Injection device and mass spectrometer for broadening the particle size transmission range of aerodynamic lens

Abstract

The present invention discloses a sampling device and a mass spectrometer for broadening the particle size transmission range of an aerodynamic lens, wherein the sampling device comprises: an aerosol delivery tube, a first focusing member, and a critical orifice plate; a focusing orifice plate is fixedly arranged inside the first focusing hole; a second focusing hole is provided on the focusing orifice plate, and the second focusing hole is used to further narrow the particle distribution in the aerosol sample; the first focusing member and the critical orifice plate cooperate with each other to form a vortex cavity, and the vortex cavity is used to generate a vortex to rectify the aerosol sample passing through the second focusing hole. By rectifying the aerosol sample through the vortex in the vortex cavity, the beam width of the aerosol sample can be effectively reduced, and the transmission efficiency of the aerodynamic lens for large-diameter particles can be improved. By using the sampling device of the present application, the particle transmission range of the aerodynamic lens can be effectively broadened, the particle size detection range of the mass spectrometer can be improved, more comprehensive data can be obtained, and the behavior and effect of particulate matter can be better understood and explained.

Description

Technical Field

[0001] The invention relates to the technical field of mass spectrometry, and in particular to a sampling device and a mass spectrometer for broadening the particle diameter transmission range of an aerodynamic lens. Background Art

[0002] In the field of atmospheric environment detection technology, mass spectrometry detection and analysis of particulate matter in air samples is a relatively common technical means. The most widely used technology is SPMS (Single Particle Mass Spectrometry), which is used to analyze the chemical composition and composition of individual particles in the atmosphere. It is usually used to study the source, chemical properties and impact of atmospheric particulate matter on the environment and health. A large part of the minerals, sea salts and bioaerosols in the atmospheric environment are in the coarse particle mode (particle size ), which is mainly limited by the inertial wall loss of the SPMS injection interface for coarse particles. The following particle detection capabilities are limited, especially If a traditional injection interface is used, The above coarse particles are too lost, which affects the final mass spectrometry detection results and cannot effectively detect a wide particle size range (particle size ) aerosol particles, which limits the application ability of SPMS in bioaerosols, atmospheric particle source analysis, atmospheric aging mechanism, etc.

[0003] The Chinese invention patent (application number: CN201711079461.2) proposes a concentrator and an aerodynamic focusing system, wherein the concentrator comprises a concentrator container, a sampling mechanism, a flow guide mechanism and a buffer container, wherein the concentrator container is provided with an air pressure chamber and a vacuum column, and the sampling mechanism is provided with a sampling channel, a flow limiting hole and a flow diversion hole connected in sequence; the flow guide mechanism is provided on the concentrator container, and the buffer container is connected to the concentrator container and / or the flow guide mechanism, and the buffer chamber is connected to the flow guide channel to meet the vacuum load requirement of the vacuum analysis equipment without affecting the vacuum load. When the above-mentioned concentrator is connected to the sampling interface of the aerodynamic lens, under the condition of using conventional vacuum load, under the impetus of the air pressure difference, the aerosol sampling flow rate can be increased, the passing rate of large-size particles can be increased, and the concentration of aerosol and the focusing of particle beams can be achieved, which will be conducive to the sampling and detection of aerosols at low concentrations.

[0004] Based on the above patents, the Chinese invention patent (application number: CN202010615218.3) proposes an aerosol mass spectrometer sampling device and an aerosol mass spectrometer with a wide particle size range. By arranging a first aerosol focusing component and a first buffer tube before the critical orifice plate, the first aerosol focusing component pre-focuses the sample aerosol before entering the critical orifice plate, thereby avoiding the loss caused by the larger particles in the sample aerosol colliding with the critical orifice plate when passing through the center hole of the critical orifice plate, improving the transmission performance of particles with a particle size of more than 1μm, and increasing the particle size range of particles passing through the center hole of the critical orifice plate, thereby realizing the detection of aerosol particles with a wide particle size range. In addition, it also greatly reduces the influence of deposition and adhesion of large particles on the critical orifice plate, and reduces the frequency of instrument maintenance and cleaning.

