Rapid analysis method for determining content of < 99 > Tc in uranium trioxide powder

Abstract

The invention discloses a rapid analysis method for determining the content of < 99 > Tc in uranium trioxide powder. The rapid analysis method comprises the following steps: S1, drawing a standard curve; s2, dissolving the sample; s3, sample price adjustment; s4, column separation; s5, ICP-MS measurement is carried out; s6, data processing; according to the method, trace < 99 > Tc is extracted from a high-uranium sample, other radioactive elements interfering technetium-99 measurement are completely removed, separation of a uranium matrix can be completed through one-time column loading and one-time elution under low acidity, and recovery of 99% Tc can be completed through one-time elution. The sample pretreatment method is simple in process operation and easy to master; personnel operation is reduced, and the risk of personnel exposure is reduced.

Description

Technical Field

[0001] This patent relates to the technical field of spent fuel post-processing analysis, specifically to a method for 99 Rapid analytical method for determination of Tc content. Background Art

[0002] In the process of recovering uranium and plutonium, 99 Tc is a high-yield, long-lived fragment nuclide in the nuclear fuel cycle with a long half-life (T 1 / 2 =2.1×10 5 a), high radioactivity, the presence of Tc will consume U(IV) and other reducing agents, affecting the reduction and stripping of plutonium. If mixed into the final uranium trioxide powder, its volatile properties will affect the uranium isotope enrichment process, so its technetium (Tc) content is an important control technical indicator. According to the requirements of the quality assurance system (technetium content is less than 3μgTc / gU), the Tc content needs to be accurately detected.

[0003] Therefore, the determination of uranium trioxide powder was established. 99 The analytical method of Tc content is of great significance and necessity for optimizing process parameters, improving sample quality, and ensuring the safety and health of workers.

[0004] In order to accurately measure 99 To determine the Tc content, Tc should first be separated from a large number of radioactive elements to remove the measurement interference of radionuclides. Common separation methods include volatilization, solvent extraction, chromatography, etc. The existing nuclear industry standard method uses 2,6-dimethylpyridine to extract Tc from an alkaline medium. The pre-treatment chemical separation process is complex, time-consuming, and has low analysis efficiency. The extraction agent treatment process is relatively complex and has a pungent odor. The analysis method needs to be optimized and improved to improve the analysis efficiency and safety and environmental protection.

[0005] At present, domestic and foreign 99 The main methods for measuring Tc content include spectrophotometry, Raman spectroscopy, radiochemistry, inductively coupled plasma mass spectrometry (ICP-AES), mass spectrometry, etc. Self-absorption during radiochemical measurement will cause measurement difficulties. Liquid scintillation counting can use scintillators and the nuclides to be measured in a homogeneous solution, which effectively avoids the problem of self-absorption, but requires the use of special liquid scintillation liquid and the analysis time is also long (greater than 1h). Mass spectrometry instruments are expensive, diluents are not easy to obtain, the operation is complicated, and the measurement range is not suitable for the determination of trace technetium. Summary of the invention

[0006] The object of the present invention is to provide a uranium trioxide powder 99 Rapid analytical method for determination of Tc content.

[0007] The technical solution of the present invention is as follows: a uranium trioxide powder 99 The rapid analytical method for determining the Tc content comprises the following steps:

[0008] S1: drawing of standard curve;

[0009] S2: sample dissolution;

[0010] S2.1: Weigh 1.0-1.5g of uranium trioxide sample into a 20-25mL beaker, pipette 3-5mL of 3-4mol / L nitric acid solution into the beaker, completely immerse the uranium trioxide sample, and shake well;

[0011] S2.2: heating the beaker, evaporating the solution to dryness after dissolution, and cooling to room temperature;

[0012] S3: Sample price adjustment;

[0013] S3.1: Add low concentration nitric acid solution to the beaker treated in S2 to dissolve the sample;

[0014] S3.2: Add potassium dichromate solution to the beaker to form TcO4 - ;

[0015] S4: Column separation

[0016] S4.1: Wash the TEVA resin with high-purity water;

