Online pretreatment device and analysis method for atmospheric particulate samples

Abstract

This disclosure provides an online pretreatment device and analytical method for atmospheric particulate matter samples, involving an analytical method for simultaneous online pretreatment and detection of nonpolar and weakly polar organic compounds. The device includes: a first delivery line, a derivatization reagent container, a second delivery line, a thermal desorption tube assembly, a first automatic delivery mechanism, and a control unit. The first delivery line leads to a solvent container. A carrier gas carrying saturated vapor of the derivatization reagent passes through the derivatization reagent container. The thermal desorption tube assembly cavity is then fed into a heating chamber, and the saturated vapor of the derivatization reagent enters the tube cavity. In the tube cavity, weakly polar organic compounds (POCs) in the atmospheric particulate matter sample react rapidly with the saturated vapor of the derivatization reagent under heating for rapid derivatization, followed by chromatographic separation and mass spectrometric analysis together with nonpolar organic compounds (NPOCs). This disclosure achieves automated pretreatment of atmospheric particulate matter samples, enabling simultaneous analysis of nonpolar and weakly polar organic compounds in a single automated pretreatment process, reducing solvent usage, and improving instrument operation and personnel efficiency.

Description

Technical Field

[0001] This disclosure relates to the field of environmental monitoring technology, and in particular to an online pretreatment device and analysis method for atmospheric particulate matter samples. Background Technology

[0002] Semi-volatile organic compounds in the atmosphere exhibit different polarities based on their molecular structures and can be classified into polar and nonpolar organic compounds. Compounds with boiling points below 350℃, molecular weights less than 400, and good thermal stability are suitable for gas chromatography / mass spectrometry (GC-MS) analysis. Polar organic compounds include those containing highly polar functional groups such as hydroxyl, amino, and carboxyl groups, or weakly polar targets with poor thermal stability, such as organic acids, monosaccharides, polysaccharides, and alcohols. Weakly polar groups such as hydroxyl, amino, and carboxyl groups do not produce peaks or exhibit peak tailing in general nonpolar chromatographic columns; substances with poor thermal stability are easily decomposed during high-temperature vaporization at the GC injection port, making them difficult to detect or quantify using nonpolar compound processing methods. However, by extracting and derivatizing these targets, their molecular weight increases, their stability improves, making them suitable for GC analysis and simultaneously improving peak shape. Because derivatization reactions must be performed in an anhydrous environment, GC-MS analysis of atmospheric particulate samples targeting weakly polar compounds such as organic acids and sugars requires extraction with a weakly polar or mixed polar solvent, followed by nitrogen concentration and drying before adding derivatization reagents to a final volume. Subsequently, the derivatization reaction must be maintained at a specific temperature for a certain time to ensure sufficient derivatization of the weakly polar target compounds in the atmospheric particulate sample. After derivatization, the sample must be rapidly transferred to a GC / MS analysis system for separation and detection; prolonged processing may lead to decomposition of the derivatization reagents.

[0003] In traditional analytical processes, the derivatization of weakly polar organic compounds during pretreatment can lead to incomplete derivatization due to factors such as temperature, time, or the thoroughness of mixing after the addition of derivatizing reagents. The U.S. Environmental Protection Agency (EPA) has specified a series of gas chromatography and liquid chromatography methods in its 8000 series of methods, covering polar and non-polar organic compounds, including methods for polycyclic aromatic hydrocarbons (PAHs), phthalates, phenols, organochlorines, and organophosphorus compounds. Among these, there are general methods applicable to the analysis of semi-volatile organic compounds (8275A) and methods for the thermal desorption of semi-volatile organic compounds (PAHs and PCBs) from soil and sludge (method 8270C). The methods promulgated in my country, such as the determination of polycyclic aromatic hydrocarbons (PAHs) in ambient air and exhaust gas by liquid chromatography (HJ646-2013), the determination of semi-volatile organic compounds (SMOs) in solid waste by gas chromatography-mass spectrometry (HJ951-2018), and the determination of semi-volatile organic compounds (SMOs) in soil and sediments by gas chromatography-mass spectrometry (HJ834-2017), all require complex pretreatment steps, such as organic solvent extraction, to extract and preserve polar organic compounds. Different polarity target compounds in the same atmospheric particulate sample can easily lead to differences in recovery rates due to different pretreatment methods, causing certain deviations in correlation analysis of different target compounds and desorption from atmospheric source models. Simultaneously, the complex pretreatment process not only requires large amounts of high-purity organic solvents but also a long pretreatment time, which cannot meet the practical needs of rapid analysis of large numbers of atmospheric particulate samples.

