Aerosol particle photoionization system

Abstract

The invention discloses an aerosol particle photoionization system, and belongs to the technical field of aerosol particle ionization. An aerosol particle photoionization system comprises a sample cell, a polarized electrode unit, a light source unit, a light source unit, a light source unit, a light source unit, a light source unit, a light source unit, a light source unit, a light source unit and a light source unit, wherein the sample cell is provided with a sample inlet and a sample outlet; the polarized electrode unit is provided with a load electrode and a collection electrode; the light source unit is arranged between the load electrode and the collection electrode; the working end of the load electrode extends into the sample pool and is arranged at the light-emitting end of the light source assembly, and the collection electrode is arranged on the sample pool and corresponds to the load electrode and is used for maintaining the flow of airflow flowing through the sample outlet to be constant by adjusting the pressure ratio of the flow limiting hole; the photoionization mode is adopted, interference of ion fragments and salt adducts can be avoided, real components of aerosol can be reserved, accurate quantification can be achieved, high-voltage breakdown can be prevented, ionization stability can be improved, competition can be eliminated, baseline drift and memory effects can be inhibited, complex correction is not needed, and standardized measurement is achieved.

Description

Technical Field

[0001] This invention relates to the field of aerosol particle ionization technology, and more particularly to an aerosol particle photoionization system. Background Technology

[0002] Aerosol particle ionization technology is a type of "soft ionization" technology that ionizes aerosols from neutral particles for subsequent online, rapid, and highly sensitive detection using mass spectrometry and other charge measurement techniques. It plays a crucial role in fields such as micro / nano manufacturing, environmental monitoring, and pharmaceutical production. However, its application in the actual measurement of aerosol particles currently faces the following challenges:

[0003] 1. Current aerosol particle ionization techniques, such as electron bombardment ionization, tend to generate uncontrollable ion fragments, making it difficult to study the true physical properties and original chemical composition of aerosol particles, and also making it impossible to perform effective quantitative analysis.

[0004] 2. For aerosol samples rich in inorganic salts, salt adducts and non-covalent compounds are formed during the traditional electrospray ionization process, which interfere with ion generation and result in poor stability of the ionization process;

[0005] 3. Traditional metal electrodes are exposed to the air and are affected by changes in air humidity. Under high voltage, the electrodes are prone to breakdown, which reduces the ionization efficiency.

[0006] 4. Various aerosol soft ionization techniques are affected by competition for ionization pathways, which complicates quantitative analysis, produces severe signal baseline drift and memory effect, requires complex blank-correction cycles, and results in the lack of standardized aerosol ionization and measurement techniques.

[0007] To address these issues, we designed an aerosol particle photoionization system. Summary of the Invention

[0008] This invention provides a photoionization system for aerosol particles. The system, through the matching of a light source unit, a polarization electrode unit, and a flow control unit, can ionize aerosol particles by photoionization, and can avoid interference from ion fragments and salt adducts, retain the true components of the aerosol and achieve accurate quantification, prevent high voltage breakdown, and solve the problem of difficult control of aerosol particle ionization mentioned in the background art.

[0009] This invention provides the following technical solution:

[0010] A photoionization system for aerosol particles includes a sample cell with a sample inlet and a sample outlet. It also includes: a light source unit disposed on the sample cell, having a light-emitting end for generating light and illuminating a position within the sample cell corresponding to the sample inlet; a polarized electrode unit having a load electrode and a collecting electrode, the light-emitting end of the light source unit positioned between the load electrode and the collecting electrode, the working end of the load electrode extending into the sample cell at the light-emitting end position of the light source unit, and the collecting electrode disposed on the sample cell corresponding to the load electrode for collecting aerosol particle ions; and a flow control unit having a flow-limiting orifice, the inlet of which is connected to the sample outlet, for maintaining a constant airflow rate through the sample outlet by adjusting the pressure ratio of the flow-limiting orifice.

[0011] As a preferred embodiment of the present invention, the light source unit includes an ultraviolet lamp, one end of which is provided with a light-emitting window. The light-emitting window extends into the sample cell and is adapted to the sample inlet. An ultraviolet beam is formed through the light-emitting window to ionize aerosol particles into aerosol particle ions.

