Atmospheric particulate organic matter high-resolution online rapid detection system and high-resolution mass spectrometry spectrum identification method

Abstract

The application provides an atmospheric particulate organic matter high-resolution on-line rapid detection system and its use in detecting at least one component selected from polar or weakly polar organic matter components in atmospheric particulate matter. The application also provides an atmospheric particulate organic matter high-resolution mass spectrum identification method. The application further provides a rapid detection method for nitrophenol and nitrobenzoic acid components in atmospheric particulate organic matter. The atmospheric particulate organic matter high-resolution on-line rapid detection system and the high-resolution mass spectrum identification method provided by the application are easy to control, fast in response, sensitive in response, high in sensitivity and mass resolution, and can achieve the purpose of automatic on-line observation of atmospheric particulate organic matter molecular ion analysis and screening.

Description

Technical Field

[0001] This invention belongs to the technical field of atmospheric pollutant monitoring, and relates to a high-resolution online rapid detection system for atmospheric particulate organic matter and a high-resolution mass spectrometry spectrum identification method. Specifically, it relates to a high-time-resolution online rapid detection system for polar / weakly polar organic matter in atmospheric particulate matter and a high-resolution mass spectrometry spectrum identification method. Background Technology

[0002] Ambient air and exhaust emissions from pollution sources contain particulate matter of varying sizes. Organic compounds within these particles can be categorized by boiling point into moderately volatile, semi-volatile, and non-volatile organic compounds, and by polarity into polar, weakly polar, and non-polar organic compounds. Compounds with boiling points below 350℃, molecular weights less than 400 amu, and good thermal stability are suitable for gas chromatography-mass spectrometry (GC-MS) analysis. Polar and weakly polar organic compounds, such as those containing highly polar functional groups like hydroxyl, amino, and carboxyl groups, or those with poor thermal stability like organic acids, monosaccharides, polysaccharides, and alcohols, typically require derivatization before GC-MS analysis. Most require extraction and concentration with organic solvents of varying polarities before analysis on liquid chromatography-mass spectrometry (LC-MS).

[0003] Traditional offline GC-MS and LC-MS methods are suitable for offline acquisition of filter membranes and require processes such as solvent extraction, concentration, and instrumental analysis, resulting in low temporal resolution. Current online mass spectrometry methods for analyzing organic matter in atmospheric particulate matter, such as AMS and TAG-GCMS, mainly obtain signals as mass spectrometry fragments. The substance category is determined by the ratio of characteristic fragments, which is easily interfered with by background substances and is not easy to infer molecular composition, becoming a limiting factor affecting the observation of atmospheric particulate organic matter. Summary of the Invention

[0004] The purpose of this invention is to provide a high-resolution online rapid detection system for atmospheric particulate organic matter and a high-resolution mass spectrometry spectrum identification method. Based on the combined use of multiple technologies such as open ionization mass spectrometry and orbital trap mass spectrometry, it can realize the rapid collection, excitation and analysis of organic components in atmospheric particulate matter. Compared with existing technologies, it has higher time resolution, makes it easier to obtain molecular ions for quantitative and qualitative analysis, and has less measurement uncertainty. It can provide an important technical means for the online analysis of organic matter in atmospheric particulate matter.

[0005] To achieve the above and other related objectives, the first aspect of the present invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter, comprising a housing, an ion transmission tube disposed on the housing, the housing being hollow and the ion transmission tube penetrating through the housing, an ionization source and a sample loading disk disposed inside the housing, the input surface of the sample loading disk cooperating with the output end of the ionization source, the output surface of the sample loading disk cooperating with the input end of the ion transmission tube, and the output end of the ion transmission tube being connected to an orbital hydrazine mass spectrometer.

[0006] The second aspect of the present invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter for detecting at least one component selected from polar or weakly polar organic components in atmospheric particulate matter.

[0007] The third aspect of the present invention provides a method for identifying atmospheric particulate organic matter using high-resolution mass spectrometry, comprising: collecting atmospheric particulate matter samples using the above-mentioned high-resolution online rapid detection system for atmospheric particulate organic matter, exciting and ionizing the ionized sample molecules, detecting the ionized sample molecules by orbital hydrazine mass spectrometry, analyzing the obtained mass spectrometry data, obtaining the corresponding ion molecular composition and response intensity by extracting the precise mass number, and determining the target component and concentration in the sample molecules.

[0008] A fourth aspect of this invention provides a rapid detection method for nitrophenol and nitrobenzoic acid components in atmospheric particulate organic matter, comprising the following steps:

[0009] 1) The atmospheric particulate matter sample was subjected to the same steps as the above-mentioned high-resolution mass spectrometry identification method for atmospheric particulate organic matter to obtain ionized sample molecules.

[0010] 2) Using the same steps as the above-mentioned high-resolution mass spectrometry identification method for atmospheric particulate organic matter, the standards of 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dimethyl-4-nitrophenol, 2,4-dinitrophenol, 4-nitroguaiacol, 4-methyl-5-nitrocatechol, 2,6-dinitro-4-methylphenol, 1,2-dihydroxy-4-nitrobenzene, 5-nitrosalicylic acid, and 3-hydroxy-4-nitrobenzoic acid are used to obtain ionized standard molecular ions;

[0011] 3) Using the same steps as the above-mentioned high-resolution mass spectrometry method for identifying atmospheric particulate organic matter, the ionized sample molecules obtained in step 1) and the ionized standard molecular ions obtained in step 2) are used to determine the target components in the sample, and the content of the target components in the sample is calculated by the external standard method based on the determination results of the standard molecular ions.

[0012] As described above, the high-resolution online rapid detection system and high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter provided by the present invention have the following beneficial effects:

[0013] (1) The present invention provides a high-resolution online rapid detection system and a high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter. Based on the combined use of multiple technologies such as open ionization mass spectrometry and orbital trap mass spectrometry, it can realize the rapid collection, excitation, and analysis of organic components in atmospheric particulate matter. Compared with existing technologies, it has higher time resolution, makes it easier to obtain molecular ions for quantitative and qualitative analysis, and reduces measurement uncertainty. The establishment of this research method can provide an important technical means for the online analysis of organic matter in atmospheric particulate matter.

[0014] (2) This invention provides a high-resolution online rapid detection system and a high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter. It integrates atmospheric pressure direct ionization technology, a dynamic particulate matter capture module, and ultra-high resolution orbital trap mass spectrometry to achieve efficient excitation and rapid detection of organic molecular ions. Its core innovations include: 1) the development of a filter membrane dynamic loading-in-situ ionization device to achieve spatiotemporal synchronization of particulate matter enrichment and ionization (response time ≤ 1 minute); 2) the development of a shunt-type dilution sampling interface and a sieve temperature control module to overcome the limitations of online adaptability for samples with a wide concentration range (0.1-1000 μg / m³). 3 3) Establish a mass spectrometry intelligent analysis algorithm based on accurate mass deviation (<5ppm), integrating fragment characteristics and mass spectrometry library machine learning matching technology to achieve automated two-dimensional (quantitative / qualitative) analysis of organic matter. Calculate the mass deviation of target compounds within 5ppm as reliable results and record them in the detection results. Based on accurate mass number molecular formula calculations, mass spectrometry library matching, and other methods, qualitatively screen common atmospheric organic compounds. Experimental verification shows that the system can achieve ppb-level detection limits (LOD = 0.03 ng / m³) for trace components such as nitrophenols (NACs). 3 This method is a hundred times more efficient than traditional offline methods.

[0015] (3) The present invention provides a high-resolution online rapid detection system and a high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter, which can realize the quantitative measurement and qualitative analysis of no less than 10 kinds of atmospheric particulate organic matter containing carbon, nitrogen, oxygen and sulfur, such as nitrophenols (NACs). The detection limits of different components are between several and thousands of ppm, and the online measurement resolution can be as low as 1 minute. At least 60 kinds of organic components containing carbon, nitrogen, oxygen and sulfur can be calibrated at multiple points using standard samples.

