Mass spectrometer

Abstract

The present invention relates to a mass spectrometer, comprising an aerosol particle size screening device and a detection and analysis device, which utilizes the principle of aerodynamics to screen the particle size of ultrafine particles, avoiding the defects of traditional optical diameter measurement and electric migration screening particle size, thereby being able to efficiently, accurately and effectively analyze information such as the particle size and chemical composition of the ultrafine particles.

Description

Technical Field

[0001] The present invention relates to the technical field of material detection, and in particular to a mass spectrometer. Background Art

[0002] Ultrafine particles refer to particles with an aerodynamic equivalent size of less than 0.1 μm, i.e. PM0.1. The impact of ultrafine particle aerosols on human health, global radiation balance and other environmental processes is becoming increasingly significant.

[0003] At present, it is difficult to detect the particle size of ultrafine particles using optical means, and single-particle mass spectrometry cannot be effectively performed. This is mainly because ultrafine particles will produce Rayleigh scattering when laser sizing (the particle size of ultrafine particles is much smaller than the wavelength of the sizing laser), resulting in weak light scattering intensity, making it very difficult to use single-particle mass spectrometry to analyze ultrafine particles. In addition, when using optical methods to measure the size, the ionization laser must be located at its rear end, and the particle beam may expand with the divergence angle, thereby reducing the particle hit rate.

[0004] In addition, there are reports on the use of DMA (Differential Mobility Analyzer) in series with TOFMS (Time of Flight Mass Spectrometer) to analyze ultrafine particles. However, this method has the effect of multiple charges when using DMA to screen particles of a specified particle size, and the accuracy of the screening particle size is poor. Summary of the invention

[0005] Based on this, it is necessary to provide a mass spectrometer that can improve the accuracy of ultrafine particle size analysis.

[0006] A mass spectrometer, comprising an aerosol particle size screening device and a detection and analysis device;

[0007] The aerosol particle size screening device comprises an outer rotating column, an inner rotating column, a partition, an aerosol air intake mechanism and a conveying gas air intake mechanism; the outer rotating column has a hollow conveying cavity, the inner rotating column is arranged in the hollow conveying cavity, the outer rotating column and the inner rotating column are coaxially arranged, a first gap is provided between the cavity wall of the hollow conveying cavity and the inner rotating column, and the outer rotating column and the inner rotating column can rotate in the same direction; the outer rotating column has an air inlet end and an air outlet end opposite to the air inlet end, the partition is arranged in the hollow In the delivery cavity and near the air inlet end of the outer rotating column, there is a second gap between the partition and the bottom surface of the inner rotating column, the partition is provided with an air vent, the aerosol air inlet mechanism extends into the air inlet end of the outer rotating column and is connected with the air vent; the delivery gas air inlet mechanism is connected to the air inlet end of the outer rotating column and is connected with the hollow delivery cavity; the air outlet end of the outer rotating column is provided with an exhaust port connected with the first gap, and the side wall of the outer rotating column close to the air outlet end is provided with a screening sample outlet connected with the first gap;

[0008] The detection and analysis device is communicated with the screening sample outlet, and is used for performing mass spectrometry analysis on the sample output from the screening sample outlet.

[0009] In one embodiment, the conveying gas intake mechanism is sleeved on the aerosol intake mechanism.

[0010] In one embodiment, the aerosol particle size screening device also includes a first support seat, the first support seat has a first ventilation cavity, the aerosol inlet mechanism and the conveying gas inlet mechanism extend into the first ventilation cavity as a whole, the input end of the aerosol inlet mechanism abuts against the inner wall of the first ventilation cavity, the first support seat is provided with a first air inlet port, the first air inlet port is connected to the input end of the aerosol inlet mechanism, the conveying gas inlet mechanism is connected to the first ventilation cavity, and the first support seat is also provided with a second air inlet port, the second air inlet port is connected to the first ventilation cavity.

[0011] In one embodiment, the sieved sample outlet extends along the periphery of the side wall of the outer rotating column.

