A method for liquid scintillation measurement 85 Kr Sample Preparation and Collection Device and Method

Abstract

The application relates to a sample preparation and collection device for liquid scintillation measurement 85 Kr sample preparation and collection device and method. The application can collect 85 Kr standard gas source or helium gas containing 85 Kr into liquid 85 Kr in a liquid scintillation vial under the environment of a liquid nitrogen cold trap, and then uses silica gel particles to adsorb and fix the liquid 85 Kr, and then contacts the silica gel particles adsorbing the liquid 85 Kr with scintillation liquid, so that the liquid 85 Kr is dissolved into the scintillation liquid in the liquid scintillation vial, and then the liquid scintillation spectrometer can be used to measure 85 Kr, effectively reduces the detection limit, and accurately measures the actual 85 Kr activity concentration. The provided 85 Kr sample preparation and collection device and method improve sample collection efficiency, ensure 85 Kr sample preparation effect and subsequent measurement.

Description

Technical Field

[0001] This invention belongs to the field of radiation monitoring technology, specifically relating to a method for measuring liquid scintillation. 85 Kr sample preparation and collection device and method. Background Technology

[0002] 85 Kr has a half-life of approximately 10.8 years, with a 99.56% probability of undergoing β decay, a maximum energy of 687 keV, and a 1m... 3 The ambient air contained approximately 1.14 mL of krypton. This is significant for the presence of krypton in ambient air or gaseous effluents. 85 Kr, by utilizing liquid scintillation measurement, can effectively reduce the detection limit, thereby accurately measuring the actual... 85 Kr activity concentration.

[0003] Measurement using liquid scintillation spectrometer 85 When Kr is used, the gas needs to be... 85 Kr dissolves in the scintillation fluid. At room temperature, the solubility of the inert gas Kr in the scintillation fluid is extremely low; without a collection device, it will dissolve significantly. 85 Kr, on the other hand, has extremely low collection efficiency, which may make it impossible to perform radioactivity measurements.

[0004] Therefore, it is necessary to develop a method for liquid scintillation measurement. 85 The Kr sample collection device improves sample collection efficiency and ensures... 85 Kr sample preparation effect. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for measuring liquid scintillation. 85 The Kr sample preparation and collection device and method can solve the problem of measuring Kr using a liquid scintillation spectrometer. 85 The technical challenges of Kr source fabrication make it particularly suitable for liquid scintillation measurements. 85 Kr sample preparation and collection is particularly suitable for collection in 20mL liquid scintillation bottles. 85 Kr created a radioactive measurement source for liquid scintillation spectrometry.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for measuring liquid scintillation. 85 Kr sample collection device, including:

[0007] Collection components, including collection bottle interface, 85 Kr gas source interface, syringe interface, helium interface; wherein, the 85 The Kr gas source interface connects to the first control valve. 85 Kr standard gas source or containing 85Kr's helium gas connection, the helium interface is connected to a high-purity helium storage tank through a third control valve;

[0008] A gas collection bottle, connected to the collection bottle interface; the bottom of the gas collection bottle is lined with silica gel particles;

[0009] Cold trap, used for liquid scintillation measurements 85 During the Kr sample preparation and collection process, the gas collection bottle is placed in liquid nitrogen inside the cold trap;

[0010] A scintillation fluid injector is connected to the injector interface via a second control valve;

[0011] A vacuum pump is connected to the connecting pipe between the third control valve and the high-purity helium storage tank via a fourth control valve.

[0012] The fifth control valve has its first pipeline end connected to the connecting pipe between the helium port and the third control valve, and its second pipeline end connected to the atmosphere.

[0013] Furthermore, the gas collection bottle is a 20 mL low-potassium borosilicate glass flash bottle;

[0014] The gas collection bottle is connected to the collection bottle interface via a thread.

[0015] Furthermore, the first control valve, the second control valve, the third control valve, the fourth control valve, and the fifth control valve are all two-way valves.

