Preparation method of proficiency testing biological ash sample for radionuclide analysis

Abstract

The invention relates to a preparation method of a proficiency testing biological ash sample for radionuclide analysis. The method comprises the following steps: selecting a biological ash sample preparation process type according to the weight of a biological ash sample to be prepared; preparing a biological ash sample by adopting 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: preparing a first biological ash matrix and a second biological ash matrix; dropping a radionuclide standard solution into a predetermined area of the first biological ash matrix, wherein the radionuclide standard solution is not in contact with the inner wall of the first container; drying the first biological ash substrate; and transferring the dried first biological ash matrix to a second container, transferring the second biological ash matrix to the second container through the first container, and carrying out mixing treatment to obtain the biological ash sample. According to the method provided by the invention, the radionuclide and the biological ash can be mixed more uniformly, and the uniformity of the proficiency testing sample is improved.

Description

Technical Field

[0001] The invention relates to the technical field of radiation environment monitoring, in particular to a method for preparing biological ash samples for capability verification of radionuclide analysis. Background Art

[0002] Proficiency testing bio-ash samples are a key tool to ensure the accuracy and reliability of laboratory analysis. These samples are not only used for quality control, helping laboratories monitor the consistency and stability of the analytical process, but also verify the effectiveness of analytical methods, including parameters such as detection limit, sensitivity and repeatability. In addition, by using standardized bio-ash samples, laboratories are able to compare results and ensure the comparability of data between different laboratories, which is critical for scientific research and regulatory compliance. In addition, proficiency testing can also help laboratories identify potential problems, thereby promoting technical improvements and improving overall analytical capabilities.

[0003] There is a lack of standard materials for radionuclides in biological ash. In laboratory internal quality control, inter-laboratory comparison and proficiency verification, the analysis of radionuclides in biological ash samples will be prepared by the standard addition method. However, since some radionuclides do not have solid standard materials, the following problems exist when mixing radionuclide standard solutions with biological ash samples:

[0004] The proficiency verification sample (biological ash sample) for evaluating the laboratory's proficiency in radionuclide analysis in biological ash is prepared by the standard addition method. Since it is impossible to ensure that the biological ash matrix and the radionuclide solution are evenly mixed, the uniformity of the proficiency verification sample is low. In the preparation process of the biological ash sample, there is a situation where the radionuclide solution may be lost on the wall of the vessel, thereby affecting the assessment accuracy. In addition, biological ash is easily affected by moisture, which easily affects the activity concentration value of the radionuclide in the biological ash sample. Therefore, the present application provides a method for preparing a proficiency verification biological ash sample for radionuclide analysis.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In view of the defects existing in the prior art, the purpose of the present invention is to provide a method for preparing biological ash samples for proficiency testing of 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 solution adopted by the present invention is: a method for preparing a biological ash sample for capability verification of radionuclide analysis, the method comprising the following steps: selecting a biological ash sample preparation process type according to the weight of the biological ash sample to be prepared; preparing the biological ash sample by using a biological ash sample preparation process corresponding to the selected biological ash sample preparation process type, the biological ash sample preparation process is as follows:

[0008] A first biological ash matrix and a second biological ash matrix are prepared for a doping operation, wherein the first biological ash matrix is ​​contained in a first container; a radioactive nuclide standard solution is dripped onto a predetermined area of ​​the first biological ash matrix, and the radioactive nuclide standard solution does not contact the inner wall of the first container; the first biological ash matrix dripped with the radioactive nuclide standard solution is dried until the first biological ash matrix is ​​in a loose fine powder state; the dried first biological ash matrix is ​​transferred to a second container, and the second biological ash matrix is ​​transferred to the second container through the first container; the first biological ash matrix and the second biological ash matrix in the second container are mixed to obtain a biological ash sample;

[0009] Among them, the bio-ash sample preparation process types include mixer sampling and pulverizer sampling. When the mixer sampling is performed, the second container is a mixer barrel; when the pulverizer sampling is performed, the second container is a pulverizing barrel of the pulverizer.

[0010] Preferably, the bio-ash sample preparation process type is selected according to the weight of the bio-ash sample to be prepared, including: when the weight of the bio-ash sample to be prepared is greater than a weight threshold, determining the bio-ash sample preparation process type to be the mixer sampling; when the weight of the bio-ash sample to be prepared is less than or equal to the weight threshold, determining the bio-ash sample preparation process type to be the pulverizer sampling.

[0011] Preferably, before the first biological ash matrix and the second biological ash matrix prepared for the doping operation are placed in the first container, the method also includes: preparing a biological sample; drying the biological sample for a first time; crushing the biological sample after the first drying, and carbonizing it until the biological sample is in a coke-like state; pulverizing the carbonized biological sample, and heating it until the biological sample is completely carbonized to obtain a carbonized sample; ashing the carbonized sample until the carbonized sample is in a white or off-white loose granular state to obtain an ashed sample; drying the ashed sample for a second time to constant weight; grinding the ashed sample after the second drying; screening the ground ashed sample to obtain the biological ash matrix, wherein the first biological ash matrix and the second biological ash matrix are both the biological ash matrix.

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

[0013] Preferably, dropping the radionuclide standard solution to a predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, includes at least one of the following: dropping the radionuclide standard solution to the central area of ​​the surface of the first biological 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 to the geometric center area of ​​the first biological 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 to the geometric center area of ​​the first container, and the radionuclide standard solution does not contact the inner wall of the first container.

[0014] Preferably, the step of dripping the radionuclide standard solution to a predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, comprises: using a pipette to absorb the radionuclide standard solution, and dripping the radionuclide standard solution to a predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

[0015] Preferably, the first biological ash matrix and the second biological ash matrix prepared for the doping operation include: weighing a first weight value of the biological ash matrix and placing it in the second container; weighing a second weight value of the first biological ash matrix from the second container and transferring it to the first container, and weighing a third weight value of the second biological ash matrix for standby use.