[0012] In one embodiment, the aerosol particle size screening device also includes a screening sample output mechanism, an exhaust gas output mechanism and a second support seat, the screening sample output mechanism is connected to the screening sample outlet, the exhaust gas output mechanism is connected to the exhaust gas port, the screening sample output mechanism is sleeved on the exhaust gas output mechanism, the second support seat has a second ventilation cavity, the screening sample output mechanism and the exhaust gas output mechanism as a whole extend into the second ventilation cavity, the output end of the exhaust gas output mechanism abuts against the inner wall of the second ventilation cavity, the second support seat is provided with a first air outlet, the first air outlet is connected to the output end of the exhaust gas output mechanism, the screening sample output mechanism is connected to the second ventilation cavity, the second support seat is also provided with a second air outlet, the second air outlet is connected to the second ventilation cavity.

[0013] In one embodiment, the mass spectrometer further includes a particle focusing device having an inlet end and an outlet end opposite to the inlet end, the inlet end is connected to the screening sample outlet, and the outlet end is connected to the detection and analysis device.

[0014] In one embodiment, the particle focusing device is an aerodynamic lens, a capillary, an electric field focusing lens or a nozzle.

[0015] In one embodiment, the mass spectrometer also includes a pressure regulating device, which has a buffer chamber and a critical hole and a pressure regulating outlet connected to the buffer chamber, the critical hole is connected to the screening sample outlet, and the pressure regulating outlet is connected to the inlet end of the particle focusing device.

[0016] In one embodiment, the critical hole has a diameter of 0.07 mm to 1.85 mm.

[0017] In one embodiment, the mass spectrometer also includes a vacuum device, which has a vacuum chamber and a mounting port connected to the vacuum chamber, a particle outlet and a vacuum port, the vacuum port is used to connect to a vacuum pump, the outlet end of the particle focusing device extends into the mounting port, and the particle outlet is connected to the detection and analysis device.

[0018] In one of the embodiments, the mass spectrometer further includes a separation cone, which is disposed in the vacuum chamber, one end of the separation cone is aligned with an outlet end of the particle focusing device, and the other end of the separation cone is connected to the detection and analysis device.

[0019] In one embodiment, there are multiple separation cones, and the multiple separation cones are arranged in sequence.

[0020] In one embodiment, the detection and analysis device is a time-of-flight mass spectrometer, a quadrupole analyzer or an ion trap mass analyzer.

[0021] In one embodiment, the detection and analysis device includes an ionization chamber, an ionization laser, an electric field generator, a detector and an analyzer. The ionization chamber is connected to the screening sample outlet. The ionization laser is used to emit laser to ionize the particles passing into the ionization chamber. The electric field generator and the detector are arranged in the ionization chamber. The electric field generator is used to generate an electric field to make the ionized particle fragments fly into the detector. The analyzer is electrically connected to the detector.

[0022] Compared with the existing solutions, the present invention has the following beneficial effects:

[0023] The above-mentioned mass spectrometer uses the principles of aerodynamics to screen the particle size of ultrafine particles, avoiding the defects of traditional optical sizing and electric migration screening particle size, so that it can efficiently, accurately and effectively analyze the particle size, chemical composition and other information of ultrafine particles.

[0024] Specifically, when the mass spectrometer is working, an aerosol sample is introduced through the aerosol inlet mechanism, and the aerosol sample reaches the second gap through the vent hole, and then enters the first gap from the second gap. The conveying gas is introduced through the conveying gas inlet mechanism, and the conveying gas enters the first gap through the side of the partition away from the inner rotating column, and then enters the first gap from the space, thereby conveying the aerosol movement. As the outer rotating column and the inner rotating column rotate in the same direction at a certain rate, the conveying gas passes through the outer rotating column and the inner rotating column rotating in the same direction at a high speed, forming a vortex, and the particles in the aerosol sample generate centrifugal force with the vortex movement, so that the particles perform centrifugal movement in the radial direction of the outer rotating column. While the centrifugal movement, the particles are also subjected to the force along the length direction of the first gap as the conveying gas moves. The particles in a specific aerodynamic equivalent particle size range perform centrifugal movement outward in the radial direction of the outer rotating column. After the particles pass through the first gap with the carrier gas flow, they just leave the hollow conveying cavity from the screening sample outlet and enter the detection and analysis device for detection and analysis. Particles larger than the aerodynamic equivalent particle size are thrown onto the inner wall of the hollow conveying cavity and stop moving axially due to the greater centrifugal force. Particles smaller than the aerodynamic equivalent particle size are subjected to less centrifugal force and do not fly out of the screening sample outlet, but are discharged from the outer rotating column through the exhaust port at the outlet end of the outer rotating column along with the conveying gas.

