Method for analyzing nitrogen isotope in lunar soil

Abstract

The invention discloses a method for analyzing nitrogen isotope in lunar soil, and relates to the technical field of lunar soil analys.The method comprises the steps that an analysis system composed of a heating cavity and a quadrupole mass spectrometer is prepared, and a connecting pipe is provided with a control valve; preparing a plurality of mixed gases of carbon monoxide and nitrogen in different proportions, measuring and recording the gas pressure linear change slope through an analysis system, and establishing a database; lunar soil is put into a heating cavity to be heated, precipitated gas is measured, the slope is recorded, the mixing proportion is determined according to the measured slope and a database, and the nitrogen isotope ratio is obtained by deducting the amount of carbon monoxide. The method effectively avoids carbon monoxide interference, improves measurement accuracy, is simple and convenient to operate, reduces in-orbit measurement load weight, and provides a reliable analysis means for scientific research of the moon and the planet.

Description

Technical Field

[0001] The present invention relates to the technical field of lunar soil analysis, and particularly to a method for analyzing nitrogen isotopes in lunar soil. Background Art

[0002] In the field of astrophysics research, in-depth exploration of lunar materials is crucial for revealing the formation and evolution mechanisms of the moon. The analysis of nitrogen isotopes plays a unique and key role in this research.

[0003] Nitrogen isotope analysis can help researchers determine the source of lunar materials and gain an in-depth understanding of the evolution process of volatile elements after the formation of the moon. Through a detailed analysis of the nitrogen isotope distribution in lunar soil and rocks, the migration law of volatile substances inside the moon and the cycle and change of nitrogen elements during the long-term evolution of the moon can be clarified. At the same time, analyzing the proportion of nitrogen isotopes in lunar soil can also be used to study the composition of nitrogen in the solar wind and its dynamic changes over time, and thus indirectly trace the evolution history of the solar wind.

[0004] In addition, the source of nitrogen on the lunar surface is relatively complex, not only from the solar wind, but also possibly from the impact of extraterrestrial materials such as comets and asteroids. The compositional characteristics of nitrogen isotopes are like "fingerprints" that can effectively distinguish these substances from different sources and provide important clues for in-depth research on the input of extraterrestrial materials. Moreover, comparing the composition of nitrogen isotopes on the lunar surface with the nitrogen isotope characteristics of planets such as the Earth and Mars helps researchers establish a more accurate material exchange model for the planetary system.

[0005] Currently, there are two stable isotopes of nitrogen, namely nitrogen-14 and nitrogen-15. By analyzing the ratio of the mass-to-charge ratios of nitrogen gas at 28 and 29, the compositional information of its isotopes can be obtained. However, in the actual measurement process, a severe technical problem is faced: the mass number of carbon monoxide released by heating is the same as that of nitrogen gas at 28. In the mass spectrometer analysis, carbon monoxide will interfere with the position of the nitrogen peak, resulting in deviation of the measurement result and inability to accurately obtain the compositional information of nitrogen isotopes, seriously affecting the accuracy and reliability of the analysis of lunar soil nitrogen isotopes and hindering the in-depth development of related research.

[0006] Therefore, there is an urgent need to develop a method that can effectively avoid the interference of carbon monoxide and accurately analyze the nitrogen isotopes in lunar soil to promote the further development of lunar science research and related fields of planetary science. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for analyzing nitrogen isotopes in lunar soil to solve the problems existing in the above-mentioned prior art and obtain the relative proportions of nitrogen-14 and nitrogen-15 in the gas released from lunar soil.

[0008] To achieve the above purpose, the present invention provides the following solution:

[0009] The present invention provides a method for analyzing nitrogen isotopes in lunar soil, comprising:

[0010] (1) Preparing an analysis system, the analysis system includes a heating chamber and a quadrupole mass spectrometer. Connect the gas outlet of the heating chamber to the gas inlet of the quadrupole mass spectrometer through a connecting pipe, and a control valve is arranged on the connecting pipe, and the control valve is used to control the on-off of the connecting pipe;