[0005] However, the device still has the following defects: the pre-focusing part of the device adopts an aerodynamic lens or nozzle. In order to improve the focusing effect, a multi-level orifice plate needs to be assembled for pre-focusing, which causes the aerosol to have too high a speed after passing through the pre-focusing part. A large buffer cavity is required to prevent the aerosol particles from colliding with the surrounding cavity walls after entering the buffer cavity. In addition, the aerodynamic lens used in the application is a seven-level lens. Since the assembly precision of the aerosol injection device is high, the more levels of the lens, the accumulated errors lead to worse coaxiality of the lens. Summary of the invention

[0006] The purpose of the present invention is to disclose a sampling device and a mass spectrometer that broaden the particle size transmission range of an aerodynamic lens, thereby solving the problems of existing aerosol sampling devices that are too large in volume and have too many lens stages, resulting in poor coaxiality.

[0007] In order to achieve the above object, the present invention adopts the following technical scheme:

[0008] A sampling device for broadening the particle size transmission range of an aerodynamic lens comprises: an aerosol delivery tube, a first focusing member, and a critical orifice plate; the first end of the aerosol delivery tube is used to receive an aerosol sample; the second end of the aerosol delivery tube is connected to the first end of the first focusing member; the second end of the first focusing member is connected to one side of the critical orifice plate; a first focusing hole is provided on the first focusing member, and the first focusing hole is used to limit the particle distribution in the aerosol sample; a focusing orifice plate is fixedly arranged inside the first focusing hole; a second focusing hole is provided on the focusing orifice plate, and the second focusing hole is used to further limit the particle distribution in the aerosol sample; a critical hole is provided on the critical orifice plate, and the critical hole is used to control the flow rate of the aerosol sample and adjust the air pressure on both sides of the critical orifice plate; the first focusing member and the critical orifice plate cooperate with each other to form a vortex cavity, and the vortex cavity is used to generate a vortex to reduce the beam width of the aerosol sample after passing through the second focusing hole.

[0009] In one embodiment, the aerosol transport tube, the first focusing hole, the second focusing hole and the critical hole are all coaxially arranged.

[0010] In one embodiment, the inner diameter of the first focusing hole is smaller than the inner diameter of the aerosol delivery tube; the first focusing member cooperates with the inner wall of the aerosol delivery tube to form a first abrupt step.

[0011] In one embodiment, the inner diameter of the second focusing hole is smaller than the inner diameter of the first focusing hole; the focusing hole plate and the inner side wall of the first focusing hole cooperate with each other to form a second abrupt step.

[0012] In one embodiment, the bottom surface of the first focusing member and the top surface of the critical orifice plate fit together; the bottom surface of the focusing orifice plate, the inner wall of the first focusing hole and the top surface of the critical orifice plate cooperate with each other to form a vortex chamber.

[0013] In one embodiment, the inner diameter of the critical hole is smaller than the inner diameter of the second focusing hole; the inner diameter of the vortex chamber is larger than the inner diameter of the second focusing hole.

[0014] In one embodiment, the inner diameter of the first focusing hole is .

[0015] In one embodiment, the inner diameter of the second focusing hole is .

[0016] In one embodiment, the height of the first abrupt step is .

[0017] In one embodiment, the height of the vortex chamber is .

[0018] In one embodiment, the diameter of the vortex chamber is .

[0019] In one embodiment, it also includes: a concentration container and a flow guide mechanism; the concentration container is fixedly connected to the other side of the critical orifice plate, and an injection port is provided on the concentration container; the injection port is communicated with the critical orifice; the flow guide mechanism is accommodated inside the concentration container; a flow guide channel is provided inside the flow guide mechanism, and the flow guide channel is coaxially arranged with the injection port; the concentration container is used to draw away the airflow in the aerosol sample to concentrate the particles in the aerosol sample.

[0020] In one embodiment, the inner diameter of the guide channel gradually increases along the particle transmission direction; and the angle between the inner side wall of the guide channel and the axis is no greater than 15°.

[0021] In one embodiment, the sample injection device further includes: a buffer chamber; the buffer chamber is fixedly connected to the concentration container; and the buffer chamber is communicated with the guide channel.