[0017] S4.2: Pipette low concentration HNO3 into TEVA resin;

[0018] S4.3: Transfer all the uranium trioxide sample solution adjusted in S3 to the TEVA resin; discard the eluent;

[0019] S4.4: Elution using high concentration HNO3 solution 99 Tc, that is, by eluting the TEVA resin with a high concentration of HNO3 solution 99 Tc, collect the eluate into a volumetric flask;

[0020] S4.5: Make up to volume with low concentration HNO3 solution;

[0021] S5: ICP-MS measurement;

[0022] S5.1: Set the measurement conditions of ICP-MS;

[0023] S5.2: Inject the sample solution treated in S4 into ICP-MS for measurement, and obtain the standard curve drawn in S1. 99 The concentration of Tc Tc , unit is μg / L;

[0024] S6: Data Processing

[0025] Calculate the uranium trioxide content in the sample according to the following formula 99 Tc content:

[0026] ω=c Tc ×v / m

[0027] Where:

[0028] ω——Uranium trioxide sample 99 Tc content, in μg / g;

[0029] c Tc ICP-MS measurement 99 The concentration of Tc is in μg / L;

[0030] V——the fixed volume of HNO3 solution in S4.5, in L;

[0031] m——mass of uranium trioxide sample, in g.

[0032] In S1, a technetium working stock solution was used with a concentration of 2.43×10 -4 g / L, and prepare nitric acid blank, 0.10μg, 0.20μg, 0.3μg, 0.40μg, 0.50μg technetium standard solutions in 10mL volumetric flasks through stepwise dilution; 99 The mass of Tc is plotted on the horizontal axis, and the corresponding ICP-MS response value is plotted on the vertical axis. 99 The working standard curve of Tc was obtained by fitting 99 Tc linear regression equation, and the linear correlation coefficient>0.995.

[0033] In S2.1, an electronic balance with a sensitivity of 0.01 mg is used; in S2.2, the beaker is placed on a hot plate and the temperature is controlled to be 80° C. to 90° C.

[0034] In S3.1, add 2-3 mL of 0.01 mol / L nitric acid solution to a beaker; in S3.2, add 2 drops of 0.5-0.6 mg / mL potassium dichromate solution, shake well, and keep the oxidation time at room temperature for 5-10 minutes to form TcO4 - .

[0035] In S4.1, TEVA resin is washed with 10-20 mL of high-purity water; in S4.2, 15-20 mL of 0.01 mol / L HNO3 is transferred into the TEVA resin to activate the TEVA resin column at a rate of 3s-4s / drop; in S4.3, 15-20 mL of 0.01 mol / L HNO3 is used to wash the beaker 4-5 times, and the washing liquid is transferred to the resin column; in S4.4, 15-20 mol / L HNO3 is used for elution three times 99 Tc.

[0036] In S4.4, the eluate is collected into a 25 mL volumetric flask. In S4.5, the volume is fixed to 25 mL with 0.01-0.2 mol / L HNO3 solution.

[0037] In S5.1, the measurement conditions of ICP-MS are set to power 1500-1600 W, nebulizer flow 0.8-0.975 L / min, auxiliary gas flow 0.5-1.00 L / min, cooling gas flow 12-14.0 L / min, and the sample is measured in parallel 2-3 times; in S5.2, 2-3 mL of sample solution is injected into ICP-MS for measurement.

[0038] In S1, 1.5 g of uranium trioxide sample was weighed into a 20 mL beaker, and 5 mL of 3 mol / L nitric acid solution was transferred into the beaker to completely immerse the uranium trioxide sample.

[0039] In the S3.2, 2 drops of 0.5 mg / mL potassium dichromate solution were added.

[0040] In S4.4, 15 ml of 9 mol / L HNO3 was used for elution three times. 99 Tc.

[0041] The remarkable effects of the present invention are:

[0042] (1) Pretreatment operation is simple and safe

[0043] From high uranium samples, trace 99 Tc is extracted and other radioactive elements that interfere with the measurement of technetium-99 are completely removed. Under low acidity, the separation of the uranium matrix can be completed with one column and one elution, and 99% Tc can be recovered with one elution. The sample pretreatment method is simple to operate and easy to master, and can be completed within 2 hours. It reduces the operation of personnel and reduces the risk of personnel exposure.