[0011] (2) Preparing multiple portions of mixed gas, each portion of the mixed gas includes carbon monoxide and nitrogen, and the mixing ratios of carbon monoxide and nitrogen in different mixed gases are different; then, sequentially measure each portion of the mixed gas through the analysis system. During the measurement, let the mixed gas enter the heating chamber, and then enter the quadrupole mass spectrometer through the connecting pipe. Screen ions with a mass-to-charge ratio of 28 through the quadrupole mass spectrometer, and record the curve slope when the air pressure in the quadrupole mass spectrometer changes linearly with time when each portion of the mixed gas is measured, and denote it as the calibration slope; establish a database according to the mixing ratio of carbon monoxide and nitrogen in each portion of the mixed gas and the corresponding calibration slope, and draw a curve graph of the calibration slope changing with the mixing ratio;

[0012] (3) Put the lunar soil to be analyzed into the heating chamber for heating, so that the lunar soil releases gas. Detect the intensities of ions with a mass-to-charge ratio of 28 and ions with a mass-to-charge ratio of 29 in the gas released by the lunar soil through the quadrupole mass spectrometer, and record the curve slope when the air pressure in the quadrupole mass spectrometer changes linearly with time when detecting the intensity of ions with a mass-to-charge ratio of 28, and denote it as the measurement slope; then calculate the relative proportion of ions with a mass-to-charge ratio of 28 to ions with a mass-to-charge ratio of 29. According to the measurement slope, the database and the curve graph, analyze and obtain the mixing ratio of carbon monoxide and nitrogen in the gas released by the lunar soil. Then, on the basis of the relative proportion, calculate the proportion of the remaining ions with a mass-to-charge ratio of 28 to ions with a mass-to-charge ratio of 29 after deducting the amount of carbon monoxide in the ions with a mass-to-charge ratio of 28, which is the relative proportion of nitrogen-14 and nitrogen-15 in the gas released by the lunar soil.

[0013] Preferably, the heating chamber includes a housing and a heating element attached to the outer wall of the housing; the housing is airtight; and a movable door is arranged on the housing.

[0014] Preferably, the heating element adopts an electric heating plate.

[0015] Preferably, the material of the housing adopts titanium alloy.

[0016] Preferably, the analysis system further includes a first storage tank and a second storage tank. The first storage tank is communicated with the housing through a first pipeline, and the second storage tank is communicated with the housing through a second pipeline. A first air pump and a first gas flowmeter are arranged on the first pipeline, and the first gas flowmeter is closer to the housing than the first air pump. A second air pump and a second gas flowmeter are arranged on the second pipeline, and the second gas flowmeter is closer to the housing than the second air pump.

[0017] Preferably, the analysis system further includes a control unit. The first gas flowmeter and the second gas flowmeter are respectively connected to the control unit in a signal manner. The control unit can close the first air pump when the detected value of the first gas flowmeter reaches a set value, and the control unit can close the second air pump when the detected value of the second gas flowmeter reaches a set value.

[0018] Preferably, the control unit adopts an FPGA.

[0019] Preferably, a first valve and a second valve are further arranged on the first pipeline. The first valve is located between the first storage tank and the first air pump, and the second valve is located between the first gas flowmeter and the housing. A third valve and a fourth valve are further arranged on the second pipeline. The third valve is located between the second storage tank and the second air pump, and the fourth valve is located between the second gas flowmeter and the housing.

[0020] Preferably, the analysis system further includes a first vacuum pump and a second vacuum pump. The heating chamber is communicated with the suction port of the first vacuum pump through a third pipeline, and a fifth valve is arranged on the third pipeline. The gas outlet of the quadrupole mass spectrometer is communicated with the suction port of the second vacuum pump through a fourth pipeline.

[0021] Preferably, the first valve, the second valve, the third valve, the fourth valve, the fifth valve and the control valve all adopt solenoid valves.

[0022] The present invention has achieved the following technical effects compared with the prior art:

[0023] In the prior art, the carbon monoxide released by heating has the same mass number as nitrogen, which is 28, and will interfere with the position of the nitrogen peak in the mass spectrometer, seriously affecting the accuracy of lunar soil nitrogen isotope analysis. The present invention uses a mixed gas of carbon monoxide and nitrogen with different mixing ratios to calibrate the slope of the curve of the internal pressure of the quadrupole mass spectrometer changing linearly with time, and establishes a database; when analyzing the gas released from lunar soil, the mixing ratio is determined based on the measured slope and the database, and then the amount of carbon monoxide is deducted, effectively avoiding the interference of carbon monoxide on the measurement of nitrogen isotopes, significantly improving the accuracy and reliability of the lunar soil nitrogen isotope analysis results, and providing more accurate data support for related research.

