 108℃-112℃. For example, a biological sample that meets the analytical requirements is placed in an oven and dried at 110℃±1℃. As another example, a biological sample that meets the analytical requirements is placed in an oven and dried at 110℃.

[0050] It should be noted that the machine can be turned frequently during the drying process to speed up the drying process.

[0051] S203 involves crushing the biological sample after the first drying process and then carbonizing it until the biological sample appears as a clump of coke.

[0052] In this embodiment, the biological sample after the first drying is crushed to make it as fine as possible to accelerate the subsequent carbonization process. During the carbonization process, the carbonization temperature is controlled below 450°C, that is, the carbonization temperature is less than or equal to 450°C. Once the biological sample presents a clump-like charcoal structure, subsequent pulverization is performed.

[0053] S204 involves pulverizing the carbonized biological sample and then heating it until the sample is completely carbonized, resulting in a carbonized sample.

[0054] In this embodiment, the apparatus for pulverizing the carbonized biological sample is not limited; any pulverizing apparatus that meets the requirements is acceptable. For example, pulverization can be performed using a pulverizer, a vibratory mill, or a roller mill.

[0055] In this embodiment of the disclosure, heat treatment can further carbonize the biological sample, thereby increasing the carbonization rate. This embodiment of the disclosure does not limit how to determine whether the biological sample is completely carbonized. For example, when no black smoke is emitted during heating, it can be considered completely carbonized. It should be noted that complete carbonization is beneficial to improving the quality of the prepared biological ash matrix.

[0056] S205, the carbonized sample is ashed until it appears as a loose granular substance in white or grayish-white form, thus obtaining the ashed sample.

[0057] In this embodiment of the disclosure, a carbonized sample can be transferred into a muffle furnace for ashing. The ashing temperature does not exceed 450°C, that is, the ashing treatment temperature is less than or equal to 450°C, until the sample presents a white or off-white loose granular form. Exemplarily, the ashing treatment temperature is any value among 300°C, 350°C, 400°C, 410°C, 420°C, 430°C, 440°C, and 445°C. For example, the ashing treatment temperature is 450°C.

[0058] In this embodiment of the disclosure, when the loose density of the sample is 0.3 g / cm³ 3 -0.8g / cm 3 When the ashing is in between, it is considered that the sample appears as a loose granular substance, either white or grayish-white.

[0059] S206, the ashed sample is dried a second time to constant weight.

[0060] In this embodiment, the drying time is not limited, as long as the carbonized sample is dried to a constant weight. Constant weight means that the weight of the carbonized sample does not change with increasing drying time. For example, the drying time can be any time between 24 and 30 hours, such as 25 hours.

[0061] For example, the ashed sample is placed in an oven and dried at 105°C for at least 24 hours until constant weight is achieved. The drying temperature of 105°C ensures that the quality of the ashed sample is not affected during the drying process.

[0062] S207, grinding the ashed sample after the second drying.

[0063] For example, the ashed sample after the second drying is placed in a ball mill for grinding, and the ball mill contains stone balls. There are no restrictions on the materials of the ball mill's inner wall and the stone balls, as long as they are materials with a hardness greater than 50 HRC (Rockwell hardness C scale). For example, the inner wall of the ball mill and the stone balls can be made of one or more of diamond, ceramic, and some high-alloy steels. Another example is that the inner wall of the ball mill is made of diamond, and the stone balls are made of ceramic. Placing stone balls inside the ball mill helps to improve grinding efficiency, thereby increasing the preparation speed of the bioash sample.

[0064] S208, the ground and ashed sample is screened to obtain a bioash matrix. Both the first and second bioash matrices are bioash matrices.

[0065] In this embodiment of the disclosure, the ground bioash is screened through an 80-mesh sieve to obtain a bioash matrix with a particle size of 80 mesh.

[0066] In this embodiment of the disclosure, the ground bioash is screened through a 100-mesh sieve to obtain a bioash matrix, the particle size of which is equal to 100 mesh.

[0067] It should be noted that the prepared bioash matrix should be sealed in a glass bottle and used when adding standards. Furthermore, bioash matrix is ​​more hygroscopic and looser (fluffier) ​​than other materials (such as soil), resulting in a smaller amount of bioash sample that can be prepared from the same volume. Because bioash matrix is ​​looser, it is extremely difficult to sieve when the particle size is small; therefore, the particle size will be larger than that of soil. For example, the particle size of bioash matrix is ​​between 80 and 100 mesh.

[0068] To ensure the reliability of the bioash sample values ​​in proficiency testing, humidity conditions need to be controlled for the bioash matrix to prevent changes in quality due to moisture, which could affect the activity concentration value. Therefore, drying treatment is carried out during the preparation of bioash.

