Mass spectrometer and sample injection mechanism thereof and single particle detection method

Abstract

The present invention relates to a mass spectrometer and a sampling mechanism thereof as well as a method for detecting single particles. The sampling mechanism comprises a particle beam forming device and a particle beam blocking device. The particle beam forming device comprises a particle beam forming channel and a sampling port and a particle beam outlet respectively arranged at two ends of the particle beam forming channel. The particle beam blocking device comprises a baffle and a driving mechanism for driving the baffle to move; the baffle has a first channel for the particle beam to pass through. When the baffle moves to the point where the first channel corresponds to the particle beam outlet, the particle beam passes through the first channel; when the baffle moves to the point where the first channel is offset from the particle beam outlet, the particle beam is blocked by the baffle. The mass spectrometer comprises the sampling mechanism, a particle accelerating electrode and a detection mechanism, and the mass spectrometer can be used to accurately detect the aerodynamic particle size and chemical composition of single particles in ultrafine particles.

Description

Technical Field

[0001] The present invention relates to the field of particle detection, and in particular to a mass spectrometer and a sample injection mechanism thereof, as well as a single particle detection method. Background Art

[0002] Fine particles in the air, especially ultrafine particles (particles with an aerodynamic size less than or equal to 100nm), have increasingly significant adverse effects on human health and environmental processes such as the global radiation balance. In order to solve such problems, it is necessary to have a certain understanding of the physical and chemical properties of ultrafine particles in the air, such as the aerodynamic size and chemical composition of single particles in ultrafine particles. After understanding the physical and chemical properties of single particles, the particles can be treated in a targeted manner. Currently, it is difficult to accurately obtain the aerodynamic size and chemical composition of single particles in ultrafine particles using commonly used detection methods. Summary of the invention

[0003] Based on this, it is necessary to provide a mass spectrometer and its injection mechanism, as well as a single particle detection method, which can accurately obtain the aerodynamic particle size and chemical composition of single particles in ultrafine particles.

[0004] A sample injection mechanism of a mass spectrometer, characterized by comprising a particle beam forming device and a particle beam blocking device;

[0005] The particle beam forming device comprises a particle beam forming channel and an injection port and a particle beam outlet respectively arranged at two ends of the particle beam forming channel; the injection port is used to add particles to be detected, and the particle beam forming channel is used to gather the particles to be detected into a particle beam and emit it from the particle beam outlet to the particle beam blocking device;

[0006] The particle beam blocking device includes a baffle and a driving mechanism for driving the baffle to move; the baffle has a first channel for the particle beam to pass through; when the baffle moves to the point where the first channel corresponds to the particle beam outlet, the particle beam passes through the first channel; when the baffle moves to the point where the first channel is offset from the particle beam outlet, the particle beam is blocked by the baffle.

[0007] In one of the embodiments, the particle beam forming device further comprises a critical hole and a buffer cavity arranged between the injection port and the particle beam forming channel; the particulate matter to be detected passes through the injection port, the critical hole, the buffer cavity, and the particle beam forming channel in sequence.

[0008] In one embodiment, the driving mechanism drives the baffle to rotate.

[0009] In one embodiment, the sample injection mechanism of the mass spectrometer further includes a vacuum chamber; the particle beam outlet and the baffle are both disposed in the vacuum chamber.

[0010] In one embodiment, a partition is provided in the vacuum chamber; the partition divides the vacuum chamber into a first vacuum chamber and a second vacuum chamber; the particle beam outlet is provided in the first vacuum chamber, and the baffle is provided in the second vacuum chamber;

[0011] The partition is provided with a second channel, the second channel corresponds to the particle beam outlet, and the particle beam emitted from the particle beam outlet moves to the particle beam blocking device through the second channel.

[0012] In one embodiment, the inner diameter of the second channel gradually increases from the particle beam outlet to the first channel.

[0013] A mass spectrometer, comprising a particle accelerating electrode, a detection mechanism and the sample injection mechanism described in any one of the above embodiments;

[0014] The particle accelerating electrode is arranged corresponding to the sample injection mechanism, and the particle accelerating electrode is used to accelerate the particle beam after passing through the first channel;

[0015] The detection mechanism is arranged corresponding to the particle accelerating electrode, and is used to detect the particle beam accelerated by the particle accelerating electrode.