[0016] Furthermore, when the first control valve is opened, 85 Kr standard gas source or containing 85 Kr's helium gas along 85 The gas enters the gas collection bottle through the Kr intake pipe;

[0017] The 85 The Kr intake pipe extends all the way into the silicone particles;

[0018] The silica gel particles are white and have a particle size of 40-120 mesh.

[0019] Furthermore, the device also includes a pressure sensor connected to the collecting component;

[0020] The pressure sensor is a pressure sensor with a digital display screen.

[0021] Furthermore, the tubing end connecting the second control valve to the scintillation liquid injector is provided with a scintillation liquid injection needle, and the scintillation liquid injection needle is equipped with a needle valve.

[0022] The present invention also includes a method for measuring liquid scintillation.85 The Kr sample preparation and collection method, the method being based on the method used for liquid scintillation measurement 85 The Kr sample collection device is used to implement this process, which includes the following steps:

[0023] S1. Replace the air in the gas collection bottle with high-purity helium;

[0024] S2, collect containing 85 Kr gas;

[0025] S3, Production 85 Kr measurement source.

[0026] Furthermore, the method for replacing the air in the gas collection bottle with high-purity helium includes the following specific steps:

[0027] S11. With all valves in the device closed, open the third control valve and the fourth control valve, and use a vacuum pump to evacuate the gas collection bottle for a certain period of time, then close the third control valve and the fourth control valve.

[0028] S12. Observe the digital display screen of the pressure sensor. After the negative pressure displayed on the digital display screen of the pressure sensor stabilizes, put the gas collection bottle into the cold trap and immerse the gas collection bottle in the liquid nitrogen in the cold trap.

[0029] S13. Open the third control valve to fill the gas collection bottle with high-purity helium gas, and confirm that the gas collection bottle has returned to normal pressure by checking the pressure displayed on the digital display screen of the pressure sensor.

[0030] Furthermore, the collection contains 85 The method using Kr gas includes the following specific steps:

[0031] S21. Open the first control valve. 85 Kr standard gas source or containing 85 Kr's helium gas along 85 The Kr intake pipe enters the gas collection bottle, which is in a liquid nitrogen cold trap environment; at the same time, the fifth control valve is opened to keep the gas collection bottle open to the atmosphere.

[0032] In collecting 85 When Kr gas is present, two-thirds of the volume of the gas collection bottle is immersed in liquid nitrogen in the cold trap;

[0033] S22, 85 After the Kr gas has been collected, the fifth control valve and the first control valve are closed simultaneously; then the third control valve and the fourth control valve are opened, and the vacuum is evacuated again.

[0034] Furthermore, the aforementioned manufacturing 85 The method for measuring Kr sources includes the following specific steps:

[0035] S31. Injecting scintillation fluid: Close the third control valve and the fourth control valve, connect the scintillation fluid injector to the scintillation fluid injection needle, and when the liquid nitrogen in the cold trap just covers the surface of the silica gel particles in the gas collection bottle, open the second control valve and the needle valve to inject the scintillation fluid into the gas collection bottle; after the scintillation fluid has been completely injected into the gas collection bottle, pull out the scintillation fluid injection needle and close the second control valve at the same time.

[0036] S32. Unscrew the gas collection bottle and quickly put the cap back on to obtain the gas collected by the liquid scintillation spectrometer. 85 Kr measurement source.