[0069] In this embodiment of the disclosure, before the standard doping operation, a bioash matrix is ​​prepared and dried during the preparation process to ensure the dryness of the bioash matrix. The particle size of the bioash matrix is ​​greater than or equal to 100 mesh, which is beneficial to obtaining a uniformly mixed bioash sample.

[0070] The bioash matrix prepared by the method disclosed herein meets the HJ 61-2021 standard (Technical Specification for Radiation Environmental Monitoring), which is beneficial to improving the evaluation accuracy of the prepared bioash samples. Furthermore, the bioash samples have high uniformity, which can effectively evaluate the ability to determine radionuclides in bioash, thereby improving the overall monitoring level and ensuring environmental protection and public safety.

[0071] The preparation of the bioash matrix has been explained above. The following section explains how to select the type of bioash sample preparation process.

[0072] In an exemplary embodiment, selecting the bioash sample preparation process type based on the weight of the bioash sample to be prepared may include: determining the bioash sample preparation process type as a mixing process when the weight of the bioash sample to be prepared is greater than a weight threshold; and determining the bioash sample preparation process type as a pulverizing process when the weight of the bioash sample to be prepared is less than or equal to the weight threshold.

[0073] In this embodiment of the disclosure, the weight threshold can be set according to the actual application scenario and specific application experience. For example, the weight threshold is 600g. Another example is a weight threshold of 200g.

[0074] When the bioash sample to be prepared is large in weight, a mixing mechanism is used. The mixing time is longer, which allows the radionuclides to be fully mixed with the bioash matrix, resulting in a more uniform mixture. This further improves the uniformity of the bioash sample for proficiency testing, thereby effectively evaluating the ability to determine radionuclides in bioash, improving the overall monitoring level, and ensuring environmental protection and public safety.

[0075] When the weight of the bioash sample to be prepared is small, a pulverizer is used for sample preparation. The mixing time is short, which can achieve rapid preparation and meet the homogeneity requirements.

[0076] In this embodiment of the disclosure, the mixing mechanism or the pulverizing mechanism is selected according to the weight of the bioash sample to be prepared, thereby meeting the sample preparation requirements and facilitating the automated preparation of bioash samples.

[0077] The above explains how to select the type of biological ash sample preparation process; the following explains the predetermined area.

[0078] In one embodiment, dropping a radionuclide standard solution onto a predetermined area of ​​a first bioash matrix, without the radionuclide standard solution contacting the inner wall of the first container, may include at least one of the following: dropping the radionuclide standard solution onto the central area of ​​the surface of the first bioash matrix contained in the first container, without the radionuclide standard solution contacting the inner wall of the first container; or, dropping the radionuclide standard solution onto the geometric center area of ​​the first bioash matrix contained in the first container, without the radionuclide standard solution contacting the inner wall of the first container; or, dropping the radionuclide standard solution onto the geometric center area of ​​the first container, without the radionuclide standard solution contacting the inner wall of the first container.

[0079] In this embodiment, the radionuclide standard solution is a radioactive material solution of a specific concentration, containing radionuclides with known and stable concentrations and radioactive properties. It should be noted that the amount of radionuclide standard solution added is determined based on the activity concentration level of the radionuclide in the prepared verification sample. For example, the radionuclide standard solution can be a certified Sr-90 (Sr-90) standard solution, with 10⁻¹⁰¹ mL added. The certified Sr-90 standard solution refers to a certified solution containing a known concentration of Sr-90 (e.g., 22.13 Bq / mL, 2009.5.15, Sr-90).

[0080] It should be noted that the preparation method disclosed herein is applicable to non-volatile radionuclides (such as strontium-90, cobalt-60, radium-226, etc.).

[0081] In this embodiment, the predetermined region can be a regular area, an irregular area, or even a point. The key is to ensure that the radionuclide standard solution dropped into the first bioash matrix does not come into contact with the first container. For example, the first container is a beaker, and the predetermined region is a point. Dropping the absorbed radionuclide standard solution into the center of the beaker (the point) ensures that the radionuclide standard solution does not diffuse to the beaker wall, guaranteeing that the added radionuclide standard solution is "entirely" within the first bioash matrix. This reduces the loss of the radionuclide standard solution and improves the evaluation accuracy of the prepared bioash sample.

[0082] In this embodiment of the disclosure, the middle part of the beaker can refer to the center of the bioash matrix inside the beaker, or it can refer to the geometric center of the shape of the bioash matrix inside the beaker, which can effectively prevent the radionuclide standard solution dripped into the beaker from diffusing to the beaker wall.

[0083] The beaker can be made of polytetrafluoroethylene (PTFE), which has extremely high chemical resistance, is not easily corroded by acids, alkalis and organic solvents, is heat resistant, and has excellent non-adhesive properties, making it easy to clean. This can reduce the adhesion of the bioash matrix to the beaker wall, which is beneficial to further improve the evaluation accuracy of the prepared bioash samples.