[0012] As a preferred embodiment of the present invention, the photon energy of the ultraviolet lamp is 10.6 eV.

[0013] As a preferred embodiment of the present invention, the polarization electrode unit includes a polarization electrode voltage regulator circuit board, which is provided with a voltage regulator positive output terminal and a voltage regulator negative output terminal. The voltage regulator positive output terminal is electrically connected to the load electrode through a wire, and the voltage regulator negative output terminal is electrically connected to the outer wall of the sample cell through a stainless steel wire. The acquisition electrode is provided with a detection and analysis component for acquiring and analyzing aerosol particle ions in the sample cell.

[0014] As a preferred embodiment of the present invention, the detection and analysis component includes a current detector, which is electrically connected to the acquisition electrode, and the current detector is connected to a data analyzer via a wire.

[0015] As a preferred embodiment of the present invention, the data analyzer is a high-sensitivity microcurrent amplification instrument or a mass spectrometry analysis instrument.

[0016] As a preferred embodiment of the present invention, the flow control unit includes a vacuum pump, the outlet end of the flow limiting orifice is connected to the vacuum pump, and the inlet end of the flow limiting orifice is connected to the sample outlet on the sample cell.

[0017] As a preferred embodiment of the present invention, the inlet end of the flow limiting orifice is provided with an airflow conduit, and the outlet of the airflow conduit is fixedly connected to the sample outlet on the sample cell.

[0018] As a preferred embodiment of the present invention, it further includes an aerosol generator, wherein the aerosol generator is provided with a compound storage tank, the compound storage tank is connected to a three-way valve, one of the ports of the three-way valve is provided with a compressed air delivery pipe, the other port of the three-way valve is connected to a particle filter, the output end of the particle filter is connected to a drying pipe, and the drying pipe is connected to the sample inlet through a pipeline.

[0019] As a preferred embodiment of the present invention, the sample cell is provided with an installation port, and the ultraviolet lamp is disposed on the installation port.

[0020] Compared with the prior art, the present invention provides an aerosol particle photoionization system, which has the following beneficial effects:

[0021] 1. This aerosol particle photoionization system replaces traditional electron bombardment ionization with photoionization, avoiding the generation of uncontrollable ion fragments, and can completely preserve the true physical properties and original chemical composition of aerosol particles, while providing a reliable basis for accurate quantitative analysis.

[0022] 2. This aerosol particle photoionization system, through a non-electrospray photoionization mechanism, can effectively avoid the formation of salt adducts and non-covalent compounds in inorganic salt aerosols during ionization, suppress the generation of interfering ions, and significantly improve the stability and consistency of the ionization process.

[0023] 3. This aerosol particle photoionization system eliminates the influence of environmental humidity on the electrodes by abandoning the traditional exposed metal electrode structure, avoids electrode breakdown under high voltage conditions, ensures stable and reliable ionization efficiency, and extends the service life of the system.

[0024] 4. This aerosol particle photoionization system eliminates the ionization path competition problem through a single, controllable photoionization path, simplifies the quantitative analysis logic, effectively suppresses signal baseline drift and memory effect, and eliminates the need for complex blank-correction loops, providing technical support for the standardization and normalization of aerosol ionization and measurement.

[0025] 5. This aerosol particle photoionization system can detect low-concentration, small-size particles, such as heavy metal ions and organic pollutants, which are difficult to detect by traditional methods, through a sample cell. It can monitor the changes in the chemical composition of aerosol particles in the atmosphere and the process of new particle formation in real time.

[0026] 6. This aerosol particle photoionization system can provide an important tool for studying the fundamental physical properties of single particles (such as charge and density), helping to verify and develop basic physical theories, promoting the progress of physics, and facilitating interdisciplinary research. In interdisciplinary fields such as biophysics, environmental science, and materials science, efficient aerosol photoionization technology provides strong support for studying particle behavior in complex systems.