[0024] Furthermore, the method for analyzing nitrogen isotopes in lunar soil of the present invention only needs to construct an analysis system composed of a heating chamber and a quadrupole mass spectrometer, and realizes the control of gas on and off by controlling the valve. During the measurement process, slope data is obtained by using the linear change of pressure with time, and the operation process is relatively simple and clear. It neither requires complex chemical reactions to convert carbon monoxide into other gases, nor uses physical removal means such as molecular sieves or membrane filtration, and there is no need to increase the mass analysis range of the mass spectrometer, avoiding the increase in the weight of the on-orbit measurement load due to the adoption of these methods, reducing the experimental cost and operation difficulty, and having high feasibility and practicality in practical applications.

[0025] Furthermore, the method for analyzing nitrogen isotopes in lunar soil of the present invention solves the measurement interference problem in the prior art, can obtain the accurate nitrogen isotope ratio in lunar soil, provides a reliable technical means for these studies, helps to promote the further in-depth development of lunar science research and related fields of planetary science, and has important scientific value and research significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a schematic structural diagram of the analysis system in the method for analyzing nitrogen isotopes in lunar soil of the present invention;

[0028] Figure 2 It is a schematic structural diagram of the heating chamber in the analysis system of the present invention;

[0029] Figure 3 It is a graph of the change of the internal pressure of the quadrupole mass spectrometer with time;

[0030] In the figure: 1. Heating cavity; 101. Housing; 102. Heating element; 103. Movable door; 2. Quadrupole mass spectrometer; 3. First storage tank; 4. First air pump; 5. First gas flowmeter; 6. Second storage tank; 7. Second air pump; 8. Second gas flowmeter; 9. First vacuum pump; 10. Second vacuum pump; 11. First valve; 12. Second valve; 13. Third valve; 14. Fourth valve; 15. Fifth valve; 16. Control valve. Detailed implementation manners

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] The purpose of the present invention is to provide a method for analyzing nitrogen isotopes in lunar soil to solve the problems existing in the above-mentioned prior art and obtain the relative proportions of nitrogen-14 and nitrogen-15 in the gas released from lunar soil.

[0033] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0034] As Figures 1 to 3 shown, this embodiment provides a method for analyzing nitrogen isotopes in lunar soil, including:

[0035] (1) Prepare an analysis system. The analysis system includes a heating cavity 1 and a quadrupole mass spectrometer 2. Connect the air outlet of the heating cavity 1 to the air inlet of the quadrupole mass spectrometer 2 through a connecting pipe, and a control valve 16 is arranged on the connecting pipe. The control valve 16 is used to control the on-off of the connecting pipe;

[0036] (2) Prepare multiple portions of mixed gas. Each portion of mixed gas includes carbon monoxide and nitrogen, and the mixing ratios of carbon monoxide and nitrogen in different mixed gases are different; then, measure each portion of mixed gas in turn through the analysis system. During the measurement, make the mixed gas flow into the heating cavity 1, and then enter the quadrupole mass spectrometer 2 through the connecting pipe. Screen ions with a mass-to-charge ratio of 28 through the quadrupole mass spectrometer 2, and record the slope of the curve when the air pressure in the quadrupole mass spectrometer 2 changes linearly with time when each portion of mixed gas is measured, and record it as the calibration slope; establish a database according to the mixing ratio of carbon monoxide and nitrogen in each portion of mixed gas and the corresponding calibration slope, and draw a curve graph of the calibration slope changing with the mixing ratio;

[0037] (3) Place the lunar soil to be analyzed into the heating chamber 1 for heating so that the lunar soil releases gas. Detect the intensities of the ions with mass-to-charge ratio of 28 and the ions with mass-to-charge ratio of 29 in the gas released from the lunar soil by the quadrupole mass spectrometer 2, and record the curve slope when the air pressure in the quadrupole mass spectrometer 2 changes linearly with time when detecting the intensity of the ions with mass-to-charge ratio of 28, and denote it as the measurement slope. Then calculate the relative proportion of the ions with mass-to-charge ratio of 28 to the ions with mass-to-charge ratio of 29. Analyze the mixing ratio of carbon monoxide and nitrogen in the gas released from the lunar soil based on the measurement slope, the database and the curve graph. Then, on the basis of the relative proportion, calculate the proportion of the remaining ions with mass-to-charge ratio of 28 to the ions with mass-to-charge ratio of 29 after deducting the amount of carbon monoxide in the ions with mass-to-charge ratio of 28, which is the relative proportion of nitrogen-14 and nitrogen-15 in the gas released from the lunar soil.