[0025] The mass spectrometer can screen out particles with different aerodynamic equivalent particle size ranges by adjusting the rotation speeds of the outer rotating column and the inner rotating column.

[0026] In addition to solving the problem of single-particle mass spectrometry analysis of ultrafine particles, the above-mentioned mass spectrometer can also simultaneously perform single-particle mass spectrometry analysis on particles of larger sizes, greatly improving the detection capability of the mass spectrometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of a mass spectrometer according to an embodiment;

[0028] Figure 2 for Figure 1 Schematic diagram of the structure of the aerosol particle size screening device in the mass spectrometer shown. DETAILED DESCRIPTION

[0029] 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.

[0030] It should be noted that when an element is referred to as being "disposed" on another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0031] 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.

[0032] Please combine Figure 1 and Figure 2 A mass spectrometer 10 according to an embodiment of the present invention includes an aerosol particle size screening device 100 and a detection and analysis device.

[0033] The aerosol particle size screening device 100 includes an outer rotating column 1110 , an inner rotating column 1120 , a partition 1130 , an aerosol air intake mechanism 1140 and a conveying gas air intake mechanism 1150 .

[0034] The outer rotating column 1110 has a hollow conveying cavity. The inner rotating column 1120 is disposed in the hollow conveying cavity, and the outer rotating column 1110 and the inner rotating column 1120 are coaxially disposed. A first gap 1160 is provided between the side wall of the hollow conveying cavity and the inner rotating column 1120, and the outer rotating column 1110 and the inner rotating column 1120 can rotate in the same direction.

[0035] As the outer rotating cylinder 1110 and the inner rotating cylinder 1120 rotate in the same direction at a certain speed, the particles in the aerosol in the first gap 1160 are acted upon by the centrifugal force in the radial direction of the outer rotating cylinder 1110, so that the particles perform centrifugal motion in the radial direction of the outer rotating cylinder 1110. While in the centrifugal motion, the particles are also acted upon by the force along the length direction of the first gap 1160 as the airflow moves.

[0036] The outer rotating column 1110 has an air inlet end 1152 and an air outlet end 1222 opposite to the air inlet end 1152. The partition 1130 is arranged in the hollow delivery chamber, and the partition 1130 is close to the air inlet end 1152 of the outer rotating column 1110. That is, the partition 1130 is arranged between the air inlet end 1152 of the outer rotating column 1110 and the inner rotating column 1120. There is a second gap 1170 between the partition 1130 and the bottom surface of the inner rotating column 1120. The partition 1130 is provided with a vent 1132, and the aerosol inlet mechanism 1140 extends into the air inlet end 1152 of the outer rotating column 1110 and communicates with the vent 1132. The gas introduced into the aerosol inlet mechanism 1140 can reach the second gap 1170 through the vent 1132, and then enter the first gap 1160 from the second gap 1170.

[0037] The conveying gas inlet mechanism 1150 is connected to the inlet end 1152 of the outer rotating column 1110 and communicates with the hollow conveying cavity. The gas introduced into the conveying gas inlet mechanism 1150 can enter the first gap 1160 through the side of the partition 1130 away from the inner rotating column 1120, that is, the gas first enters the space between the partition 1130 and the inlet end 1152 of the outer rotating column 1110, and then enters the first gap 1160 from the space, thereby conveying aerosol movement.

[0038] The gas introduced into the conveying gas inlet mechanism 1150 may be clean air. When the conveying gas passes through the outer rotating column 1110 and the inner rotating column 1120 rotating in the same direction at high speed, a swirl is formed, and the particles generate centrifugal force as they move along the swirl.

[0039] A sieve sample outlet 1180 connected to the first gap 1160 is provided on the side wall of the outer rotating column 1110 near the air outlet end 1222. Particles of a specific aerodynamic equivalent particle size range move centrifugally outward in the radial direction of the outer rotating column 1110. After the particles pass through the first gap 1160 with the carrier airflow, they just leave the outer rotating column 1110 from the sieve sample outlet 1180. Particles larger than the aerodynamic equivalent particle size are thrown onto the inner wall of the hollow conveying cavity and stop moving axially due to the greater centrifugal force.