[0016] Preferably, when the sample mixer is used for sampling, the first biological ash matrix and the second biological ash matrix in the second container are mixed to obtain a biological ash sample, including: adding a plurality of mixing balls into the mixing barrel, the plurality of 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 barrel on the mixing machine for mixing to obtain a biological ash sample; wherein the mixing time is greater than 100 hours, and the mixing balls are stainless steel balls.

[0017] Preferably, when the pulverizer is used for sampling, the first bio-ash matrix and the second bio-ash matrix in the second container are mixed to obtain a bio-ash sample, including: turning on the pulverizer, mixing the first bio-ash matrix and the second bio-ash matrix in the pulverizing barrel, the pulverizer is pulverized 4-10 times, and each pulverization takes 0.5-2 minutes.

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

[0019] Preferably, the first container is a beaker; wherein, drying the first biological ash matrix dripped with the radionuclide standard solution comprises: placing the beaker containing the first biological ash matrix in an oven for drying, wherein the first biological ash matrix in the beaker is dripped with the radionuclide standard solution, wherein the drying temperature of the oven is any value between 100°C and 110°C.

[0020] Preferably, the beaker is a polytetrafluoroethylene beaker.

[0021] The beneficial effects of the present disclosure are: using a bio-ash sample preparation method for capability verification of radionuclide analysis provided by the present disclosure, selecting a bio-ash sample preparation process type according to the weight of the bio-ash sample to be prepared; using the bio-ash sample preparation process corresponding to the selected bio-ash sample preparation process type to prepare the bio-ash sample, the bio-ash sample preparation process is as follows: preparing a first bio-ash matrix and a second bio-ash matrix for a doping operation, the first bio-ash matrix being placed in a first container; dropping a radionuclide standard solution onto a predetermined area of ​​the first bio-ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container; drying the first bio-ash matrix with the radionuclide standard solution dropped thereon until the first bio-ash matrix is ​​in a loose fine powder state; transferring the dried first bio-ash matrix to a second container, and transferring the second bio-ash matrix to the second container through the first container; mixing the first bio-ash matrix and the second bio-ash matrix in the second container to obtain a bio-ash sample; wherein the bio-ash sample preparation process types include sample mixing machine sampling and sample grinding machine sampling, in the case of sample mixing machine sampling, the second container is a sample mixing barrel; in the case of sample grinding machine sampling, the second container is a crushing barrel of a crusher.

[0022] The present invention selects a suitable bio-ash sample preparation process according to the weight of the bio-ash sample to be prepared to prepare the bio-ash sample, thereby improving the mixing uniformity and preparation efficiency, and also reducing the loss of the bio-ash sample.

[0023] Furthermore, the radionuclide standard solution is dripped into a predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, which can reduce the loss of the radionuclide standard solution during the biological ash sample preparation process, thereby improving the accuracy of the biological ash assessment of the verification sample.

[0024] Furthermore, the first biological ash matrix dripped with the radionuclide standard solution is dried and mixed in a sealed environment to prevent the sample from being damp, thereby ensuring that the activity concentration value is not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a schematic flow chart of a method for preparing biological ash samples for proficiency testing of radionuclide analysis according to an embodiment of the present invention.

[0026] Figure 2 It is a schematic diagram of the process of preparing the bioash matrix in the embodiment of the present disclosure.

[0027] Figure 3 It is a schematic flow chart of a method for preparing biological ash samples for proficiency testing of radionuclide analysis according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example 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 various steps described in the method embodiments of the present disclosure may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present disclosure is not limited in this respect.

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

[0031] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0032] The following is a description of the method for preparing biological ash samples for proficiency testing of radionuclide analysis.

[0033] Figure 1 FIG. 1 is a flow chart of a method for preparing a biological ash sample for capability verification of radionuclide analysis according to an embodiment of the present disclosure. Figure 1 As shown, an embodiment of the present invention provides a method for preparing biological ash samples for proficiency testing of radionuclide analysis, and the method includes the following S101 and S102.

[0034] S101, selecting a bio-ash sample preparation process type according to the weight of the bio-ash sample to be prepared.

[0035] S102, preparing a biological ash sample by 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 S1021 to S1025.

[0036] S1021, preparing a first bio-ash matrix and a second bio-ash matrix for a doping operation, wherein the first bio-ash matrix is ​​placed in a first container.

[0037] S1022, dripping the radionuclide standard solution into a predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

[0038] S1023, drying the first biological ash matrix dripped with the radionuclide standard solution until the first biological ash matrix appears in a loose fine powder state.

[0039] S1024, transferring the dried first bio-ash matrix to a second container, and transferring the second bio-ash matrix to the second container through the first container.

[0040] S1025, mixing the first bio-ash matrix and the second bio-ash matrix in the second container to obtain a bio-ash sample.

[0041] Among them, the bio-ash sample preparation process types include mixer sampling and pulverizer sampling. In the case of mixer sampling, the second container is a mixer barrel; in the case of pulverizer sampling, the second container is a pulverizing barrel of a pulverizer.

[0042] The present invention selects a suitable bio-ash sample preparation process to prepare the bio-ash sample according to the weight of the bio-ash sample to be prepared, thereby improving the uniformity of mixing and the preparation efficiency, and can also reduce the loss of the bio-ash sample. The radionuclide standard solution is dripped into a predetermined area of ​​the first bio-ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, which can reduce the loss of the radionuclide standard solution during the bio-ash sample preparation process, thereby improving the accuracy of the bio-ash assessment of the verification sample. The first bio-ash matrix dripped with 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.

