A method for detecting and estimating organic aerosols generated in the atmospheric liquid phase

Abstract

The present invention provides a method for detecting and estimating organic aerosols generated by the liquid phase of the atmosphere, which can effectively detect the change process of the reaction intensity of the liquid phase of the atmosphere to generate organic aerosols and the liquid phase to generate SOA pollution more quickly and accurately, thereby improving the theoretical basis and guidance for the control and prevention measures of atmospheric pollution; the method comprises the following steps: S1, collecting a number of atmospheric fog water samples during high humidity periods in the target observation area; S2, measuring the mass spectrum of the organic components in the atmospheric fog water samples to obtain CH2SO2 in the mass spectrum of the atmospheric fog water samples + 、CH3SO2 + and CH4SO3 + The average value of the proportion of three characteristic organic fragments; S3, continuous observation of actual atmospheric aerosol components, obtain CH2SO2 + 、CH3SO2 + and CH4SO3 + The sum of the proportions of characteristic organic fragments in the atmospheric OA mass spectrum; S4, based on the mass spectrum of organic components of fog water samples and the CH2SO2 in the actual atmospheric aerosol OA mass spectrum + 、CH3SO2 + and CH4SO3 + The concentration of liquid-phase SOA in actual atmospheric aerosols is obtained by summing the percentage of characteristic organic fragments.

Description

Technical Field

[0001] The present invention relates to the field of environmental science and protection technology, and in particular to a method for detecting and estimating organic aerosol generated by an atmospheric liquid phase. Technical Background

[0002] With the continuous advancement of industrialization and urbanization in my country, fine particulate matter pollution in many cities has become a highly concerning environmental issue over the past decade. Its emission sources and formation mechanisms have long been a focus of research in environmental science. Based on their source, fine particulate matter (also known as aerosols) can be divided into primary aerosols (directly emitted) and secondary aerosols (generated through atmospheric redox reactions), primarily consisting of inorganic salts, organic matter, and metals. The largest components of atmospheric aerosols in Chinese cities are secondary inorganic aerosols (SNAs, consisting of sulfates, nitrates, and ammonium salts) and organic aerosols (OAs). The latter, comprising 40% to 50% of particulate matter, can be further divided into primary organic aerosols (POAs) and secondary organic aerosols (SOAs). Observational studies have shown that the generation of SNAs and SOAs is a primary cause of many severe air pollution events. While the formation mechanisms of SNAs are relatively well understood, the formation pathways of SOAs remain less clear due to the diverse species and molecular structures of organic matter and the complex chemical reactions involved.

[0003] Generally speaking, the formation pathways of secondary organic aerosols (SOA) include: volatile organic compounds (VOCs) emitted directly from pollution sources or semi-volatile organic compounds (SVOCs) emitted from particulate organic matter (POA) are oxidized by oxidizing gases and free radicals in the atmosphere into low-volatility substances, which then undergo physicochemical processes such as condensation and aggregation to form SOA; or these SVOCs dissolve into droplets or deliquescing particulate matter, become oxidized through liquid-phase chemical reactions, and then evaporate into SOA after the water evaporates. Atmospheric oxidizing properties, humidity, gaseous pollutants, and SNA components all influence SOA formation, especially humidity: under high humidity conditions, the hygroscopic growth of SNA particle seeds, the deliquescent transformation of aerosols into a liquid state, and the presence of droplets all promote aerosol-liquid-phase reactions and the formation of secondary species such as liquid-phase SOA and sulfates. Under the combined effects of high humidity and unfavorable diffusion conditions, the generation of liquid-phase SOA and sulfate aerosols in the atmosphere has become the main cause of severe air pollution in many regions. These aerosols not only endanger human health, but also change the atmospheric radiation balance, greatly affecting regional and even global climates. Therefore, quantifying organic aerosols generated by liquid-phase chemical reactions in the atmosphere is of great significance for further revealing the generation mechanism of secondary organic aerosols and thus carrying out targeted pollution prevention and control.