[0022] In one embodiment, the buffer cavity is cylindrical; the buffer cavity is coaxially arranged with the guide channel.

[0023] In one embodiment, the sample injection device further includes: a second focusing component; the second focusing component is fixedly connected to the outer shell of the buffer chamber; and the second focusing component is also communicated with the buffer chamber.

[0024] In one embodiment, the second focusing element is a five-stage aerodynamic lens.

[0025] An aerosol mass spectrometer comprises the above-mentioned sampling device for broadening the particle size transmission range of the aerodynamic lens, and also comprises a mass spectrometer vacuum detection mechanism, wherein the mass spectrometer vacuum detection mechanism is used for performing mass spectrometry detection on the aerosol particles focused by the sampling device.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention provides a sampling device and a mass spectrometer for broadening the particle size transmission range of an aerodynamic lens, comprising: an aerosol delivery tube, a first focusing member, and a critical orifice plate; a first focusing hole is provided on the first focusing member, and the first focusing hole is used to limit the particle distribution in an aerosol sample; a focusing orifice plate is fixedly arranged inside the first focusing hole; a second focusing hole is provided on the focusing orifice plate; a critical hole is provided on the critical orifice plate, and the critical hole is used to control the flow rate of the aerosol sample and adjust the air pressure on both sides of the critical orifice plate; the first focusing member and the critical orifice plate cooperate with each other to form a vortex cavity, and the vortex cavity is used to generate a vortex to rectify the aerosol sample passing through the second focusing hole; in summary, the present invention rectifyes the aerosol sample by the vortex in the vortex cavity, which can effectively reduce the beam width of the aerosol sample, improve the transmission efficiency of the aerodynamic lens for large-diameter particles, and can also reduce the number of aerodynamic lenses used to transmit large-diameter particles, thereby reducing the difficulty of assembling the equipment. Using the sampling device of the present application can effectively broaden the particle transmission range of the aerodynamic lens, thereby improving the particle size detection range of the mass spectrometer, so that more comprehensive and integrated data can be obtained, covering all size segments from smaller to larger particles, and can also better understand and explain the behavior and effects of particulate matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0029] Figure 1 It is a schematic diagram of the external structure of the sampling device for broadening the particle diameter transmission range of the aerodynamic lens of the present invention;

[0030] Figure 2 yes Figure 1 Schematic diagram of the internal structure cross section of the AA part;

[0031] Figure 3 yes Figure 2 A magnified schematic diagram of part A;

[0032] Figure 4 yes Figure 3 A magnified schematic diagram of part B;

[0033] Figure 5 It is a schematic diagram of the separation and transmission of particles and airflow in an aerosol sample;

[0034] Figure 6 is a schematic diagram of the dimensions of the first focusing member;

[0035] Figure 7 is a simulation diagram of particle transmission efficiency of the embodiment and the comparative example;

[0036] In the figure, 1, aerosol delivery tube; 2, first focusing component; 21, first focusing hole; 22, focusing orifice plate; 23, second focusing hole; 24, first sudden contraction step; 25, second sudden contraction step; 3, critical orifice plate; 31, critical hole; 4, vortex chamber; 5, concentration container; 51, injection port; 6, flow guide mechanism; 61, flow guide channel; 7, buffer chamber; 8, second focusing component. DETAILED DESCRIPTION