[0004] Patent application CN201720341988.7 discloses an online derivatization device for detecting polar compounds using gas chromatography or gas chromatography-mass spectrometry, comprising a derivatization reagent bottle, a three-way connector, a three-way valve, a double-needle set, and connecting tubing. Patent application CN201911075024.2 discloses a heat-assisted online derivatization gas chromatography method for determining the content of 80 different forms of fatty acids in polysorbate, which can determine the amount and percentage content of 80 free fatty acids and bound fatty acids in polysorbate through a two-step experiment. Patent publication number CN108614045A discloses a method for preparing a formaldehyde sampling tube and a method for detecting formaldehyde in ambient air. Modified bacterial cellulose-based nano-activated carbon fiber adsorbent loaded with PFBHA derivatizing agent is filled into an atmospheric particulate sample tube. This specially prepared formaldehyde sampling tube is used for online derivatization, adsorption, and collection of formaldehyde in ambient air, allowing for detection using a direct thermal desorption-capillary gas chromatograph. Patent CN217133067U discloses a derivatization detection device for a gas chromatograph. By setting an adjustment device and a four-way valve, the reaction chamber volume is adjustable, ensuring that the reaction chamber volume is variable when the derivatized gas reacts and expands with the atmospheric particulate sample. Patent CN109187797A discloses a method for online derivatization using a flowing gaseous derivatizing reagent. Heated derivatizing reagent is purged into an atmospheric particulate sample cell, causing the gaseous polar target in the sample cell to undergo a derivatization reaction. The derivatized product is then absorbed by an absorption liquid.

[0005] Patent CN201911075024.2 is only applicable to the determination of liquid atmospheric particulate samples. The apparatus in the CN201720341988.7 scheme requires manual online addition of derivatization reagents to each atmospheric particulate sample, and cannot achieve continuous analysis. The CN108614045A scheme is only applicable to the analysis of gaseous formaldehyde in the air. The CN217133067U scheme is a gas chromatography derivatization bypass improvement; its adjustable chamber design is not suitable for the rapid thermal desorption and vaporization of atmospheric particulate samples. The CN109187797A scheme is only applicable to gaseous atmospheric samples. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this disclosure is to provide an online pretreatment device and analysis method for atmospheric particulate matter samples to solve the problems in the related technologies.

[0007] This disclosure provides an online pretreatment device for atmospheric particulate samples, comprising: a first delivery line including a first input end and a first output end, the first input end being for supplying carrier gas; a sealed derivatization reagent container for loading derivatization reagent; wherein the first output end of the first delivery line is connected to the derivatization reagent container to allow the carrier gas to flow in, thereby forming a carrier gas carrying saturated vapor of the derivatization reagent; a second delivery line including a second input end and a second output end, the second input end being connected to the surface of the derivatization reagent in the derivatization reagent container to collect the carrier gas carrying saturated vapor of the derivatization reagent; a plurality of thermal desorption tube components; each thermal desorption tube component including a connected third input end, a lumen, and a third output end; and a second delivery line of the second delivery line. The output end is connected to the third input end for introducing the carrier gas carrying the saturated vapor of the derivatization reagent into the cavity, and the cavity is used to accommodate the atmospheric particulate sample and the carrier gas carrying the saturated vapor of the derivatization reagent; a first automatic delivery mechanism is used to transport the plurality of thermal desorption tube components to the thermal desorption system, so that the thermal desorption tube components can be heated in the thermal desorption system to react the atmospheric particulate sample with the saturated vapor of the derivatization reagent to obtain the target substance; the target substance includes derivatized substances of weakly polar target substances and non-polar target substances; a control unit is communicatively connected to and controls the first automatic delivery mechanism; wherein, the third output end is used to output the carrier gas carrying the target substance for simultaneous mass spectrometry analysis of the derivatized substances of the weakly polar target substances and non-polar target substances.

[0008] In an embodiment of the first aspect, the third output terminal is connected to a gas chromatography-mass spectrometry (GC-MS) apparatus; the GC-MS apparatus includes: a nonpolar gas chromatography column, including a fourth input terminal and a fourth output terminal; the fourth input terminal is connected to the third output terminal of a thermal desorption tube component to obtain the target substance; and a mass spectrometry analysis device, connected to the fourth output terminal, for collecting the target substance and performing mass spectrometry analysis.