[0027] The parts of this device not covered are the same as or can be implemented using existing technologies. This invention uses photoionization, which can avoid interference from ion fragments and salt adducts, retain the true components of aerosols and achieve accurate quantification, prevent high voltage breakdown, improve ionization stability, eliminate competition, suppress baseline drift and memory effect, and achieve standardized measurement without complex calibration. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of an aerosol particle photoionization system proposed in this invention;

[0029] Figure 2 This is a schematic diagram of the sample cell of an aerosol particle photoionization system proposed in this invention from a first-view perspective.

[0030] Figure 3 This is a schematic diagram of the sample cell of an aerosol particle photoionization system proposed in this invention from a second perspective.

[0031] Figure 4 This is a schematic diagram of the internal structure of the sample cell of an aerosol particle photoionization system proposed in this invention;

[0032] Figure 5 This is a schematic diagram of the flow-limiting orifice structure of an aerosol particle photoionization system proposed in this invention;

[0033] Figure 6 This is a schematic diagram of the load electrode and the acquisition electrode of an aerosol particle photoionization system proposed in this invention;

[0034] Figure 7 This is a schematic diagram of the structure of a lamp control circuit board for an aerosol particle photoionization system proposed in this invention;

[0035] Figure 8 This is a schematic diagram of the voltage regulator circuit board for an aerosol particle photoionization system proposed in this invention.

[0036] In the diagram: 100, Sample cell; 101, Sample inlet; 102, Sample outlet; 103, Mounting port; 200, UV lamp; 201, Quartz window; 202, Inert gas; 203, Excitation electrode; 204, Lamp housing; 300, Lamp control circuit board; 301, Positive voltage output terminal; 302, Negative voltage output terminal; 303, DC input terminal; 400, Voltage regulator circuit board; 401, Regulated positive output terminal; 402, Regulated negative output terminal; 500, Load electrode; 600, Acquisition electrode; 601, Current detector; 602, Data analyzer; 700, Vacuum pump; 800, Flow restrictor; 801, Airflow duct; 900, Aerosol generator; 901, Compound storage tank; 902, Three-way valve; 903, Compressed air delivery pipe; 904, Particulate filter; 905, Drying tube. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Aerosol particle photoionization systems can be applied to a wide range of technical fields, including: analytical chemistry (mass spectrometry, inorganic / organic / biological mass spectrometry), ionization methodologies (soft ionization, laser desorption / ionization, plasma); nanoscience and particle technology (single particle capture, growth and charge transfer mechanisms, online analysis of ultrafine nanoparticles); precision instruments (coupling design of high-vacuum systems, RF power supplies, microfluidic interfaces, time-of-flight systems, quadrupole mass spectrometers, etc.); and artificial intelligence and big data (real-time PMF source apportionment algorithms for PM2.5, AI-based toxic agent libraries, and 5G-IoT data transmission).

[0039] Example:

[0040] Reference Figure 1 - Figure 8 A photoionization system for aerosol particles can be applied to numerous technical fields, including: analytical chemistry (mass spectrometry, inorganic / organic / biological mass spectrometry), ionization methodologies (soft ionization, laser desorption, plasma); nanoscience and particle technology (single particle capture, growth and charge transfer mechanisms, online analysis of ultrafine nanoparticles); precision instruments (coupling design of high-vacuum systems, RF power supplies, microfluidic interfaces, time-of-flight systems, quadrupoles, and other high-end mass spectrometry technologies); and artificial intelligence and big data (real-time PMF source apportionment algorithms for PM2.5, AI-based toxic agent libraries, and 5G-IoT data transmission).

[0041] Specifically, the basic components of this aerosol particle photoionization system mainly include a sample cell 100, made of stainless steel. The sample cell 100 has a square structure and an internal cavity for accommodating aerosol particles. A sample inlet 101 and a sample outlet 102 are respectively provided on the sample cell 100. An installation port 103 is also provided on the sample cell 100, which is the interface of the ultraviolet lamp 200, used to connect the ultraviolet lamp 200 and the aerosol particle sample cell 100. The ultraviolet beam generated by the ultraviolet lamp 200 is introduced into the sample cell 100 to irradiate the aerosol particle sample in the sample cell 100, generating aerosol particle ions for the measurement and analysis of aerosol particles.