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0038] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. The terms "vertical", "horizontal", "left", "right", "above", "below" and similar expressions are for illustrative purposes only, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0040] In order to facilitate the understanding of the technical solution, the prior art is briefly described first. Aerodynamic Lens is a device that manipulates tiny particles or aerosol particles by focusing airflow. The particles and airflow pass through a contracting nozzle, the airflow speed increases, and the air resistance of the particles increases. The airflow accelerates the particles to a high speed and concentrates them in the central area of ​​the nozzle. Through a series of contraction-expansion structures (usually a series of annular nozzles or holes), the speed and pressure of the airflow change repeatedly. This periodic acceleration and deceleration will continuously adjust the trajectory of the particles so that they are finally focused in a narrow area, that is, forming a "particle beam". With each additional lens, the particles in the airflow will undergo a new acceleration and deceleration process, which further concentrates the particles. More levels of aerodynamic lenses mean that the particles can be gradually focused at a longer distance, thereby improving the final focusing accuracy and stability. The multi-stage aerodynamic lens system can better adapt to particles of different particle sizes. Each level of lens has different focusing effects on particles of different particle sizes. The combination of multiple levels can cover a wider range of particle sizes and enhance the versatility of the system. However, the more stages of aerodynamic lenses, the better. This is because there will be certain errors after each stage of lenses is assembled together. When multiple stages of lenses are connected to each other, their errors will also accumulate, which will affect the coaxiality of the central through hole of the aerodynamic lens. When the error accumulation exceeds the allowable range, it will affect the transmission effect of the particles and reduce the transmission efficiency of the particles. In addition, due to the different sizes of particles and different inertia, the larger the particles, the more difficult it is to change the transmission direction. Therefore, in order to increase the aerodynamic particle size transmission range, the prior art usually adopts the method of increasing the number of aerodynamic lenses to increase the aerodynamic particle size transmission range. For example, a Chinese invention patent (application number: CN202010615218.3) proposes an aerosol mass spectrometer injection device and an aerosol mass spectrometer with a wide particle size range. By setting two stages of focusing components for pre-focusing before the critical orifice plate and setting a seven-stage lens after the buffer chamber, the particle size transmission range of the traditional seven-stage lens can be increased from. Expand to , but the application still has the following defects: 1. The pre-focusing method introduced in the application improves the focusing effect of the particle beam, which will increase the transmission speed of the aerosol sample, resulting in a larger particle divergence angle in the buffer cavity. In order to avoid particle loss, a larger buffer cavity needs to be set to avoid collision between particles and the side walls of the buffer cavity. 2. The aerodynamic lens after the buffer cavity in the application uses a seven-stage lens, plus a two-stage pre-focusing lens, which has a large number of series stages and is difficult to assemble. In addition, the error accumulation will affect the transmission efficiency of the sample injection device.

[0041] Embodiment 1

[0042] like Figure 1-6 The sample introduction device for widening the particle size transmission range of the aerodynamic lens shown in the figure comprises: an aerosol delivery tube 1, a first focusing member 2, and a critical orifice plate 3; the first end of the aerosol delivery tube 1 is used to receive an aerosol sample; the second end of the aerosol delivery tube 1 is connected to the first end of the first focusing member 2; the second end of the first focusing member 2 is connected to one side of the critical orifice plate 3; the first focusing member 2 is provided with a first focusing hole 21, and the first focusing hole 21 is used to limit the particle distribution in the aerosol sample; a focusing orifice plate 22 is fixedly arranged inside the first focusing hole 21; the focusing orifice plate 22 is provided with a second focusing hole 23, and the second focusing hole 23 is used to further limit the particle distribution in the aerosol sample; the critical orifice plate 3 is provided with a critical hole 31, and the critical hole 31 is used to control the flow rate of the aerosol sample and adjust the air pressure on both sides of the critical orifice plate 3; the first focusing member 2 and the critical orifice plate 3 cooperate with each other to form a vortex chamber 4, and the vortex chamber 4 is used to generate a vortex to reduce the beam width of the aerosol sample after passing through the second focusing hole 23.