[0038] Regarding the phenomenon that the air pressure changes linearly with time during the measurement of the mixed gas by the quadrupole mass spectrometer 22, the specific description is as follows:

[0039] Assume that the partial pressure of the gas to be measured in the heating chamber 11 is P1. Open the control valve 163 and introduce the gas into the quadrupole mass spectrometer 22 through the connecting pipe 4. Here, define the partial pressure of this gas in the mass spectrometer chamber as P2. At this time, define the inlet gas conductance of the quadrupole mass spectrometer 22 as U1 and the exhaust gas conductance as U2. At the same time, assume that the lunar surface environment is an absolute vacuum. Since the exhaust gas volume is relatively small compared to the inlet gas volume during the pressure balance process of the two, assume that the partial pressure P1 before inlet remains unchanged. Then, after the two are balanced, the following relational expression is satisfied: P1 * U1 = P2 * U2; and the actual situation is that the air pressure in the mass spectrometer chamber first increases rapidly, and then gradually decreases as ionization and exhaust occur. When the gas is in a stable equilibrium, the air pressure basically decreases linearly, and its change with time is as Figure 3 shown;

[0040] The slope of the air pressure change curve after equilibrium mainly varies due to different gas discharge rates and ionization efficiencies. And this air pressure change enables the quadrupole mass spectrometer 2 to measure the mass-to-charge ratios of 28 and 29 respectively throughout the entire cycle of air pressure change. After measuring the calibration slopes during the measurement of nitrogen and carbon monoxide with different mixing ratios and establishing a database, draw a curve graph of the calibration slope changing with the mixing ratio. When measuring a mixture of nitrogen and carbon monoxide with an unknown ratio, the slope of the change curve of the peak height of the ions with mass-to-charge ratio of 28 after stabilization can reflect the mixing ratio of nitrogen and carbon monoxide; then, after deducting the amount of carbon monoxide from the total amount of the ions with mass-to-charge ratio of 28 according to the mixing ratio of nitrogen and carbon monoxide mentioned above, the relative proportion of nitrogen-14 and nitrogen-15 in the gas released from the lunar soil can be obtained.

[0041] In this embodiment, by using a mixed gas of carbon monoxide and nitrogen with different mixing ratios, the slope of the curve of the linear change of the air pressure in the quadrupole mass spectrometer 2 with time is calibrated, a database is established, and a curve graph of the calibrated slope changing with the mixing ratio is plotted; when analyzing the outgassing of lunar soil, the mixing ratio is determined based on the measured slope and the database, and then the amount of carbon monoxide is deducted, effectively avoiding the interference of carbon monoxide on the measurement of nitrogen isotopes, significantly improving the accuracy and reliability of the analysis results of lunar soil nitrogen isotopes, and providing more accurate data support for related research.

[0042] The heating cavity 1 is a containing cavity, as long as it can achieve heating of the substances in the cavity; in this embodiment, as Figure 2 shown, the heating cavity 1 includes a housing 101 and a heating element 102 attached to the outer wall of the housing 101; the housing 101 is airtight, and a movable door 103 is provided on the housing 101; the movable door 103 is provided to facilitate the addition of lunar soil into the heating cavity 1. It is easy to understand that the movable door 103 can be opened and closed. It should be noted that, in order to improve the heating effect, the heating element 102 can cover the entire outer wall of the housing 101 and the outer wall of the movable door 103. In practical applications, technicians can adaptively adjust the installation position and quantity of the heating element 102 according to actual needs.

[0043] In an alternative solution of this embodiment, the heating element 102 is an electric heating plate, which is attached to the outer wall of the housing 101. The electric heating plate can quickly heat the housing 101, and the temperature distribution of the electric heating plate is uniform, which can improve the uniformity of heating of the housing 101.

[0044] In an alternative solution of this embodiment, the material of the housing 101 is titanium alloy. Titanium alloy has high strength and can withstand large external forces and pressures, ensuring that the housing 101 maintains a stable structure and is not easily deformed under various complex working environments. At the same time, its density is relatively small, much lighter than many traditional metal materials such as steel. For some equipment or products with weight requirements, this helps to reduce the overall weight, improve the transportation efficiency, reduce energy consumption, and enhance the portability of the equipment.