[0043] The method provided by the present disclosure can make the radionuclides and the bioash matrix mix more evenly, and improve the uniformity of the proficiency testing sample. In addition, the bioash sample prepared by the method provided by the present disclosure can effectively evaluate the determination capability of the radionuclides in the bioash, thereby improving the overall monitoring level and ensuring environmental protection and public safety.

[0044] The evaluation accuracy of the biological ash sample used for proficiency testing is related to the quality of the biological ash matrix. The biological ash sample prepared from a biological ash matrix with good quality has high evaluation accuracy. In order to improve the evaluation accuracy of the biological ash sample, the present disclosure provides a method for preparing the biological ash matrix. The following is an explanation of how to prepare the biological ash matrix through exemplary embodiments.

[0045] In an exemplary embodiment, if Figure 2 As shown, before the first biological ash matrix and the second biological ash matrix are prepared for the doping operation and the first biological ash matrix is ​​placed in the first container, the method may further include S201 to S208.

[0046] S201, prepare biological samples.

[0047] In the embodiments of the present disclosure, biological samples are biological samples that meet the analysis requirements. Biological samples that meet the analysis requirements refer to samples that can be used for analysis after pretreatment of plant and animal samples. For example, for grass samples, dust, dead leaves and other debris should be removed; for poultry and livestock, the edible parts should be washed and the surface moisture should be dried.

[0048] S202, performing a first drying process on the biological sample.

[0049] In the disclosed embodiment, the biological sample is placed in an oven for a first drying process, and the drying temperature is 108°C-112°C. For example, a biological sample that meets the analysis requirements is placed in an oven for drying at 110°C±1°C. For another example, a biological sample that meets the analysis requirements is placed in an oven for drying at 110°C.

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

[0051] S203, crushing the biological sample after the first drying and performing carbonization treatment until the biological sample appears in a coke-like state.

[0052] In the disclosed embodiment, the biological sample after the first drying is crushed to be as fine as possible to speed up the subsequent carbonization process. During the carbonization process, the carbonization temperature is controlled below 450° C., that is, the temperature of the carbonization process is less than or equal to 450° C. When the biological sample appears to be agglomerated coke, subsequent crushing is performed.

[0053] S204, crushing the carbonized biological sample and performing a heating treatment until the biological sample is completely carbonized to obtain a carbonized sample.

[0054] In the embodiments of the present disclosure, the device for crushing the carbonized biological sample is not limited, and any crushing device that can meet the requirements can be used, for example, crushing is performed by a crusher, a vibration mill, a roller mill, etc.

[0055] In the embodiments of the present disclosure, the heating treatment can further carbonize the sample, thereby increasing the carbonization rate of the biological sample. The embodiments of the present disclosure do not limit how to judge whether the biological sample is completely carbonized. For example, when no black smoke is emitted during the heating process, it can be considered to be completely carbonized. It should be noted that complete carbonization is conducive to improving the quality of the prepared biological ash matrix.

[0056] S205, performing an ashing treatment on the carbonized sample until the carbonized sample appears in a white or grayish white loose granular state, thereby obtaining an ashed sample.

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

[0058] In the embodiment of the present disclosure, when the loose density of the sample is 0.3 g / cm 3 -0.8g / cm 3 When the particle size is between 0.01 and 0.05, the ashing sample is considered to be white or grayish white loose granules.

[0059] S206, drying the ashed sample for a second time until the sample reaches a constant weight.

[0060] In the embodiments of the present disclosure, there is no limitation on the drying time, as long as the carbonized sample is dried to a constant weight, where the constant weight means that the weight of the carbonized sample does not change with the increase of the drying time. For example, the drying time is any time between 24 hours and 30 hours. For example, 25 hours.

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

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

[0063] Exemplarily, the ash sample after the second drying is put into a ball mill for grinding, and stone balls are placed in the ball mill. There is no limitation on the material of the inner wall of the ball mill and the stone balls, as long as the material has a hardness greater than 50HRC (Rockwell hardness C scale). For example, the material of the inner wall of the ball mill and the stone balls can be one or more of diamond, ceramic and some high alloy steels. For another example, the inner wall of the ball mill is made of diamond, and the material of the stone balls is ceramic. Placing the stone balls in the ball mill is conducive to improving the efficiency of grinding, thereby increasing the preparation speed of the biological ash sample.

[0064] S208, screening the ground ash sample to obtain a biological ash matrix, wherein the first biological ash matrix and the second biological ash matrix are both biological ash matrices.

[0065] In the disclosed embodiment, the ground bio-ash is sieved through an 80-mesh sieve to obtain a bio-ash matrix, and the particle size of the bio-ash matrix is ​​equal to 80 mesh.

[0066] In the disclosed embodiment, the ground bio-ash is sieved through a 100-mesh sieve to obtain a bio-ash matrix, and the particle size of the bio-ash matrix is ​​equal to 100 mesh.

[0067] It should be noted that the prepared bioash matrix is ​​placed in a glass bottle and sealed for use when the standard addition operation is performed. In addition, the bioash matrix is ​​more hygroscopic and looser (fluffy) than other substances (such as soil), so the amount of bioash sample that can be prepared under the same volume will be less. The bioash matrix is ​​looser and extremely difficult to sieve when the particle size is small, so the particle size will be larger than that of soil. For example, the particle size of the bioash matrix is ​​between 80 mesh and 100 mesh.

[0068] In order to ensure the reliability of the value of the bio-ash sample in the proficiency test, the humidity conditions of the bio-ash matrix need to be controlled to prevent the quality from changing due to moisture and thus affecting the activity concentration value. Therefore, drying treatment is carried out during the preparation of the bio-ash.