[0016] (4) The present invention provides a high-resolution online rapid detection system and a high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter. This system enables the ionization of ground-state carrier gas molecules into excited-state atoms or molecules using direct ionization technology under open atmospheric pressure, thereby exciting and ionizing particulate samples enriched in real-time on a quartz filter membrane. Ions, electrons, and excited-state gas molecules ejected from the ion source are used to generate molecular ions from the ionization of the analyte in atmospheric particulate matter through thermal conduction. These molecular ions are then introduced into the orbital hydrazine mass spectrometer via a vacuum gradient at the mass spectrometer inlet, achieving high-time-resolution online detection of particulate organic matter in the atmosphere and ensuring direct real-time analysis of ambient air and atmospheric particulate matter samples from pollution sources.

[0017] (5) The present invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter and a high-resolution mass spectrometry spectrum identification method. The detection system provided is easy to assemble and disassemble, which can effectively improve the efficiency of instrument operation and personnel operation. After assembly, no manual pretreatment operation is required, which avoids the differences between different batches of samples caused by pretreatment operation or reagent differences. One assembly can be used for real-time sample analysis for multiple days.

[0018] (6) The present invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter and a high-resolution mass spectrometry spectrum identification method. It is easy to maintain, and the dilution and concentration methods are applicable to high time-resolution and high-resolution online measurement methods of particulate organic matter in ambient air and exhaust gas from pollution sources such as motor vehicle exhaust. It does not require solvents or pretreatment, is highly efficient and fast, and has high resolution. It can obtain high time-resolution and high-resolution molecular information of particulate organic matter.

[0019] (7) The present invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter and a high-resolution mass spectrometry spectrum identification method. The ionization and analysis time resolution are high, avoiding the sample extraction and transfer losses, waiting time on the instrument, and the lack of molecular formula and structure judgment in conventional online analysis when there are no molecular ions.

[0020] (8) This invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter and a high-resolution mass spectrometry identification method. It provides a connection between the acquisition and ionization device and the Orbitrap mass spectrometer, ensuring that the mass deviation of the target compounds for qualitative screening is controlled within 5 ppm to 20 ppm. The instrument is easy to assemble, has high temporal and mass resolution, and is suitable for long-term online observation of atmospheric particulate organic matter and instantaneous changes in the composition of substances in atmospheric emissions from pollution sources.

[0021] (9) The present invention provides a high-resolution online rapid detection system and a high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter. It is an online acquisition, particulate matter enrichment, real-time ionization and online observation method. It has fewer steps, less loss, is easy to control, fast response, sensitive response and high mass resolution. It can realize the purpose of automatic online observation, molecular ion analysis and screening of atmospheric particulate organic matter. Attached Figure Description

[0022] Figure 1 The diagram shows the structure of the high-resolution online rapid detection system for atmospheric particulate organic matter in solid particulate matter according to the present invention.

[0023] Figure 2 The diagram shows the structure of the high-resolution online rapid detection system for atmospheric particulate organic matter in this invention.

[0024] Figure 3 This diagram illustrates the technical roadmap for the high-resolution mass spectrometry method for identifying atmospheric particulate organic matter in this invention.

[0025] Figure 4 The flowchart shown is a process for online acquisition, ionization, and mass spectrometry detection of the high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter in this invention.

[0026] Figure 5 The flowchart shown is a process for analyzing orbital trap mass spectrometry data in the high-resolution mass spectrometry spectrum identification method for atmospheric particulate organic matter in this invention.

[0027] Figure 6 shows the liquid chromatograms and mass spectra of 11 nitrophenols and nitrobenzoic acids. Figure 6a1 The image shows the liquid chromatogram of 4-nitrophenol. Figure 6a2 This is the mass spectrum of 4-nitrophenol. Figure 6b1 The liquid chromatograms are for 2-methyl-4-nitrophenol and 3-methyl-4-nitrophenol. Figure 6b2 The mass spectrum is for 2-methyl-4-nitrophenol. Figure 6b3 This is the mass spectrum of 3-methyl-4-nitrophenol. Figure 6c1 The image shows the liquid chromatogram of 2,6-dimethyl-4-nitrophenol. Figure 6c2 The mass spectrum is for 2,6-dimethyl-4-nitrophenol. Figure 6d1 The image shows the liquid chromatogram of 2,4-dinitrophenol. Figure 6d2 This is the mass spectrum of 2,4-dinitrophenol. Figure 6e1 The liquid chromatograms are for 4-nitroguaiacol and 4-methyl-5-nitrocatechol. Figure 6e2 This is the mass spectrum of 4-nitroguaiacol. Figure 6e3 The mass spectrum is for 4-methyl-5-nitrocatechol. Figure 6f1The image shows the liquid chromatogram of 2,6-dinitro-4-methylphenol. Figure 6f2 The mass spectrum of 2,6-dinitro-4-methylphenol is shown. Figure 6g1 The liquid chromatogram of 1,2-dihydroxy-4-nitrobenzene. Figure 6g2 The mass spectrum is for 1,2-dihydroxy-4-nitrobenzene. Figure 6h1 The liquid chromatograms are of 5-nitrosalicylic acid and 3-hydroxy-4-nitrobenzoic acid. Figure 6h2 This is the mass spectrum of 5-nitrosalicylic acid. Figure 6h3 This is the mass spectrum of 3-hydroxy-4-nitrobenzoic acid.

[0028] Figure Labels

[0029] 1 Ionization source

[0030] 2 ion transport tubes

[0031] 3. Orbital hydrazine mass spectrometry

[0032] 4 Sample Loading Disks

[0033] 41 membrane support

[0034] 42 sample positions

[0035] 43 filter membrane

[0036] 5. Shell

[0037] 6 cutting heads

[0038] 7 Sampling tubes

[0039] 8. Air extraction pipe

[0040] 9. Air pump

[0041] 10 Stable gas inlet pipe

[0042] 11 Atmospheric Transmission Pipe Detailed Implementation

[0043] After extensive research and exploration, the inventors of this invention will now describe the specific technical details of the high-resolution online rapid detection system for atmospheric particulate organic matter and the high-resolution mass spectrometry identification method.

[0044] The first aspect of this invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter, such as... Figure 1 , 2As shown, it includes a housing with an ion transmission tube mounted on it. The housing is hollow and the ion transmission tube penetrates through it. An ionization source and a sample loading disk are located inside the housing. The input surface of the sample loading disk is matched with the output end of the ionization source, and the output surface of the sample loading disk is matched with the input end of the ion transmission tube. The output end of the ion transmission tube is connected to an orbital hydrazine mass spectrometer.

[0045] In the above-described device, the housing is rectangular in shape, and at least one observation window is provided on each of the four side walls of the housing. The housing seals the ionization source and sample loading disk within it. The observation windows are used to observe the ionization nozzle, the position of the filter membrane, and the position of the ion transmission tube, facilitating adjustment.

[0046] In one specific embodiment, observation windows are provided on all four side walls of the housing.

[0047] In one specific embodiment, the casing is made of passivated stainless steel or aluminum oxide. This ensures that the casing will not participate in the reaction of reactive substances in the atmosphere.

[0048] In one specific embodiment, the observation window is made of heat-resistant quartz.

[0049] In the above-mentioned device, the ion transport tube is made of copper.

[0050] In the above-described device, the output end of the ion transmission tube is connected to the gas inlet of the orbital hydrazine mass spectrometer.

[0051] The aforementioned quadrupole-electrostatic orbital trap mass spectrometer, manufactured by Thermo Fisher Scientific based on Orbitrap technology, is a mass spectrometer with an ultra-high resolution mass analyzer. It boasts ultra-high mass resolution, ultra-high mass accuracy, ultra-high sensitivity, and quantitative capabilities comparable to high-end triple quadrupole spectrometers. The aforementioned quadrupole-electrostatic orbital trap mass spectrometer is also an open ion trap mass spectrometer.

[0052] After a stable gas is introduced through a stable gas input tube, the ion transmission tube and ionization source are used to transport the thermionic electrons generated by the collision and ionization of particulate organic matter into the orbital hydrazine mass spectrometer for detection.