[0044] (2) Low detection limit and fast analysis speed

[0045] ICP-MS measurements 99The Tc content has high resolution, low interference, and a detection limit of 0.0011μg, which is 2-3 orders of magnitude lower than the liquid scintillation method. The measurement precision is better than 3%. A sample measurement can be completed within 3 minutes, the analysis speed is fast, and the instrument automatically gives the analysis results, which improves the efficiency of post-processing analysis and is widely used.

[0046] (3) Less waste

[0047] No organic reagents are used in the pretreatment process, and the reagent materials used are small, almost no solid radioactive waste is generated, the instrument measurement injection volume is about 2mL, and the amount of waste liquid generated is small, reducing environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Schematic diagram of TEVA resin structure; DETAILED DESCRIPTION

[0049] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application, so the present application is not limited by the specific implementation disclosed below.

[0050] The terms used in one or more embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of the present application. The singular forms of "a", "said" and "the" used in one or more embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of the present application refers to and includes any or all possible combinations of one or more associated listed items.

[0051] It should be understood that, although the terms first, second, etc. may be used to describe various information in one or more embodiments of the present application, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0052] The technical solution of the present invention is to optimize the uranium mass selection test, the oxidant selection test, the TEVA resin washing uranium and the adsorption of TcO4 - The key experimental conditions such as TEVA resin enrichment of trace technetium in the sample were obtained, and the optimal separation conditions of uranium and technetium were obtained by TEVA resin. 99 The precision and recovery of Tc standard solution were tested. ICP-MS was set up to measure the 99The optimal measurement conditions for Tc content were obtained. 99 The exact content of Tc.

[0053] Measuring principle: Tc is priced and then dissolved in uranium trioxide solution as TcO4 - TEVA resin is resistant to pertechnetate anions (TcO4 - ) has strong adsorption capacity, anion TcO4 - In low concentration HNO3 solution, the R group is replaced and adsorbed on the resin. In high concentration acid solution, TcO4 - NO3 - The test solution is introduced into the ICP-MS plasma torch to form plasma, and the ions of the technetium element to be measured are separated according to the charge-to-mass ratio in the mass spectrometer, and quantitative analysis is performed based on the ion current intensity.

[0054] TEVA resin is a mixture of quaternary ammonium salts with a structure such as Figure 1 As shown. Under the condition of pH 2-10, TcO4 can be selectively adsorbed - .

[0055] A uranium trioxide powder 99 The rapid analytical method for determining the Tc content comprises the following steps:

[0056] S1: Drawing of standard curve

[0057] Using the technetium working stock solution (2.43×10 -4 g / L), and prepare nitric acid blank, 0.10μg, 0.20μg, 0.3μg, 0.40μg, and 0.50μg technetium standard solutions in 10mL volumetric flasks through graded dilution. 99 The mass of Tc is plotted on the horizontal axis and the corresponding ICP-MS response value (cps) on the vertical axis. 99 The working standard curve of Tc was obtained by fitting 99 Tc linear regression equation, linear correlation coefficient should be > 0.995.

[0058] S2: Sample dissolution

[0059] S2.1: Weigh 1.0-1.5g (accurate to 0.01mg) of uranium trioxide sample (i.e., the content of uranium trioxide in the powder sample to be determined) on an electronic balance (sensitivity 0.01mg). 99 Tc content) in a 20-25mL small beaker, pipette 3-5mL of 3-4mol / L nitric acid solution, and completely immerse the uranium trioxide sample solid. Shake well and cover the specific surface.

[0060] S2.2: Place the beaker on a hot plate and control the temperature to 80℃~90℃. After dissolution, evaporate the solution to dryness and cool to room temperature.

[0061] S3: Sample price adjustment

[0062] S3.1: Remove the watch glass, add 2-3 mL of 0.01 mol / L nitric acid solution into the beaker (i.e. the low concentration HNO3 solution described in the measurement principle) to dissolve the sample. Redissolve the sample in low acid and keep it consistent with the acidity of the column. Experiments have shown that the sample can be completely dissolved at this acidity.