[0043] When the above-mentioned sampling device is working, the aerosol sample is first transmitted to the aerosol delivery tube 1 through one end of the aerosol delivery tube 1; the aerosol sample passes through the first focusing hole 21 on the first focusing member 2, and is subjected to the first focusing treatment by the first focusing hole 21 to reduce the beam width of the aerosol sample, and then the aerosol sample passes through the second focusing hole 23 on the focusing hole plate 22 for the second focusing treatment, which can further reduce the beam width. After two focusings, the aerosol sample enters the vortex chamber 4, where the diffusion movement of high-speed gas will generate vortices, which rectify the subsequent airflow, and can further reduce the gas beam width; finally, the aerosol sample that has been rectified multiple times passes through the critical hole 31 and enters the subsequent concentration container 5 and the buffer chamber 7 to perform the subsequent steps. When the aerosol sample passes through the critical orifice plate 3, the pressure difference before and after the critical orifice plate 3 changes greatly, so the aerosol particles will obtain a greater speed, and after passing through the critical hole 31, the aerosol particles will diverge in the buffer chamber 7 to form a conical transmission trajectory. The sampling device provided in this embodiment can reduce the beam width of the aerosol sample by rectifying the aerosol sample by utilizing the vortex formed in the vortex chamber 4. At the same time, it can also reduce the incident angle of the aerosol sample before passing through the critical hole 31, so that the aerosol sample is more concentrated before passing through the critical hole 31, thereby reducing the divergence angle of the aerosol sample after passing through the critical hole 31. In summary, the present application can effectively reduce the beam width of the aerosol sample by setting a vortex chamber 4 between the first focusing member 2 and the critical orifice plate 3 and rectifying the aerosol sample by utilizing the vortex generated in the vortex chamber 4.

[0044] In summary, after the aerosol sample is pre-focused by the sample introduction device described in the present application, the particle size focusing range of the existing sample introduction device can be widened. In the prior art, the particle size range that can be focused by the five-stage aerodynamic lens is usually between For aerosol samples with a particle size exceeding If the sample introduction device of the present application is arranged at the input end of the five-stage aerodynamic lens, the transmission efficiency of the five-stage aerodynamic lens for particles with a size between The transmission efficiency of particles is improved, so that the transmission range of the five-stage aerodynamic lens is expanded to .

[0045] In one embodiment, the aerosol delivery tube 1, the first focusing hole 21, the second focusing hole 23 and the critical hole 31 are all coaxially arranged. In practical applications, only when the aerosol delivery tube 1, the first focusing hole 21, the second focusing hole 23 and the critical hole 31 are all coaxially arranged can the particles be prevented from colliding with the parts around the focusing hole during the transmission process, resulting in particle loss. The coaxial arrangement of the holes is conducive to improving the transmission efficiency of the particles.

[0046] In one embodiment, the inner diameter of the first focusing hole 21 is smaller than the inner diameter of the aerosol delivery tube 1; the first focusing member 2 cooperates with the inner wall of the aerosol delivery tube 1 to form a first sudden contraction step 24. The first sudden contraction step 24 can focus the aerosol sample flowing in the aerosol delivery tube for the first time, so that the airflow in the aerosol sample stably contracts inwardly, so as to drive the particles in the aerosol sample to move toward the central axis.

[0047] In one embodiment, the inner diameter of the second focusing hole 23 is smaller than the inner diameter of the first focusing hole 21; the focusing hole plate 22 cooperates with the inner side wall of the first focusing hole 21 to form a second abrupt step 25. The second abrupt step 25 forms a continuous step with the first abrupt step 24, so that the airflow in the aerosol sample further contracts inward, so as to drive the particles in the aerosol sample to move toward the central axis.

[0048] In one embodiment, the bottom surface of the first focusing member 2 and the top surface of the critical orifice plate 3 are in contact with each other; the bottom surface of the focusing orifice plate 22, the inner side wall of the first focusing hole 21 and the top surface of the critical orifice plate 3 cooperate with each other to form a vortex chamber 4. In the present application, since the first focusing hole 21 is divided into two parts, the upper and lower parts of the first focusing hole 21 may have the same inner diameter or may not have the same inner diameter. When the upper and lower parts of the first focusing hole 21 have the same inner diameter, the inner diameter of the vortex chamber 4 is not equal to the inner diameter of the first focusing hole 21.

[0049] In one embodiment, the inner diameter of the critical hole 31 is smaller than the inner diameter of the second focusing hole 23 ; the inner diameter of the vortex chamber 4 is larger than the inner diameter of the second focusing hole 23 .