[0084] In another embodiment, the radionuclide standard solution is dropped onto a predetermined area of ​​the first bioash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, comprising: using a pipette to draw up the radionuclide standard solution and dropping the radionuclide standard solution onto a predetermined area of ​​the first bioash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

[0085] In another embodiment, the radionuclide standard solution is dropped onto a predetermined area of ​​the first bioash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, comprising: using a pipette to draw up the radionuclide standard solution and dropping the radionuclide standard solution onto the predetermined area of ​​the first bioash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

[0086] It should be noted that pipettes are used for small-volume, high-precision liquid transfer. Because the density of the bioash matrix is ​​low, less radionuclide standard solution is required. Therefore, when preparing bioash samples, using a pipette to draw the radionuclide standard solution can further improve the preparation accuracy.

[0087] The present disclosure does not limit the measurement of the pipette. For example, a 1 ml (milliliters) pipette is used to draw up a radionuclide standard solution.

[0088] In this embodiment of the disclosure, using a pipette with high measurement accuracy to aspirate the radionuclide standard solution is beneficial to improving the evaluation accuracy of the prepared bioash sample.

[0089] The predetermined area has been explained above; the following section explains the mixed sample preparation method and the pulverized sample preparation method.

[0090] The following biological ash samples were prepared using a mixed sampling method.

[0091] In one embodiment, the first container is a beaker, and the second container is a mixing container. The preparation of the first and second bioash substrates for the standard mixing operation may include the following steps A1 and A2.

[0092] Step A1: Weigh out the first weight of the bioash substrate and place it into the second container.

[0093] In this embodiment, the first weight value is determined according to the preparation requirements. For example, to improve the evaluation accuracy of the prepared bioash sample, the first weight value is set to be greater than the theoretically required weight value, thus compensating for losses incurred during the preparation of the bioash matrix. For instance, when the required first weight value is 3200g, the bioash matrix weighed in this embodiment is 3200.01g, where 0.01g is an additional increment. This embodiment does not limit the value of the additional increment and determines it based on actual weight losses. For example, the first weight value is 3200.01g.

[0094] For example, the first weight value ranges from 2500 grams to 5000 grams.

[0095] In this embodiment, the particle size of the bioash matrix is ​​100 mesh. Ensuring a sufficiently small particle size of the bioash matrix, while meeting sieving requirements, improves the thoroughness of mixing, thereby enhancing the reliability and accuracy of the verification samples. It should be noted that the particle size may vary depending on the radionuclide being analyzed.

[0096] Step A2: Weigh a second weight of the first bioash substrate from the second container and transfer it to the first container, and weigh a third weight of the second bioash substrate for later use.

[0097] The second and third weight values ​​are determined according to the preparation requirements. For example, the second weight value is any value between 50g and 200g, such as 100g. The third weight value is any value between 100g and 1000g, such as 100g, 150g, 300g, 400g, 500g, 600g, 700g, 800g, and 900g.

[0098] The second bioash matrix is ​​used to clean the containers (such as beakers) that hold the first bioash matrix, thereby solving the problem of low evaluation accuracy caused by the contact of radioactive nuclide standard solutions with the container walls during the transfer process.

[0099] For example, the dried first bioash matrix is ​​transferred to a mixing tank, and the second bioash matrix is ​​transferred to the mixing tank via a beaker.

[0100] In this embodiment, the second bioash matrix is ​​transferred from the beaker to the mixing container, which is equivalent to cleaning the beaker with the second bioash matrix. The number of cleaning cycles is not limited; for example, it can be any number of cycles between 5 and 10. For instance, the beaker can be cleaned 7 times. By using a spare bioash matrix (the second bioash matrix) to clean the beaker multiple times, this embodiment can further reduce the loss of radionuclides and thus further improve the accuracy of the evaluation.

[0101] It should be noted that when cleaning the beaker, special attention should be paid to cleaning the bottom wall and the joint between the bottom wall and the inner wall.

[0102] In another embodiment, when using a mixing machine to sample, mixing the first and second bioash matrices in the second container to obtain a bioash sample may include: adding multiple mixing balls to a mixing bucket, the multiple mixing balls including at least a first mixing ball and a second mixing ball, the first mixing ball and the second mixing ball having different masses; fixing the mixing bucket on a mixing machine for mixing to obtain a bioash sample; wherein the mixing time is greater than 100 hours, and the mixing balls are stainless steel balls.

[0103] In this embodiment of the disclosure, the number of mixing balls added is not limited. The more bioash substrate in the mixing container, the more mixing balls are added. The multiple mixing balls have different masses, meaning they can be of various sizes; this embodiment is not limited to only two types: first mixing balls and second mixing balls.