[0009] In an embodiment of the first aspect, the temperature of the non-polar gas chromatography column when collecting the target substance is much lower than the heating temperature of the thermal desorption tube component, so that the target substance is a gaseous semi-volatile target substance after thermal desorption at the column head of the gas chromatography column.

[0010] In an embodiment of the first aspect, the online pretreatment device for atmospheric particulate samples includes: a first heating unit located in the thermal desorption system for gradient heating of the thermal desorption tube components to rapidly derivatize the atmospheric particulate samples online; and a second heating unit for heating the non-polar gas chromatography column so that the semi-volatile target substances condensed at the column head are heated and carried by the carrier gas to pass through the non-polar gas chromatography column into the mass spectrometry analysis device for desorption.

[0011] In an embodiment of the first aspect, the first automatic conveying mechanism includes: a movable support tray for loading a heat desorption tube component, a first moving mechanism connected to the support tray, and a first drive motor tractably connected to the first moving mechanism; the first drive motor is communicatively connected to and controlled by the control unit.

[0012] In an embodiment of the first aspect, the first automatic conveying mechanism includes a plurality of said carrier trays that can move in parallel for sequentially conveying each thermal desorption tube component into the thermal desorption system.

[0013] In an embodiment of the first aspect, a second automatic conveying mechanism is used to load the loaded atmospheric particulate sample into the thermal desorption tube component; the second automatic conveying mechanism includes: a movable thermal desorption tube carrier for loading the atmospheric particulate sample, a second moving mechanism connected to the sample carrier, and a second drive motor tractably connected to the second moving mechanism; the second drive motor is communicatively connected to and controlled by the control unit.

[0014] In the first aspect of the embodiment, the online pretreatment device for atmospheric particulate samples has at least one of the following conditions: 1) the first delivery pipeline is a stainless steel or brass pipeline with a passivated inner surface; 2) the atmospheric particulate sample is cut into an elongated shape to fit the lumen of the thermal desorption tube component; 3) the size of the atmospheric particulate sample (generally a quartz filter membrane sample) is divided into 2 or 3 equal parts of 1cm*1cm; 4) the derivatization reagent bottle includes: a bottle body made of quartz glass or high-purity glass, and a bottle cap made of polytetrafluoroethylene; 5) the 6) The derivatization reagent bottle has 1 / 2 to 1 / 4 of its space above the liquid surface; 7) The carrier gas is an inert gas with a purity of 99.99% to 99.999%; 8) The third output end of the thermal desorption tube component is filled with a quartz gasket, a stainless steel mesh gasket, or silanized glass wool; 9) The thermal desorption tube component is placed vertically during use, with the third input end at the top and the third output end at the bottom; 10) The derivatized substance and the non-polar target are organic compounds; 11) The first output end is located below the liquid surface of the derivatization reagent; The thermal desorption tube component is aged; 12) The thermal desorption system is connected to a target adsorption storage device on the side near the third output end. The target adsorption storage device has a fifth input end and a fifth output end. The fifth input end is used to connect to the third input end of the thermal desorption tube component entering the thermal desorption system, and the fifth output end is used to connect to a gas chromatography-mass spectrometry device. The target adsorption storage device is used to be cooled to retain and temporarily store the target substance and allow the carrier gas to pass through, or heated to release the target substance, so as to achieve the same effect as before. When the target substance of the previous sample is in the gas chromatography-mass spectrometry (GC-MS) apparatus, the target substance of the next sample is temporarily stored; or, the fourth output end of the target substance adsorption storage device is connected to the first input port of a three-way valve, the first output port of the three-way valve is connected to the exhaust channel, the second output port of the three-way valve is connected to the GC-MS apparatus, and the three-way valve controls the connection between the first input port and the second output port so as to block the target substance of the next sample from entering the GC-MS apparatus when the target substance of the previous sample is in the GC-MS apparatus.