[0069] In the disclosed embodiment, before the doping operation is performed, a bioash matrix is ​​first 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 conducive to obtaining a uniformly mixed bioash sample.

[0070] The bioash matrix prepared by the preparation method of the present invention meets the HJ 61-2021 standard (technical specification for radiation environment monitoring), which is conducive to improving the evaluation accuracy of the prepared bioash samples, and the bioash samples have high uniformity, which can effectively evaluate the determination ability of radioactive nuclides in bioash, thereby improving the overall monitoring level and ensuring environmental protection and public safety.

[0071] The above describes the preparation of the bioash matrix, and the following describes how to select the type of bioash sample preparation process.

[0072] In an exemplary embodiment, selecting the type of bio-ash sample preparation process based on the weight of the bio-ash sample to be prepared may include: when the weight of the bio-ash sample to be prepared is greater than a weight threshold, determining the type of bio-ash sample preparation process to be a mixer sampling; when the weight of the bio-ash sample to be prepared is less than or equal to the weight threshold, determining the type of bio-ash sample preparation process to be a crusher sampling.

[0073] In the embodiment of the present disclosure, the weight threshold can be set according to the actual application scenario and specific application experience. For example, the weight threshold is 600g (grams). For another example, the weight threshold is 200g.

[0074] When the weight of the bio-ash sample to be prepared is large, a sample mixer is used for sampling with a long mixing time, which can enable the radioactive nuclides to be fully mixed with the bio-ash matrix and mix more evenly, thereby further improving the uniformity of the proficiency test bio-ash sample, and then effectively evaluating the determination capability of radionuclides in bio-ash, 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 crusher is used for sampling, and the mixing time is short, which can achieve rapid preparation and meet the uniformity requirements.

[0076] In the embodiment of the present disclosure, a mixer or a pulverizer is selected according to the weight of the biological ash sample to be prepared, thereby meeting the sample preparation requirements and facilitating the automated preparation of the biological ash sample.

[0077] The above explains how to select the type of bioash sample preparation process, and the following explains the predetermined area.

[0078] In one embodiment, dripping the radionuclide standard solution to a predetermined area of ​​the first bio-ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, may include at least one of the following: dripping the radionuclide standard solution to the central area 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, dripping the radionuclide standard solution to the geometric center area 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, dripping the radionuclide standard solution to the geometric center area of ​​the first container, and the radionuclide standard solution does not contact the inner wall of the first container.

[0079] In the disclosed embodiment, the radionuclide standard solution is a radioactive material solution of a specific concentration, and the radionuclides contained therein have known and stable concentrations and radioactive properties. It should be noted that the amount of the radionuclide standard solution added is determined according to the activity concentration level of the radionuclides in the prepared verification sample. For example, the radionuclide standard solution can be a Sr-90 (strontium-90) certified standard solution, and 10-1-101 mL of the radionuclide standard solution is added, wherein the Sr-90 certified 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 in the present invention is applicable to non-volatile radionuclides (such as strontium-90, cobalt-60, radium-226, etc.).

[0081] In the disclosed embodiment, the predetermined area can be a regular area, an irregular area, or a point. As long as the radionuclide standard solution dripped into the first biological ash matrix in the first container does not contact the first container. Exemplarily, the first container is a beaker, and the predetermined area is a point area. The absorbed radionuclide standard solution is dripped into the middle of the beaker (point area), which can ensure that the radionuclide standard solution will not diffuse to the wall of the beaker, and ensure that the added radionuclide standard solution is "all" in the first biological ash matrix, thereby reducing the loss of the radionuclide standard solution and improving the evaluation accuracy of the prepared biological ash sample.

[0082] In the disclosed embodiment, the middle of the beaker may refer to the center of the bio-ash matrix in the beaker, or may refer to the geometric center of the shape of the bio-ash matrix in the beaker, which can effectively prevent the radioactive nuclide standard solution dropped into the beaker from diffusing to the wall of the beaker.

[0083] The beaker can be a polytetrafluoroethylene beaker, which has extremely high chemical resistance, is not easily corroded by acids, alkalis and organic solvents, is resistant to high temperatures, has excellent non-adhesive properties, and is easy to clean, thereby reducing the adhesion of the bioash matrix to the beaker wall, which is beneficial to further improve the evaluation accuracy of the prepared bioash sample.

[0084] In another embodiment, the radionuclide standard solution is dripped into a predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container, including: using a pipette to absorb the radionuclide standard solution, and dripping the radionuclide standard solution into the predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

[0085] In yet another embodiment, dripping the radionuclide standard solution into a predetermined area of ​​the first biological ash matrix without the radionuclide standard solution contacting the inner wall of the first container comprises: using a pipette to absorb the radionuclide standard solution, and dripping the radionuclide standard solution into the predetermined area of ​​the first biological ash matrix without the radionuclide standard solution contacting the inner wall of the first container.

[0086] It should be noted that the pipette is used for liquid transfer with small volume and high precision. Since the density of the biological ash matrix is ​​relatively small, less radionuclide standard solution is required. Therefore, when preparing the biological ash sample, a pipette is used to absorb the radionuclide standard solution, thereby further improving the preparation accuracy.

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

[0088] In the disclosed embodiment, using a pipette with higher measurement accuracy to draw the radionuclide standard solution is beneficial to improving the assessment accuracy of the prepared biological ash sample.

[0089] The predetermined area is explained above, and the mixing mechanism and the crushing mechanism are explained below.

[0090] The bioash samples were prepared using a sample mixer as follows.

[0091] In one embodiment, the first container is a beaker, and the second container is a mixing barrel. The preparation of the first biological ash matrix and the second biological ash matrix for the doping operation may include the following steps A1 and A2.