[0042] Specifically, aerosol particle samples can be generated by an aerosol generator 900. The aerosol generator 900 is equipped with a compound storage tank 901, which stores aromatic organic compounds. A three-way valve 902 is connected to the compound storage tank 901. One port of the three-way valve 902 is connected to a compressed air delivery pipe 903 for supplying compressed air. The other port of the three-way valve 902 is connected to a particle filter 904 for filtration. The output of the particle filter 904 is connected to a drying pipe 905, which is connected to a sample inlet 101 via a pipe to provide aerosol particle samples to the cavity of the sample cell 100. It should be noted that the aerosol particle samples input to the sample inlet 101 can come from the atmospheric environment or be generated by other instruments, such as a high-performance liquid chromatograph (HPLC). The sample outlet 102 on the sample cell 100 is connected to a flow control unit to ensure the continuous flow of aerosol particle samples.

[0043] Specifically, the ultraviolet lamp 200 is equipped with an excitation electrode 203 and a lamp housing 204. The ultraviolet lamp 200 is controlled by a lamp control circuit board 300. The main function of the ultraviolet lamp 200 is to provide a high-energy ultraviolet light source with highly stable illumination intensity for the aerosol particle sample in the sample cell 100. The energy range of the ultraviolet photons generated by this ultraviolet light source is 10.3 eV-10.9 eV, and this system can reach 10.6 eV, which meets the energy requirements for the ionization of most organic compounds, thereby ionizing the organic compounds in the aerosol particles. The external lamp 200 is also equipped with a sealed inert gas 202. The ultraviolet light comes from the sealed inert gas 202 being excited under a strong electric field, forming plasma light emission. The lamp control circuit board 300 is equipped with a positive voltage output terminal 301, a negative voltage output terminal 302, and a 24V DC power input terminal 303. The 24V DC power input terminal 303 is used to connect to an external power source. The control circuit of the ultraviolet lamp 200 inputs a 24V DC voltage, which is converted into a 2000V high-voltage isolated DC power through a low-energy DC boost converter.

[0044] Specifically, the polarization electrode unit includes a polarization electrode voltage regulator circuit board 400, which is provided with a voltage regulator positive output terminal 401 and a voltage regulator negative output terminal 402. The voltage regulator positive output terminal 401 is electrically connected to the load electrode 500 through a wire, and the voltage regulator negative output terminal 402 is electrically connected to the outer wall of the sample cell 100 through a stainless steel wire. The acquisition electrode 600 is provided with a detection and analysis component for collecting and analyzing aerosol particle ions in the sample cell 100 and outputting the results through the positive voltage output terminal 301 and the negative voltage output terminal 302.

[0045] The positive voltage output terminal 301 on the lamp control circuit board 300 is electrically connected to the excitation electrode 203 through a wire, and the negative voltage output terminal 302 is electrically connected to the lamp housing 204 through a wire, forming a ground wire, which is connected to the housing of the ultraviolet lamp 200 and the ground wire of the entire device. The quartz window 201 of the ultraviolet lamp 200 emits an ultraviolet light source with an ultraviolet photon energy of 10.6eV into the sample cell 100. When the ultraviolet lamp 200 is started, the excitation voltage is usually 1500V, and the voltage after stable operation is 400-500V. After the inert gas 202 is excited, the ultraviolet beam formed is output through the quartz window 201 at the bottom of the ultraviolet lamp 200 and enters the aerosol particle sample cell 100, ionizing the aerosol particles to form aerosol particle ions.

[0046] Specifically, the polarization electrode unit has a load electrode 500 and a collection electrode 600. The quartz window 201 at the bottom of the ultraviolet lamp 200 is located between the load electrode 500 and the collection electrode 600, that is, the load electrode 500 and the collection electrode 600 are located on both sides of the ultraviolet beam. The working end of the load electrode 500 extends into the sample cell 100 and is located at the light-emitting end of the light source assembly. The collection electrode 600 is located on the sample cell 100 and corresponds to the load electrode 500, and is used to collect aerosol particle ions.

[0047] Specifically, the acquisition electrode 600 is equipped with a detection and analysis component, which mainly includes a current detector 601. The current detector 601 is electrically connected to the acquisition electrode 600. The current detector 601 is connected to a data analyzer 602 through wires. The data analyzer 602 can be a high-sensitivity microcurrent amplification instrument or a mass spectrometry analysis instrument.