[0104] In this embodiment, the mixing ball can be a stainless steel ball. Stainless steel balls facilitate rapid and uniform mixing of the bioash matrix and radionuclides. It should be noted that the mixing ball can also be other spheres that can accelerate the mixing process. Furthermore, the surface material of the mixing ball can be an anti-sticking material, which can further improve the evaluation accuracy of the prepared bioash sample.

[0105] In this embodiment of the present disclosure, an appropriate amount of stainless steel balls of different sizes are added to the mixing tank. The movement of the balls in the mixing tank can promote sample homogenization.

[0106] In this embodiment of the disclosure, the mixing time can be greater than or equal to 100 hours. For example, the mixing time can be any value between 95 and 105 hours. For instance, the mixing time is 105 hours. It should be noted that a mixing time greater than 100 hours results in higher uniformity of the mixed samples.

[0107] In another embodiment, an annular inner gasket is provided between the lid and the body of the mixing tank, and the annular inner gasket is installed on the lid of the mixing tank.

[0108] In this embodiment, the mixing container is a well-sealed mixing container. The annular inner gasket on the mixing container can further ensure the sealing of the mixing container, thereby ensuring good drying of the mixture of biological ash matrix and radionuclide during a long mixing time, and further ensuring that the activity concentration value is not affected.

[0109] For example, the annular inner pad can be an elastic annular inner pad, which can further improve the sealing of the mixing container.

[0110] In another embodiment, the first container is a beaker; wherein drying the first bioash matrix containing the radionuclide standard solution may include: placing the beaker containing the first bioash matrix in an oven for drying, wherein the first bioash matrix in the beaker contains the radionuclide standard solution, wherein the drying temperature of the oven is any value between 100°C and 110°C.

[0111] To ensure the reliability of bioash sample values ​​in proficiency testing, this embodiment of the invention requires controlled humidity conditions for the bioash samples to prevent changes in quality due to moisture, which could affect the activity concentration values. Loose, fine powder indicates a fully dried, non-dampened (non-caking) state. This facilitates subsequent mixing and ensures accurate measurement.

[0112] In this embodiment, humidity conditions need to be controlled for the bioash sample to prevent moisture absorption and subsequent changes in quality, which could affect the activity concentration value. Adding the radionuclide standard solution dropwise into the first bioash matrix for drying reduces moisture content and ensures the activity concentration value remains unaffected. It should be noted that the first bioash matrix is ​​a loose, fine powder, indicating that it is fully dried and not damp (clumped), which facilitates subsequent mixing and ensures accurate measurement.

[0113] In this embodiment of the disclosure, the drying temperature of the oven is any value between 100°C and 110°C. For example, the drying temperature of the oven is 105°C. In this embodiment of the disclosure, using a temperature of 105°C to dry the first bioash matrix containing the radionuclide standard solution generally does not affect the activity of the radionuclide, thus ensuring that it does not adversely affect the measurement results.

[0114] In this embodiment of the disclosure, the drying completion is determined by the state of the first bioash substrate. For example, drying until the bioash substrate is in a loose, fine powder state indicates that it is sufficiently dried, which is beneficial for subsequent mixing. In addition, the drying time (i.e., the time until the bioash substrate is in a loose, fine powder state) can also be determined based on the magnitude of the second weight value, that is, the time when the drying operation ends.

[0115] The method provided in this disclosure enables more uniform mixing of radionuclides and bioash matrix, improving the homogeneity of proficiency testing samples. This disclosure also reduces the loss of radionuclide standard solutions during bioash sample preparation, thereby improving the accuracy of bioash evaluation in the testing samples. Furthermore, this disclosure uses an oven for drying and performs mixing in a sealed environment to prevent the bioash from becoming damp, thus ensuring that the activity concentration values ​​remain unaffected.

[0116] The following bioash samples were prepared using a pulverizer.

[0117] In one embodiment, preparing a first bioash matrix and a second bioash matrix for standardization includes: weighing a first weight value of bioash matrix and placing it into a second container; weighing a second weight value of the first bioash matrix from the second container and transferring it to the first container; and weighing a third weight value of the second bioash matrix for later use.

[0118] In this embodiment, the first weight value is determined according to the preparation requirements. For example, to improve the evaluation accuracy of the prepared bioash sample, the first weight value is set to be greater than the theoretically required weight value, thus compensating for losses incurred during the preparation of the bioash matrix. For instance, when the required first weight value is 500g, the bioash matrix weighed in this embodiment is 500.01g, where 0.01g is an additional increment. The value of this additional increment is not limited in this embodiment and is determined based on the specific weight loss observed in practical experience.