[0016] In one embodiment, the detection mechanism includes an ionization laser, a cation reflection electrode, an anion reflection electrode, a cation detector, and an anion detector;

[0017] The ionization laser is arranged corresponding to the particle acceleration electrode, and is used to ionize the particle beam entering the particle acceleration electrode;

[0018] The cation reflection electrode and the anion reflection electrode are respectively arranged corresponding to the particle acceleration electrode, and the cations formed after ionization move toward the cation reflection electrode, and the anions formed after ionization move toward the anion reflection electrode;

[0019] The cation detector is arranged corresponding to the cation reflection electrode, and the anion detector is arranged corresponding to the anion reflection electrode.

[0020] In one of the embodiments, the mass spectrometer further comprises an analysis device; the analysis device is electrically connected to the particle beam blocking device, the ionization laser, the cation detector, and the anion detector respectively.

[0021] A method for detecting a single particle, using the mass spectrometer described in any of the above embodiments, the detection method comprises the following steps:

[0022] The particles to be detected are added from the injection port, and then pass through the particle beam forming channel to form a particle beam. After passing through the first channel, the particle beam is accelerated by the particle accelerating electrode, and the accelerated particle beam enters the detection mechanism for detection;

[0023] Determining the aerodynamic particle size of a single particle in the particulate matter to be detected according to the time taken for the particle beam to move from the first channel to the particle accelerating electrode;

[0024] The chemical composition of a single particle in the particulate matter to be detected is determined according to the mass spectrum acquired by the detection mechanism.

[0025] The injection mechanism of the mass spectrometer includes a particle beam forming device and a particle beam blocking device. The particles to be detected form a particle beam in the particle beam forming device, and then the particle beam moves toward the particle beam blocking device. The particle beam blocking device includes a baffle and a driving mechanism for driving the baffle to move, and the baffle has a first channel for the particle beam to pass through. When the baffle moves to the first channel corresponding to the particle beam outlet, the particle beam can pass through the first channel; when the baffle moves to the first channel and staggered with the particle beam outlet, the particle beam is blocked by the baffle. The first channel is smaller than the baffle, and the time period in which the particle beam can pass through the first channel is shorter, so that the number of particles passing through the first channel each time during the detection process is small. And by adjusting the movement cycle of the baffle, there can be no mutual influence between the particles passing through the first channel each time, so that the aerodynamic particle size and chemical composition of single particles in ultrafine particles can be accurately obtained during the detection process.

[0026] The mass spectrometer includes a particle acceleration electrode, a detection mechanism and the injection mechanism. The particles to be detected form a particle beam after passing through the injection mechanism, and the particle beam moves toward the particle acceleration electrode after passing through the first channel, and then the particle beam enters the detection mechanism after passing through the particle acceleration electrode. During the detection process, there is no mutual influence between the particles, and the aerodynamic particle size and chemical composition of single particles in ultrafine particles can be accurately obtained.

[0027] The above-mentioned single particle detection method uses the above-mentioned mass spectrometer to determine the aerodynamic particle size of the single particle in the particle beam based on the time it takes for the particle beam to move from the first channel to the particle acceleration electrode, combined with the relationship between the movement time and particle size of the particle under mass spectrometry conditions. At the same time, using the above-mentioned mass spectrometer, the detection mechanism can obtain the mass spectrum of the single particle in the particle beam, and then determine the chemical composition of the single particle through the mass spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 FIG. 4 is a schematic diagram of the structure of a mass spectrometer in one embodiment of the present invention.

[0029] Figure 2 for Figure 1 Top view of the particle beam stop corresponding to the mass spectrum.

[0030] Figure 3 Graph showing the relationship between the aerodynamic diameter of a single particle and the flight time in one embodiment of the present invention.

[0031] Explanation of the marks in the figure: 10: particle beam forming device; 11: injection port; 12: critical hole; 13: buffer chamber; 14: vacuum gauge; 15: particle beam forming channel; 16: particle beam outlet; 20: particle beam blocking device; 21: baffle; 22: first channel; 30: vacuum chamber; 31: partition; 32: first vacuum chamber; 33: second vacuum chamber; 34: third vacuum chamber; 35: second channel; 40: mass spectrometer; 41: particle accelerating electrode; 42: ionization laser; 43: cation reflecting electrode; 44: anion reflecting electrode; 45: cation detector; 46: anion detector; 47: analysis device. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0033] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0035] like Figure 1As shown, an embodiment of the present invention provides a mass spectrometer 40, including a particle acceleration electrode 41, a detection mechanism and a sample injection mechanism. The particle acceleration electrode 41 is arranged corresponding to the sample injection mechanism, and the particle acceleration electrode 41 is used to accelerate the particle beam after passing through the first channel 22. The detection mechanism is arranged corresponding to the particle acceleration electrode 41, and the detection mechanism is used to detect the particle beam after being accelerated by the particle acceleration electrode 41.