[0004] At present, the quantitative method for liquid-phase SOA is mainly to use a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) to continuously observe the main components of atmospheric aerosols and obtain the mass spectrum of the organic component OA, and then use the positive matrix factor analysis method (PMF) to perform factor analysis on OA. The emission source or SOA type associated with each factor is further analyzed based on the concentration and mass spectrum characteristics of each factor, such as the CCOA factor emitted by coal combustion, the HOA factor mainly from petroleum hydrocarbons emitted by motor vehicles, and the aq-SOA factor generated by atmospheric liquid-phase chemical reactions. The aq-SOA factor has a high degree of oxidation, and its concentration is closely related to relative humidity, aerosol liquid water concentration, and C2H2O2 in the mass spectrum. + 、CH3SO2 + Liquid-phase SOA studies are highly correlated with characteristic organic fragments of liquid-phase reactions. However, due to the complex composition of OA and the uncertainties of the AMS-PMF method, as well as the diversity of pollutant sources and atmospheric conditions in different regions, some analytical processes may not be able to resolve independent aq-SOA factors, which brings difficulties to liquid-phase SOA research. Moreover, the AMS-PMF method requires unified processing and source attribution of a large number of data points after multiple days of continuous AMS observations. This time-consuming analysis process makes it difficult to quickly and timely understand the formation of liquid-phase SOA. Summary of the Invention

[0005] To address the above issues, the present invention provides a method for detecting and estimating the generation of organic aerosols from the liquid phase of the atmosphere. The method can effectively and quickly detect the intensity of the reaction of organic aerosols generated from the liquid phase of the atmosphere and the changing process of SOA pollution generated from the liquid phase, thereby improving the theoretical basis and guidance for the control and prevention measures of atmospheric pollution.

[0006] The technical solution is as follows: a method for detecting and estimating organic aerosol generated by the atmospheric liquid phase, comprising the following steps:

[0007] S1. Collect several atmospheric fog water samples during high humidity periods in the target observation area; high humidity periods are when aerosols are completely deliquesced into liquid form;

[0008] S2. Measure the mass spectrum of organic components in atmospheric mist water samples to obtain liquid phase reaction characteristic organic fragments CH2SO2 + 、CH3SO2 + and CH4SO3 + The proportion of all ion fragments in the mass spectrum, and according to the formula:

[0009]

[0010] Obtain CH2SO2 in the mass spectra of N atmospheric mist water samples + 、CH3SO2 + and CH4SO3 + The average of the proportions and values ​​of the three characteristic organic fragments;

[0011] CH2SO2 + 、CH3SO2 + and CH4SO3 + They are the characteristic organosulfur species fragments formed by methanesulfonic acid in an aerosol mass spectrometer;

[0012] Where, f fog,MSA is the average value of the proportion of methanesulfonic acid characteristic organic fragments in the mass spectra of organic components of N atmospheric mist water samples;

[0013] N is the total number of atmospheric fog water samples;

[0014] f m,CH2SO2 CH2SO2 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments;

[0015] f m,CH3SO2 CH3SO2 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments;

[0016] f m,CH4SO3 CH4SO3 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments;

[0017] S3. Continuously observe the actual atmospheric aerosol components during the target time period to obtain CH2SO2 + 、CH3SO2 + and CH4SO3 + The sum of the proportions of characteristic organic fragments in the mass spectrum of atmospheric OA;

[0018] S4, according to the mass spectrum of the organic components of the fog water sample obtained in steps S2 and S3 and the CH2SO2 in the actual atmospheric aerosol OA mass spectrum, + 、CH3SO2 + and CH4SO3 + The concentration of liquid-phase SOA in actual atmospheric aerosols is obtained by summing the percentage of characteristic organic fragments.

[0019] Furthermore, in step S1, when the relative humidity in the target observation area exceeds 77%, an active mist collector is used to collect atmospheric mist samples, and solid impurities are filtered using a 0.45 μm filter. The filtrate is transferred to a glass bottle, sealed, and stored in a refrigerator;

[0020] Furthermore, in step S2, the stored atmospheric mist water sample is first generated into an aerosol using a constant flow atomizing aerosol generator, dried in a diffusion drying tube, and then a 300 nm monodisperse aerosol is screened out using a differential mobility analyzer. The aerosol components are then measured in an aerosol mass spectrometer to obtain a mass spectrum of the organic components in the atmospheric mist water sample;

[0021] Furthermore, in step S3, the actual atmospheric aerosol components are continuously observed using an aerosol mass spectrometer to obtain an atmospheric OA mass spectrum with high time resolution, and then according to the formula:

[0022]

[0023] Get CH2SO2 in each group of atmospheric OA mass spectra + 、CH3SO2 + and CH4SO3 + The sum of the proportions of characteristic organic fragments;