[0053] In the above-mentioned device, the ionization source is an atmospheric pressure direct ionization ionization source, that is, an atmospheric pressure ionization source.

[0054] The ionization source has a discharge chamber that can be filled with a stable gas, which comes into contact with the discharge needle to form a glow discharge. The generated high-energy gas atoms or molecules, along with excited-state ions and electrons, are ejected from the ion source.

[0055] In the above-mentioned device, such as Figure 1 , 2As shown, the input end of the ionization source is connected to a stable gas input pipe.

[0056] In one specific implementation, such as Figure 1 , 2 As shown, the stable gas input pipe penetrates the housing and is connected to the input end of the ionization source via the output end of the stable gas input pipe.

[0057] In one specific embodiment, the stable gas input tube is made of carbon black or copper. Please specify the stable gas used for Penning ionization, such as helium (He), argon (Ar), or nitrogen (N2).

[0058] In the above-mentioned device, such as Figure 1 , 2 As shown, the sample loading disk includes a membrane holder, which is a flat sieve. The membrane holder has a sample position that is concave downward relative to the membrane holder. A filter membrane is disposed on the sample position. The particulate sample surface of the filter membrane is matched with the output end of the ionization source. The membrane holder is matched with the input end of the ion transmission tube.

[0059] In one specific implementation, such as Figure 1 , 2 As shown, the side of the membrane holder away from the filter membrane is matched with the input end of the ion transport tube.

[0060] The sample-loaded surface of the filter membrane is aligned with the output end of the ionization source, meaning the sample-loaded surface of the filter membrane faces the output end of the ionization source. The membrane holder is aligned with the input end of the ion transmission tube, meaning the position of the membrane holder is directly opposite the input end of the ion transmission tube; specifically, the side of the membrane holder furthest from the filter membrane is directly opposite the input end of the ion transmission tube.

[0061] In one specific embodiment, the screen on the membrane holder is a passivated copper screen. Sample positions can be provided on it for placing a filter membrane of a fixed area and for supporting the filter membrane.

[0062] In one specific embodiment, the temperature of the screen on the membrane holder is controlled between room temperature and 300°C. The room temperature is 20-30°C.

[0063] In one specific embodiment, the material of the membrane support, excluding the screen, is polytetrafluoroethylene (PTFE).

[0064] In one specific embodiment, the depth of the sample site is 1 to 2 mm.

[0065] In one specific embodiment, the sample area is equal to the surface area of ​​the filter membrane. The sample area is where the filter membrane is placed on a membrane support.

[0066] In one specific embodiment, the filter membrane is made of quartz fiber. The filter membrane collects atmospheric particulate matter and can be replaced periodically depending on observation conditions.

[0067] In the above-mentioned device, such as Figure 2 As shown, a sampling tube is also matched on the input surface of the sample loading disk. The sampling tube penetrates the shell and the output end of the sampling tube faces the input surface of the sample loading disk. The input end of the sampling tube is provided with a cutting head, and the cutting head is also connected to an atmospheric transmission tube.

[0068] In one specific implementation, such as Figure 2 As shown, the output end of the sampling tube is directly opposite the loading surface of the filter membrane, and the diameter of the sampling tube is smaller than the area of ​​the loading surface of the filter membrane.

[0069] In one specific embodiment, the output end of the sampling tube is perpendicular to the extension direction of the filter membrane's loading surface, and the vertical distance between the output end of the sampling tube and the loading surface of the filter membrane is 0.2–3 cm, preferably 0.2–2 cm. The output end of the sampling tube is perpendicular to the filter membrane and the membrane holder, and the vertical distance between the output end of the sampling tube and the loading surface of the filter membrane is adjustable. The diameter of the sampling tube is smaller than the surface area of ​​the filter membrane that receives particulate matter, and the corresponding fixing clamp of the filter membrane is located outside the ionization region.

[0070] In one specific embodiment, the sampling tube and the atmospheric transmission tube are selected from at least one of carbon black (PEAK) tubes or passivated (internal inert) copper tubes. They are used to collect atmospheric particulate matter samples, inputting particulate matter from ambient air such as exhaust gas from pollution sources and dilution gas. The sampling tube and atmospheric transmission tube may also be omitted, such as... Figure 1 As shown, TSP particles were collected directly through the sample loading disk.

[0071] In one specific embodiment, the cutting head is a conventionally used commercial cutting head for cutting atmospheric particulate matter. Specifically, the different particle size ranges of the cutting head are selected from PM2.5. 1.0 PM 2.5 PM 10 At least one of the following. That is, the cutting head has different particle size grades, and by adding cutting heads of different particle size ranges, PM can be achieved. 10 PM 2.5 PM 1.0 Collection of atmospheric samples with different particle sizes.

[0072] In one specific embodiment, the sampling tube is equipped with a T-junction. The T-junction is a conventionally used T-junction fitting, which allows for the introduction of high-purity nitrogen gas in different proportions for dilution when the concentration of the input atmospheric sample is too high or the mass spectrometry signal response exceeds the measurement range.

[0073] In the above-mentioned device, such as Figure 2 As shown, the housing is equipped with an extraction pipe that penetrates the housing and has its output end located inside the housing. An extraction pump is installed at the input end of the extraction pipe. This pump is used to control the atmospheric sampling flow rate for atmospheric sample collection.

[0074] In one specific embodiment, the exhaust pipe is made of copper.

[0075] In one specific embodiment, the pump is a conventional small to medium flow vacuum pump.

[0076] The input surface of the sample loading disk is aligned with the output end of the ionization source, meaning the input surface of the sample loading disk faces the output end of the ionization source. Similarly, the output surface of the sample loading disk is aligned with the input end of the ion transmission tube, meaning the output surface of the sample loading disk faces the input end of the ion transmission tube.

[0077] In the above-mentioned device, the system further includes a controller, which is communicatively connected to the ionization source and the orbital hydrazine mass spectrometer, respectively, and is used to send an excitation ionization command to the ionization source to drive the ionization source to perform excitation ionization, and to send a detection command to the orbital hydrazine mass spectrometer to drive the orbital hydrazine mass spectrometer to perform component detection.

[0078] In one specific embodiment, the controller is also communicatively connected to the air pump, and is used to send start or stop air pumping commands to the air pump to drive the air pump to perform air pumping or stop air pumping.

[0079] In one specific embodiment, the controller is a conventionally used controller. As those skilled in the art will understand, the controller's calculation, comparison, judgment, and instruction output processes can all be implemented using existing integrated circuit modules, programmable logic devices, other hardware, or by installing corresponding software modules. The controller is externally powered.

[0080] The second aspect of the present invention provides a high-resolution online rapid detection system for atmospheric particulate organic matter for detecting at least one component selected from polar or weakly polar organic components in atmospheric particulate matter.

[0081] A third aspect of this invention provides a method for identifying high-resolution mass spectra of atmospheric particulate organic matter, such as... Figure 3 As shown, the process includes: collecting atmospheric particulate matter samples using the aforementioned high-resolution online rapid detection system, followed by excitation and ionization; detecting the ionized sample molecules using orbital hydrazine mass spectrometry; analyzing the obtained mass spectrum data; extracting precise mass numbers to obtain the corresponding ion molecular composition and response intensity; and determining the target component and concentration in the sample molecules. For detailed detection procedures, see [link to specific procedures]. Figure 3 , 4 5.

[0082] In the above method, the atmospheric particulate matter samples are collected using the high-resolution online rapid detection system for atmospheric particulate organic matter, including any of the following:

[0083] A) When the sample is an offline collected atmospheric particulate matter sample, such as Figure 1 As shown, the filter membrane is placed directly on the sample position of the membrane holder for sampling;

[0084] B) When the sample is an online collected atmospheric particulate matter sample, such as Figure 2 As shown, the filter membrane is placed directly on the sample position of the membrane holder. Air is drawn through the air extraction tube by the air pump, and the atmospheric particulate matter sample is collected by passing through the air transmission tube, the cutting head, and the sampling tube sequentially into the filter membrane.