[0063] S3.2: Add 2 drops of 0.5-0.6 mg / mL potassium dichromate solution, shake well, and keep the oxidation time at room temperature for 5-10 minutes to adjust the technetium in the uranium trioxide solution to form TcO4 - .

[0064] Compared with the solvent extraction method, S2 and S3 do not use organic reagents, use less reagent materials, and have low costs. The sample pretreatment method is simple to operate and easy to master, and can be completed within 1 hour. It reduces personnel operations and reduces the risk of personnel exposure. At the same time, it meets the requirements of quality control for analysis timeliness when analyzing multiple samples.

[0065] S4: Column separation

[0066] S4.1: Wash the TEVA chromatography resin with 10 to 20 mL of high-purity water.

[0067] S4.2: Use a pipette to transfer 15-20 mL of 0.01 mol / L HNO3 into the TEVA column, and activate the TEVA column at a rate of 3-4 seconds per drop to allow pre-equilibration.

[0068] S4.3: Transfer all the sample solution after adjustment to the TEVA chromatography resin; wash the beaker 4-5 times with 15-20mL 0.01mol / L HNO3, and transfer the washing solution to the resin column. - It is adsorbed on the TEVA column, and the uranium matrix is ​​washed off and the eluent is discarded.

[0069] S4.4: Use 15-20 mol / L HNO3 (i.e., the high concentration HNO3 solution described in the measurement principle) to elute Tc three times, and collect the eluate into a 25 mL volumetric flask. This process is a high acid elution process.

[0070] S4.5: Make up to 25 mL with 0.01-0.2 mol / L HNO3 solution.

[0071] In S4, TEVA resin (which can realize automated separation) and nitric acid solution were used to separate trace amounts of uranium from the uranium sample.99 Tc is extracted quickly, and other radioactive elements that interfere with the measurement of technetium-99 are completely removed. Under low acidity, the separation of the uranium matrix can be completed with one column loading and one elution, and 99% Tc can be recovered with one elution.

[0072] S5: ICP-MS measurement

[0073] S5.1: Set the main measurement conditions of ICP-MS to power 1500~1600W, nebulizer flow rate 0.8~0.975L / min, auxiliary gas flow rate 0.5~1.00L / min, cooling gas flow rate 12~14.0L / min, and measure the samples in parallel 2~3 times.

[0074] S5.2: Inject 2-3 mL of sample solution into ICP-MS for measurement. After measurement, record the intensity of the technetium response value (cps) collected by the instrument and obtain the value according to the standard curve drawn in S1. 99 The concentration of Tc Tc , the unit is micrograms per liter (μg / L);

[0075] The instrument does not require the addition of additional reagents, the injection volume is small, and the amount of waste liquid generated is small, which reduces the cost of waste liquid treatment. 99 The Tc content has high resolution, low interference, and a detection limit of 0.0011μg, which is 2-3 orders of magnitude lower than the liquid scintillation method. The measurement precision is better than 3%. Two parallel sample measurements can be completed within 3 minutes, the analysis speed is fast, and the instrument automatically gives the analysis results, which improves the efficiency of post-processing analysis and is widely used.

[0076] S6: Data Processing

[0077] Calculate the sample according to the following formula 99 Tc content:

[0078] ω=c Tc ×v / m

[0079] Where:

[0080] ω——Uranium trioxide sample 99 The content of Tc, in micrograms per gram (μg / g);

[0081] c Tc ——Instrument measurement 99 The concentration of Tc is in micrograms per liter (μg / L);

[0082] V——the volume of HNO3 solution in S4.5, (L)

[0083] m——weight of uranium trioxide sample, (g).

[0084] The samples were measured twice in parallel, and the results were reported as the average of the two measurement results with three significant figures retained.