[0037] The beneficial effects of this invention are as follows: The liquid scintillation measurement method provided by this invention... 85 The Kr sample preparation and collection device and method, through the setting of collection components, gas collection bottle, cold trap, vacuum pump, scintillation liquid injector, and first control valve, second control valve, third control valve, fourth control valve, fifth control valve, and needle valve, can collect... 85 Kr standard gas source or containing 85 Kr's helium gas was liquefied in a liquid scintillation bottle under liquid nitrogen cold trap conditions. 85 Kr, and uses silica gel particles to adsorb and fix the liquid. 85 Kr, and then adsorbed liquid 85 Kr's silica gel particles come into contact with the scintillation fluid, thereby allowing the liquid to... 85 Kr dissolves in the scintillation fluid within the liquid scintillation bottle, thus enabling measurement using a liquid scintillation spectrometer. 85 Kr effectively reduces the detection limit and accurately measures the actual value. 85 Kr activity concentration. The present invention provides a method for measuring liquid scintillation. 85 The Kr sample preparation and collection device and method improve sample collection efficiency and ensure 85 The invention also demonstrates the effectiveness of Kr sample preparation and subsequent measurements. Furthermore, it provides a novel technical approach for the collection of other radioactive inert gases that can be measured using liquid scintillation spectrometry. Attached Figure Description

[0038] Figure 1 The liquid scintillation measurement provided for embodiments of the present invention 85 Schematic diagram of the Kr sample preparation and collection device;

[0039] Figure 2 The liquid scintillation measurement provided for embodiments of the present invention 85 A schematic diagram of the Kr sample preparation and collection device.

[0040] Figure 3 The liquid scintillation measurement provided for embodiments of the present invention 85A flowchart illustrating the Kr sample preparation and collection method. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be further clearly and completely described below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that in the description of the embodiments of the present invention, the terms "upper," "lower," "front," "rear," "front face," "back face," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] To address the challenge of the extremely low solubility of inert gas Kr in scintillation fluid at room temperature, this invention provides a method for measuring liquid scintillation. 85 The Kr sample preparation and collection device and method utilize the properties of the inert gas Kr, which has a melting point of -156℃ and a boiling point of -153℃. Firstly, the sample is collected... 85 Kr standard gas source or containing 85 Kr's helium gas was liquefied in a liquid scintillation bottle under liquid nitrogen cold trap conditions. 85 Kr, and uses silica gel particles to adsorb and fix the liquid. 85 Kr, and then adsorbed liquid 85 Kr's silica gel particles come into contact with the scintillation fluid, thereby allowing the liquid to... 85 Kr dissolves in the scintillation fluid within the liquid scintillation bottle, thus enabling measurement using a liquid scintillation spectrometer. 85 Kr effectively reduces the detection limit and accurately measures the actual value. 85 Kr activity concentration.

[0044] like Figure 1 As shown, this embodiment provides a method for measuring liquid scintillation. 85 The Kr sample preparation and collection device mainly includes: a collection component, a gas collection bottle, a cold trap, a vacuum pump, and a scintillation liquid injector.

[0045] The collection component includes a collection bottle interface, 85The system includes a Kr gas source interface, a syringe interface, and a helium interface, wherein the collection bottle interface is threadedly connected to the gas collection bottle. 85 The Kr gas source interface connects to the first control valve V1. 85 Kr standard gas source or containing 85 The helium gas connection of Kr is such that the syringe interface is connected to the scintillation liquid syringe through the second control valve V2, and the helium interface is connected to the high-purity helium storage tank through the third control valve V3.

[0046] During liquid scintillation measurement 85 During the Kr sample collection process, the gas collection bottle is placed in the coolant of the cold trap;

[0047] Specifically, the gas collection bottle is a 20mL low-potassium borosilicate glass flash bottle. The bottom of the gas collection bottle is lined with white silica gel particles with a particle size of 40–120 mesh.

[0048] Optionally, when the first control valve V1 is opened, 85 Kr standard gas source or containing 85 Kr's helium gas along 85 The Kr intake pipe enters the gas collection bottle, 85 The Kr intake pipe extends all the way into the silicone particles.

[0049] Optionally, the amount of silica gel particles used is 1 to 3 g.

[0050] Optionally, the cold trap is a liquid nitrogen cold trap, wherein the coolant is liquid nitrogen.

[0051] The vacuum pump is connected to the connecting pipe between the third control valve V3 and the high-purity helium storage tank via the fourth control valve V4.