[0036] In a specific example, the detection mechanism includes an ion laser 42 , a cation reflection electrode 43 , an anion reflection electrode 44 , a cation detector 45 , and an anion detector 46 .

[0037] The ionization laser 42 is disposed corresponding to the particle acceleration electrode 41 , and is used to ionize the particle beam entering the particle acceleration electrode 41 .

[0038] The cation reflective electrode 43 and the anion reflective electrode 44 are respectively arranged corresponding to the particle accelerating electrode 41 . The cations formed after ionization move toward the cation reflective electrode 43 , and the anions formed after ionization move toward the anion reflective electrode 44 .

[0039] The cation detector 45 is provided corresponding to the cation reflecting electrode 43 , and the anion detector 46 is provided corresponding to the anion reflecting electrode 44 .

[0040] In this embodiment, the detection mechanism is a bipolar reflection time-of-flight mass analyzer, the particle beam is ionized in the ion acceleration electrode 41 to form cations and anions, and then the cations and anions move to the cation reflection electrode 43 and the anion reflection electrode 44 respectively, and then the mass spectrum of the single particle in the particle to be detected is obtained through the cation detector 45 and the anion detector 46. It can be understood that the detection mechanism in the present invention can also be a single-stage reflection time-of-flight mass analyzer, that is, the detection mechanism includes a cation reflection electrode or anion reflection electrode, and a corresponding cation detector or anion detector, the particle beam is ionized in the ion acceleration electrode to form cations and anions, and the mass spectrum of the single particle in the particle to be detected is obtained according to the cation detector or the anion detector, and then the chemical composition of the single particle in the particle to be detected is determined according to the mass spectrum.

[0041] In a specific example, the mass spectrometer 40 further includes an analysis device 47 ; the analysis device 47 is electrically connected to the particle beam blocking device 20 , the ionization laser 42 , the cation detector 45 , and the anion detector 46 , respectively.

[0042] The analysis device 47 is electrically connected to the particle beam blocking device 20, and can detect and record the time when the particle beam reaches the first channel 22. The analysis device 47 is electrically connected to the ionization laser 42, and can control the ionization laser 42 to emit laser to ionize the particle beam entering the particle acceleration electrode 41, and detect and record the ionization laser trigger signal at the same time, and the time when the ionization laser trigger signal is detected is used as the time when the particle beam enters the particle acceleration electrode 41. The flight time of a single particle is the time when the particle beam moves from the first channel 22 to the particle acceleration electrode 41, and the aerodynamic particle size of a single particle in the particle to be detected is determined based on the flight time.

[0043] In this embodiment, the analysis device 47 is electrically connected to the cation detector 45 and the anion detector 46 respectively, and a mass spectrum of a single particle in the particle to be detected is obtained according to the cation detector 45 and the anion detector 46, and then the chemical composition of the single particle in the particle to be detected is determined according to the mass spectrum.

[0044] In this embodiment, the mass spectrometer includes a particle acceleration electrode 41, a detection mechanism, and an injection mechanism. The particles to be detected form a particle beam after passing through the injection mechanism, and the particle beam moves toward the particle acceleration electrode 41 after passing through the first channel 22, and then the particle beam enters the detection mechanism after passing through the particle acceleration electrode 41. During the detection process, there is no mutual influence between the particles, and the aerodynamic particle size and chemical composition of a single particle in the ultrafine particles can be accurately obtained.

[0045] The sample injection mechanism of the mass spectrometer in this embodiment includes a particle beam forming device 10 and a particle beam blocking device 20 .

[0046] The particle beam forming device 10 has a particle beam forming channel 15 and an injection port 11 and a particle beam outlet 16 respectively arranged at both ends of the particle beam forming channel 15; the injection port 11 is used to add the particulate matter to be detected, and the particle beam forming channel 15 is used to gather the particulate matter to be detected into a particle beam, and the particle beam passes through the particle beam outlet 16 and then is emitted to the particle beam blocking device 20.