[0040] The outlet end 1222 of the outer rotating column 1110 is provided with an exhaust port 1190 connected to the first gap 1160. Particles smaller than the above-mentioned aerodynamic equivalent particle size are subjected to less centrifugal force and do not fly out from the screening sample outlet 1180, and are discharged from the outer rotating column 1110 through the exhaust port 1190 of the outlet end 1222 of the outer rotating column 1110 along with the conveying gas.

[0041] The detection and analysis device is connected to the screening sample outlet 1180 , and is used to perform mass spectrometry analysis on the sample output from the screening sample outlet 1180 .

[0042] like Figure 2 As shown, the hollow conveying cavity of the outer rotating column 1110 is a cylindrical cavity, the inner rotating column 1120 is cylindrical, the outer rotating column 1110 and the inner rotating column 1120 are coaxially arranged, and the first gap 1160 formed between the side wall of the hollow conveying cavity and the inner rotating column 1120 is an annular cavity, and the width of the first gap 1160 is consistent at all locations.

[0043] The mass spectrometer 10 can screen out particles with different aerodynamic equivalent particle size ranges by adjusting the rotation speed of the outer rotating column 1110 and the inner rotating column 1120. In addition, the aerodynamic equivalent particle size of the screened particles is also related to factors such as the flow rate of the conveying gas, the width and length of the first gap 1160, etc.

[0044] like Figure 2 As shown, in one example, the transport gas inlet mechanism 1150 is sleeved on the aerosol inlet mechanism 1140. Figure 2 In the specific example shown, the aerosol particle size screening device 100 also includes a first support seat 1, the first support seat 1 has a first ventilation cavity 1201, and the aerosol inlet mechanism 1140 and the conveying gas inlet mechanism 1150 are integrally extended into the first ventilation cavity 1201. The input end 1152 of the aerosol inlet mechanism 1140 abuts against the inner wall of the first ventilation cavity 1201, and the first support seat 1 is provided with a first air inlet 1202 at this position, and the first air inlet 1202 is connected to the input end 1152 of the aerosol inlet mechanism 1140 for inputting aerosol samples. The first support seat 1 is also provided with a second air inlet 1203 connected to the first ventilation cavity 1201 for inputting conveying gas, and the conveying gas inlet mechanism 1150 is connected to the first ventilation cavity 1201.

[0045] like Figure 2 As shown, in one example, the sieved sample outlet 1180 extends along the periphery of the side wall of the outer rotating column 1110. Figure 2In the specific example shown, the aerosol particle size screening device 100 further includes a screening sample output mechanism 1210 and an exhaust gas output mechanism 1220. The screening sample output mechanism 1210 is connected to the screening sample outlet 1180, and the exhaust gas output mechanism 1220 is connected to the exhaust gas outlet 1190. The screening sample output mechanism 1210 is sleeved on the exhaust gas output mechanism 1220. The aerosol particle size screening device 100 further includes a second support seat 1230, and the second support seat 1230 has a second ventilation cavity 1231. The screening sample output mechanism 1210 and the exhaust gas output mechanism 1220 are integrally extended into the second ventilation cavity 1231. The output end 1222 of the exhaust gas output mechanism 1220 abuts against the inner wall of the second ventilation cavity 1231. The second support seat 1230 is provided with a first outlet 1232 at this position, and the first outlet 1232 is connected to the output end 1222 of the exhaust gas output mechanism 1220. The second support seat 1230 is further provided with a second air outlet 1233 communicating with the second ventilation cavity 1231 , and the screening sample output mechanism 1210 is communicated with the second ventilation cavity 1231 .

[0046] exist Figure 2 In the specific example shown, a first bearing 1240 is provided in the first ventilation cavity 1201, the conveying gas intake mechanism 1150 is supported on the first bearing 1240, a second bearing 1250 is provided in the second ventilation cavity 1231, and the screening sample output mechanism 1210 is supported on the second bearing 1250, so that the aerosol particle size screening device 100 is supported as a whole by the first bearing 1240 and the second bearing 1250.

[0047] exist Figure 2 In the specific example shown, a rotating shaft gear 1260 is also provided on the conveying gas intake mechanism 1150 for driving the rotating column to rotate.

[0048] like Figure 1 As shown, in one example, the mass spectrometer 10 also includes a particle focusing device 300, which has an inlet end 310 and an outlet end 320 opposite to the inlet end 310, the inlet end 310 is connected to the screening sample outlet 1180, and the outlet end 320 is connected to the detection and analysis device.