[0052] The first pipeline end of the fifth control valve V5 is connected to the connecting pipeline between the helium port and the third control valve V3, and the second pipeline end of the fifth control valve V5 is open to the atmosphere.

[0053] Optionally, the device further includes a pressure sensor connected to the collecting component. The pressure sensor is a pressure sensor with a digital display screen, capable of displaying the positive and negative pressure values ​​inside the gas collecting bottle in real time.

[0054] Specifically, a sealing silicone gasket is provided between the collection bottle interface and the gas collection bottle to ensure... 85 During the Kr sample preparation and collection process, the collection bottle interface is sealed to the gas collection bottle.

[0055] In one specific embodiment, the first control valve V1, the second control valve V2, the third control valve V3, the fourth control valve V4, and the fifth control valve V5 are all stainless steel two-way valves.

[0056] A scintillation fluid injection needle is pre-installed in the tubing connecting the second control valve V2 and the scintillation fluid injector. A needle valve V6 is installed on the scintillation fluid injection needle. The scintillation fluid injector is connected to the second control valve V2 via the scintillation fluid injection needle.

[0057] In this embodiment, a liquid scintillation measurement method is also provided. 85 The Kr sample preparation and collection method, the method being based on the method used for liquid scintillation measurement 85 The method is implemented using a Kr sample collection device; the method includes the following steps:

[0058] S1. Replace the air in the gas collection bottle with high-purity helium;

[0059] Before replacing the air in the gas collection bottle with high-purity helium, check and confirm the sealed and secure connection between the gas collection bottle and the collection bottle interface, and also check the connection used for liquid scintillation measurement. 85 The sealing connections of each component in the Kr sample collection device and the smooth opening and closing of valves are all ensured.

[0060] The method of replacing the air in the gas collection bottle with high-purity helium includes the following steps:

[0061] S11. With all valves in the device closed (i.e., the first control valve V1, the second control valve V2, the third control valve V3, the fourth control valve V4, the fifth control valve V5, and the needle valve V6 are all closed), open the third control valve V3 and the fourth control valve V4, and use a vacuum pump to evacuate the gas collection bottle for a certain period of time, then close the third control valve V3 and the fourth control valve V4.

[0062] S12. Observe the digital display screen of the pressure sensor. After the negative pressure displayed on the digital display screen of the pressure sensor stabilizes, put the gas collection bottle into the cold trap and immerse the gas collection bottle in the liquid nitrogen in the cold trap.

[0063] S13. Open the third control valve V3 to fill the gas collection bottle with high-purity helium. Confirm that the gas collection bottle has returned to normal pressure by checking the pressure displayed on the digital display screen of the pressure sensor.

[0064] In one specific embodiment, the gas collecting bottle is threadedly connected to the collecting bottle interface, and a sealing silicone gasket is provided between the collecting bottle interface and the gas collecting bottle to ensure that... 85 During the Kr sample preparation and collection process, the gas collection bottle and the collection bottle interface are in a sealed and fixed connection state.

[0065] Replacing the air in the gas collection bottle with high-purity helium can prevent other gases in the air from liquefying at low temperatures and being adsorbed into the silica gel particles.

[0066] S2, collect containing 85 Kr gas;

[0067] In collecting 85 When Kr gas is present, two-thirds of the volume of the gas collection bottle is immersed in liquid nitrogen in the cold trap.

[0068] In this embodiment, the collection contains 85 The method using Kr gas includes the following steps:

[0069] S21. Open the first control valve V1. 85 Kr standard gas source or containing 85 Kr's helium gas along 85 The Kr intake pipe enters the gas collection bottle, which is in a liquid nitrogen cold trap environment; at the same time, the fifth control valve V5 is opened to keep the gas collection bottle connected to the atmosphere, so that the inside of the gas collection bottle is kept at normal pressure.