[0085] Example 1

[0086] S1: Use technetium working stock solution (2.43×10 -4 g / L), and then prepare nitric acid blank, 0.10μg, 0.20μg, 0.3μg, 0.40μg, 0.50μg technetium standard solutions in 10mL volumetric flasks after graded dilution. 99 The mass of Tc is plotted on the horizontal axis, and the corresponding ICP-MS response value (cps) is plotted on the vertical axis. 99 The working standard curve of Tc was obtained by fitting 99 Tc linear regression equation, linear correlation coefficient should be > 0.995;

[0087] S2: Sample dissolution

[0088] S2.1: Weigh 1.5g (accurate to 0.01mg) of uranium trioxide sample on an electronic balance (sensitivity 0.01mg) into a 20mL beaker, pipette 5mL of 3mol / L nitric acid solution to completely immerse the solid. Shake well and cover the surface.

[0089] S2.2: Place the beaker on a hot plate and control the temperature to 80℃~90℃. After dissolution, evaporate the solution to dryness and cool to room temperature.

[0090] S3: Sample price adjustment

[0091] S3.1: Remove the watch glass and add 2 mL of 0.01 mol / L nitric acid solution into the beaker to dissolve the sample.

[0092] S3.2: Add 2 drops of 0.5 mg / mL potassium dichromate solution, shake well, and keep the oxidation time at room temperature for 5 minutes.

[0093] S4: Column separation

[0094] S4.1: Wash the TEVA chromatography resin with 20 mL of high-purity water.

[0095] S4.2: Pipette 15 mL of 0.01 mol / L HNO3 into the TEVA column, and activate the TEVA column at a rate of 3s-4s / drop to allow pre-equilibration.

[0096] S4.3: Load all the sample solution after price adjustment onto the column, wash the beaker 4-5 times with 15mL 0.01mol / L HNO3, and transfer the washing solution to the resin column. - After adsorption on the TEVA column, U is washed off and the eluent is discarded.

[0097] S4.4: Use 15 ml, 9 mol / L HNO3 to elute Tc three times and collect the eluate into a 25 mL volumetric flask.

[0098] S4.5: Make up to 25 mL with 0.01 mol / L HNO3 solution.

[0099] S5: ICP-MS measurement

[0100] S5.1: Set the main measurement conditions of ICP-MS as power 1600W, nebulizer flow rate 0.975L / min, auxiliary gas flow rate 1.00L / min, cooling gas flow rate 14.0L / min, and measure the sample in parallel 3 times.

[0101] S5.2: Inject 2 mL of sample solution into ICP-MS for measurement. After the measurement is completed, record the intensity of the technetium response value (cps) collected by the instrument. The measurement result is automatically given.

[0102] S6: Data Processing

[0103] Calculate the sample according to the following formula 99 Tc content:

[0104] ω=c Tc ×v / m

[0105] Where:

[0106] ω——in the sample 99 The content of Tc, in micrograms per gram (μg / g);

[0107] c Tc ——Instrument measurement 99 The concentration of Tc is in micrograms per liter (μg / L);

[0108] V——sample solution volume, (L)

[0109] m——sample weight, (g).

[0110] Example 2

[0111] S1: Drawing of standard curve

[0112] Using the technetium working stock solution (2.43×10 -4 g / L), and prepare nitric acid blank, 0.10μg, 0.20μg, 0.3μg, 0.40μg, and 0.50μg technetium standard solutions in 10mL volumetric flasks through graded dilution. 99 The mass of Tc is plotted on the horizontal axis, and the corresponding ICP-MS response value (cps) is plotted on the vertical axis. 99 The working standard curve of Tc was obtained by fitting99 Tc linear regression equation, linear correlation coefficient should be > 0.995.

[0113] S2: Sample dissolution

[0114] S2.1: Weigh 1.0 g (accurate to 0.01 mg) of uranium trioxide sample (i.e., the content of uranium trioxide in the powder sample to be determined) on an electronic balance (sensitivity 0.01 mg). 99 Tc content) in a 20mL beaker, pipette 3mL of 3mol / L nitric acid solution, and completely immerse the uranium trioxide sample solid. Shake well and cover the specific surface.