[0045] In an alternative embodiment of the present embodiment, preferably, the analysis system further includes a first storage tank 3 and a second storage tank 6. The first storage tank 3 is connected to the housing 101 through a first pipeline, and the second storage tank 6 is connected to the housing 101 through a second pipeline. The first storage tank 3 is used to store CO, and the second storage tank 6 is used to store nitrogen. A first air pump 4 and a first gas flowmeter 5 are provided on the first pipeline. The first gas flowmeter 5 is closer to the housing 101 than the first air pump 4. The coordinated operation of the first air pump 4 and the first gas flowmeter 5 can achieve the quantitative delivery of carbon monoxide gas. A second air pump 7 and a second gas flowmeter 8 are provided on the second pipeline. The second gas flowmeter 8 is closer to the housing 101 than the second air pump 7. The coordinated operation of the second gas flowmeter 8 and the second air pump 7 can achieve the quantitative delivery of nitrogen to the heating chamber 1, facilitating the control of the mixing ratio of carbon monoxide and nitrogen.

[0046] In an alternative embodiment of the present embodiment, preferably, the analysis system further includes a control unit. The first gas flowmeter 5 and the second gas flowmeter 8 are respectively connected to the control unit in a signal manner. The control unit can turn off the first air pump 4 when the detected value of the first gas flowmeter 5 reaches the set value, and the control unit can turn off the second air pump 7 when the detected value of the second gas flowmeter 8 reaches the set value. By setting the set values of carbon monoxide gas and nitrogen gas in the control unit, it is possible to automatically turn off the corresponding air pumps after delivering the set amounts of carbon monoxide and nitrogen, improving the automation.

[0047] In an alternative embodiment of the present embodiment, the control unit uses an FPGA. An FPGA is an existing programmable logic chip, and its working principle and the like will not be elaborated in this embodiment.

[0048] In an alternative embodiment of the present embodiment, preferably, a first valve 11 and a second valve 12 are further provided on the first pipeline. The first valve 11 is located between the first storage tank 3 and the first air pump 4, and the second valve 12 is located between the first gas flowmeter 5 and the housing 101. A third valve 13 and a fourth valve 14 are further provided on the second pipeline. The third valve 13 is located between the second storage tank 6 and the second air pump 7, and the fourth valve 14 is located between the second gas flowmeter 8 and the housing 101.

[0049] In an alternative embodiment of the present embodiment, preferably, the analysis system further includes a first vacuum pump 9 and a second vacuum pump 10. The heating chamber 1 is connected to the suction port of the first vacuum pump 9 through a third pipeline, and a fifth valve 15 is provided on the third pipeline; the outlet of the quadrupole mass spectrometer 2 is connected to the suction port of the second vacuum pump 10 through a fourth pipeline. The reason for setting the first vacuum pump 9 is that before introducing the mixed gas into the heating chamber 1, the heating chamber 1 can be evacuated by the first vacuum pump 9 to prevent the original gas in the heating chamber 1 from mixing into the mixed gas and affecting the detection result; similarly, before using the quadrupole mass spectrometer 2 for detection, the cavity of the quadrupole mass spectrometer 2 can be evacuated by the second vacuum pump 10 to prevent the original gas in the cavity of the quadrupole mass spectrometer 2 from affecting the detection result.

[0050] In an alternative embodiment of the present embodiment, preferably, the first valve 11, the second valve 12, the third valve 13, the fourth valve 14, the fifth valve 15 and the control valve 16 all adopt solenoid valves; the response speed of the solenoid valve is extremely fast, and it can realize the opening and closing actions in a short time.