[0119] For example, the first weight value ranges from 300 grams to 1500 grams. For instance, 500 grams of bioash substrate is accurately weighed using an electronic balance and placed into a pulverizing bin.

[0120] In this embodiment, the particle size of the bioash matrix is ​​100 mesh. Ensuring a sufficiently small particle size of the bioash matrix, while meeting sieving requirements, improves the thoroughness of mixing, thereby enhancing the reliability and accuracy of the verification samples. It should be noted that the particle size may vary depending on the radionuclide being analyzed.

[0121] The second and third weight values ​​are determined according to the preparation requirements. For example, the second weight value is any value between 20g and 80g, such as 50g. The third weight value is any value between 50g and 600g, such as 100g, 150g, 200g, 300g, 350g, 400g, 450g, 500g, and 550g.

[0122] The second bioash matrix is ​​used to clean the containers holding the first bioash matrix, thereby solving the problem of low evaluation accuracy caused by the contact of radioactive nuclide standard solutions with the container walls during the transfer process.

[0123] For example, the dried first bioash substrate is transferred to a pulverizing hopper, and the second bioash substrate is transferred to the pulverizing hopper via a beaker.

[0124] In this embodiment, the second bioash matrix is ​​transferred from the beaker to the pulverizing tank, which is equivalent to cleaning the beaker with the second bioash matrix. The number of cleaning cycles is not limited; for example, it can be any number of cycles between 5 and 10. For instance, the beaker can be cleaned 7 times. By using a spare bioash matrix (the second bioash matrix) to clean the beaker multiple times, this embodiment can further reduce the loss of radionuclides and thus further improve the accuracy of the evaluation.

[0125] It should be noted that when cleaning the beaker, special attention should be paid to cleaning the bottom wall and the joint between the bottom wall and the inner wall.

[0126] In another embodiment, when using a pulverizer to sample, the first and second bioash substrates in the second container are mixed to obtain a bioash sample, including: turning on the pulverizer, mixing the first and second bioash substrates in the pulverizer bucket, and pulverizing the sample 4-10 times, with each pulverization lasting 0.5-2 minutes.

[0127] For example, the pulverizer can be set to pulverize 5 times, with each pulverization lasting 1 minute. It should be noted that the number of pulverization cycles and the pulverization time can be set according to actual needs.

[0128] This disclosure utilizes a pulverizer for pulverization and mixing, employing multiple short-time pulverization and mixing processes. This facilitates rapid sample preparation of biological ash samples while meeting the required sample quality.

[0129] In another embodiment, an annular inner gasket is provided between the lid and the body of the grinding barrel, and the annular inner gasket is installed on the lid of the grinding barrel.

[0130] The pulverizer is a well-sealed pulverizer. The annular inner gasket on the pulverizer further ensures the airtightness of the pulverizer, thereby ensuring good drying of the mixture of bioash matrix and radionuclide during a long mixing time, and further ensuring that the activity concentration value is not affected.

[0131] In another embodiment, the first container is a beaker; wherein drying the first bioash matrix containing the radionuclide standard solution includes: placing the beaker containing the first bioash matrix in an oven for drying, wherein the first bioash matrix in the beaker contains the radionuclide standard solution, wherein the drying temperature of the oven is any value between 100°C and 110°C.

[0132] The reason for performing drying in this embodiment has been explained in the above embodiments and will not be repeated here.

[0133] This embodiment controls humidity conditions (e.g., drying) to prevent moisture absorption from altering the quality and affecting the activity concentration value. Loose, fine powder indicates a fully dried and moisture-free state. This facilitates subsequent mixing and ensures accurate measurement.

[0134] The method provided in this disclosure enables more uniform mixing of radionuclides and bioash matrix, improving the homogeneity of proficiency testing samples. This disclosure also reduces the loss of radionuclide standard solutions during bioash sample preparation, thereby improving the accuracy of bioash evaluation in the testing samples. Furthermore, this disclosure uses an oven for drying and performs mixing in a sealed environment to prevent the bioash from becoming damp, thus ensuring that the activity concentration values ​​remain unaffected.

[0135] Example 1

[0136] like Figure 2 As shown in the embodiment of the present invention, a method for preparing bioash samples for proficiency testing of radionuclide analysis is provided. The method may include the following steps S101 to S103.

[0137] S101. Select the bioash sample preparation process type based on the weight of the bioash sample to be prepared.

[0138] S102, prepare a biological ash sample using a biological ash sample preparation process corresponding to the selected biological ash sample preparation process type. The biological ash sample preparation process includes the following steps S1021 to S1025.

[0139] S1021, a first bioash matrix and a second bioash matrix are prepared for the standard mixing operation, with the first bioash matrix placed in a first container.