[0115] S2.2: Place the beaker on a hot plate and control the temperature to 80°C. After dissolution, evaporate the solution to dryness and cool to room temperature.

[0116] S3: Sample price adjustment

[0117] S3.1: Remove the watch glass, add 2mL of 0.01mol / L nitric acid solution into the beaker (i.e. the low concentration HNO3 solution described in the measurement principle) to dissolve the sample. Redissolve the sample in low acid and keep it consistent with the acidity of the column. Experiments have shown that the sample can be completely dissolved at this acidity.

[0118] S3.2: Add 2 drops of 0.5 mg / mL potassium dichromate solution, shake well, and keep the oxidation time at room temperature for 5 minutes to adjust the technetium in the uranium trioxide solution to form TcO4 - .

[0119] S4: Column separation

[0120] S4.1: Wash the TEVA chromatography resin with 10 mL of high-purity water.

[0121] S4.2: Pipette 15 mL of 0.01 mol / L HNO3 into the TEVA column, and activate the TEVA column at a rate of 3 s / drop to allow pre-equilibration.

[0122] S4.3: Transfer all the sample solution after adjustment to the TEVA chromatography resin; wash the beaker 4-5 times with 15mL 0.01mol / L HNO3, and transfer the washing solution to the resin column. - It is adsorbed on the TEVA column, and the uranium matrix is ​​washed off and the eluent is discarded.

[0123] S4.4: Use 15 mol / L HNO3 (i.e. the high concentration HNO3 solution described in the measurement principle) to elute Tc three times, and collect the eluate into a 25 mL volumetric flask. This process is a high acid elution process

[0124] S4.5: Make up to 25 mL with 0.01 mol / L HNO3 solution.

[0125] S5: ICP-MS measurement

[0126] S5.1: Set the main measurement conditions of ICP-MS as power 1500W, nebulizer flow rate 0.8L / min, auxiliary gas flow rate 0.5L / min, cooling gas flow rate 12L / min, and measure the samples in parallel 2 to 3 times.

[0127] S5.2: Inject 2 mL of sample solution into ICP-MS for measurement. After the measurement, record the signal intensity (cps) collected by the instrument and obtain the standard working curve drawn in S1. 99 The concentration of Tc Tc , the unit is micrograms per liter (μg / L);

[0128] S6: Data Processing

[0129] Calculate the sample according to the following formula 99 Tc content:

[0130] ω=c Tc ×v / m

[0131] Where:

[0132] ω——Uranium trioxide sample 99 The content of Tc, in micrograms per gram (μg / g);

[0133] c Tc ——Instrument measurement 99 The concentration of Tc is in micrograms per liter (μg / L);

[0134] V——the volume of HNO3 solution in S4.5, (L)

[0135] m——weight of uranium trioxide sample, (g).

[0136] The samples were measured twice in parallel, and the results were reported as the average of the two measurement results with three significant figures retained.

[0137] Example 3

[0138] S1: Drawing of standard curve

[0139] Using the technetium working stock solution (2.43×10 -4 g / L), and prepare nitric acid blank, 0.10μg, 0.20μg, 0.3μg, 0.40μg, and 0.50μg technetium standard solutions in 10mL volumetric flasks through graded dilution. 99The mass of Tc is plotted on the horizontal axis, and the corresponding ICP-MS net count rate is plotted on the vertical axis. 99 The working standard curve of Tc was obtained by fitting 99 Tc linear regression equation, linear correlation coefficient should be > 0.995.

[0140] S2: Sample dissolution

[0141] S2.1: Weigh 1.5g (accurate to 0.01mg) of uranium trioxide sample (i.e., the content of uranium trioxide in the powder sample to be determined) on an electronic balance (sensitivity 0.01mg) 99 Tc content) in a 25mL beaker, pipette 5mL of 4mol / L nitric acid solution, and completely immerse the uranium trioxide sample solid. Shake well and cover the specific surface.

[0142] S2.2: Place the beaker on a hot plate and control the temperature to 90°C. After dissolution, evaporate the solution to dryness and cool to room temperature.