[0024] Where, f i,MSA is the sum of the proportions of methanesulfonic acid-type characteristic organic fragments in the atmospheric OA mass spectrum observed within time i;

[0025] f i,CH2SO2 is the CH2SO2 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments;

[0026] f i，CH3SO2 is the CH3SO2 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments;

[0027] f i,CH4SO3 is the CH4SO3 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments;

[0028] Furthermore, in step S4, according to the formula:

[0029]

[0030] Obtain the concentration of liquid phase SOA in actual atmospheric aerosol;

[0031] Where c i,aqSOA is the concentration of SOA generated from liquid phase reaction in atmospheric aerosol at time i;

[0032] c i,OA is the atmospheric OA concentration observed at time i;

[0033] Furthermore, it also includes verifying the rationality of the actual concentration result of liquid-phase SOA in atmospheric aerosol, that is, based on the time series of the concentration of sulfate in atmospheric aerosol observed by the aerosol mass spectrometer and the time series of the actual concentration of liquid-phase SOA in atmospheric aerosol obtained in step S4, performing a correlation analysis, and determining the rationality of the actual concentration result of liquid-phase SOA in atmospheric aerosol if a strong correlation is found;

[0034] Furthermore, it also includes verification of the rationality of the concentration results of liquid phase SOA in actual atmospheric aerosol, that is, including the following steps:

[0035] a. Based on the atmospheric aerosol component concentration, temperature, and humidity data observed by the aerosol mass spectrometer, the Isorropia-II model is used to obtain the time series of aerosol liquid water concentration;

[0036] b. Based on the time series of the concentration of aerosol liquid water and the time series of the concentration of liquid phase SOA in the actual atmospheric aerosol obtained in step S4, a correlation analysis is performed. If a strong correlation is found, the rationality of the result of the concentration of liquid phase SOA in the actual atmospheric aerosol is determined.

[0037] The beneficial effect of the present invention is that it can reduce the uncertainty of the liquid-phase SOA factor analyzed by the traditional PMF method, and can directly and quickly estimate the concentration of liquid-phase generated SOA based on the atmospheric OA concentration and mass spectrum observed by the aerosol mass spectrometer AMS, shortening the analysis cycle, which can help to grasp the high-time resolution change process of liquid-phase generated organic aerosol pollution in the atmosphere more quickly and clearly, and further explore the generation and aging mechanism, influencing factors, possible precursor emission sources, etc. of liquid-phase organic aerosols, thereby providing a basis for more efficient and reasonable pollution prevention and control measures. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. After reading the present invention, modifications to various equivalent forms of the present invention made by those skilled in the art fall within the scope defined by the appended claims.

[0039] A method for detecting and estimating organic aerosol generated by an atmospheric liquid phase comprises the following steps:

[0040] S1. Select an observation station representative of the target observation area, with no obvious pollution sources or obstructions in the surrounding area. When the relative humidity in the target observation area exceeds 77%, use an active fog collector to collect atmospheric fog samples. Use a 0.45μm filter to filter out solid impurities. Transfer the filtrate to a glass bottle, seal it, and store it in a refrigerator until analysis. During the collection process, multiple atmospheric fog samples can be collected in parallel.

[0041] Whether it's a laboratory-prepared mixed aerosol of ammonium sulfate and ammonium nitrate or a sample of actual atmospheric fine particulate matter, they absorb moisture and grow as relative humidity rises, gradually deliquescing and transforming into a liquid state. The deliquescing process occurs in two steps: the first deliquescing point, at a relative humidity of approximately 61%, represents a mixed solid-liquid state. The second deliquescing point, at a relative humidity of approximately 77%, completely transforms the aerosol into a liquid state, hence the term "complete deliquescing point." After this point, the aerosol reaches its weathering point, completely evaporating its water content and transforming it into a solid state, only when the relative humidity drops below 50%. Field observations have shown that the rate and amount of liquid SOA formation increase significantly when the relative humidity exceeds the complete deliquescing point. It is believed that the complete deliquescing of the aerosol into a liquid state promotes the oxidation of soluble organic precursors into the liquid phase, generating large amounts of liquid SOA. Solid aerosol then forms when the relative humidity decreases and the water evaporates. The mass spectra of organic components in the atmospheric fog water samples are very similar to the mass spectra of SOA factors analyzed using the AMS-PMF method during the same period. Generally speaking, POA has poor water solubility, while SOA has a higher degree of oxidation and is also more water soluble. In addition, this liquid-phase oxidation pathway is also the main pathway for the conversion of SO2 to sulfate, which is also an important secondary aerosol species. Therefore, the organic components in the atmospheric fog water samples collected at relative humidity exceeding 77% are a good representative of the formation of SOA through atmospheric liquid-phase reactions.