[0092] Step A1, weighing a biological ash matrix of a first weight value and putting it into a second container.

[0093] In the disclosed embodiment, the first weight value is determined according to the preparation needs. Exemplarily, in order 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, so that the loss of the bioash matrix during the preparation process can be compensated. For example, when the required first weight value is 3200g, the bioash matrix weighed in the disclosed embodiment is 3200.01g, wherein 0.01g is an additional increment. The disclosed embodiment does not limit the value of the corresponding additional increment, and it is determined according to the specific weight value lost in actual experience. Exemplarily, the first weight value is 3200.01 grams.

[0094] Exemplarily, the first weight value ranges from 2500 g to 5000 g.

[0095] In the disclosed embodiment, the particle size of the biological ash matrix is ​​equal to 100 mesh. When the sieving is satisfied, making the particle size of the biological ash matrix small enough can improve the adequacy of mixing, thereby improving the reliability and evaluation accuracy of the verification sample. It should be noted that the size of the particle size will vary depending on the different radionuclides analyzed.

[0096] Step A2, weighing a second weight value of the first biological ash matrix from the second container and transferring it to the first container, and weighing a third weight value of the second biological ash matrix for standby use.

[0097] The second weight value and the third weight value are determined according to the preparation requirements. Exemplarily, the second weight value is any value between 50 grams and 200 grams, for example, the second weight value is 100 grams. The third weight value is any value between 100 grams and 1000 grams, for example, the third weight value is 100 grams, 150 grams, 300 grams, 400 grams, 500 grams, 600 grams, 700 grams, 800 grams and 900 grams.

[0098] The second bioash matrix is ​​used to clean the vessel (such as a beaker) containing the first bioash matrix, thereby solving the problem of low assessment accuracy caused by the radionuclide standard solution contacting the vessel wall during the transfer process.

[0099] Exemplarily, the dried first bio-ash matrix is ​​transferred to a sample mixing barrel, and the second bio-ash matrix is ​​transferred to the sample mixing barrel via a beaker.

[0100] In the disclosed embodiment, the second biological ash matrix is ​​transferred to the mixing barrel through the beaker, which is equivalent to cleaning the beaker with the second biological ash matrix. There is no limitation on the number of cleanings, for example, the number of cleanings is any one of 5 to 10 times. For example, the number of times the beaker is cleaned is 7 times. The disclosed embodiment can further reduce the loss of radionuclides and further improve the assessment accuracy by using the spare biological ash matrix (second biological ash matrix) to clean the beaker multiple times.

[0101] It should be noted that when cleaning the beaker, focus on cleaning the bottom wall of the beaker and the junction of the bottom wall and the inner wall.

[0102] In another embodiment, when a sample mixer is used for sampling, the first biological ash matrix and the second biological ash matrix in the second container are mixed to obtain a biological ash sample, which may include: adding a plurality of mixing balls into a mixing barrel, the plurality of 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 barrel on the mixing machine for mixing to obtain a biological ash sample; wherein the mixing time is greater than 100 hours, and the mixing balls are stainless steel balls.

[0103] In the embodiment of the present disclosure, the number of sample mixing balls added is not limited. The more biological ash matrix there is in the sample mixing barrel, the more sample mixing balls are added. The masses of the multiple sample mixing balls are different, that is, the sizes of the sample mixing balls can be of various types, and the embodiment of the present disclosure is not limited to the first sample mixing balls and the second sample mixing balls.

[0104] In the disclosed embodiment, the mixing ball can be a stainless steel iron ball. The stainless steel iron ball is conducive to the rapid and uniform mixing of the biological ash matrix and the radioactive nuclides. It should be noted that the mixing ball can also be other spheres that can accelerate the mixing speed. Furthermore, the material of the surface of the mixing ball can be an anti-adhesion material, which can further improve the assessment accuracy of the prepared biological ash sample.

[0105] In the disclosed embodiment, a proper amount of stainless steel balls of different sizes are added to the sample mixing barrel, and the movement of the balls in the sample mixing barrel can promote the uniformity of the sample.

[0106] In the disclosed embodiment, the mixing time may be greater than or equal to 100 hours. Exemplarily, the mixing time is any value between 95 hours and 105 hours. For example, the mixing time is 105 hours. It should be noted that when the mixing time is greater than 100 hours, the uniformity of the mixed sample is higher.

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

[0108] In the disclosed embodiment, the mixing barrel is a mixing barrel with good sealing performance. The annular inner pad on the mixing barrel can further ensure the sealing performance of the mixing barrel, thereby ensuring that the biological ash matrix and the radioactive nuclide mixture are well dried during a long mixing time, further ensuring that the activity concentration value is not affected.

[0109] Exemplarily, the annular inner gasket may be an elastic annular inner gasket, which may further improve the sealing performance of the mixing barrel.

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

[0111] In order to ensure the reliability of the value of the biological ash sample in the proficiency test, the embodiment of the present disclosure needs to control the humidity conditions for the biological ash sample to prevent the quality from changing due to moisture and thus affecting the activity concentration value. The loose fine powder is a state of being fully dried and not damp (caking). This is conducive to subsequent mixing and also to the accurate guarantee of the value.

[0112] In the disclosed embodiment, for the biological ash sample, the humidity condition needs to be controlled to prevent the quality from changing due to moisture, thereby affecting the activity concentration value. When the radionuclide standard solution is dripped into the first biological ash matrix for drying, the moisture can be reduced to ensure that the activity concentration value is not affected. It should be noted that the first biological ash matrix is ​​in the form of loose fine powder, indicating that the first biological ash matrix is ​​fully dried and not damp (caked), which is conducive to subsequent mixing and accurate measurement.