[0070] Specifically, the aforementioned 85 The Kr intake pipe extends all the way into the silica gel granules laid at the bottom of the gas collection bottle. 85 Kr standard gas source or containing 85 When Kr's helium gas enters the cryogenic gas collection bottle, 85 Kr will liquefy and adhere to the silica gel particles laid at the bottom of the gas collection bottle and the inner wall of the gas collection bottle, with a portion of it adsorbed and fixed within the silica gel particles.

[0071] S22, 85 After the Kr gas has been collected, simultaneously close the fifth control valve V5 and the first control valve V1. Then open the third control valve V3 and the fourth control valve V4, and evacuate again.

[0072] In one specific embodiment 85 Kr gas is supplied by a gas chromatography workstation, therefore, the collection of Kr gas is performed. 85 The start time and collection completion time of Kr gas correspond to the times obtained by the gas chromatography workstation. 85 Kr peak start and end times.

[0073] S3, Production 85 Kr measurement source;

[0074] In this embodiment, the fabrication 85 The method for measuring the Kr source includes the following steps:

[0075] S31. Injecting scintillation fluid: Close the third control valve V3 and the fourth control valve V4. Connect the scintillation fluid syringe containing 18 mL of scintillation fluid to the scintillation fluid injection needle. When the liquid nitrogen in the cold trap just covers the surface of the silica gel particles in the gas collection bottle, open the second control valve V2 and the needle valve V6 to quickly inject the scintillation fluid into the gas collection bottle. After the scintillation fluid has been completely injected into the gas collection bottle, pull out the scintillation fluid injection needle and close the second control valve V2 at the same time.

[0076] Adsorbed liquid 85 Kr's silica gel particles come into contact with the scintillation fluid in the injected gas collection bottle, and the liquid in the silica gel particles... 85 Kr desorbs and dissolves into the scintillation fluid, thus allowing the liquid to... 85 Kr dissolved in the scintillation fluid inside the gas collection bottle.

[0077] In this embodiment, the timing of rapidly injecting the scintillation fluid into the gas collection bottle is chosen when the liquid nitrogen in the cold trap just covers the surface of the silica gel particles in the gas collection bottle. This is because if the liquid nitrogen submerges the gas collection bottle too much, the scintillation fluid entering the bottle will prematurely come into contact with the low temperature, thus preventing the scintillation fluid from reaching the liquid state. 85 Kr becomes viscous, which is not conducive to a liquid state. 85 Kr dissolves in the scintillation fluid; if the liquid nitrogen immersion in the gas collection bottle is insufficient, the liquid adsorbed in the silica gel particles will... 85 Kr will desorb prematurely due to increased temperature, leading to the liquid dissolving in the scintillation fluid. 85 Kr decreases, reduces 85 The collection efficiency of Kr.

[0078] S32. Unscrew the gas collection bottle and quickly put the cap back on to obtain the gas collected by the liquid scintillation spectrometer. 85 Kr measurement source; thus enabling measurement using a liquid scintillation spectrometer. 85 Kr effectively reduces the detection limit and accurately measures the actual value. 85 Kr activity concentration.

[0079] Obviously, the above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for measuring liquid scintillation. 85 The Kr sample preparation and collection device is characterized by... include: Collection components, including collection bottle interface, 85 Kr gas source interface, syringe interface, helium interface; wherein, the 85 The Kr gas source interface connects to the first control valve. 85 Kr standard gas source or containing 85 Kr's helium gas connection, the helium interface is connected to a high-purity helium storage tank through a third control valve; A gas collection bottle, connected to the collection bottle interface; the bottom of the gas collection bottle is lined with silica gel particles; when the first control valve is opened, 85 Kr standard gas source or containing 85 Kr's helium gas along 85 The Kr intake pipe leads into the gas collection bottle; 85 The Kr intake pipe extends all the way into the silicone particles; Cold trap, used for liquid scintillation measurements 85 During the Kr sample preparation and collection process, the gas collection bottle is placed in liquid nitrogen inside the cold trap; A scintillation liquid injector is connected to the injector interface via a second control valve; the end of the tubing connecting the second control valve to the scintillation liquid injector is provided with a scintillation liquid injection needle, and the scintillation liquid injection needle is equipped with a needle valve. A vacuum pump is connected to the connecting pipe between the third control valve and the high-purity helium storage tank via a fourth control valve. The fifth control valve has its first pipeline end connected to the connecting pipe between the helium port and the third control valve, and its second pipeline end connected to the atmosphere.