[0042] S2. First, the atmospheric mist water sample after storage was generated into aerosol using a constant flow atomizer. After drying in a diffusion drying tube, a 300 nm monodisperse aerosol was screened out using a differential mobility analyzer (DMA). The aerosol components were then measured in an aerosol mass spectrometer (AMS) to obtain the mass spectrum of the organic components in the atmospheric mist water sample to obtain the liquid phase reaction characteristic organic fragment CH2SO2 + 、CH3SO2 + and CH4SO3 + The proportion of all ion fragments in the mass spectrum, for parallel samples and atmospheric mist water samples collected and measured at different times (a total of N atmospheric mist water samples), is based on the formula:

[0043]

[0044] Obtain CH2SO2 in the mass spectra of N atmospheric mist water samples + 、CH3SO2 + and CH4SO3 + The average of the proportions and values ​​of the three characteristic organic fragments;

[0045] Where, f fog,MSAis the average value of the proportion of methanesulfonic acid characteristic organic fragments in the mass spectra of organic components of N atmospheric mist water samples;

[0046] N is the total number of fog water samples;

[0047] f m,CH2SO2 CH2SO2 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments;

[0048] f m,CH3SO2 CH3SO2 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments;

[0049] f m,CH4SO3 CH4SO3 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments;

[0050] Among them, CH2SO2 + 、CH3SO2 + and CH4SO3 + It is methanesulfonic acid (MSA, CH3SO3H) or methanesulfonate (CH3SO3 - ) are characteristic organic sulfur species fragments formed in the aerosol mass spectrometer AMS, and their relative proportions do not change much; methanesulfonic acid mainly comes from the oxidation of precursors such as dimethyl sulfide and dimethyl sulfoxide, and the presence of such species can often be observed in land-based atmospheric observations. In existing studies, CH2SO2 + 、CH3SO2 + and CH4SO3 + The concentration of characteristic fragments is highly correlated with the concentration of secondary organic aerosol generated by the liquid phase analyzed by the AMS-PMF method, namely the aq-SOA factor; moreover, CH2SO2 + 、CH3SO2 + and CH4SO3 + The estimated methanesulfonic acid concentration in atmospheric aerosols is also highly correlated with sulfate concentration, which indicates that liquid phase chemical reaction is the main production pathway of methanesulfonic acid. Therefore, methanesulfonic acid is an important representative substance for the production of SOA in the atmospheric liquid phase. + 、CH3SO2 + and CH4SO3 + Characteristic fragments are also important indicator fragments of SOA generated in the atmospheric liquid phase. Their proportion in the mass spectrum of organic components of fog water samples during high humidity periods is approximately the same as their proportion in the mass spectrum of SOA generated in the atmospheric liquid phase.

[0051] S3. Use the aerosol mass spectrometer AMS to continuously and directly observe the actual atmospheric aerosol components during the target time period to obtain the atmospheric OA mass spectrum with high time resolution, and then use the formula:

[0052]

[0053] Get CH2SO2 in each group of atmospheric OA mass spectra + 、CH3SO2 + and CH4SO3 + The sum of the proportions of characteristic organic fragments;

[0054] Where, f i,MSA is the sum of the proportions of methanesulfonic acid-type characteristic organic fragments in the atmospheric OA mass spectrum observed within time i;

[0055] f i,CH2SO2 is the CH2SO2 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments;

[0056] f i，CH3SO2 is the CH3SO2 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments;

[0057] f i,CH4SO3 is the CH4SO3 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments;

[0058] Among them, the atmospheric non-refractory submicron aerosol NR-PM was continuously observed using the aerosol mass spectrometer AMS at the same observation station. 1.0 The concentration of the main components can be used to obtain a time series of organic matter concentration, mass spectrum and inorganic ion concentration with high time resolution. Usually, you can choose to generate a set of mass spectrum data every minute; during the observation season, you can choose a typical 15 to 30 days in that season or conduct continuous observation of the pollution process;

[0059] The aerosol mass spectrometer AMS is a high-resolution mass spectrometer. By using the aerosol mass spectrometer AMS to continuously and directly observe the actual atmospheric aerosol components, the atmospheric OA mass spectrum with high time resolution can be obtained.