[0085] The aforementioned high-resolution online rapid detection system for atmospheric particulate organic matter includes a data acquisition unit, an excitation ionization source, and an orbital trap mass spectrometer. System parameters were adjusted to ensure the target analyte signal response reached a suitable range. Mass calibrators and internal standards were used to perform system mass calibration and signal response calibration.

[0086] In A), the atmospheric particulate matter sample is an offline collected ambient air or particulate matter filter membrane sample from a pollution source. Specifically, the atmospheric particulate matter sample is the aforementioned particulate matter of different sizes or TSP particles.

[0087] The mass of atmospheric particulate matter sample added can be determined based on the actual sample collected, but the filter membrane cut-off area is limited by the size of the sieve.

[0088] In section B), the atmospheric particulate matter sample can be cut with different particle sizes according to user requirements. Specifically, the atmospheric particulate matter sample is PM2.5. 10 When preparing the sample, the particle size of the cutting head used was PM. 10 The atmospheric particulate matter sample is PM2.5. 2.5 When preparing the sample, the particle size of the cutting head used was PM. 2.5 The atmospheric particulate matter sample is PM2.5. 1.0 When preparing the sample, the particle size of the cutting head used was PM. 1.0 .

[0089] In B), the loading amount of the atmospheric particulate matter sample is determined by the user, but the filter membrane size must be within the sieve range and not less than the sample site area.

[0090] In step B), when the response value of the target substance in the atmospheric particulate matter sample exceeds the maximum response range of the mass spectrometer, nitrogen is introduced through a three-way valve on the sampling tube for dilution. The ratio of nitrogen input to sampling flow rate is 1:1 to 50:1, preferably 1:1 to 20:1. When the response value of the atmospheric particulate matter sample concentration is within the maximum response range of the mass spectrometer, it is not necessary to open the nitrogen valve for dilution.

[0091] In B), the input flow rate of the atmospheric particulate matter sample is 3 to 100 mL / min.

[0092] In either A) or B), the temperature of the membrane holder in the sample loading tray is 0–30°C, preferably room temperature to 30°C. The membrane holder is electronically refrigerated and heated, allowing for control of sample loading at different temperatures according to the requirements of the target analyte. The aforementioned room temperature is 20–25°C. It can ionize target analytes ranging from low to high boiling point particulate organics to reactive organics.

[0093] In the above methods, such as Figure 4 As shown, the excitation ionization includes: after inputting a stable gas into an ionization source and discharging it, the excited-state ions, electrons or gas molecules obtained collide with the collected atmospheric particulate matter, ionize, and obtain ionized sample molecules.

[0094] In one specific embodiment, the stabilizing gas is selected from any one or a mixture of helium (He), argon (Ar), or nitrogen (N2). The purity of the stabilizing gas is at least 99.99%.

[0095] In one specific embodiment, the discharge voltage is 1–5 kV. The discharge occurs in the discharge chamber of the ionization source when a stable gas comes into contact with a corona discharge needle to form a glow discharge, generating excited-state ions, electrons, excited-state metastable helium atoms, argon atoms, or excited-state metastable nitrogen molecules in plasma.

[0096] In a preferred embodiment, during the excitation of the discharge, the excited-state ions, electrons, or gas molecules are selected from at least one of excited-state metastable helium atoms (He*, 19.8 eV), excited-state metastable argon atoms (Ar*, 11.5 eV), and excited-state metastable nitrogen molecules (N2*, 8.5–11.5 eV). The higher energy states of the aforementioned excited-state ions, electrons, or gas molecules are greater than 11.5 eV. Most organic compounds have an ionization energy of around 10 eV. Using the aforementioned reactive gases allows for the ionization of organic molecules without generating excessive fragment ions, i.e., high-energy gas atoms or molecules.

[0097] In one specific embodiment, the ionization source in the excited ionization can be selected as either a positive ion mode or a negative ion mode. Hot electrons are generated through Penning ionization, achieving proton transfer and charge transfer.

[0098] In one specific embodiment, the distance between the tip of the ionization source probe and the filter membrane on which the atmospheric particulate matter sample is placed is 1–10 cm; the angle between the ionization source probe and the input surface of the sample loading disk on which the atmospheric particulate matter sample is placed is 30°–90°; the distance between the tip of the ionization source probe and the inlet of the mass analyzer for the orbital hydrazine mass spectrometer is 1–10 cm; and the angle between the ionization source probe and the inlet of the mass analyzer for the orbital hydrazine mass spectrometer is 30°–180°. The above-mentioned distances and angles are systematically adjusted based on the sample concentration and the intensity of the mass spectrometry response signal, i.e., manually adjusted based on the intensity of the mass spectrometry response signal during previous tests.

[0099] In a preferred embodiment, the voltage of the probe of the ionization source is 250–500V.

[0100] In the above method, the ionized sample molecules are input into the orbital hydrazine mass spectrometer via an ion transmission tube.

[0101] Atmospheric particulate matter samples collected on the filter membrane are ionized by bombardment with an open ionization source. The ionized sample molecules are then introduced into the ion transmission tube by the pressure difference caused by the vacuum at the ion transmission tube of the orbital hydrazine mass spectrometer. Under the pressure of the primary vacuum, the ions then enter the orbital hydrazine mass spectrometer for mass spectrometry scanning and detection.

[0102] In one specific embodiment, the carrier gas for the ionized sample molecules input into the ion transmission tube is an inert gas. Specifically, the carrier gas is selected from any one or more combinations of nitrogen, helium, or nitrogen, preferably from any one of nitrogen, helium, a mixture of nitrogen and nitrogen, or a mixture of helium and nitrogen. All of the aforementioned nitrogen, helium, or nitrogen are high-purity gases (purity greater than 99.999%).

[0103] In one specific embodiment, the pressure difference between the ionized sample molecules and the input ion transmission tube is 1 to 2 mbar (0.1 to 0.2 kPa).

[0104] In the above method, the measurement conditions for the orbital hydrazine mass spectrometry include: the intensity of the mass spectrometry response signal is 10E. 5 ~10E 9 The time resolution is 1–10 s (based on the integration of the signal response); the carrier gas flow rate is 0.2–2.5 L / min; a DC voltage of 100–300 V is applied to the electrodes; the plasma is argon or helium plasma; the plasma is generated by atmospheric pressure antiglow discharge, and the total power of the discharge is maintained below 4 W; under operating conditions of 2–20 mA, the temperature of the argon plasma gas is 40–100 °C, and the temperature of the helium plasma gas is 20–80 °C.

[0105] In the above-mentioned measurement conditions for orbital hydrazine mass spectrometry, the ionization conditions are optimized by adjusting the current and gas flow rate.

[0106] In one specific embodiment, the determination conditions for the orbital hydrazine mass spectrometry further include: the ion source is an ESI source; and the detection mode is positive ion electrospray ionization mode (ESI). + Or negative ion electrospray ionization mode ESI - Spray voltage: 2.0–4.0 kV; ion source temperature: 310–330 °C; sheath gas flow rate: 30–40 units; auxiliary gas flow rate: 5–15 units; purge gas flow rate: 0 units; scanning mode: full-spectrum MS or secondary mass spectrometry ddMS. 2 In full-spectrum scanning, the scanning range is 50–2000 amu; the mass resolution is ≥70000; in secondary mass spectrometry scanning, the voltage is selected from any one or more combinations of 20 eV, 40 eV, or 60 eV.

[0107] In one specific embodiment, during the orbital hydrazine mass spectrometry determination, a mass calibration solution is used to calibrate the mass axis in both positive and negative scan modes of the mass spectrometer. The mass calibration solution is a commercially available, commonly used mass calibration solution, specifically Thermo Scientific Pierce FlexMix calibration solution such as A39239 Pierce. TM FlexMix TM Calibration solution (a mixture of 16 high-purity, ionizable components, with a mass range of m / z: 50–3000).

[0108] In a preferred embodiment, the m / z mass range of the calibration solution is 74–1922. This ensures that the accuracy error of the mass of each substance after calibration is within 2 ppm.