[0140] S1022, a radioactive nuclide standard solution is dropped onto a predetermined area of ​​the first biological ash matrix, and the radioactive nuclide standard solution does not come into contact with the inner wall of the first container.

[0141] S1023, the first biological ash matrix containing the radioactive nuclide standard solution is dried until the first biological ash matrix appears as a loose fine powder.

[0142] S1024, the dried first bioash substrate is transferred to the second container, and the second bioash substrate is transferred from the first container to the second container.

[0143] S1025, the first and second bioash substrates in the second container are mixed to obtain a bioash sample.

[0144] Among them, the biological ash sample preparation process types include mixing mechanism sample preparation and pulverizing mechanism sample preparation. In the case of mixing mechanism sample preparation, the second container is a mixing bucket; in the case of pulverizing mechanism sample preparation, the second container is the pulverizing bucket of the pulverizer.

[0145] S101 to S102 have been described in the above embodiments and will not be repeated here.

[0146] S103, the uniformity of the bioash sample is tested. If the test is passed, the bioash sample is packaged into plastic bottles to facilitate the transportation and storage of the bioash sample.

[0147] For example, the bioash sample is aliquoted into 30ml plastic bottles, each containing 2.5g, and then sealed.

[0148] In this embodiment of the disclosure, the bioash sample is dispensed into plastic bottles and sealed for storage to prevent the bioash sample from getting damp, thereby improving the accuracy of the bioash evaluation of the verification sample.

[0149] It should be noted that the bioash samples prepared by the method disclosed herein have good uniformity and can meet practical needs.

[0150] The method provided in this disclosure enables more uniform mixing of radionuclides and bioash matrix, improving the homogeneity of proficiency testing samples. This disclosure also reduces the loss of radionuclide standard solutions during bioash sample preparation, thereby improving the accuracy of bioash evaluation in the testing samples. Furthermore, this disclosure includes drying and mixing in a sealed environment to prevent sample moisture absorption, thus ensuring that the activity concentration values ​​remain unaffected.

[0151] The method provided in this disclosure can effectively assess the ability to determine radionuclides in bioash samples, thereby improving the overall monitoring level and ensuring environmental protection and public safety.

[0152] Example 2

[0153] Accurately weigh 3200 g of biological ash matrix using an electronic balance and place it in a pulverizer. Take approximately 100 g of the biological ash matrix (the first biological ash matrix) and transfer it to a polytetrafluoroethylene beaker. Additionally, take out approximately 200 g of the biological ash matrix (the second biological ash matrix) for later use (it can be placed in other containers, such as a beaker). Use a pipette to transfer a certified radioactive nuclide standard solution (such as a certified Sr-90 standard solution), and carefully drop it into the middle of the polytetrafluoroethylene beaker (ensure that the liquid does not spread to the beaker wall). Place the polytetrafluoroethylene beaker in an oven at 105 °C to dry. At this time, the biological ash matrix呈现松散的细粉状 (appears as a loose fine powder). Transfer all the biological ash matrix in the beaker to a mixing bucket, and use the spare biological ash matrix to wash the beaker and the spoon used for transfer 7 times, with particular attention to washing the bottom of the beaker and the junction of the bottom and the beaker wall. Then transfer all the spare biological ash matrix to the mixing bucket and start mixing.

[0154] The mixing bucket has good airtightness and is lined with a ring-shaped inner pad, which can ensure good dryness of the sample during a long mixing time. Add an appropriate amount of stainless steel balls of different sizes to the mixing bucket. The movement of the stainless steel balls in the mixing bucket can promote the uniformity of the sample. Fix the mixing bucket on a mixer and mix for more than 100 hours. After the mixing of the spiked biological ash sample is completed, conduct a homogeneity test. After passing the test,分装至塑料瓶中 (pack it into plastic bottles) for sample sending and storage. Among them, the biological ash sample is packed into 50 mL plastic bottles, with about 30 g in each bottle, and sealed.

[0155] After the preparation and packaging of the Sr-90 proficiency testing samples in biological ash are completed as described above, conduct a homogeneity test on the samples in the final packaging unit. Randomly select 10 samples, take samples separately for each sample, and test 2 times under repeated conditions. The homogeneity test data is shown in Table 1, where the biological ash sample in each plastic bottle is one sample.

[0156] Table 1 Homogeneity test results of proficiency testing biological ash samples (unit: Bq / kg (Becquerel per kilogram))

[0157]

[0158]

[0159] As can be seen from Table 1, using the one-way analysis of variance method, the statistic F = 1.09 is obtained, and F < F0.05(9,10) = 3.02, indicating that there is no significant difference within and between the samples, and the samples are homogeneous. Using the Ss ≤ 0.3σ criterion, Ss = 0.44, and Ss ≤ 0.3σ = 1.64. The biological ash samples used are considered to be homogeneous in this proficiency testing. Among them, Ss is the standard deviation of inhomogeneity between samples.