[0051] Specific examples are used in the present invention to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for analyzing nitrogen isotopes in lunar soil, characterized in that, Comprising: (1) Prepare an analysis system, the analysis system includes a heating chamber and a quadrupole mass spectrometer, connect the gas outlet of the heating chamber to the gas inlet of the quadrupole mass spectrometer through a connecting pipe, and a control valve is arranged on the connecting pipe, and the control valve is used to control the on-off of the connecting pipe; (2) Prepare multiple portions of mixed gas, each portion of the mixed gas includes carbon monoxide and nitrogen, and the mixing ratios of carbon monoxide and nitrogen in different mixed gases are different; then, measure each portion of the mixed gas sequentially through the analysis system. During measurement, make the mixed gas enter the heating chamber, and then enter the quadrupole mass spectrometer through the connecting pipe. Screen ions with a mass-to-charge ratio of 28 through the quadrupole mass spectrometer, and record the curve slope when the air pressure in the quadrupole mass spectrometer changes linearly with time when each portion of the mixed gas is measured, and denote it as the calibration slope; establish a database according to the mixing ratio of carbon monoxide and nitrogen in each portion of the mixed gas and the corresponding calibration slope, and draw a curve graph of the calibration slope changing with the mixing ratio; (3) Place the lunar soil to be analyzed in the heating chamber for heating to cause the lunar soil to release gas. Detect the intensities of ions with a mass-to-charge ratio of 28 and ions with a mass-to-charge ratio of 29 in the gas released by the lunar soil through the quadrupole mass spectrometer, and record the curve slope when the air pressure in the quadrupole mass spectrometer changes linearly with time when detecting the intensity of ions with a mass-to-charge ratio of 28, and denote it as the measurement slope; then calculate the relative proportion of ions with a mass-to-charge ratio of 28 to ions with a mass-to-charge ratio of 29. Analyze the mixing ratio of carbon monoxide and nitrogen in the gas released by the lunar soil based on the measurement slope, the database, and the curve graph. Then, on the basis of the relative proportion, calculate the proportion of the remaining ions with a mass-to-charge ratio of 28 to ions with a mass-to-charge ratio of 29 after deducting the amount of carbon monoxide in the ions with a mass-to-charge ratio of 28, which is the relative proportion of nitrogen-14 and nitrogen-15 in the gas released by the lunar soil.

2. The method for analyzing nitrogen isotopes in lunar soil according to claim 1, characterized in that: The heating chamber includes a housing and a heating element attached to the outer wall of the housing; the housing is airtight; a movable door is arranged on the housing.

3. The method for analyzing nitrogen isotopes in lunar soil according to claim 2, characterized in that: The heating element uses an electric heating plate.

4. The method for analyzing nitrogen isotopes in lunar soil according to claim 2, characterized in that: The material of the housing uses titanium alloy.

5. The method for analyzing nitrogen isotopes in lunar soil according to claim 2, characterized in that: The analysis system further includes a first storage tank and a second storage tank. The first storage tank is connected to the housing through a first pipeline, and the second storage tank is connected to the housing through a second pipeline; a first air pump and a first gas flow meter are arranged on the first pipeline, and the first gas flow meter is closer to the housing than the first air pump; A second air pump and a second gas flow meter are arranged on the second pipeline, and the second gas flow meter is closer to the housing than the second air pump.

6. The method for analyzing nitrogen isotopes in lunar soil according to claim 5, wherein: The analysis system further includes a control unit. The first gas flowmeter and the second gas flowmeter are respectively connected to the control unit in a signal connection. The control unit is capable of closing the first air pump when the detected value of the first gas flowmeter reaches a set value, and the control unit is capable of closing the second air pump when the detected value of the second gas flowmeter reaches a set value.

7. The method for analyzing nitrogen isotopes in lunar soil according to claim 6, wherein: The control unit uses an FPGA.

8. The method for analyzing nitrogen isotopes in lunar soil according to claim 5, characterized in that: A first valve and a second valve are further provided on the first pipeline. The first valve is located between the first storage tank and the first air pump, and the second valve is located between the first gas flowmeter and the housing; a third valve and a fourth valve are further provided on the second pipeline. The third valve is located between the second storage tank and the second air pump, and the fourth valve is located between the second gas flowmeter and the housing.

9. The method for analyzing nitrogen isotopes in lunar soil according to claim 8, wherein: The analysis system further includes a first vacuum pump and a second vacuum pump. The heating chamber is communicated with the suction port of the first vacuum pump through a third pipeline, and a fifth valve is provided on the third pipeline; the air outlet of the quadrupole mass spectrometer is communicated with the suction port of the second vacuum pump through a fourth pipeline.

10. The method for analyzing nitrogen isotopes in lunar soil according to claim 9, characterized in that: The first valve, the second valve, the third valve, the fourth valve, the fifth valve and the control valve all use solenoid valves.

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