[0047] The particle beam blocking device 20 includes a baffle 21 and a driving mechanism (not shown in the figure) for driving the baffle to move; the baffle 21 has a first channel 22 for the particle beam to pass through; when the baffle 21 moves to the point where the first channel 22 corresponds to the particle beam outlet 16, the particle beam passes through the first channel 22; when the baffle 21 moves to the point where the first channel 22 is offset from the particle beam outlet 16, the particle beam is blocked by the baffle 21.

[0048] In this embodiment, the particle beam forming channel 15 uses an aerodynamic lens to gather the particles to be detected into a particle beam. The aerodynamic lens has high working efficiency and can quickly gather the particles to be detected into a particle beam. It can be understood that in this embodiment, other devices with particle gathering functions can also be used to gather the particles to be detected into a particle beam. For example, the device with particle gathering function can be a capillary, a focusing lens, etc.

[0049] like Figure 2 As shown, in this embodiment, the baffle plate 21 is a circular baffle plate, and the first channel 22 is arranged at the edge of the circular baffle plate. After the particle beam is formed in the particle beam forming channel 15, it passes through the particle beam outlet 16 and then shoots toward the particle beam blocking device 20. The baffle plate 21 moves under the drive of its driving mechanism. When the baffle plate 21 moves to the first channel 22 corresponding to the particle beam outlet 16, the particle beam can pass through the first channel 22, and the particle beam after passing through the first channel 22 continues to move, and subsequent acceleration and detection are performed, thereby obtaining the required detection result. When the baffle plate 21 moves to the first channel 22 and staggers with the particle beam outlet 16, the particle beam is blocked by the baffle plate 21, and this part of the particle beam cannot pass through the first channel 22 for subsequent detection.

[0050] In the sample injection mechanism of the mass spectrometer in this embodiment, the first channel 22 is smaller than the baffle 21, and the time period during which the particle beam can pass through the first channel 22 is shorter, so that the number of particles passing through the first channel 22 each time during the detection process is smaller. In addition, by adjusting the movement cycle of the baffle 21, it is possible to prevent the particles passing through the first channel 22 each time from influencing each other, so that the aerodynamic particle size and chemical composition of a single particle can be accurately obtained during the detection process.

[0051] In a specific example, the particle beam forming device 10 also has a critical hole 12 and a buffer cavity 13 arranged between the injection port 11 and the particle beam forming channel 15; the particulate matter to be detected passes through the injection port 11, the critical hole 12, the buffer cavity 13, and the particle beam forming channel 15 in sequence.

[0052] Since the mass spectrometer is usually in a vacuum state during the detection process, it is necessary to ensure that the particles and particle beams move in a vacuum environment. The critical hole 12 and the buffer chamber 13 are set between the injection port 11 and the particle beam forming channel 15, which can improve the vacuum degree of the injection mechanism and meet the vacuum degree requirements of the particle beam forming channel 15. When the particles to be detected (such as aerosols) are added from the injection port 11, they pass through the critical hole 12. At this time, the pressure loss is large, which can improve the vacuum degree in the buffer chamber 13. The movement speed of the particles after passing through the critical hole 12 is accelerated, and then the particles are buffered in the buffer chamber 13, and the speed is reduced, so that the speed of the particles meets the working conditions of the particle beam forming channel 15. After the particles are buffered by the buffer chamber 13, the particle beam forming channel 15 can stably aggregate the particles and reduce the loss of the particles caused by hitting the wall.

[0053] Preferably, a vacuum gauge 14 is provided on the buffer chamber 13. The vacuum gauge 14 can monitor the vacuum degree inside the buffer chamber 13, and provide a reference for adjusting the particle velocity and pressure, so that the particle velocity meets the working conditions of the particle beam forming channel 15. It can be understood that the vacuum gauge 14 can be other devices capable of measuring the vacuum degree or pressure, such as a vacuum meter.

[0054] In a specific example, the driving mechanism drives the baffle 21 to rotate. The baffle 21 rotates, which facilitates setting the rotation period of the baffle 21, so that there is no mutual influence between the particles passing through the first channel 22 each time, so that the aerodynamic particle size and chemical composition of a single particle can be accurately obtained during the detection process.