[0113] In the embodiment of the present 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 the embodiment of the present disclosure, using a temperature of 105° C. to dry the first biological ash matrix to which the radionuclide standard solution is added generally does not affect the activity of the radionuclide, thereby ensuring that there is no adverse effect on the measurement result.

[0114] In the embodiment of the present disclosure, whether the drying is completed is determined by the state of drying the first biological ash matrix. For example, if the biological ash matrix is ​​dried to a loose fine powder, it means that it is fully dried, which is conducive to subsequent mixing. In addition, the drying time (i.e., the time when the biological ash matrix is ​​dried to a loose fine powder) can also be determined according to the size of the second weight value, that is, the time when the drying operation is completed.

[0115] The method provided by the present disclosure can make the radionuclide and the biological ash matrix mix more evenly, thereby improving the uniformity of the proficiency verification sample. The present disclosure can also reduce the loss of the radionuclide standard solution during the preparation of the biological ash sample, thereby improving the accuracy of the biological ash assessment of the verification sample. In addition, the present disclosure uses an oven for drying and performs the mixing process in a sealed environment to prevent the biological ash from getting damp, thereby ensuring that the activity concentration value is not affected.

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

[0117] In one embodiment, preparing the first biological ash matrix and the second biological ash matrix for a doping operation includes: weighing a first weight value of the biological ash matrix and placing it in a second container; weighing a second weight value of the first biological ash matrix from the second container and transferring it to the first container, and weighing a third weight value of the second biological ash matrix for standby use.

[0118] In the embodiment of the present disclosure, the first weight value is determined according to the preparation needs. Exemplarily, in order 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, so that the loss of the bioash matrix during the preparation process can be supplemented. For example, when the required first weight value is 500g, the bioash matrix weighed in the embodiment of the present disclosure is 500.01g, where 0.01g is an additional increment. The value of the corresponding additional increment in the embodiment of the present disclosure is not limited, and is determined based on the specific weight value lost in actual experience.

[0119] Exemplarily, the first weight value ranges from 300 g to 1500 g. For example, 500 g of the bioash matrix is ​​accurately weighed by an electronic balance and put into a crushing barrel.

[0120] In the disclosed embodiment, the particle size of the biological ash matrix is ​​equal to 100 mesh. When the sieving is satisfied, making the particle size of the biological ash matrix small enough can improve the adequacy of mixing, thereby improving the reliability and evaluation accuracy of the verification sample. It should be noted that the size of the particle size will vary depending on the different radionuclides analyzed.

[0121] The second weight value and the third weight value are determined according to the preparation requirements. Exemplarily, the second weight value is any value between 20 grams and 80 grams, for example, the second weight value is 50 grams. The third weight value is any value between 50 grams and 600 grams, for example, the third weight value is 100 grams, 150 grams, 200 grams, 300 grams, 350 grams, 400 grams, 450 grams, 500 grams and 550 grams.

[0122] The second biological ash matrix is ​​used to clean the container containing the first biological ash matrix, thereby solving the problem of low assessment accuracy caused by the radionuclide standard solution contacting the container wall during the transfer process.

[0123] Exemplarily, the dried first bioash matrix is ​​transferred to a crushing barrel, and the second bioash matrix is ​​transferred to the crushing barrel via a beaker.

[0124] In the disclosed embodiment, the second biological ash matrix is ​​transferred to the crushing barrel through the beaker, which is equivalent to cleaning the beaker with the second biological ash matrix. There is no limitation on the number of cleanings, for example, the number of cleanings is any one of 5 to 10 times. For example, the number of times the beaker is cleaned is 7 times. The disclosed embodiment can further reduce the loss of radionuclides and further improve the assessment accuracy by using the spare biological ash matrix (second biological ash matrix) to clean the beaker multiple times.

[0125] It should be noted that when cleaning the beaker, focus on cleaning the bottom wall of the beaker and the junction of the bottom wall and the inner wall.

[0126] In another embodiment, when a pulverizer is used for sampling, the first bio-ash matrix and the second bio-ash matrix in the second container are mixed to obtain a bio-ash sample, including: starting the pulverizer, mixing the first bio-ash matrix and the second bio-ash matrix in the pulverizing barrel, the pulverizer is pulverized 4-10 times, and each pulverization takes 0.5-2 minutes.

[0127] Exemplarily, the crushing machine is crushed 5 times, and each crushing lasts for 1 minute. It should be noted that according to actual needs, the appropriate crushing times and crushing time can be set.

[0128] The present invention uses a pulverizer to perform pulverization and mixing, and pulverizes and mixes for multiple times in a short time, which is conducive to realizing rapid sample preparation of biological ash samples while meeting sample preparation quality requirements.

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

[0130] The crushing barrel is a crushing barrel with good sealing performance. The annular inner pad on the crushing barrel can further ensure the sealing performance of the crushing barrel, thereby ensuring that the biological ash matrix and the radionuclide mixture are well dried during a long mixing time, further ensuring that the activity concentration value is not affected.

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

[0132] As to why the drying process is performed in this embodiment, it has been explained in the above embodiment and will not be repeated here.

[0133] The disclosed embodiment controls the humidity condition (such as drying) to prevent the quality from changing due to moisture, thereby affecting the activity concentration value. The loose fine powder is a state of being fully dried and not damp. This is conducive to subsequent mixing and also to the accurate guarantee of the value.

[0134] The method provided by the present disclosure can make the radionuclide and the biological ash matrix mix more evenly, thereby improving the uniformity of the proficiency verification sample. The present disclosure can also reduce the loss of the radionuclide standard solution during the preparation of the biological ash sample, thereby improving the accuracy of the biological ash assessment of the verification sample. In addition, the present disclosure uses an oven for drying and performs the mixing process in a sealed environment to prevent the biological ash from getting damp, thereby ensuring that the activity concentration value is not affected.