[0050] In the present application, since the inner diameter of the second focusing hole 23 and the inner diameter of the critical hole 31 are both smaller than the inner diameter of the first focusing hole 21, when the bottom surface of the first focusing member 2 and the critical hole plate 3 fit each other, the upper surface of the critical hole plate 3 and the lower surface of the focusing hole plate and the inner wall of the first focusing hole form a cylindrical vortex chamber 4; when the aerosol sample after focusing enters the vortex chamber 4, due to the diffusion movement of the gas, a vortex will be formed inside the vortex chamber 4, and the vortex can rectify the subsequent aerosol sample, so that the aerosol sample can be more concentrated, and driven by the airflow, the particles of the aerosol sample move toward the axis, thereby improving the focusing effect. For aerosol particles, the larger the diameter of the particle, the worse the focusing effect of the particle, and the present application uses the vortex chamber 4 to form a vortex to rectify the airflow, which can effectively push large-sized particles to move toward the axis, and avoid the particles that are not aligned with the critical hole 31 colliding with the critical hole plate 3, resulting in particle loss. The rectifying effect of the eddy current can also reduce the angle at which the airflow enters the critical hole 31. If the angle at which the airflow enters the critical hole 31 becomes smaller, then the divergence angle of the particles after passing through the critical hole 31 and entering the buffer chamber 7 will also become smaller.

[0051] In one embodiment, the inner diameter of the first focusing hole 21 is for .

[0052] In one embodiment, the inner diameter of the second focusing hole 24 is for .

[0053] In one embodiment, the inner diameter of the vortex chamber 4 is for .

[0054] In one embodiment, the height of the first abrupt step 24 is for .

[0055] In one embodiment, the height of the vortex chamber 4 is for .

[0056] Based on the above-mentioned size constraints, it can be known that the inner diameter of the first focusing hole 21 is The inner diameter of the vortex chamber 4 The same size or different sizes can be used. However, the inner diameter of the second focusing hole 24 is must be smaller than the inner diameter of the first focusing hole 21 And the inner diameter of the vortex chamber 4 In this way, the second focusing hole 24 can further focus the aerosol based on the first focusing hole 21, and can also make the airflow form a vortex in the vortex chamber 4, and further rectify the aerosol sample to reduce the beam width of the airflow in the vortex chamber 4.

[0057] In one embodiment, Figure 5 As shown, it also includes: a concentration container 5 and a guide mechanism 6; the concentration container 5 is fixedly connected to the other side of the critical orifice plate 3, and an injection port 51 is provided on the concentration container 5; the injection port 51 is connected to the critical hole 31; the guide mechanism 6 is contained inside the concentration container 5; a guide channel 61 is provided inside the guide mechanism 6, and the guide channel 61 is coaxially arranged with the injection port 51; the concentration container 5 is used to extract the airflow in the aerosol sample to concentrate the particles in the aerosol sample. Since the inertia of the particles is greater than that of the gas molecules, after being accelerated through the critical hole 31, the particles can smoothly enter the guide channel 61 by inertia, while the gas molecules in the aerosol sample are more easily extracted to achieve the concentration of the particles.

[0058] In one embodiment, the inner diameter of the guide channel 61 gradually increases along the particle transmission direction; the angle between the inner side wall of the guide channel 61 and the axis is not greater than 15°. When the particles pass through the rectifying effect of the eddy current, the angle of the airflow entering the critical hole 31 can be reduced. The angle of the airflow entering the critical hole 31 becomes smaller, and then the divergence angle of the particles after passing through the critical hole 31 and entering the buffer chamber 7 will also become smaller. The injection device of the present application is installed at the front end of the aerodynamic lens, which can effectively reduce the divergence angle of the particles, and the divergence angle of the smallest particles can be controlled within 12°. Therefore, the angle of the guide channel 61 can be controlled within 15°. By adjusting the angle of the guide channel 61, the size of the subsequent buffer chamber 7 can be reduced.