[0055] In a specific example, the sample injection mechanism of the mass spectrometer further includes a vacuum chamber 30 ; the particle beam outlet 16 and the baffle 21 are both disposed in the vacuum chamber 30 .

[0056] In a specific example, a partition 31 is provided in the vacuum chamber; the partition 31 divides the vacuum chamber into a first vacuum chamber 32 and a second vacuum chamber 33 ; the particle beam outlet 16 is provided in the first vacuum chamber 32 , and the baffle 21 is provided in the second vacuum chamber 33 .

[0057] Preferably, the first vacuum chamber 32 is divided into a plurality of sub-vacuum chambers. Dividing the first vacuum chamber 32 into a plurality of sub-vacuum chambers can improve the vacuum degree of the mass spectrometer during the detection process.

[0058] The partition plate 31 is provided with a second channel 35 , which corresponds to the particle beam outlet 16 . The particle beam emitted from the particle beam outlet 16 passes through the second channel 35 and moves to the particle beam blocking device 20 .

[0059] In a specific example, the inner diameter of the second channel 35 gradually increases from the particle beam outlet 16 to the first channel 22 .

[0060] In this embodiment, there are two partitions 31, and the first vacuum chamber 32 is divided into two sub-vacuum chambers. It can be understood that in the design of the mass spectrometer, the first vacuum chamber can be divided into multiple sub-vacuum chambers so that the vacuum environment can meet the detection requirements of the mass spectrometer.

[0061] In this embodiment, two partitions 31 divide the vacuum chamber 30 into a first vacuum chamber 32, a second vacuum chamber 33 and a third vacuum chamber 34. The third vacuum chamber 34 is arranged at the outer edge of the first vacuum chamber 32. In order to meet the vacuum conditions of the mass spectrometer detection process and monitor the vacuum conditions, the first vacuum chamber 32, the second vacuum chamber 33 and the third vacuum chamber 34 are set, and a vacuum gauge 14 is provided on the first vacuum chamber 32, the second vacuum chamber 33 and the third vacuum chamber 34. It can be understood that the vacuum gauge 14 can be other devices capable of measuring vacuum degree or pressure, such as a vacuum gauge. It can be understood that the first vacuum chamber 32, the second vacuum chamber 33 and the third vacuum chamber 34 are respectively connected to vacuum pumps (not shown in the figure), and the vacuum environment of the vacuum chamber is provided by the vacuum pumps.

[0062] In this embodiment, the two partitions 31 are provided with a second channel 35, and the second channels 35 on the two partitions 31 correspond to each other and correspond to the particle beam outlet 16. The particle beam passes through the second channel 35 after passing through the particle beam outlet 16. In this embodiment, the second channel 35 is conical, and the inner diameter of the second channel 35 gradually decreases from the first channel 22 to the particle beam outlet 16. The conical shape of the second channel 35 can reduce the divergence of the particles at the edge of the particle beam and reduce the loss of the particle beam during the vacuum chamber 30 evacuation process. It can be understood that the second channel 35 can also be other shapes, such as cylindrical, which can enable the particle beam to pass through the partition smoothly.

[0063] An embodiment of the present invention further provides a single particle detection method, using the mass spectrometer 40, the detection method comprises the following steps:

[0064] The particles to be detected are added from the injection port 11, and then pass through the particle beam forming channel 15 to form a particle beam. After passing through the first channel 22, the particle beam is accelerated by the particle accelerating electrode 41. The accelerated particle beam enters the detection mechanism for detection.

[0065] Determine the aerodynamic particle size of a single particle in the particulate matter to be detected according to the time it takes for the particle beam to move from the first channel 22 to the particle acceleration electrode 41;

[0066] The chemical composition of a single particle in the particulate matter to be detected is determined based on the mass spectrum obtained by the detection agency.

[0067] Under the set mass spectrometry conditions, there is a certain fitting relationship between the aerodynamic particle size and the flight time of a single particle. Figure 3 As shown, the flight time refers to the time it takes for the particle beam to move from the first channel 22 to the particle acceleration electrode 41 .

[0068] In the present embodiment, during the detection of the aerodynamic particle size of a single particle, the flight time of the particle beam can be obtained by the analysis device 47. Figure 3 , determine the aerodynamic size of a single particle among the particles to be detected.