[0135] Example 1

[0136] like Figure 2 As shown, an embodiment of the present invention provides a method for preparing a biological ash sample for proficiency testing of radionuclide analysis, and the method may include the following S101 to S103.

[0137] S101, selecting a bio-ash sample preparation process type according to the weight of the bio-ash sample to be prepared.

[0138] S102, preparing a biological ash sample by 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 S1021 to S1025.

[0139] S1021, preparing a first bio-ash matrix and a second bio-ash matrix for a doping operation, wherein the first bio-ash matrix is ​​placed in a first container.

[0140] S1022, dripping the radionuclide standard solution into a predetermined area of ​​the first bioash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

[0141] S1023, drying the first biological ash matrix dripped with the radionuclide standard solution until the first biological ash matrix appears in a loose fine powder state.

[0142] S1024, transferring the dried first bio-ash matrix to a second container, and transferring the second bio-ash matrix to the second container through the first container.

[0143] S1025, mixing the first bio-ash matrix and the second bio-ash matrix in the second container to obtain a bio-ash sample.

[0144] Among them, the bio-ash sample preparation process types include mixer sampling and pulverizer sampling. In the case of mixer sampling, the second container is a mixer barrel; in the case of pulverizer sampling, the second container is a pulverizing barrel of a pulverizer.

[0145] The above S101 to S102 have been explained in the above embodiment and will not be repeated here.

[0146] S103, performing a uniformity test on the biological ash sample, and if the test is passed, packaging the biological ash sample into plastic bottles to facilitate transportation and storage of the biological ash sample.

[0147] Exemplarily, the bioash sample is divided into 30 ml plastic bottles, each containing 2.5 g, and sealed.

[0148] In the disclosed embodiment, the biological ash samples are packaged into plastic bottles and sealed for storage to prevent the biological ash samples from getting damp, thereby improving the accuracy of the biological ash assessment of the verification samples.

[0149] It should be noted that the biological ash sample prepared by the method disclosed in the present invention has good uniformity and can meet practical needs.

[0150] The method provided by the present disclosure can make the radionuclide and the biological ash matrix mix more evenly, and improve the uniformity of the proficiency verification sample. The present disclosure can also reduce the loss of the radionuclide standard solution in the biological ash sample preparation process, thereby improving the accuracy of the biological ash assessment of the verification sample. In addition, the present disclosure performs drying and mixing in a sealed environment to prevent the sample from getting damp, thereby ensuring that the activity concentration value is not affected.

[0151] The bioash sample prepared by the method provided in the present disclosure can effectively evaluate the determination capability of radionuclides in bioash, 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 standby (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 and dry it at 105 °C. At this time, the biological ash matrix presents a loose fine powder. Transfer all the biological ash matrix in the beaker to a mixing bucket, and use the standby biological ash matrix to wash the beaker and the spoon used for transfer 7 times, focusing on washing the bottom of the beaker and the junction of the bottom and the beaker wall. Then transfer all the standby 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, sub-pack it into plastic bottles for sample sending and storage. Among them, the biological ash sample is sub-packed into 50 mL plastic bottles, with about 30 g in each bottle and sealed.

[0155] After the preparation and sub-packing 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, 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, Ss ≤ 0.3σ = 1.64, and 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 how to calculate relevant data between samples and within samples, please refer to CNAS-GL003:2018 "Guidelines for the Evaluation of Uniformity and Stability of Proficiency Testing Samples".

[0161] The method provided by the present disclosure can make the radionuclide and the biological ash matrix mix more evenly, and improve the uniformity of the proficiency verification sample. The present disclosure can also reduce the loss of the radionuclide standard solution in the biological ash sample preparation process, thereby improving the accuracy of the biological ash assessment of the verification sample. In addition, the present disclosure performs drying and mixing in a sealed environment to prevent the sample from getting damp, thereby ensuring that the activity concentration value is not affected.

[0162] The bioash sample prepared by the method provided in the present disclosure can effectively evaluate the determination capability of radionuclides in bioash, thereby improving the overall monitoring level and ensuring environmental protection and public safety.

[0163] Example 3

[0164] Use an electronic balance to accurately weigh 500.00g of biological ash matrix in the crushing barrel of the grinder, take 50g of the biological ash matrix (the first biological ash matrix) and transfer it to a polytetrafluoroethylene beaker, and take out about 100g of the biological ash matrix (the second biological ash matrix) for standby use; use a pipette with a full scale of 1ml to transfer the certified standard solution of radionuclides, and carefully add it to the middle of the polytetrafluoroethylene beaker (make sure that the liquid does not diffuse to the wall of the beaker); place the polytetrafluoroethylene beaker in an oven at 105℃ to dry, at this time the first biological ash matrix is ​​in a loose fine powder state, transfer all the first biological ash matrix to the crushing barrel, and use the second biological ash matrix to clean the beaker and the transfer spoon 7 times, focusing on cleaning the bottom of the beaker and the junction between the bottom and the cup wall, and then transfer all to the crushing barrel for crushing and mixing. Crush 5 times, 1 minute each time. The crusher has good sealing and is padded with a ring inner pad to ensure that the sample is sealed and dry during multiple crushing processes. After the crushing and mixing is completed, the bioash sample is divided into 30mL plastic bottles, each bottle contains 2.5g, and sealed. Alternatively, the bioash sample is divided into 30mL plastic bottles, each bottle contains about 5g, and sealed.