[0109] In the above methods, such as Figure 5 As shown, when analyzing the mass spectrometry data, the mass spectrometry data is matched with data in the spectral library for similarity. If the similarity is ≥0.75, the target analyte in the sample is determined. A similarity of ≥0.75 is sufficient to classify a compound as a target compound.

[0110] In one specific embodiment, the spectral library can refer to online spectral libraries such as mzCloud, commercial spectral libraries, or self-built spectral libraries. Alternatively, it can be selected based on the deviation between the precise mass of the compound and the theoretical value. The criteria for judgment can be selected according to the research needs, with the deviation between the precise mass of the target analyte and the theoretical value being within 5 to 20 ppm.

[0111] In one specific implementation, such as Figure 5As shown, the mass spectrometry data was analyzed using the standard analysis process for mass spectrometry data in orbital hydrazine mass spectrometry. Specifically, the random forest (RF) algorithm was used to automatically identify noise and signal peaks in the mass spectrum. Then, after extracting the precise mass-to-charge ratio (m / z) of the ions, peak detection, peak matching, peak integration, and molecular formula calculation were performed to establish the primary and secondary functional group mass spectra of the target analyte. Based on the precise mass number measured by mass spectrometry, similarity matching was performed with data in the spectral library under the control of the workstation. Simultaneously, the deviation between the measured and theoretical molecular formula values ​​(<5 ppm) was calculated, and isotope detection was performed to determine the target analyte composition in the sample. All the aforementioned mass spectrometry peaks exhibited a normal Gaussian shape.

[0112] In a preferred embodiment, the workstation uses Tracer Finder, Orbitool, or MZmine software. The workstation is used for viewing mass spectra, confirming molecular formula composition, screening substances, qualitative screening and integration of large datasets of target compounds in the sample.

[0113] The above-mentioned full-spectrum scan or secondary mass spectrometry scan can obtain the mass spectrum of all components within the set mass range in a single scan. Based on the precise mass number measured by mass spectrometry, the mass spectrum can be viewed, the molecular formula composition can be confirmed and the substance can be screened in the instrument's accompanying software Tracer Finder, or other software such as Orbitool can be used for online qualitative screening and integration of the compound and processing of long-term sequence spectra.

[0114] In one specific implementation, after determining the target analyte in the sample, principal component analysis (PCA) is performed on the results of different samples from the same batch or similar samples from different batches. Multi-sample peak detection and peak identification are then performed with cloud data and spectral libraries to obtain the sample detection results and multi-sample data clustering analysis results.

[0115] During the above-mentioned Orbitrap mass spectrometry detection, once the atmospheric sample flow rate is stabilized, the sample can be continuously analyzed. The scanning settings of the Orbitrap mass spectrometer, as well as the instrument parameters such as the ion source and gas flow rate, can be adjusted by adjusting the distance and angle of the identified target substances in the same sample collected offline on the quartz filter membrane, based on previous offline analysis. They can also be adjusted based on the abundance values ​​of common substances in the atmosphere from the real-time response signal of the mass spectrometer.

[0116] In the above method, after sample detection, sampling and mass spectrometry acquisition are stopped, the high-resolution online rapid detection system for atmospheric particulate organic matter is inspected and cleaned, the filter membrane is replaced, the membrane holder is cleaned, and the ion transmission tube is cleaned or replaced, etc., and then online sampling and mass spectrometry detection can continue.

[0117] A fourth aspect of this invention provides a rapid detection method for nitrophenol and nitrobenzoic acid components in atmospheric particulate organic matter, comprising the following steps:

[0118] 1) The atmospheric particulate matter sample was subjected to the same steps as the above-mentioned high-resolution mass spectrometry identification method for atmospheric particulate organic matter to obtain ionized sample molecules.

[0119] 2) Using the same steps as the above-mentioned high-resolution mass spectrometry identification method for atmospheric particulate organic matter, the standards of 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dimethyl-4-nitrophenol, 2,4-dinitrophenol, 4-nitroguaiacol, 4-methyl-5-nitrocatechol, 2,6-dinitro-4-methylphenol, 1,2-dihydroxy-4-nitrobenzene, 5-nitrosalicylic acid, and 3-hydroxy-4-nitrobenzoic acid are used to obtain ionized standard molecular ions;

[0120] 3) Using the same steps as the above-mentioned high-resolution mass spectrometry method for identifying atmospheric particulate organic matter, the ionized sample molecules obtained in step 1) and the ionized standard molecular ions obtained in step 2) are used to determine the target components in the sample, and the content of the target components in the sample is calculated by the external standard method based on the determination results of the standard molecular ions.

[0121] In step 2), the concentrations of 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dimethyl-4-nitrophenol, 2,4-dinitrophenol (also known as 2,4-dinitrophenol), 4-nitroguaiacol, 4-methyl-5-nitrocatechol, 2,6-dinitro-4-methylphenol (also known as 2,6-dinitro-p-cresol), 1,2-dihydroxy-4-nitrobenzene (also known as 4-nitrocatechol), 5-nitrosalicylic acid, and 3-hydroxy-4-nitrobenzoic acid are 10-1000 mg / L.

[0122] The above-mentioned standards for 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dimethyl-4-nitrophenol, 2,4-dinitrophenol, 4-nitroguaiacol, 4-methyl-5-nitrocatechol, 2,6-dinitro-4-methylphenol, 1,2-dihydroxy-4-nitrobenzene, 5-nitrosalicylic acid, and 3-hydroxy-4-nitrobenzoic acid are all commonly used standards and can be purchased from the market.

[0123] In step 2), the above-mentioned standard is also subjected to the same mass-to-charge ratio m / z peak detection, peak matching, peak integration and molecular formula calculation of the target molecule. At the same time, based on the mass spectra of the primary and secondary functional groups of the target molecule, the target quantitative ion is accurately identified by comparing with self-built spectral libraries and online spectral libraries such as mzCloud, or commercial spectral libraries, so as to achieve rapid interpretation of mass spectra.

[0124] In step 3), the external standard method includes: taking a series of different volumes of nitrophenol and nitrobenzoic acid standards to prepare a series of standard solutions with different concentration gradients; analyzing these solutions using the same steps as the high-resolution mass spectrometry method for identifying atmospheric particulate organic matter described above; obtaining the linear relationship between the concentration of each nitrophenol and nitrobenzoic acid component in the standard solution and the mass spectrometry peak area; plotting a corresponding standard working curve with the mass spectrometry peak area corresponding to its corresponding concentration; and calculating the regression equation of the standard working curve. Then, the atmospheric particulate matter sample is analyzed using the same steps as the high-resolution mass spectrometry method for identifying atmospheric particulate organic matter described above. The obtained mass spectrometry peak areas of the target components in the sample molecules are substituted into the regression equation of the standard working curve to obtain the concentration of the corresponding target components in the sample molecules.

[0125] The above detection method, through the design of an open-type ionization mass spectrometer, enables real-time, in-situ, and rapid analysis of organic compounds in samples in open environments. It features stable performance, rapid ionization, and direct sample injection. Standard samples or alternative standards, such as nitrophenols, are prepared as gradient standard solutions and added to blank filter samples at the corresponding open-type ionization mass spectrometer excitation sites. The excitation voltage is adjusted according to the mass spectrometric response to ensure the linear concentration response value of the standard curve is within the instrument's allowable range. Specifically, based on the characteristic ions of nitrophenols and nitrobenzoic acids in organic compounds, the precise mass numbers are extracted from the full-scan mass spectrometry spectrum of atmospheric particulate samples to obtain the corresponding ion molecular composition and response intensity, thus determining the target molecule components and concentrations in the sample molecules. Since this method does not involve liquid chromatography separation, it only calculates the total concentration for isomers and cannot distinguish them. When individual substance content detection is required, traditional liquid chromatography-mass spectrometry methods can be used for separation and identification. The mass spectrometry concentrations and information obtained by this method can be cross-checked with those obtained by liquid chromatography-mass spectrometry.

[0126] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0127] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0128] Example 1

[0129] 1. Collection

[0130] like Figure 1 As shown, a quartz filter membrane with a surface area equal to that of the sample was cut and placed directly on the membrane holder to collect atmospheric particulate matter samples. The temperature of the membrane holder was room temperature.