[0069] This embodiment can obtain a mass spectrum of a single particle in the particles to be detected through a detection mechanism, and then determine the chemical composition of the single particle in the particles to be detected based on the mass spectrum.

[0070] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A sample injection mechanism for a mass spectrometer, characterized in that: including a particle beam forming device and a particle beam blocking device; The particle beam forming device comprises a particle beam forming channel and an injection port and a particle beam outlet respectively arranged at two ends of the particle beam forming channel; the injection port is used to add particles to be detected, and the particle beam forming channel is used to gather the particles to be detected into a particle beam and emit it from the particle beam outlet to the particle beam blocking device; The particle beam blocking device comprises a baffle and a driving mechanism for driving the baffle to move; the baffle has a first channel for the particle beam to pass through; when the baffle moves to the point where the first channel corresponds to the particle beam outlet, the particle beam passes through the first channel; when the baffle moves to the point where the first channel is offset from the particle beam outlet, the particle beam is blocked by the baffle; The baffle is a circular baffle, and the first channel is arranged at the edge of the circular baffle; the driving mechanism drives the baffle to rotate.

2. The sample injection mechanism of a mass spectrometer according to claim 1, characterized in that: The particle beam forming device also has a critical hole and a buffer cavity arranged between the injection port and the particle beam forming channel; the particles to be detected pass through the injection port, the critical hole, the buffer cavity, and the particle beam forming channel in sequence.

3. The sample injection mechanism of a mass spectrometer according to claim 1, characterized in that: The particle beam forming channel uses an aerodynamic lens to gather the particles to be detected into the particle beam.

4. The sample injection mechanism of a mass spectrometer according to any one of claims 1 to 3, characterized in that: It also includes a vacuum chamber; the particle beam outlet and the baffle are both arranged in the vacuum chamber.

5. The sample injection mechanism of the mass spectrometer according to claim 4, characterized in that: A partition is provided in the vacuum chamber; the partition divides the vacuum chamber into a first vacuum chamber and a second vacuum chamber; the particle beam outlet is provided in the first vacuum chamber, and the baffle is provided in the second vacuum chamber; The partition is provided with a second channel, the second channel corresponds to the particle beam outlet, and the particle beam emitted from the particle beam outlet moves to the particle beam blocking device through the second channel.

6. The sample injection mechanism of the mass spectrometer according to claim 5, characterized in that: From the particle beam outlet to the first channel, the inner diameter of the second channel gradually increases.

7. A mass spectrometer, characterized in that: It comprises a particle accelerating electrode, a detection mechanism and a sample introduction mechanism as claimed in any one of claims 1 to 6; The particle accelerating electrode is arranged corresponding to the sample injection mechanism, and the particle accelerating electrode is used to accelerate the particle beam after passing through the first channel; The detection mechanism is arranged corresponding to the particle accelerating electrode, and is used to detect the particle beam accelerated by the particle accelerating electrode.

8. The mass spectrometer according to claim 7, characterized in that: The detection mechanism includes an ionization laser, a cation reflection electrode, an anion reflection electrode, a cation detector and an anion detector; The ionization laser is arranged corresponding to the particle acceleration electrode, and is used to ionize the particle beam entering the particle acceleration electrode; The cation reflection electrode and the anion reflection electrode are respectively arranged corresponding to the particle acceleration electrode, and the cations formed after ionization move toward the cation reflection electrode, and the anions formed after ionization move toward the anion reflection electrode; The cation detector is arranged corresponding to the cation reflection electrode, and the anion detector is arranged corresponding to the anion reflection electrode.

9. The mass spectrometer according to any one of claims 7 to 8, characterized in that: It also includes an analysis device; the analysis device is electrically connected to the particle beam blocking device, the ionization laser, the cation detector, and the anion detector respectively.

10. A method for detecting a single particle, characterized in that: Using the mass spectrometer according to any one of claims 7 to 9, the detection method comprises the following steps: The particles to be detected are added from the injection port, and then pass through the particle beam forming channel to form a particle beam. After passing through the first channel, the particle beam is accelerated by the particle accelerating electrode, and the accelerated particle beam enters the detection mechanism for detection; Determining the aerodynamic particle size of a single particle in the particulate matter to be detected according to the time taken for the particle beam to move from the first channel to the particle accelerating electrode; The chemical composition of a single particle in the particulate matter to be detected is determined according to the mass spectrum acquired by the detection mechanism.

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