[0143] S3: Sample price adjustment

[0144] S3.1: Remove the watch glass, add 3mL of 0.01mol / L nitric acid solution into the beaker (i.e. the low concentration HNO3 solution described in the measurement principle) to dissolve the sample. Redissolve the sample in low acid and keep it consistent with the acidity of the column. Experiments have shown that the sample can be completely dissolved at this acidity.

[0145] S3.2: Add 2 drops of 0.6 mg / mL potassium dichromate solution, shake well, and keep the oxidation time at room temperature for 10 minutes to adjust the technetium in the uranium trioxide solution to form TcO4 - .

[0146] S4: Column separation

[0147] S4.1: Wash the TEVA chromatography resin with 10 to 20 mL of high-purity water.

[0148] S4.2: Pipette 20 mL of 0.01 mol / L HNO3 into the TEVA column, and activate the TEVA column at a rate of 4 s / drop to allow pre-equilibration.

[0149] S4.3: Transfer all the sample solution after adjustment to the TEVA chromatography resin; wash the beaker 4-5 times with 20mL 0.01mol / L HNO3, and transfer the washing solution to the resin column. - It is adsorbed on the TEVA column, and the uranium matrix is ​​washed off and the eluent is discarded.

[0150] S4.4: Use 20 mol / L HNO3 (i.e., the high concentration HNO3 solution described in the measurement principle) to elute Tc three times, and collect the eluate into a 25 mL volumetric flask. This process is a high acid elution process.

[0151] S4.5: Make up to 25 mL with 0.2 mol / L HNO3 solution.

[0152] S5: ICP-MS measurement

[0153] S5.1: Set the main measurement conditions of ICP-MS to power 1600W, nebulizer flow rate 0.975L / min, auxiliary gas flow rate 1.00L / min, cooling gas flow rate 14.0L / min, and measure the samples in parallel 2 to 3 times.

[0154] S5.2: Inject 3 mL of sample solution into ICP-MS for measurement. After the measurement, record the signal intensity (cps) collected by the instrument and obtain the standard working curve drawn in S1. 99 The concentration of Tc Tc , the unit is micrograms per liter (μg / L);

[0155] S6: Data Processing

[0156] Calculate the sample according to the following formula 99 Tc content:

[0157] ω=c Tc ×v / m

[0158] Where:

[0159] ω——Uranium trioxide sample 99 The content of Tc, in micrograms per gram (μg / g);

[0160] c Tc ——Instrument measurement 99 The concentration of Tc is in micrograms per liter (μg / L);

[0161] V——the volume of HNO3 solution in S4.5, (L)

[0162] m——weight of uranium trioxide sample, (g).

[0163] Weigh 1.4993g of a uranium trioxide sample and measure the content of the eluent by ICP-MS. 99 The concentration of Tc is 0.00157 μg / L. The volume of the sample solution is 25 mL. The measurement result is 3.19×10 -5 μgTc / gU.

[0164] Weigh 1.49996g of a uranium trioxide sample and measure the content of the eluent by ICP-MS. 99 The concentration of Tc is 0.00203 μg / L. The volume of the sample solution is 25 mL. The measurement result is 4.13×10 -5 μgTc / gU.

[0165] Weigh 1.49999g of a uranium trioxide sample and measure the content of the eluent by ICP-MS. 99 The concentration of Tc is 0.00238μg / L. The volume of the sample solution is 25mL. The measurement result is 4.83×10 -4 μgTc / gU.

[0166] The above description is only a preferred embodiment of this patent and is not intended to limit this patent. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this patent should be included in the scope of protection of this patent.

[0167] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0168] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0169] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The optional embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can understand and use the present application well.