[0131] 2. Excitation ionization

[0132] Turn on the ionization source switch, and introduce helium gas (99.99% purity) as a stabilizing gas into the ionization source via the stable gas input tube for excitation. The helium gas enters the discharge chamber and contacts the 3.5kV discharge needle to form a glow discharge, producing high-energy helium atoms (He*, 19.8 eV). The obtained excited-state ions, electrons, and gas atoms collide with particulate matter in the collected sample, causing ionization and obtaining ionized target molecules. The distance between the ionization source probe tip and the filter membrane containing the atmospheric particulate matter sample is 5 cm; the angle between the ionization source probe and the input surface of the sample loading disk containing the atmospheric particulate matter sample is 60°; the distance between the ionization source probe tip and the mass analyzer inlet of the orbital hydrazine mass spectrometer is 5 cm; and the angle between the ionization source probe and the mass analyzer inlet of the orbital hydrazine mass spectrometer is 120°. The voltage of the electrocautery needle is 300V, and the ion source can be selected in negative mode during excitation ionization.

[0133] 3. Testing

[0134] The ionized target molecules are introduced into the ion transmission tube by the pressure difference caused by the vacuum at the ion transmission tube of the orbital hydrazine mass spectrometer, and then input into the orbital hydrazine mass spectrometer for detection. The obtained mass spectrum data is analyzed, and the corresponding ion molecular composition and response intensity are obtained by extracting the precise mass number, thereby determining the target component and concentration in the sample molecules.

[0135] The pressure difference between the ionized target molecules and the input ion transport tube is 1 mbar. High-purity helium is used as the carrier gas. The measurement conditions for orbital hydrazine mass spectrometry include: a mass spectrometry response signal intensity of 10 E. 7The time resolution is 1 s (based on the integration of the signal response); the carrier gas flow rate is 1.0 L / min; a DC voltage of 200 volts is applied to the electrodes; the plasma is argon plasma; the plasma is generated by atmospheric pressure antiglow discharge, and the total power of the discharge is maintained below 4 W; under the working condition of 10 mA, the temperature of the argon plasma gas is 40–100 °C.

[0136] The determination conditions for orbital hydrazine mass spectrometry also include: an ESI ion source; and a negative ion electrospray ionization (ESI) detection mode. - The spray voltage was 3.0 kV; the ion source temperature was 320 °C; the sheath gas flow rate was 35 units; the auxiliary gas flow rate was 10 units; the purge gas flow rate was 0 units; the scanning mode was full-spectrum MS; in full-spectrum MS, the scanning range was 90–600 amu; the mass resolution at m / z 200 was 140,000. For orbital hydrazine mass spectrometry, the mass axis was calibrated in both positive and negative scanning modes using a Thermo Scientific Pierce FlexMix calibration solution, such as Pierce A39239. TM FlexMix TM Calibration solution. The m / z mass range of the mass calibration solution is 74–1922.

[0137] When analyzing mass spectrometry (MS) data, the MS data is matched with data in the spectral library for similarity. A similarity score of 0.80 ensures that the deviation between the precise mass number of the target analyte and the theoretical value is within 10 ppm, thus identifying the target analyte component in the sample. The spectral library used in the orbital hydrazine mass spectrometry search is mzCloud. The standard analysis process for MS data from orbital hydrazine mass spectrometry is employed, using a random forest (RF) algorithm to automatically identify noise and signal peaks in the mass spectrum. Then, after extracting the precise mass-to-charge ratio (m / z) of quantitative ions, peak detection, peak matching, peak integration, and molecular formula calculation are performed to establish the primary and secondary functional group mass spectra of the target analyte. Based on the precise mass number measured by mass spectrometry, similarity matching is performed with data in the spectral library using TracerFinder software as the workstation. Simultaneously, the deviation between the measured and theoretical molecular formula values ​​(<5 ppm) and isotope detection are performed to determine the target analyte component in the sample. All the aforementioned mass spectrometry peaks exhibited a normal Gaussian shape. After determining the target analyte composition in the sample, principal component analysis (PCA) is performed on the results of different samples from the same batch or similar samples from different batches. This is then combined with cloud data and spectral libraries for multi-sample peak detection and identification, thereby obtaining the sample detection results and multi-sample data clustering analysis results. The aforementioned ionization source, orbital hydrazine mass spectrometry, etc., are all under the control of the controller.

[0138] Example 2

[0139] 1. Collection

[0140] like Figure 2 As shown, a quartz filter membrane of equal size to the sample surface area was cut and placed directly on the membrane holder. Air was drawn in through the suction tube using a vacuum pump, and the atmospheric particulate matter sample was introduced into the filter membrane at a rate of 50 mL / min via the atmospheric transfer tube, cutting head, and sampling tube. The membrane holder was kept at room temperature, and the atmospheric particulate matter sample was PM2.5. 10 The particle size of the atmospheric particulate matter cutting head used at that time was PM 10 When the response value of the target substance in the atmospheric particulate matter sample exceeds the highest response range of the mass spectrometer, nitrogen gas is introduced through a three-way valve on the sampling tube for dilution. The nitrogen input flow rate can be adjusted by a flow valve, and the ratio of nitrogen input to sampling flow rate is 10:1.

[0141] 2. Excitation ionization

[0142] Turn on the ionization source switch, and introduce argon (Ar) gas as a stable gas for excitation through the stable gas input tube. The purity of the Ar gas input is 99.99%. The Ar gas enters the discharge chamber and contacts the 4kV discharge needle to form a glow discharge, producing excited-state metastable argon atoms (Ar*, 11.5 eV). The obtained excited-state ions, electrons, and gas atoms collide with particulate matter in the collected sample, causing ionization and obtaining ionized target molecules. The distance between the tip of the ionization source probe and the filter membrane containing the atmospheric particulate matter sample is 8 cm; the angle between the ionization source probe and the input surface of the sample loading disk containing the atmospheric particulate matter sample is 50°; the distance between the tip of the ionization source probe and the inlet of the orbital hydrazine mass spectrometer is 8 cm; and the angle between the ionization source probe and the inlet of the orbital hydrazine mass spectrometer is 90°. The voltage of the electrocautery needle is 400V, and the ion source can be selected in positive mode during excitation ionization.

[0143] 3. Testing

[0144] The ionized target molecules are introduced into the ion transmission tube by the pressure difference caused by the vacuum at the ion transmission tube of the orbital hydrazine mass spectrometer, and then input into the orbital hydrazine mass spectrometer for detection. The obtained mass spectrum data is analyzed, and the corresponding ion molecular composition and response intensity are obtained by extracting the precise mass number, thereby determining the target component and concentration in the sample molecules.

[0145] The pressure difference between the ionized target molecules and the input ion transport tube is 2 mbar. The carrier gas is high-purity nitrogen. The measurement conditions for the orbital hydrazine mass spectrometry include: a mass spectrometry response signal intensity of 10E. 8The time resolution is 5 s (based on the integration of the signal response); the carrier gas flow rate is 2.0 L / min; a DC voltage of 150 volts is applied to the electrodes; the plasma is helium plasma; the plasma is generated by atmospheric pressure antiglow discharge, and the total power of the discharge is maintained below 4 W; under the working condition of 15 mA, the temperature of the helium plasma gas is 20–80 °C.

[0146] The determination conditions for orbital hydrazine mass spectrometry also include: an ESI ion source; and a positive ion electrospray ionization (ESI) detection mode. + The spray voltage was 3.0 kV; the ion source temperature was 320 °C; the sheath gas flow rate was 35 units; the auxiliary gas flow rate was 10 units; the purge gas flow rate was 0 units; and the scanning mode was secondary mass spectrometry (ddMS). 2 Secondary mass spectrometry (ddMS) 2 In the mass spectrometry analysis, the voltages were 20 eV, 40 eV, and 60 eV. During the orbital hydrazine mass spectrometry determination, the mass axis was calibrated using a mass calibration solution in both positive and negative scan modes. The mass calibration solution was Thermo Scientific Pierce FlexMix calibration solution, such as A39239 Pierce. TM FlexMix TM Calibration solution. The m / z mass range of the mass calibration solution is 74–1922.