[0059] In one embodiment, it further comprises: a buffer chamber 7; the buffer chamber 7 is fixedly connected to the concentration container 5; the buffer chamber 7 is connected to the guide channel 61. Figure 5As shown, the guide channel 61 is used to guide the concentrated aerosol sample that has not been extracted into the buffer chamber 7. Since the inertia of the particles is greater than that of the gas molecules, after being accelerated by the critical hole 31, the particles can smoothly enter the guide channel 61 by relying on inertia, and the gas molecules in the aerosol sample are more easily extracted to achieve the concentration of the particles. The particles pass through the guide channel 61 and enter the buffer chamber 7 which is close to vacuum. The buffer chamber 7 can change the aerosol sample from a turbulent state to a laminar state, which is convenient for subsequent focusing and bundling. In the present application, since the divergence angle of the particles becomes smaller after entering the buffer chamber, the size of the buffer chamber can be significantly reduced, so as to facilitate the miniaturization of the equipment. In the prior art, the cross-sectional diameter of the buffer chamber is , the length of the buffer cavity also needs In order to meet the particle transfer efficiency, the diameter of the buffer cavity in this application can be reduced to , the length of the buffer cavity can be reduced to , the particle transfer efficiency can be met.

[0060] In one embodiment, the buffer cavity 7 is cylindrical; the buffer cavity 7 is coaxially arranged with the guide channel 61 .

[0061] In one embodiment, it further includes: a second focusing component 8; the second focusing component 8 is fixedly connected to the outer shell of the buffer cavity 7; and the second focusing component 8 is also communicated with the buffer cavity 7.

[0062] In one embodiment, the second focusing element 8 is a five-stage aerodynamic lens.

[0063] The traditional five-stage aerodynamic lens can only focus between of particles, for The transmission efficiency of particles with a particle size range of 200-300 mm / s will be significantly reduced. Combining the sample injection device of the present application with the five-stage aerodynamic lens can effectively improve the Compared with the prior art, the aerodynamic lens has fewer stages and smaller assembly errors, which can effectively reduce the difficulty of assembling the equipment.

[0064] Embodiment 2

[0065] An aerosol mass spectrometer includes a sampling device for widening the particle size transmission range of an aerodynamic lens as described in Example 1, and also includes a mass spectrometer vacuum detection mechanism, wherein the mass spectrometer vacuum detection mechanism is used to perform mass spectrometry detection on aerosol particles focused by the sampling device. Using the sampling device in Example 1 can effectively widen the particle transmission range of the aerodynamic lens, thereby improving the particle size detection range of the aerosol mass spectrometer, so that more comprehensive and integrated data can be obtained, covering all size segments from smaller to larger particles, and the behavior and effects of particulate matter can be better understood and explained.

[0066] Embodiment 3

[0067] like Figure 7 As shown, the present application also provides two comparative examples to highlight the technical effect of the sample introduction device including the first focusing member recorded in Example 1. The comparative examples specifically include the following three structures:

[0068] Embodiment 1: A sample injection device as provided in Embodiment 1 is used, wherein a vortex chamber is provided between the first focusing member and the critical orifice plate, and the second focusing member is a five-stage aerodynamic lens.

[0069] Comparative Example 1: An aerosol mass spectrometer sampling device with a wide particle size range proposed in the invention patent (application number: CN202010615218.3) is adopted, and a two-stage aerodynamic lens is set before the buffer cavity for pre-focusing, and a seven-stage aerodynamic lens is set after the buffer cavity.

[0070] Comparative Example 2: A two-stage aerodynamic lens is provided before the buffer cavity for pre-focusing, and a five-stage aerodynamic lens is provided after the buffer cavity for focusing.

[0071] Comparing Example 1 with Comparative Example 1, the structure in Comparative Example 1 can transmit particles with a diameter of Particle size particles; The structure in Example 1 can achieve the same transfer efficiency while reducing the number of aerodynamic lens stages, effectively reducing the difficulty of assembling the sampling device and avoiding the impact of error accumulation during the assembly of multi-stage aerodynamic lenses on the final equipment stability.

[0072] Comparing Example 1 with Comparative Example 2, in the case of using a five-stage aerodynamic lens in Comparative Example 2, even if two stages of aerodynamic lenses are added between the critical aperture plates for pre-focusing, of range, its transfer efficiency will be significantly reduced; and the sample introduction device in Example 1 of the present application cooperates with the five-stage aerodynamic lens to effectively improve The transfer efficiency of particles in a wide range.