[0048] It should be explained that the load electrode 500 within the polarization electrode unit is made of stainless steel and is electrically connected to the regulated positive output terminal 401 on the voltage regulator circuit board 400 via a wire. The applied DC voltage is typically 100-200V. Generally, the regulated negative output terminal 402 on the voltage regulator circuit board 400 is connected to the outer wall of the aerosol particle sample cell 100 via a stainless steel wire, serving as the ground wire for the entire device. The voltage regulator circuit board 400 also has an input terminal for connecting to an external power source.

[0049] Specifically, the collecting electrode 600 in the polarization electrode unit is mainly used to collect aerosol particle ions in the sample cell 100, and then to test and analyze the physicochemical properties of the aerosol particles. It can be connected to other high-sensitivity analytical instruments, such as high-sensitivity microcurrent amplification instruments and mass spectrometry instruments. The voltage regulator circuit board 400 can convert 220V AC voltage into a stable DC voltage of 100-200V. It generally includes two parts: AC-DC conversion and DC voltage regulation. In order to ensure the low noise level of DC voltage output, we use LDO voltage regulator technology. At the same time, the output voltage of the circuit is controlled by the main control chip on the voltage regulator circuit board 400.

[0050] Specifically, the flow control unit has a flow-limiting orifice 800, the inlet of which is connected to the sample outlet 102. By adjusting the pressure ratio of the flow-limiting orifice 800, the flow rate of the gas flowing through the sample outlet 102 is maintained constant. It mainly consists of a vacuum pump 700, the flow-limiting orifice 800, and a gas flow duct 801. The functions of each part are as follows: the vacuum pump 700 provides the flowability of the sample gas, achieving a vacuum level of 1% of one atmosphere, with a maximum flow rate of 100 cubic centimeters per second; the gas flow duct 801 connects the sample outlet 102 of the aerosol particle sample cell 100 to the inlet of the flow-limiting orifice 800. The gas flow duct 801 can be a metal or plastic tube, while the flow-limiting orifice 800 is mainly a cylindrical component made of metal, such as... Figure 5 As shown. The inlet end of the flow restrictor 800 is connected to the airflow duct 801, and the outlet end of the flow restrictor 800 is connected to the vacuum pump 700. According to the choke principle, a constant airflow rate can be maintained by adjusting the pressure ratio on both sides of the flow restrictor 800.

[0051] The working principle is as follows: A high-intensity 10.6 eV ultraviolet light source is used to irradiate the gaseous aerosol particle sample. Since the photon energy is higher than the ionization energy (IP) of the organic compounds in the aerosol particles, photoionization of the aerosol particles can be achieved. That is, the aerosol particle absorbs the energy of one photon, exciting the electrons of the organic compounds into an ionized state, generating an aerosol particle ion and a free electron.

[0052] formula:

[0053] Here, M represents an aerosol particle, and e represents an electron. Aerosol particle ions obtained through photoionization can be used to detect their basic physical characteristics using various ion measurement techniques such as mass spectrometry, thereby obtaining important information about the physicochemical properties of aerosol particles.

[0054] For example, assuming that aerosol particles carry only one positive charge, the number of charges measured per second equals the number of aerosol particles. According to Coulomb's law, the number of charges per second is the current value, i.e.:

[0055] (1) 1A = 1 coulomb / second

[0056] If the measured current value is I (in amperes), the gas flow rate of the sample is FL (in cubic centimeters per second), and the particle concentration of the collected sample is N (in particles per cubic centimeter), then:

[0057] (2)

[0058] Meanwhile, if the radius of the aerosol particles is known to be r (in nanometers) and the density of the aerosol particles is known to be g / cm³, then the mass concentration C of the aerosol particles can be obtained through the following calculation:

[0059] (3)

[0060] Based on the above principles and methods, the number and mass concentration of aerosol particles can be ionized using a high-efficiency aerosol particle photoionization system, and then accurately obtained by measuring the current value of the particle ions.