[0015] The second aspect of this disclosure provides an online analysis method for atmospheric particulate samples, applied to an online pretreatment device for atmospheric particulate samples as described in any one of the first aspects. The method includes: feeding an atmospheric particulate sample loaded into a thermal desorption tube into the cavity of a thermal desorption tube component; sequentially feeding each thermal desorption tube into a thermal desorption system via a first automatic conveying mechanism; and controlling a flow regulating valve to introduce a carrier gas carrying saturated vapor of a derivatizing reagent through a second conveying line into the cavity of the thermal desorption tube component, thereby heating the carrier gas carrying the saturated vapor of the derivatizing reagent and reacting it with a weakly polar target compound in the atmospheric particulate sample to form a gas chromatography-mass spectrometry (GC-MS) product. The derivatized substances for mass spectrometry classification, along with nonpolar target substances from atmospheric particulate matter samples, are used as target substances. The target substances are output to a nonpolar gas chromatography column via a thermal desorption tube component to form gaseous semi-volatile nonpolar target substances and weakly polar target substances as derivatized substances. These gaseous semi-volatile nonpolar target substances and weakly polar target substances are simultaneously fed into the gas chromatography nonpolar column by a carrier gas and heated to achieve separation. Finally, the gaseous semi-volatile nonpolar target substances and weakly polar target substances are sent to a mass spectrometry analyzer for simultaneous mass spectrometry analysis.

[0016] As described above, this disclosure provides an online pretreatment device and analysis method for atmospheric particulate samples. The device includes: a first delivery line, a derivatization reagent container, a second delivery line, a thermal desorption tube assembly, a first automatic delivery mechanism, and a control unit. The first delivery line leads to a solvent container. The carrier gas transported through the first delivery line passes through the derivatization reagent in the derivatization reagent container, generating saturated vapor of the derivatization reagent. The first automatic delivery mechanism then delivers the cavity of the thermal desorption tube assembly into a heating chamber. The saturated vapor of the derivatization reagent is then introduced into the cavity of the thermal desorption tube assembly within the heating chamber, allowing the atmospheric particulate sample in the tube to react rapidly with the saturated vapor of the derivatization reagent under heating conditions. This results in the rapid derivatization of the polar target substance within the sample. Subsequently, the target substance is output along with the carrier gas for chromatographic separation and mass spectrometry analysis. This disclosure automates the entire derivatization process of polar target substances in atmospheric particulate samples, reducing solvent usage and improving instrument operation and personnel efficiency. Attached Figure Description

[0017] Figure 1 This diagram illustrates the structure of an online pretreatment device for atmospheric particulate samples according to one embodiment of the present disclosure.

[0018] Figure 2 This diagram illustrates the structure of an online pretreatment device for atmospheric particulate samples according to one embodiment of the present disclosure.

[0019] Figure 3 This illustration shows a flowchart of an online pretreatment method for atmospheric particulate samples according to one embodiment of the present disclosure. Detailed Implementation

[0020] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the information disclosed herein. This disclosure can also be implemented or applied through other different specific embodiments, and various details in this disclosure can be modified or changed according to different viewpoints and application modules without departing from the spirit of this disclosure. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this disclosure can be combined with each other.

[0021] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, so that those skilled in the art to which this disclosure pertains can readily implement it. This disclosure may be embodied in many different forms and is not limited to the embodiments described herein.

[0022] In this disclosure, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic represented in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. Furthermore, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in any one or a group of embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples represented in this disclosure, as well as the features of those different embodiments or examples.

[0023] Furthermore, the terms "first" and "second" are configured for illustrative purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the representation of this disclosure, "a set" means two or more, unless otherwise explicitly specified.

[0024] For the purpose of clarity, devices unrelated to the description are omitted, and the same or similar components throughout the specification are given the same reference numerals.

[0025] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Furthermore, when it is said that a device "comprises" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather implies that other constituent elements may be included.

[0026] While the terms first, second, etc., are used in some examples herein to refer to various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, first interface and second interface, etc., are used. Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, step, operation, element, module, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, modules, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0027] The technical terms used herein are configured only to refer to specific embodiments and are not intended to limit the disclosure. The singular form used herein includes the plural form unless the statement explicitly indicates otherwise. The word "comprising" as used in the specification means to specify a particular characteristic, region, integer, step, operation, element, and / or component, and does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements, and / or components.