[0060] S4. The organic components of the atmospheric mist water sample in step S1 are considered to represent the atmospheric liquid phase SOA species, CH2SO2 formed by methanesulfonic acid + 、CH3SO2 + and CH4SO3 + The organic fragments are also the fingerprint fragments of liquid phase SOA. Therefore, the mass spectra of the organic components of the fog water sample obtained in steps S2 and S3 and the CH2SO2 in the actual atmospheric aerosol OA mass spectrum can be used to identify the organic components of the fog water sample. + 、CH3SO2 + and CH4SO3 +The concentration of liquid phase SOA in actual atmospheric aerosols is estimated based on the proportion of characteristic organic fragments:

[0061]

[0062] Where c i,aqSOA is the concentration of SOA generated from liquid phase reaction in atmospheric aerosol at time i;

[0063] c i,OA is the atmospheric OA concentration observed at time i.

[0064] The present invention also includes verifying the rationality of the actual concentration results of liquid-phase SOA in atmospheric aerosols. One verification implementation method is to perform a correlation analysis based on the time series of the sulfate concentration in the atmospheric aerosol observed by the aerosol mass spectrometer and the time series of the actual concentration of liquid-phase SOA in the atmospheric aerosol obtained in step S4. If there is a strong correlation, the rationality of the actual concentration results of liquid-phase SOA in atmospheric aerosols is determined.

[0065] Another verification implementation of the present invention includes the following steps:

[0066] a. Based on the atmospheric aerosol component concentration, temperature, and humidity data observed by the aerosol mass spectrometer, the Isorropia-II model is used to obtain the time series of aerosol liquid water concentration;

[0067] b. Based on the time series of the concentration of aerosol liquid water and the time series of the concentration of liquid phase SOA in the actual atmospheric aerosol obtained in step S4, a correlation analysis is performed. If a strong correlation is found, the rationality of the result of the concentration of liquid phase SOA in the actual atmospheric aerosol is determined.

[0068] The present invention collects atmospheric fog water samples after complete deliquescence of aerosols, measures the organic components dissolved therein, and obtains the proportion of methanesulfonic acid characteristic fragments in the mass spectrum of liquid-phase SOA species. Therefore, when the aerosol mass spectrometer AMS continuously observes atmospheric aerosols, the concentration of liquid-phase generated organic aerosols in the actual atmosphere can be estimated based on the concentration of atmospheric OA and the proportion of methanesulfonic acid characteristic fragments in its mass spectrum. It can reduce the uncertainty of the liquid-phase SOA factor analyzed by the traditional PMF method, and can directly and quickly estimate the concentration of liquid-phase generated SOA based on the atmospheric OA concentration and mass spectrum observed by the aerosol mass spectrometer AMS, thereby shortening the analysis cycle. This can help to grasp the high-time resolution change process of liquid-phase generated organic aerosol pollution in the atmosphere more quickly and clearly, and further explore the generation and aging mechanism, influencing factors, possible precursor emission sources, etc. of liquid-phase organic aerosols, thereby providing a basis for more efficient and reasonable pollution prevention and control measures.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0070] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for detecting and estimating organic aerosols generated in the atmospheric liquid phase, characterized by: It includes the following steps: S1. Collect several atmospheric fog water samples during high humidity periods in the target observation area; high humidity periods are when aerosols are completely deliquesced into liquid form; S2. Measure the mass spectrum of organic components in atmospheric mist water samples to obtain liquid phase reaction characteristic organic fragments CH2SO2 + 、CH3SO2 + and CH4SO3 + The proportion of all ion fragments in the mass spectrum, and according to the formula: Obtain CH2SO2 in the mass spectra of N atmospheric mist water samples + 、CH3SO2 + and CH4SO3 + The average of the proportions and values ​​of the three characteristic organic fragments; CH2SO2 + 、CH3SO2 + and CH4SO3 + They are the characteristic organosulfur species fragments formed by methanesulfonic acid in an aerosol mass spectrometer; Where, f fog,MSA is the average value of the proportion of methanesulfonic acid characteristic organic fragments in the mass spectra of organic components of N atmospheric mist water samples; N is the total number of atmospheric fog water samples; f m,CH2SO2 CH2SO2 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments; f m,CH3SO2 CH3SO2 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments; f m,CH4SO3 CH4SO3 in the mass spectrum of the organic component of the fog water sample m + The proportion of fragments; S3. Continuously observe the actual atmospheric aerosol components during the target time period to obtain CH2SO2 + 、CH3SO2 + and CH4SO3 + The sum of the proportions of characteristic organic fragments in the mass spectrum of atmospheric OA; S4, according to the mass spectrum of the organic components of the fog water sample obtained in steps S2 and S3 and the CH2SO2 in the actual atmospheric aerosol OA mass spectrum, + 、CH3SO2 + and CH4SO3 + The concentration of liquid-phase SOA in actual atmospheric aerosols is obtained by summing the percentage of characteristic organic fragments.