2. The liquid scintillation measurement according to claim 1 85 The Kr sample preparation and collection device is characterized by... The gas collection bottle is a 20 mL low-potassium borosilicate glass flash bottle; The gas collection bottle is connected to the collection bottle interface via a thread.

3. A liquid scintillation measurement according to claim 1 85 The Kr sample preparation and collection device is characterized by... The first control valve, the second control valve, the third control valve, the fourth control valve, and the fifth control valve are all two-way valves.

4. A liquid scintillation measurement according to claim 1 85 The Kr sample preparation and collection device is characterized by... The silica gel particles are white and have a particle size of 40-120 mesh.

5. A liquid scintillation measurement device according to any one of claims 1-4. 85 The Kr sample preparation and collection device is characterized by... The device also includes a pressure sensor connected to the collecting component; The pressure sensor is a pressure sensor with a digital display screen.

6. A method for measuring liquid scintillation. 85 The Kr sample preparation and collection method is characterized by... The method is based on the liquid scintillation measurement described in claim 5. 85 The Kr sample collection device is used to implement this process, which includes the following steps: S1. Replace the air in the gas collection bottle with high-purity helium; S2, collect containing 85 Kr gas; S3, Production 85 Kr measurement source.

7. A liquid scintillation measurement according to claim 6 85 The Kr sample preparation and collection method is characterized by... The method for replacing the air in the gas collection bottle with high-purity helium includes the following specific steps: S11. With all valves in the device closed, open the third control valve and the fourth control valve, and use a vacuum pump to evacuate the gas collection bottle for a certain period of time, then close the third control valve and the fourth control valve. S12. Observe the digital display screen of the pressure sensor. After the negative pressure displayed on the digital display screen of the pressure sensor stabilizes, put the gas collection bottle into the cold trap and immerse the gas collection bottle in the liquid nitrogen in the cold trap. S13. Open the third control valve to fill the gas collection bottle with high-purity helium gas, and confirm that the gas collection bottle has returned to normal pressure by checking the pressure displayed on the digital display screen of the pressure sensor.

8. A liquid scintillation measurement according to claim 6 85 The Kr sample preparation and collection method is characterized by... The collection contains 85 The method using Kr gas includes the following specific steps: S21. Open the first control valve. 85 Kr standard gas source or containing 85 Kr's helium gas along 85 The Kr intake pipe enters the gas collection bottle, which is in a liquid nitrogen cold trap environment; at the same time, the fifth control valve is opened to keep the gas collection bottle open to the atmosphere. In collecting 85 When Kr gas is present, two-thirds of the volume of the gas collection bottle is immersed in liquid nitrogen in the cold trap; S22, 85 After the Kr gas has been collected, the fifth control valve and the first control valve are closed simultaneously; then the third control valve and the fourth control valve are opened, and the vacuum is evacuated again.

9. A liquid scintillation measurement according to claim 8 85 The Kr sample preparation and collection method is characterized by... The production 85 The method for measuring Kr sources includes the following specific steps: S31. Injecting scintillation fluid: Close the third control valve and the fourth control valve, connect the scintillation fluid injector to the scintillation fluid injection needle, and when the liquid nitrogen in the cold trap just covers the surface of the silica gel particles in the gas collection bottle, open the second control valve and the needle valve to inject the scintillation fluid into the gas collection bottle; after the scintillation fluid has been completely injected into the gas collection bottle, pull out the scintillation fluid injection needle and close the second control valve at the same time. S32. Unscrew the gas collection bottle and quickly put the cap back on to obtain the gas collected by the liquid scintillation spectrometer. 85 Kr measurement source.

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