[0160] It should be noted that for information on how to calculate relevant data between and within samples, please refer to CNAS-GL003:2018 "Guidelines for evaluating the homogeneity and stability of proficiency testing samples".

[0161] The method provided in this disclosure enables more uniform mixing of radionuclides and bioash matrix, improving the homogeneity of proficiency testing samples. This disclosure also reduces the loss of radionuclide standard solutions during bioash sample preparation, thereby improving the accuracy of bioash evaluation in the testing samples. Furthermore, this disclosure includes drying and mixing in a sealed environment to prevent sample moisture absorption, thus ensuring that the activity concentration values ​​remain unaffected.

[0162] The method provided in this disclosure can effectively assess the ability to determine radionuclides in bioash samples, thereby improving the overall monitoring level and ensuring environmental protection and public safety.

[0163] Example 3

[0164] Accurately weigh 500.00g of bioash matrix into the grinding hopper using an electronic balance. Transfer 50g of the bioash matrix (first bioash matrix) to a polytetrafluoroethylene (PTFE) beaker, and set aside approximately 100g of bioash matrix (second bioash matrix) for later use. Using a 1ml full-capacity pipette, carefully add a certified radionuclide standard solution to the center of the PTFE beaker (ensuring the liquid does not spread to the beaker wall). Place the PTFE beaker in an oven at 105℃ to dry. At this point, the first bioash matrix will be a loose, fine powder. Transfer all of the first bioash matrix to the grinding hopper, and wash the beaker and the spoon used for transfer seven times with the second bioash matrix, paying particular attention to cleaning the bottom of the beaker and the area where the bottom meets the beaker wall. Then transfer all of the second bioash matrix to the grinding hopper and grind and mix. Grind five times, one minute each time. The grinding hopper has good sealing properties and is lined with an annular inner gasket to ensure the sample remains sealed and dry well during multiple grinding processes. After grinding and mixing, aliquot the bioash sample into 30mL plastic bottles, 2.5g per bottle, and seal. Alternatively, aliquot the bioash sample into 30mL plastic bottles, approximately 5g per bottle, and seal.

[0165] After the preparation and packaging of the bioash samples are completed, the homogeneity of the samples in the final packaging unit is tested. The homogeneity test is as follows.

[0166] Ten samples were randomly selected, and each sample was individually tested twice under repeated conditions using a trace uranium analyzer. The homogeneity test results are shown in Table 2 below.

[0167] Table 2. Results of homogeneity test of bioash samples (unit: μg / g)

[0168]

[0169] As can be seen from Table 2, by using the one-way analysis of variance method, the statistic F = 1.37 is obtained, and F < F0.05(9,10) = 3.02, indicating that there is no significant difference within and between the bio-ash samples, and the samples are homogeneous. Using the Ss ≤ 0.3σ criterion, Ss = 0.56, and Ss ≤ 0.3σ = 3.0. The bio-ash samples used are considered to be homogeneous in this proficiency testing.

[0170] It should be noted that regarding how to calculate the relevant data between and within the samples, reference can be made to CNAS-GL003:2018 "Guidelines for the Evaluation of the Homogeneity and Stability of Proficiency Testing Samples".

[0171] The method of the present disclosure using a crusher for sample preparation can achieve rapid preparation of bio-ash samples.

[0172] The method provided by the present disclosure can make the mixing of radionuclides and the bio-ash matrix more uniform, improving the homogeneity of the proficiency testing samples. The present disclosure can also reduce the loss of radionuclide standard solutions during the preparation of bio-ash samples, thereby improving the accuracy of the verification samples for the evaluation of bio-ash. In addition, the present disclosure conducts drying and performs mixing treatment in a sealed environment to avoid sample moisture absorption, thereby ensuring that the activity concentration value is not affected.

[0173] The bio-ash samples prepared by the method provided by the present disclosure can effectively evaluate the measurement ability of radionuclides in bio-ash, thereby improving the overall monitoring level and ensuring environmental protection and public safety. [[ID=X]] [[ID=Y]]

[0174] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure aims to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include well-known knowledge or conventional technical means in the technical field not disclosed by the present disclosure. The specification and examples are only considered exemplary, and the true scope of the present disclosure is pointed out by the appended claims.