[0061] For example, the compound storage tank 901 on the aerosol generator 900 is filled with aromatic compound aerosol particles, which are environmental pollutants generated in large quantities in industrial fields such as chemical production and pharmaceutical preparation, and are a significant source of PM2.5 in the atmosphere. Rapid detection of the concentration of aromatic compound aerosol particles is crucial for effective monitoring of the atmospheric environment. In this example, high-efficiency aerosol particle photoionization technology can be applied to quickly and accurately measure the concentration of aromatic compound aerosol particles.

[0062] Specifically, refer to Figure 1A constant-flow pneumatic aerosol generator (aerosol generator 900) uses 3 atmospheres of compressed air to create a high-speed airflow through a 100-micron metal flow-limiting orifice 800. Utilizing the siphon effect, the aqueous solution of aromatic compounds in the compound storage tank 901 is converted into aerosol particles with a diameter of approximately 100 nanometers. These particles then pass through a 30-centimeter-long drying tube 905 to remove moisture. Finally, at a sample gas flow rate of 1.5 cubic centimeters per second provided by the flow control unit, the aerosol particles are introduced into the sample cell 100 of a high-efficiency aerosol particle photoionization device. 10.6 eV photons from the ultraviolet lamp 200 ionize the aromatic compounds in the aerosol particles, forming aerosol particle ions. These aerosol particle ions, driven by the electric field formed by the polarized electrode unit in the sample cell 100, move to the collecting electrode 600 of the polarized electrode unit, where they release their charge. The weak current formed by these charges can be converted into a voltage signal by a high-sensitivity microcurrent amplifier. The obtained voltage signal can be used to calculate the current intensity of aerosol particle ions according to Ohm's law, and then the mass concentration of aromatic compound aerosol particles can be obtained according to formula (3). The measured current value is compared with the theoretical mass concentration of aerosol particles. The results show that the high-efficiency aerosol particle photoionization technology combined with high-sensitivity microcurrent measurement technology can improve the detection limit of aromatic compound aerosol particles to a measurement level of 1 ppb, which is far higher than the current domestic instrument monitoring level of 50 ppb.

[0063] The above solution has significant application value and broad beneficial effects in multiple fields, as follows:

[0064] In the field of environmental monitoring, especially in the study of secondary organic aerosols, ionization energy (IP) and binding energy (AE) can be used to identify different chemical components. This allows for the investigation of aerosol kinetic mechanisms in environmental chemical reactions such as the photo-oxidation of aromatic compounds and ozone generation.

[0065] In the field of online atmospheric monitoring: it can detect low-concentration, small-diameter particles that are difficult to detect by traditional methods, such as heavy metal ions and organic pollutants, and can monitor changes in the chemical composition of aerosol particles in the atmosphere and the formation process of new particles in real time.

[0066] In the medical and biological fields, especially in bioaerosol detection, pathogens can be identified, and pollen, bacteria, and fungal isolates can be detected.

[0067] In the field of health and toxicology research: it can be used for online monitoring of harmful fumes in in vitro exposure studies, and can analyze the chemical composition of elemental carbon and organic carbon components in aerosols, which helps in source apportionment and toxicity characterization.

[0068] In the industrial production sector:

[0069] Combustion process monitoring: emission monitoring of aircraft and ship engines. Photochemical process research of novel fuel combustion.

[0070] Petroleum and fuel analysis: Characterizing the performance properties of petroleum products at the molecular level. Providing a scientific basis for the development of new fuels and the improvement of the performance of existing fuels.

[0071] In the field of scientific research: This highly efficient aerosol photoionization technology system can provide an important tool for studying the basic physical properties of single particles (such as charge and density), which helps to verify and develop basic physical theories, promote the progress of physics, and facilitate interdisciplinary research. In interdisciplinary fields such as biophysics, environmental science, and materials science, the highly efficient aerosol photoionization technology provides strong support for studying the behavior of particles in complex systems.

[0072] In the field of public health: it can enhance disease prevention capabilities. Through efficient aerosol photoionization technology, harmful particulate matter in the environment can be detected in a timely manner, reducing the risk of public exposure to harmful substances. This helps to formulate more effective public health policies, protect public health, and support medical diagnosis and treatment. In medical imaging and diagnosis, efficient aerosol photoionization technology can provide clearer images and more accurate diagnostic results, which helps to improve the cure rate and recovery rate of diseases and improve the quality of life of patients.