[0073] In summary, by adopting the sampling device for broadening the particle size transmission range of the aerodynamic lens described in this application, the particle size range in the prior art can be The five-stage aerodynamic lens widens the particle size transmission range to While achieving the transmission of particles in this wide particle size range, the number of aerodynamic lenses can be reduced, thereby reducing the accumulation of assembly errors and reducing the difficulty of assembly.

[0074] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.

Claims

1. A sampling device for broadening the particle size transmission range of an aerodynamic lens, characterized in that: include: an aerosol delivery tube, a first focusing member, and a critical orifice plate; The first end of the aerosol delivery tube is used to receive an aerosol sample; The second end of the aerosol delivery tube is connected to the first end of the first focusing member; the second end of the first focusing member is connected to one side of the critical orifice plate; The first focusing member is provided with a first focusing hole, and the first focusing hole is used to limit the particle distribution in the aerosol sample; A focusing hole plate is fixedly arranged inside the first focusing hole; a second focusing hole is opened on the focusing hole plate, and the second focusing hole is used to further narrow the particle distribution in the aerosol sample; A critical hole is provided on the critical orifice plate, and the critical hole is used to control the flow rate of the aerosol sample and adjust the air pressure on both sides of the critical orifice plate; The aerosol delivery tube, the first focusing hole, the second focusing hole and the critical hole are all coaxially arranged; The bottom surface of the first focusing member and the top surface of the critical orifice plate are in contact with each other; the bottom surface of the focusing orifice plate, the top surface of the critical orifice plate, and the inner side wall of the first focusing hole located between the bottom surface of the focusing orifice plate and the top surface of the critical orifice plate cooperate with each other to form a vortex cavity, and the vortex cavity is used to generate a vortex to reduce the beam width of the aerosol sample after passing through the second focusing hole; The inner diameter of the first focusing hole between the second end of the aerosol transport tube and the top surface of the focusing hole plate is The first focusing member cooperates with the inner wall of the aerosol delivery tube to form a first constricted step; The inner diameter of the second focusing hole smaller than the inner diameter of the first focusing hole The top surface of the focusing hole plate cooperates with the inner side wall of the first focusing hole to form a second constricted step; The inner diameter of the critical hole is smaller than the inner diameter of the second focusing hole ; The inner diameter of the vortex chamber Greater than the inner diameter of the second focusing hole ; The inner diameter of the first focusing hole for ; The inner diameter of the second focusing hole for ; The inner diameter of the vortex chamber for ; The height of the first concave step for ; The height of the vortex chamber for .

2. The sampling device for broadening the particle size transmission range of the aerodynamic lens according to claim 1, characterized in that: Also includes: A concentration container and a flow guide mechanism; the concentration container is fixedly connected to the other side of the critical orifice plate, and an injection port is provided on the concentration container; the injection port is connected to the critical orifice; The flow guiding mechanism is accommodated inside the concentration container; a flow guiding channel is provided inside the flow guiding mechanism, and the flow guiding channel is coaxially arranged with the injection port; The concentration container is used to extract the airflow in the aerosol sample to concentrate the particles in the aerosol sample.

3. The sampling device for broadening the particle size transmission range of the aerodynamic lens according to claim 2, characterized in that: The inner diameter of the guide channel gradually increases along the particle transmission direction; the angle between the inner side wall of the guide channel and the axis is not greater than 15°.

4. The sampling device for broadening the particle size transmission range of the aerodynamic lens according to claim 3, characterized in that: Also includes: A buffer chamber and a second focusing component; the buffer chamber is fixedly connected to the concentration container; the buffer chamber is communicated with the guide channel; the second focusing component is fixedly connected to the outer shell of the buffer chamber; the second focusing component is also communicated with the buffer chamber; the second focusing component is a five-level aerodynamic lens.

5. An aerosol mass spectrometer, characterized in that: It comprises a sampling device for broadening the particle size transmission range of an aerodynamic lens as described in any one of claims 1 to 4, and also comprises a mass spectrometer vacuum detection mechanism, wherein the mass spectrometer vacuum detection mechanism is used to perform mass spectrometer detection on aerosol particles focused by the sampling device.

Images