[0147] When analyzing mass spectrometry (MS) data, the MS data is matched with data in the spectral library for similarity. A similarity score of 0.75 ensures that the deviation between the precise mass number of the target analyte and the theoretical value is within 8 ppm, thus identifying the target analyte component in the sample. The spectral library used in the orbital hydrazine mass spectrometry search is mzCloud. The MS data analysis follows the standard process for mass spectrometry data analysis in orbital hydrazine mass spectrometry, employing a random forest (RF) algorithm for automatic identification of noise and signal peaks in the mass spectrum. Then, after extracting the precise mass-to-charge ratio (m / z) of quantitative ions, peak detection, peak matching, peak integration, and molecular formula calculation are performed to establish the primary and secondary functional group mass spectra of the target analyte component. Based on the precise mass number measured by mass spectrometry, similarity matching is performed with data in the spectral library using Orbitool software as the workstation. Simultaneously, the deviation between the measured and theoretical molecular formula values ​​(<5 ppm) and isotope detection are performed to determine the target analyte component in the sample. All the aforementioned mass spectrometry peaks exhibit a normal Gaussian shape. After determining the target analyte composition in the sample, principal component analysis (PCA) is performed on the results of different samples from the same batch or similar samples from different batches. This is then combined with cloud data and spectral libraries for multi-sample peak detection and identification, thereby obtaining the sample detection results and multi-sample data clustering analysis results. The aforementioned ionization source, orbital hydrazine mass spectrometry, etc., are all under the control of the controller.

[0148] Example 3

[0149] The atmospheric particulate matter sample was subjected to the same steps as in Example 1 to obtain ionized sample molecules.

[0150] A standard curve was prepared using standards of 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dimethyl-4-nitrophenol, 2,4-dinitrophenol, 4-nitroguaiacol, 4-methyl-5-nitrocatechol, 2,6-dinitro-4-methylphenol, 1,2-dihydroxy-4-nitrobenzene, 5-nitrosalicylic acid, and 3-hydroxy-4-nitrobenzoic acid at concentration gradients of 10, 50, 100, 500, and 1000 mg / L for analysis. The same steps as in Example 1 were used to obtain a series of ionized standard molecular ions.

[0151] The sample molecules to be ionized and the standard molecular ions to be ionized are used in the same steps as in Example 1 to determine the target component in the sample, and the content of the target component in the sample is calculated by external standard method based on the determination results of the standard molecular ions.

[0152] Specifically, a series of different volumes of nitrophenol and nitrobenzoic acid standards were transferred to prepare a series of standard solutions with different concentration gradients. These solutions were analyzed using the same steps as in Example 1 to obtain the linear relationship between the concentration of each nitrophenol and nitrobenzoic acid component in the standard solutions and the mass spectrometry peak area. A corresponding standard working curve was plotted, with the mass spectrometry peak area corresponding to its concentration, and the regression equation for the standard working curve was calculated. Then, atmospheric particulate matter samples were analyzed using the same steps as in Example 1. The mass spectrometry peak areas of the target components in the samples were substituted into the regression equation of the standard working curve to obtain the concentration of the corresponding target components in the samples.

[0153] The limits of detection (LOD), limits of quantitation (LOQ), relative standard deviations (RSD%), and linear correlations (R) of the detection methods for 11 nitrophenols and nitrobenzoic acids in the samples were analyzed. 2 The results are shown in Table 1. Meanwhile, the mass spectra of 11 nitrophenols and nitrobenzoic acids are shown in [Table 1]. Figure 6a2 , 6b2 6b3, 6c2, 6d2, 6e2, 6e3, 6f2, 6g2, 6h2, 6h3. From Table 1 and... Figure 6a2 , 6b2 As can be seen from 6b3, 6c2, 6d2, 6e2, 6e3, 6f2, 6g2, 6h2, and 6h3, this method can effectively perform quantitative and qualitative analysis on 11 nitrophenols and nitrobenzoic acids in atmospheric particulate matter.

[0154] Table 1

[0155]

[0156] Note: RSD is defined as 10 ng / mL. -1 The relative standard deviation obtained from seven repeated injections of the standard solution, the limit of detection (LOD), and the limit of quantitation (LOQ) are defined as 1 ng·mL⁻¹. -1 3 times and 10 times the standard deviation of the standard solution signal.

[0157] Example 4

[0158] Eleven nitrophenols and nitrobenzoic acids were determined using the existing high-performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS) method. The samples were pretreated offline before being analyzed by UPLC-HRMS. The results are shown in Figure 6. Figure 6a1 , 6b1 From 6c1, 6d1, 6e1, 6f1, 6g1, and 6h1, it can be seen that the existing method can separate and detect 11 nitrophenols and nitrobenzoic acid derivatives. Meanwhile, from... Figure 6a2 , 6b2 As can be seen from 6b3, 6c2, 6d2, 6e2, 6e3, 6f2, 6g2, 6h2, and 6h3, comparing the mass spectrometry concentrations and information obtained by the existing method with those obtained by the detection method in Example 3 reveals that the precise mass numbers and other information of the components obtained by both methods are completely consistent, thus verifying the accuracy of this method. This method is suitable for rapid detection because it can be performed online from sample injection to direct mass spectrometry detection. Compared with the existing method, which requires offline sample pretreatment before UPLC-HRMS determination, the detection speed is significantly faster. However, since this method does not involve liquid chromatography separation, it only calculates the total concentration for isomers and cannot distinguish them. When it is necessary to detect the content of individual substances, traditional liquid chromatography-mass spectrometry methods can be used for separation and identification.

[0159] In summary, the high-resolution online rapid detection system and high-resolution mass spectrometry method for atmospheric particulate organic matter provided by this invention are easy to control, have a fast response, high sensitivity, and high mass resolution, enabling automatic online observation, molecular ion analysis, and screening of atmospheric particulate organic matter. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value. This method can also be referenced for the detection of cyclohexane residues using headspace gas chromatography.

[0160] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A high-resolution online rapid detection system for atmospheric particulate organic matter, characterized in that, It includes a shell (5), on which an ion transport tube (2) is provided. The shell (5) is hollow and the ion transport tube (2) passes through the shell (5). An ionization source (1) and a sample loading disk (4) are provided inside the shell (5). The input surface of the sample loading disk (4) is matched with the output end of the ionization source (1), and the output surface of the sample loading disk (4) is matched with the input end of the ion transport tube (2). The output end of the ion transport tube (2) is connected to an orbital trap mass spectrometer (3). The sample loading tray (4) includes a membrane holder (41), which is a flat sieve. The membrane holder (41) has a sample position (42) that is concave downward relative to the membrane holder (41). A filter membrane (43) is provided on the sample position (42). The particulate sample surface of the filter membrane (43) is matched with the output end of the ionization source (1). The membrane holder (41) is matched with the input end of the ion transport tube (2). The sample loading disk (4) is also matched with a sampling tube (7), which penetrates the shell (5) and the output end of the sampling tube (7) is facing the input surface of the sample loading disk (4). The input end of the sampling tube (7) is provided with a cutting head (6), and the cutting head (6) is also connected to an atmospheric transmission tube (11). The housing is provided with an air extraction pipe (8), which penetrates the housing (5) and the output end of the air extraction pipe (8) is located inside the housing (5). An air pump (9) is provided on the input end of the air extraction pipe (8). The side of the membrane holder (41) away from the filter membrane (43) is matched with the input end of the ion transport tube (2); The output end of the sampling tube (7) is directly opposite the loading surface of the filter membrane (43), and the diameter of the sampling tube (7) is smaller than the area of ​​the loading surface of the filter membrane (43). The output end of the sampling tube (7) is perpendicular to the extension direction of the loading surface of the filter membrane (43), and the vertical distance between the output end of the sampling tube (7) and the loading surface of the filter membrane (43) is 0.2~3cm. The detection system collects atmospheric particulate matter samples. When the sample is an offline atmospheric particulate matter sample, the filter membrane is placed directly on the sample position of the membrane holder for collection. When the sample is an online atmospheric particulate matter sample, the filter membrane is placed directly on the sample position of the membrane holder, and air is drawn through the air extraction pipe by the air extraction pump. The atmospheric particulate matter sample is then input into the filter membrane through the atmospheric transmission pipe, the cutting head, and the sampling tube for collection.