[0073] In summary, high-efficiency aerosol photoionization technology has important application value and a wide range of beneficial effects in many fields, providing strong support for scientific research, environmental protection, medical diagnosis, industrial production and social development.

[0074] Components not described in detail in this article are existing technologies.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aerosol particle photoionization system, comprising a sample cell (100), wherein a sample inlet (101) and a sample outlet (102) are respectively provided on the sample cell (100), characterized in that, Also includes: A light source unit is disposed on the sample cell (100). The light source unit has a light-emitting end, which is used to generate a light source and illuminate the position in the sample cell (100) corresponding to the sample inlet (101). The polarized electrode unit has a load electrode (500) and a collection electrode (600). The light-emitting end of the light source unit is located between the load electrode (500) and the collection electrode (600). The working end of the load electrode (500) extends into the sample cell (100) and is located at the light-emitting end of the light source assembly. The collection electrode (600) is located on the sample cell (100) and corresponds to the load electrode (500) for collecting aerosol particle ions. The flow control unit has a flow restrictor (800) with its inlet end connected to the sample outlet (102). By adjusting the pressure ratio of the flow restrictor (800), the flow rate of the airflow through the sample outlet (102) is kept constant.

2. The aerosol particle photoionization system according to claim 1, characterized in that, The light source unit includes an ultraviolet lamp (200), one end of which is provided with a quartz window (201). The quartz window (201) extends into the sample cell (100) and is adapted to the sample inlet (101). An ultraviolet beam is formed through the quartz window (201) to ionize aerosol particles into aerosol particle ions.

3. The aerosol particle photoionization system according to claim 2, characterized in that, The photon energy of the ultraviolet lamp (200) is 10.6 eV.

4. The aerosol particle photoionization system according to claim 1, characterized in that, The polarization electrode unit includes a polarization electrode voltage regulator circuit board (400), on which a voltage regulator positive output terminal (401) and a voltage regulator negative output terminal (402) are provided. The voltage regulator positive output terminal (401) is electrically connected to the load electrode (500) through a wire, and the voltage regulator negative output terminal (402) is electrically connected to the outer wall of the sample cell (100) through a stainless steel wire. The acquisition electrode (600) is provided with a detection and analysis component for collecting and analyzing aerosol particle ions in the sample cell (100).

5. The aerosol particle photoionization system according to claim 4, characterized in that, The detection and analysis component includes a current detector (601), which is electrically connected to the acquisition electrode (600), and the current detector (601) is connected to a data analyzer (602) via a wire.

6. The aerosol particle photoionization system according to claim 5, characterized in that, The data analyzer (602) is a high-sensitivity microcurrent amplification instrument or a mass spectrometry analysis instrument.

7. The aerosol particle photoionization system according to claim 1, characterized in that, The flow control unit includes a vacuum pump (700), the outlet end of the flow limiting orifice (800) is connected to the vacuum pump (700), and the inlet end of the flow limiting orifice (800) is connected to the sample outlet (102) on the sample cell (100).

8. The aerosol particle photoionization system according to claim 7, characterized in that, The inlet end of the flow limiting orifice (800) is provided with an airflow duct (801), and the outlet of the airflow duct (801) is fixedly connected to the sample outlet (102) on the sample cell (100).

9. The aerosol particle photoionization system according to claim 1, characterized in that, It also includes an aerosol generator (900), on which a compound storage tank (901) is provided, and a three-way valve (902) is connected to the compound storage tank (901). A compressed air delivery pipe (903) is provided on one port of the three-way valve (902), and a particulate filter (904) is connected to the other port of the three-way valve (902). A drying tube (905) is connected to the output end of the particulate filter (904), and the drying tube (905) is connected to the sample inlet (101) through a pipe.

10. The aerosol particle photoionization system according to claim 2, characterized in that, The sample cell (100) has an installation port (103), and the ultraviolet lamp (200) is installed on the installation port (103).

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