[0049] Optionally, the particle focusing device 300 may use an aerodynamic lens, a capillary, an electric field focusing lens or a nozzle, etc.

[0050] like Figure 1 As shown, in one example, the mass spectrometer 10 also includes a pressure regulating device 400, which has a buffer chamber 410 and a critical hole 420 and a pressure regulating outlet 430 connected to the buffer chamber 410, the critical hole 420 is connected to the screening sample outlet 1180, and the pressure regulating outlet 430 is connected to the inlet end 310 of the particle focusing device 300.

[0051] Since the particle focusing device 300 has certain requirements for the sample gas pressure, such as the inlet environmental pressure of the aerodynamic lens is generally required to be several hundred to several thousand Pa, while the standard atmospheric pressure is 101 KPa. By setting a critical hole 420 (equivalent to a nozzle), the gas at the critical hole 420 flows supersonic, causing the atmospheric pressure to drop to low pressure, and a buffer chamber 410 is set to buffer the sample gas flow to a laminar state, ensuring that the sample gas flow can stably enter the aerodynamic lens for particle focusing. By setting a pressure regulating device 400, the particle focusing device 300 can operate stably, and the effectively focused particles move in a narrow and fine particle beam to the detection and analysis device behind.

[0052] The aperture of the critical hole 420 is preferably 0.07 mm to 1.85 mm, such as 0.1 mm, which can generate a huge pressure loss when the gas passes through.

[0053] like Figure 1 As shown, in one example, the mass spectrometer 10 further includes a vacuum device 500, which has a vacuum chamber 510 and a mounting port 520 connected to the vacuum chamber 510, a particle outlet, and a vacuum port 540. The vacuum port 540 is used to communicate with a vacuum pump, and the outlet end 320 of the particle focusing device 300 extends into the mounting port 520, and the particle outlet is connected to the detection and analysis device. By setting the vacuum device 500, the conveying gas is evacuated, and the particles to be detected enter the detection and analysis device for detection.

[0054] Furthermore, the vacuum device 500 further includes a vacuum pump, which is connected to the vacuum port 540. Preferably, the vacuum pump is a molecular pump.

[0055] Furthermore, if Figure 1 As shown, in one example, the mass spectrometer 10 further includes a separation cone 600, which is disposed in the vacuum chamber 510, one end of the separation cone 600 is aligned with the outlet end 320 of the particle focusing device 300, and the other end of the separation cone 600 is connected to the detection and analysis device. Furthermore, there are multiple separation cones 600, which are arranged in sequence, so as to better separate the transport gas and particulate matter. Figure 1 In the specific example shown, there are two separation cones 600 .

[0056] Optionally, the detection and analysis device may be a time-of-flight mass spectrometer, a quadrupole analyzer, an ion trap mass analyzer, or the like.

[0057] In one example, the detection and analysis device is a time-of-flight mass spectrometer 670 .

[0058] like Figure 1As shown, in one example, the detection and analysis device includes an ionization chamber 610, an ionization laser 640, an electric field generator 650, a detector 660 and an analyzer 670. The ionization chamber 610 is connected to the screening sample outlet 1180. The ionization laser 640 is used to emit laser to ionize the particles passing into the ionization chamber 610. The electric field generator 650 and the detector 660 are arranged in the ionization chamber 610. The electric field generator 650 is used to generate an electric field to make the ionized particles fly to the detector 660. The analyzer 670 is electrically connected to the detector 660.

[0059] More specifically, if Figure 1 As shown, the ionization chamber 610 is a vacuum chamber 510, which is provided with an injection port 620 and an air pumping port 630. The air pumping port 630 is used to communicate with a vacuum pumping device (preferably a molecular pump) to maintain the vacuum state of the ionization chamber 610. After the particles are passed into the ionization chamber 610 from the injection port 620, they first pass through a space without electric field, and then enter an electric field space. At this time, the ionization laser 640 emits laser to ionize the particles to generate positive ion fragments and negative ion fragments, and the positive ion fragments and the negative ion fragments move in opposite directions under the action of the electric field. An electric field generator 650 is arranged on both sides of the ionization chamber 610, and an electric field is generated to make the positive ion fragments and the negative ion fragments turn to move. A detector 660 (microchannel plate can be selected) is arranged on both sides of the ionization chamber 610, and the positive ion fragments and the negative ion fragments move to the detector 660 after turning to move under the action of the electric field of the electric field generator 650. The analyzer 670 (a computer may be used) is electrically connected to the detector 660 to obtain the signal detected by the analysis detector 660. The detector 660 signal and the ionization laser control signal can be controlled in real time by the analyzer 670 with a data acquisition card, and the corresponding spectra, chemical composition and other information of the particles can be obtained through software analysis.