2. The high-resolution online rapid detection system for atmospheric particulate organic matter according to claim 1, characterized in that, Includes one or more of the following conditions: A1) The shell (5) is rectangular in shape and at least one observation window is provided on the four side walls of the shell (5); A2) The output end of the ion transmission tube (2) is connected to the gas inlet of the orbital trap mass spectrometer (3); A3) The input end of the ionization source (1) is connected to a stable gas input pipe (10). A4) The depth of the sample position (42) is 1~2mm; A5) The sample site (42) has the same surface area as the filter membrane (43); A6) The sampling tube (7) is equipped with a three-way valve.

3. The high-resolution online rapid detection system for atmospheric particulate organic matter according to claim 2, characterized in that, Includes one or more of the following conditions: B1) In item A1), observation windows are provided on all four side walls of the housing (5); B2) In item A3), the stable gas input pipe (10) passes through the housing (5) and is connected to the input end of the ionization source (1) at the output end of the stable gas input pipe (10).

4. The use of the high-resolution online rapid detection system for atmospheric particulate organic matter according to any one of claims 1-3 in detecting at least one component selected from polar or weakly polar organic components in atmospheric particulate matter.

5. A method for identifying atmospheric particulate organic matter using high-resolution mass spectra, comprising: The atmospheric particulate organic matter high-resolution online rapid detection system according to any one of claims 1-3 is used to collect atmospheric particulate matter samples and then excite and ionize them. The ionized sample molecules are detected by orbital trap mass spectrometry. The obtained mass spectrum data is analyzed, and the corresponding ion molecular composition and response intensity are obtained by extracting the precise mass number, thereby determining the target component and concentration in the sample molecules.

6. The method for identifying high-resolution mass spectrometry patterns of atmospheric particulate organic matter according to claim 5, characterized in that, Includes one or more of the following conditions C1 to C5: C1) Atmospheric particulate matter samples are collected using the high-resolution online rapid detection system for atmospheric particulate organic matter according to any one of claims 1-3, including any one of the following A and B: A) When the sample is an atmospheric particulate matter sample collected offline, place the filter membrane directly on the sample position of the membrane holder for collection; B) When the sample is an online atmospheric particulate matter sample, place the filter membrane directly on the sample position of the membrane holder, use an air pump to draw air through the air extraction tube, and input the atmospheric particulate matter sample into the filter membrane through the air transmission tube, cutting head, and sampling tube for collection. C2) The excitation ionization includes: after inputting a stable gas into an ionization source and discharging it, the excited-state ions, electrons or gas molecules obtained collide with the collected atmospheric particulate matter, ionize, and obtain ionized sample molecules; C3) The ionized sample molecules are input into the orbital trap mass spectrometer via an ion transfer tube; C4) The measurement conditions for the orbital trap mass spectrometry include: the intensity of the mass spectrometry response signal is 10E. 5 ~10E 9 The time resolution is 1~10s; the carrier gas flow rate is 0.2~2.5 L / min; a DC voltage of 100~300V is applied to the electrodes; the plasma is argon or helium plasma; the plasma is generated by atmospheric pressure antiglow discharge, and the total power of the discharge is maintained below 4W; under the working conditions of 2~20mA, the temperature of argon plasma is 40~100℃, and the temperature of helium plasma is 20~80℃. When analyzing the mass spectrometry data described in C5), the mass spectrometry data is matched with the data in the spectral library for similarity. If the similarity is ≥0.75, the target analyte in the sample is determined.

7. The method for identifying high-resolution mass spectra of atmospheric particulate organic matter according to claim 6, characterized in that, Includes one or more of the following conditions: D1) In section B) of C1), the different particle size ranges of the cutting head are selected from PM. 1.0 PM 2.5 PM 10 At least one of them; D2) In section B of item C1), when the response value of the target substance in the atmospheric particulate matter sample exceeds the highest response range of the mass spectrometer, nitrogen is introduced through the three-way valve on the sampling tube for dilution. The ratio of nitrogen input to sampling flow rate is 1:1 to 50:

1. D3) In section B of item C1), the input flow rate of the atmospheric particulate matter sample is 3~100 mL / min; D4) In item C1) A) or B), the temperature of the film holder of the sample loading disk is 0~300℃; D5) In item C2), the stable gas is selected from at least one of helium (He), argon (Ar), or nitrogen (N2); D6) In item C2), the discharge voltage is 1~5kV; D7) In item C2), the ionization source in the excitation ionization can be selected as either positive ion mode or negative ion mode; D8) In item C2), the distance between the tip of the ionization source probe and the filter membrane on which the atmospheric particulate matter sample is placed is 1~10cm; the angle between the ionization source probe and the input surface of the sample loading disk on which the atmospheric particulate matter sample is placed is 30°~90°; the distance between the tip of the ionization source probe and the mass analyzer inlet of the orbital trap mass spectrometer is 1~10cm; and the angle between the ionization source probe and the mass analyzer inlet of the orbital trap mass spectrometer is 30°~180°. D9) In item C3), the carrier gas for the ionized sample molecules input into the ion transmission tube is an inert gas; In item D10) of C3), the pressure difference between the ionized sample molecules and the input ion transport tube is 1~2 mbar. In item C4) of D11), during the orbital trap mass spectrometry measurement, the mass axis is calibrated in the positive and negative scanning modes of the mass spectrometer using a mass calibration solution, and the mass calibration solution is Thermo Scientific Pierce FlexMix calibration solution.

8. The method for identifying high-resolution mass spectra of atmospheric particulate organic matter according to claim 7, characterized in that, Includes one or more of the following conditions: E1) In item D6), when the discharge is excited, the excited-state ions, electrons or gas molecules are selected from at least one of excited-state metastable helium atoms, excited-state metastable argon atoms, and excited-state metastable nitrogen molecules; E2) In item D8), the voltage of the probe of the ionization source is 250~500V; E3) In item D11), the m / z mass range of the mass calibration solution is 74~1922; E4) In item D4), the temperature of the film holder of the sample loading disk is room temperature to 300°C.

9. A rapid detection method for nitrophenol and nitrobenzoic acid components in atmospheric particulate organic matter, comprising the following steps: 1) The atmospheric particulate matter sample is subjected to the same steps as the high-resolution mass spectrometry method for identifying atmospheric particulate organic matter according to any one of claims 5-8 to obtain ionized sample molecules; 2) Using the same steps as the high-resolution mass spectrometry method for identifying atmospheric particulate organic matter according to any one of claims 5-8, ionized standard molecular ions are obtained from 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dimethyl-4-nitrophenol, 2,4-dinitrophenol, 4-nitroguaiacol, 4-methyl-5-nitrocatechol, 2,6-dinitro-4-methylphenol, 1,2-dihydroxy-4-nitrobenzene, 5-nitrosalicylic acid, and 3-hydroxy-4-nitrobenzoic acid standards. 3) Using the ionized sample molecules obtained in step 1) and the ionized standard molecular ions obtained in step 2), the same steps as the high-resolution mass spectrometry method for identifying atmospheric particulate organic matter according to any one of claims 5-8 are used to determine the target component in the sample, and the content of the target component in the sample is calculated by the external standard method based on the determination results of the standard molecular ions.

10. The rapid detection method for nitrophenol and nitrobenzoic acid components in atmospheric particulate organic matter according to claim 9, characterized in that, In step 2), the concentrations of 4-nitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, 2,6-dimethyl-4-nitrophenol, 2,4-dinitrophenol, 4-nitroguaiacol, 4-methyl-5-nitrocatechol, 2,6-dinitro-4-methylphenol, 1,2-dihydroxy-4-nitrobenzene, 5-nitrosalicylic acid, and 3-hydroxy-4-nitrobenzoic acid are 10-1000 mg / L.

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