Claims

1. A method for preparing a biological ash sample for radionuclide analysis, comprising the following steps: S101. Selecting a biological ash sample preparation process type according to the weight of a biological ash sample to be prepared; S102. Preparing the biological ash sample using a biological ash sample preparation process corresponding to the selected biological ash sample preparation process type, wherein the biological ash sample preparation process comprises the following steps: S1021. Preparing a first biological ash substrate and a second biological ash substrate for spiking operation, wherein the first biological ash substrate is contained in a first container; S1022. Dropping a radionuclide standard solution onto a predetermined area of the first biological ash substrate, and the radionuclide standard solution does not contact the inner wall of the first container; S1023. Drying the first biological ash substrate with the radionuclide standard solution until the first biological ash substrate presents a loose fine powder; S1024. Transferring the dried first biological ash substrate to a second container, and transferring the second biological ash substrate to the second container through the first container; S1025. Mixing the first biological ash substrate and the second biological ash substrate in the second container to obtain a biological ash sample; wherein the biological ash sample preparation process type includes a mixing mechanism sample and a pulverizer mechanism sample, and in the case of the mixing mechanism sample, the second container is a mixing barrel; and in the case of the pulverizer mechanism sample, the second container is a pulverizing barrel of a pulverizer. Step S101 comprises the following steps:

2. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, In the case that the weight of the biological ash sample to be prepared is greater than a weight threshold, determining that the biological ash sample preparation process type is the mixing mechanism sample; In the case that the weight of the biological ash sample to be prepared is less than or equal to the weight threshold, determining that the biological ash sample preparation process type is the pulverizer mechanism sample. Before step S1021, the method further comprises the following steps:

3. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, Preparing a biological sample; Performing first drying treatment on the biological sample; Grinding the first dried biological sample and performing carbonization treatment until the biological sample presents a clumped coke; Pulverizing the carbonized biological sample and performing heating treatment until the biological sample is completely carbonized to obtain a carbonized sample; Performing ashing treatment on the carbonized sample until the carbonized sample presents a loose granular white or off-white color to obtain an ashed sample; Performing second drying treatment on the ashed sample until a constant weight is obtained; Performing grinding treatment on the second dried ashed sample; Performing screening treatment on the ground ashed sample to obtain the biological ash substrate, and the first biological ash substrate and the second biological ash substrate are both the biological ash substrate. The first drying treatment is performed in an oven, and the drying temperature is 108-112°C; the carbonization treatment is performed at a temperature less than or equal to 450°C; the ashing treatment is performed in a muffle furnace at a temperature less than or equal to 450°C; the second drying treatment is performed in an oven at a drying temperature of 105°C, and the drying time is greater than or equal to 24 hours; and the screened ashed sample is screened through a 100-mesh sieve.

4. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 3, wherein, ​ 5. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, The step S1022 includes at least one of the following: The radionuclide standard solution is dropped to the central region of the surface of the first bio-ash substrate in the first container, and the radionuclide standard solution does not contact the inner wall of the first container; Or, The radionuclide standard solution is dropped to the geometric center region of the first bio-ash substrate in the first container, and the radionuclide standard solution does not contact the inner wall of the first container; Or, The radionuclide standard solution is dropped to the geometric center region of the first container, and the radionuclide standard solution does not contact the inner wall of the first container.

6. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, The step S1022 includes: The radionuclide standard solution is dropped to the central region of the surface of the first bio-ash substrate in the first container, and the radionuclide standard solution does not contact the inner wall of the first container; 7. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, The first bio-ash substrate and the second bio-ash substrate prepared for the spiking operation include: A first weight value of bio-ash substrate is weighed and placed in the second container; A second weight value of the first bio-ash substrate is weighed from the second container and transferred to the first container, and a third weight value of the second bio-ash substrate is weighed for standby.

8. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, In the case of using the mixing mechanism, the mixing treatment of the first bio-ash substrate and the second bio-ash substrate in the second container to obtain a bio-ash sample includes: A plurality of mixing balls are added to the mixing barrel, the plurality of mixing balls at least including a first mixing ball and a second mixing ball, the mass of the first mixing ball and the second mixing ball being different; The mixing barrel is fixed on the mixing machine for mixing treatment to obtain a bio-ash sample; Wherein, the mixing time is greater than 100 hours, and the mixing ball is a stainless steel ball.

9. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, In the case of using the pulverizer mechanism, the mixing treatment of the first bio-ash substrate and the second bio-ash substrate in the second container to obtain a bio-ash sample includes: The pulverizer is started, and the first bio-ash substrate and the second bio-ash substrate in the pulverizing barrel are mixed, the pulverizing frequency of the pulverizer being 4-10 times, and each pulverizing time being 0.5-2 minutes.

10. The proficiency testing biological ash sample preparation method for radionuclide analysis of claim 1, wherein, A ring-shaped inner gasket is arranged between the barrel cover and the barrel body of the mixing barrel, and the ring-shaped inner gasket is installed on the barrel cover of the mixing barrel; A ring-shaped inner gasket is arranged between the barrel cover and the barrel body of the pulverizing barrel, and the ring-shaped inner gasket is installed on the barrel cover of the pulverizing barrel.

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