[0060] The ionization laser 640 may be a gas laser (such as an excimer ionization laser 640 ) or a solid laser (such as an Nd-YAG laser).

[0061] The mass spectrometer 10 uses the principle of aerodynamics to screen the ultrafine particles, avoiding the defects of traditional optical sizing and electric migration screening, so that the particle size, chemical composition and other information of the ultrafine particles can be analyzed efficiently, accurately and effectively.

[0062] Specifically, when the mass spectrometer 10 is working, an aerosol sample is introduced through the aerosol inlet mechanism 1140, and the aerosol sample reaches the second gap 1170 through the vent hole 1132, and then enters the first gap 1160 from the second gap 1170. The conveying gas is introduced through the conveying gas inlet mechanism 1150, and the conveying gas enters the first gap 1160 through the side of the partition 1130 away from the inner rotating column 1120, and then enters the first gap 1160 from the space, so that the conveying aerosol moves. As the outer rotating column 1110 and the inner rotating column 1120 rotate in the same direction at a certain speed, the conveying gas passes through the outer rotating column 1110 and the inner rotating column 1120 that rotate in the same direction at a high speed, forming a vortex, and the particles in the aerosol sample generate centrifugal force with the vortex motion, so that the particles perform centrifugal motion in the radial direction of the outer rotating column 1110. While the centrifugal motion, as the conveying gas moves, the particles are also subjected to a force along the length direction of the first gap 1160. Particles within a specific aerodynamic equivalent particle size range move centrifugally outward in the radial direction of the outer rotating column 1110. After passing through the first gap 1160 with the carrier gas flow, the particles leave the hollow conveying cavity from the screening sample outlet 1180 and enter the detection and analysis device for detection and analysis. Particles larger than the aerodynamic equivalent particle size are thrown onto the inner wall of the hollow conveying cavity and stop moving axially due to the greater centrifugal force. Particles smaller than the aerodynamic equivalent particle size are subjected to less centrifugal force and do not fly out from the screening sample outlet 1180, but are discharged from the outer rotating column 1110 through the exhaust port 1190 at the outlet end 1222 of the outer rotating column 1110 along with the conveying gas.

[0063] The mass spectrometer 10 can screen out particles with different aerodynamic equivalent particle size ranges by adjusting the rotation speeds of the outer rotating column 1110 and the inner rotating column 1120 .

[0064] In addition to solving the problem of single-particle mass spectrometry analysis of ultrafine particles, the mass spectrometer 10 can also perform single-particle mass spectrometry analysis on particles with larger particle sizes, greatly improving the detection capability of the mass spectrometer 10.

[0065] 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.

[0066] 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 mass spectrometer, characterized in that It includes an aerosol particle size screening device and a detection and analysis device; The aerosol particle size screening device comprises an outer rotating column, an inner rotating column, a partition, an aerosol air intake mechanism and a conveying gas air intake mechanism; the outer rotating column has a hollow conveying cavity, the inner rotating column is arranged in the hollow conveying cavity, the outer rotating column and the inner rotating column are coaxially arranged, a first gap is provided between the cavity wall of the hollow conveying cavity and the inner rotating column, and the outer rotating column and the inner rotating column can rotate in the same direction; the outer rotating column has an air inlet end and an air outlet end opposite to the air inlet end, the partition is arranged in the hollow In the delivery cavity and near the air inlet end of the outer rotating column, there is a second gap between the partition and the bottom surface of the inner rotating column, the partition is provided with an air vent, the aerosol air inlet mechanism extends into the air inlet end of the outer rotating column and is connected with the air vent; the delivery gas air inlet mechanism is connected to the air inlet end of the outer rotating column and is connected with the hollow delivery cavity; the air outlet end of the outer rotating column is provided with an exhaust port connected with the first gap, and the side wall of the outer rotating column close to the air outlet end is provided with a screening sample outlet connected with the first gap; The detection and analysis device is communicated with the screening sample outlet, and is used for performing mass spectrometry analysis on the sample output from the screening sample outlet.