Claims

1. A uranium trioxide powder 99 The rapid analytical method for determining Tc content is characterized by: The following steps are involved: S1: drawing of standard curve; S2: sample dissolution; S2.1: Weigh 1.0-1.5g of uranium trioxide sample into a 20-25mL beaker, pipette 3-5mL of 3-4mol / L nitric acid solution into the beaker, completely immerse the uranium trioxide sample, and shake well; S2.2: heating the beaker, evaporating the solution to dryness after dissolution, and cooling to room temperature; S3: Sample price adjustment; S3.1: Add low concentration nitric acid solution to the beaker treated in S2 to dissolve the sample; S3.2: Add potassium dichromate solution to the beaker to form TcO4 - ; S4: column separation; S4.1: Wash TEVA resin with high purity water; S4.2: Pipette low concentration HNO3 into TEVA resin; S4.3: Transfer all the uranium trioxide sample solution adjusted in S3 to the TEVA resin; discard the eluent; S4.4: Elution using high concentration HNO3 solution 99 Tc, that is, by eluting the TEVA resin with a high concentration of HNO3 solution 99 Tc, collect the eluate into a volumetric flask; S4.5: Make up to volume with low concentration HNO3 solution; S5: ICP-MS measurement; S5.1: Set the measurement conditions of ICP-MS; S5.2: Inject the sample solution treated in S4 into ICP-MS for measurement, and obtain the standard curve drawn in S1. 99 The concentration of Tc Tc , unit is μg / L; S6: Data processing; Calculate the uranium trioxide content in the sample according to the following formula 99 Tc content: ω=c Tc ×v / m Where: ω——Uranium trioxide sample 99 Tc content, in μg / g; c Tc ICP-MS measurement 99 The concentration of Tc, in μg / L; V——the fixed volume of HNO3 solution in S4.5, in L; m——mass of uranium trioxide sample, in g.

2. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In S1, a technetium working stock solution was used with a concentration of 2.43×10 -4 g / L, and prepare nitric acid blank, 0.10μg, 0.20μg, 0.3μg, 0.40μg, 0.50μg technetium standard solutions in 10mL volumetric flasks through graded dilution. 99 The mass of Tc is plotted on the horizontal axis, and the corresponding ICP-MS response value is plotted on the vertical axis. 99 The working standard curve of Tc was obtained by fitting 99 Tc linear regression equation, and the linear correlation coefficient>0.

995.

3. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In S2.1, an electronic balance with a sensitivity of 0.01 mg is used; in S2.2, the beaker is placed on a hot plate and the temperature is controlled to be 80° C. to 90° C.

4. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In S3.1, add 2-3 mL of 0.01 mol / L nitric acid solution to a beaker; in S3.2, add 2 drops of 0.5-0.6 mg / mL potassium dichromate solution, shake well, and keep the oxidation time at room temperature for 5-10 minutes to form TcO4 - .

5. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In S4.1, 10-20 mL of high-purity water is used to wash the TEVA resin; in S4.2, 15-20 mL of 0.01 mol / L HNO3 is introduced into the TEVA resin to activate the TEVA resin column at a speed of 3s-4s / drop; In S4.3, 15-20 mL 0.01 mol / L HNO3 was used to wash the beaker 4-5 times, and the washing liquid was transferred to the resin column; in S4.4, 15-20 mol / L HNO3 was used to elute three times 99 Tc.

6. The uranium trioxide powder according to claim 5 99 The rapid analytical method for determining Tc content is characterized by: In S4.4, the eluate is collected into a 25 mL volumetric flask. In S4.5, the volume is fixed to 25 mL with 0.01-0.2 mol / L HNO3 solution.

7. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In S5.1, the measurement conditions of ICP-MS are set to power 1500-1600 W, nebulizer flow 0.8-0.975 L / min, auxiliary gas flow 0.5-1.00 L / min, cooling gas flow 12-14.0 L / min, and the sample is measured in parallel 2-3 times; in S5.2, 2-3 mL of sample solution is injected into ICP-MS for measurement.

8. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In S1, 1.5 g of uranium trioxide sample was weighed into a 20 mL beaker, and 5 mL of 3 mol / L nitric acid solution was transferred into the beaker to completely immerse the uranium trioxide sample.

9. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In the S3.2, 2 drops of 0.5 mg / mL potassium dichromate solution were added.

10. The uranium trioxide powder according to claim 1 99 The rapid analytical method for determining Tc content is characterized by: In S4.4, 15 ml of 9 mol / L HNO3 was used for elution three times. 99 Tc.

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