[0165] After the above preparation and packaging of the bio-ash samples are completed, the samples of the final packaging unit are tested for uniformity. The uniformity test is as follows.

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

[0167] Table 2 Homogeneity test results of biological ash samples (unit: μg / g (micrograms per gram))

[0168]

[0169] As can be seen from Table 2, by using the one-way analysis of variance method, the statistic F = 1.37 was 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 test.

[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 Test Samples".

[0171] The method of sample preparation using a crusher in the embodiments of the present disclosure 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 test 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 assessment of bio-ash. In addition, the present disclosure performs drying and carries out mixing treatment in a sealed environment to avoid sample moisture absorption, thus 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 determination ability of radionuclides in bio-ash, thereby improving the overall monitoring level and ensuring environmental protection and public safety.

[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 is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common general 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 biological ash samples for proficiency testing of radionuclide analysis, characterized in that: The method comprises the following steps: S101, selecting a bio-ash sample preparation process type according to the weight of the bio-ash sample to be prepared; S102, 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: S1021, preparing a first biological ash matrix and a second biological ash matrix for a doping operation, wherein the first biological ash matrix is ​​contained in a first container; S1022, dropping a radionuclide standard solution onto a predetermined area of ​​the first biological ash matrix, wherein the radionuclide standard solution does not contact the inner wall of the first container; S1023, drying the first biological ash matrix dripped with the radionuclide standard solution until the first biological ash matrix is ​​in a loose fine powder state; S1024, transferring the dried first bio-ash matrix to a second container, and transferring the second bio-ash matrix to the second container through the first container; S1025, mixing the first biological ash matrix and the second biological ash matrix in the second container to obtain a biological ash sample; Among them, the bio-ash sample preparation process types include mixer sampling and pulverizer sampling. When the mixer sampling is performed, the second container is a mixer barrel; when the pulverizer sampling is performed, the second container is a pulverizing barrel of the pulverizer.

2. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: Step S101 includes the following steps: When the weight of the biological ash sample to be prepared is greater than the weight threshold, determining the biological ash sample preparation process type to be the sample mixer sampling; When the weight of the bio-ash sample to be prepared is less than or equal to the weight threshold, the bio-ash sample preparation process type is determined to be the pulverizer sampling.

3. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: Before step S1021, the following steps are also included: Preparation of biological samples; performing a first drying process on the biological sample; The biological sample after the first drying is crushed and carbonized until the biological sample appears in a coke-like state; The carbonized biological sample is crushed and subjected to a heating treatment until the biological sample is completely carbonized to obtain a carbonized sample; The carbonized sample is subjected to an ashing treatment until the carbonized sample appears in a white or off-white loose granular state, thereby obtaining an ashed sample; The ashing sample is dried for a second time to a constant weight; Grinding the ashed sample after the second drying; The ground ash sample is screened to obtain the biological ash matrix, and the first biological ash matrix and the second biological ash matrix are both the biological ash matrix.

4. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 3, characterized in that: The first drying treatment is carried out in an oven at a drying temperature of 108°C-112°C; the temperature of the carbonization treatment is less than or equal to 450°C; the ashing treatment is carried out in a muffle furnace at a temperature less than or equal to 450°C; the second drying treatment is carried out in an oven at a drying temperature of 105°C, and the drying time is greater than or equal to 24 hours; the ground ashing sample is screened through a 100-mesh sieve.

5. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: Step S1022 includes at least one of the following: Dropping a radionuclide standard solution onto the central area of ​​the surface of the first bioash matrix contained in the first container, wherein the radionuclide standard solution does not contact the inner wall of the first container; or, Dropping a radionuclide standard solution into a geometric center area of ​​a first bioash matrix contained in a first container, wherein the radionuclide standard solution does not contact an inner wall of the first container; or, The radionuclide standard solution is dropped into the geometric center area of ​​the first container, and the radionuclide standard solution does not contact the inner wall of the first container.

6. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: Step S1022 includes: The radionuclide standard solution is sucked by a pipette and dropped into a predetermined area of ​​the first biological ash matrix, and the radionuclide standard solution does not contact the inner wall of the first container.

7. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: The first biological ash matrix and the second biological ash matrix to be subjected to the doping operation include: Weigh a biological ash matrix of a first weight value and put it into the second container; The first biological ash matrix having a second weight value is weighed from the second container and transferred to the first container, and the second biological ash matrix having a third weight value is weighed for later use.

8. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: In the case of adopting the sample mixer to collect samples, the mixing of the first biological ash matrix and the second biological ash matrix in the second container to obtain the biological ash sample includes: Adding a plurality of sample mixing balls into the sample mixing barrel, wherein the plurality of sample mixing balls include at least a first sample mixing ball and a second sample mixing ball, and the first sample mixing ball and the second sample mixing ball have different masses; The sample mixing barrel is fixed on a sample mixing machine for mixing to obtain a biological ash sample; The mixing time is greater than 100 hours, and the mixing balls are stainless steel balls.

9. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: In the case of adopting the pulverizer to prepare the sample, the mixing of the first biological ash matrix and the second biological ash matrix in the second container to obtain the biological ash sample comprises: The pulverizer is turned on, and the first bioash matrix and the second bioash matrix in the pulverizing barrel are mixed. The pulverizer is pulverized 4 to 10 times, and each pulverization takes 0.5 to 2 minutes.

10. The method for preparing biological ash samples for proficiency testing of radionuclide analysis according to claim 1, characterized in that: An annular inner gasket is provided between the barrel cover and the barrel body of the mixing barrel, and the annular inner gasket is installed on the barrel cover of the mixing barrel; An annular inner gasket is arranged between the barrel cover and the barrel body of the crushing barrel, and the annular inner gasket is installed on the barrel cover of the crushing barrel.

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