2. The method for detecting and estimating organic aerosol generated in the atmospheric liquid phase according to claim 1, characterized in that: In step S1, when the relative humidity in the target observation area exceeds 77%, an active mist collector is used to collect atmospheric mist samples, and a 0.45 μm filter is used to filter solid impurities. The filtrate is transferred to a glass bottle, sealed, and stored in a refrigerator.

3. The method for detecting and estimating organic aerosol generated in the atmospheric liquid phase according to claim 1, characterized in that: In step S2, the stored atmospheric mist water sample is first generated into an aerosol using a constant flow atomizing aerosol generator. After drying through a diffusion drying tube, a 300 nm monodisperse aerosol is screened out using a differential mobility analyzer, and then the aerosol components are measured in an aerosol mass spectrometer to obtain a mass spectrum of the organic components in the atmospheric mist water sample.

4. The method for detecting and estimating organic aerosol generated in the atmospheric liquid phase according to claim 1, characterized in that: In step S3, the actual atmospheric aerosol components are continuously observed by an aerosol mass spectrometer to obtain an atmospheric OA mass spectrum with high time resolution, and then according to the formula: Get CH2SO2 in each group of atmospheric OA mass spectra + 、CH3SO2 + and CH4SO3 + The sum of the proportions of characteristic organic fragments; Where, f i,MSA is the sum of the proportions of methanesulfonic acid-type characteristic organic fragments in the atmospheric OA mass spectrum observed within time i; f i,CH2SO2 is the CH2SO2 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments; f i，CH3SO2 is the CH3SO2 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments; f i,CH4SO3 is the CH4SO3 in the atmospheric OA mass spectrum observed during time i + The proportion of fragments.

5. The method for detecting and estimating organic aerosol generated in the atmospheric liquid phase according to claim 4, characterized in that: In step S4, according to the formula: Obtain the concentration of liquid phase SOA in actual atmospheric aerosol; Where c i,aqSOA is the concentration of SOA generated from liquid phase reaction in atmospheric aerosol at time i; c i,OA is the atmospheric OA concentration observed at time i.

6. The method for detecting and estimating organic aerosol generated in the atmospheric liquid phase according to claim 5, characterized in that: It also includes verifying the rationality of the actual concentration result of liquid-phase SOA in atmospheric aerosol, that is, based on the time series of sulfate concentration in atmospheric aerosol observed by the aerosol mass spectrometer and the time series of liquid-phase SOA concentration in atmospheric aerosol obtained in step S4, a correlation analysis is performed. If there is a strong correlation, the rationality of the actual concentration result of liquid-phase SOA in atmospheric aerosol is determined.

7. The method for detecting and estimating organic aerosol generated in the atmospheric liquid phase according to claim 5, characterized in that: It also includes the verification of the rationality of the concentration results of liquid phase SOA in actual atmospheric aerosols, which includes the following steps: a. Based on the atmospheric aerosol component concentration, temperature, and humidity data observed by the aerosol mass spectrometer, the Isorropia-II model is used to obtain the time series of aerosol liquid water concentration; b. Based on the time series of the concentration of aerosol liquid water and the time series of the concentration of liquid phase SOA in the actual atmospheric aerosol obtained in step S4, a correlation analysis is performed. If a strong correlation is found, the rationality of the result of the concentration of liquid phase SOA in the actual atmospheric aerosol is determined.

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