2. The mass spectrometer according to claim 1, characterized in that The conveying gas intake mechanism is sleeved on the aerosol intake mechanism.

3. The mass spectrometer according to claim 2, characterized in that The aerosol particle size screening device also includes a first support seat, the first support seat has a first ventilation cavity, the aerosol air inlet mechanism and the conveying gas air inlet mechanism extend into the first ventilation cavity as a whole, the input end of the aerosol air inlet mechanism abuts against the inner wall of the first ventilation cavity, the first support seat is provided with a first air inlet port, the first air inlet port is connected with the input end of the aerosol air inlet mechanism, the conveying gas air inlet mechanism is connected with the first ventilation cavity, the first support seat is also provided with a second air inlet port, the second air inlet port is connected with the first ventilation cavity.

4. The mass spectrometer according to claim 1, characterized in that The sieved sample outlet extends along the periphery of the side wall of the outer rotating column.

5. The mass spectrometer according to claim 4, characterized in that The aerosol particle size screening device also includes a screening sample output mechanism, an exhaust gas output mechanism and a second supporting seat. The screening sample output mechanism is connected to the screening sample outlet, and the exhaust gas output mechanism is connected to the exhaust gas port. The screening sample output mechanism is sleeved on the exhaust gas output mechanism. The second supporting seat has a second ventilation cavity. The screening sample output mechanism and the exhaust gas output mechanism are integrally extended into the second ventilation cavity. The output end of the exhaust gas output mechanism abuts against the inner wall of the second ventilation cavity. The second supporting seat is provided with a first air outlet, which is connected to the output end of the exhaust gas output mechanism. The screening sample output mechanism is connected to the second ventilation cavity. The second supporting seat is also provided with a second air outlet, which is connected to the second ventilation cavity.

6. The mass spectrometer according to any one of claims 1 to 5, characterized in that: It also includes a particle focusing device, which has an inlet end and an outlet end opposite to the inlet end, the inlet end is connected to the screening sample outlet, and the outlet end is connected to the detection and analysis device.

7. The mass spectrometer according to claim 6, characterized in that The particle focusing device is an aerodynamic lens, a capillary, an electric field focusing lens or a nozzle.

8. The mass spectrometer according to claim 6, characterized in that It also includes a pressure regulating device, which has a buffer chamber, a critical hole connected to the buffer chamber, and a pressure regulating outlet, the critical hole is connected to the screening sample outlet, and the pressure regulating outlet is connected to the inlet end of the particle focusing device.

9. The mass spectrometer according to claim 8, characterized in that The critical hole has a diameter of 0.07 mm to 1.85 mm.

10. The mass spectrometer according to any one of claims 7 to 9, characterized in that It also includes a vacuum device, which has a vacuum cavity and a mounting port connected to the vacuum cavity, a particle outlet and a vacuum port, the vacuum port is used to connect to a vacuum pump, the outlet end of the particle focusing device extends into the mounting port, and the particle outlet is connected to the detection and analysis device.

11. The mass spectrometer according to claim 10, characterized in that It also includes a separation cone, which is arranged in the vacuum chamber, one end of the separation cone is aligned with the outlet end of the particle focusing device, and the other end of the separation cone is connected to the detection and analysis device.

12. The mass spectrometer according to claim 11, characterized in that There are multiple separation cones, and the multiple separation cones are arranged in sequence.

13. The mass spectrometer according to any one of claims 1 to 5, 7 to 9, and 12, characterized in that: The detection and analysis device is a time-of-flight mass spectrometer, a quadrupole analyzer or an ion trap mass analyzer.

14. The mass spectrometer according to any one of claims 1 to 5, 7 to 9, and 12, characterized in that: The detection and analysis device includes an ionization chamber, an ionization laser, an electric field generator, a detector and an analyzer. The ionization chamber is connected to the screening sample outlet. The ionization laser is used to emit laser to ionize the particles passing into the ionization chamber. The electric field generator and the detector are arranged in the ionization chamber. The electric field generator is used to generate an electric field to make the ionized particle fragments fly to the detector. The analyzer is electrically connected to the detector.

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