[0028] Although not explicitly defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with the relevant technical literature and the message of the present disclosure, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0029] Environmental monitoring includes monitoring the degree of air pollution. Related technologies utilize liquid chromatography, gas chromatography, and mass spectrometry to analyze the concentration of target compounds in atmospheric particulate samples, thereby reflecting the degree of air pollution. Before analysis, atmospheric particulate samples require pretreatment, including the derivatization of polar organic compounds. However, due to different pretreatment methods, different polar target compounds within the same atmospheric particulate sample can easily lead to differences in recovery rates, and can cause certain biases in correlation analysis of different target compounds and desorption from atmospheric source models. Furthermore, complex pretreatment processes not only require large amounts of high-purity organic solvents but also a long pretreatment time, which cannot meet the practical needs of rapid analysis of large numbers of atmospheric particulate samples.

[0030] To address this, some pretreatment schemes have been provided in related technologies. However, these schemes are either only applicable to the determination of liquid or gaseous particulate samples, and some are limited to specific types of gaseous particulate samples (such as formaldehyde), thus restricting the analytes; or they have structural deficiencies in the pretreatment devices, such as requiring manual online derivatization reagent addition for each particulate sample or adding each particulate sample individually, or the adjustable chamber method is not suitable for the rapid thermal desorption and vaporization of particulate samples.

[0031] Based on the above problems, this disclosure provides an online pretreatment device suitable for atmospheric particulate samples, which solves the problems in the related technology by means of automated processing, transportation, and batch pretreatment of atmospheric particulate samples.

[0032] like Figure 1 The diagram shown illustrates the structure of an online pretreatment device for atmospheric particulate samples according to an embodiment of this disclosure.

[0033] The online atmospheric particulate sample processing device includes: a first delivery pipeline 1, a derivatization reagent container 2, a second delivery pipeline, multiple thermal desorption tube components 4 (i.e., TD tubes), a first automatic delivery mechanism 9, and a control unit 11, etc.

[0034] The first delivery line 1 includes a first input end and a first output end, with the first input end for supplying carrier gas. In some embodiments, the first delivery line 1 can be a metal line with a passivated inner surface, such as a stainless steel or brass line. In some embodiments, the carrier gas is an inert gas with a purity of 99.99% to 99.999%, such as helium.

[0035] The derivatization reagent container 2 is used to load the derivatization reagent. In some embodiments, the first output end of the first delivery line 1 is connected to the derivatization reagent container 2. Exemplarily, the first output end can be as follows: Figure 1 The image shows the derivatization reagent penetrating below the liquid surface. The carrier gas enters the derivatization reagent container 2, purging the derivatization reagent to form a saturated carrier gas carrying saturated vapor of the derivatization reagent, which then reaches above the liquid surface. In some embodiments, the derivatization reagent bottle includes: a bottle body made of quartz glass or high-purity glass, and a bottle cap made of polytetrafluoroethylene.

[0036] The second delivery line includes a second input end and a second output end. The second input end is connected to the liquid surface of the derivatization reagent in the derivatization reagent container 2 to collect the carrier gas carrying the saturated vapor of the derivatization reagent. The second output end is connected to the lumen of each thermal desorption tube component 4. The second delivery line may have only one second output end, which can be reused to connect to the lumen of each thermal desorption tube component 4. Alternatively, the second delivery line may form multiple branches, each branch having a second output end, to simultaneously connect to the lumen of each thermal desorption tube component 4. In some embodiments, approximately 1 / 2 to 1 / 4 of the space at the top of the reagent bottle needs to be left to ensure sufficient carrier gas carrying the saturated vapor of the derivatization reagent in the upper space, facilitating extraction by the second delivery line. In some embodiments, a flow regulating valve 3 is provided between the second input end and the second output end of the second delivery line. By controlling the flow regulating valve 3, the flow of carrier gas into the thermal desorption tube component 4 can be controlled. Understandably, in some embodiments, the first delivery line 1 may also be provided with a flow regulating valve 3 between the first input end and the first output end to control the flow of carrier gas into the derivatization reagent container 2.

[0037] Each of the thermal desorption tube components 4 includes a third input terminal, a cavity, and a third output terminal that are connected in series. Figure 1 In the example, the third input terminal is located at the upper end of the thermal desorption tube component 4, the lumen is located in the middle, and the third output terminal is located at the lower end; all three are connected. Specifically, the second output terminal of the second atmospheric particulate sample 6 delivery pipeline is connected to the third input terminal to allow the carrier gas carrying the saturated vapor of the derivatizing reagent to enter the lumen, and the lumen is used to accommodate the atmospheric particulate sample 6 and the carrier gas carrying the saturated vapor of the derivatizing reagent. In some embodiments, the thermal desorption tube component 4 may be aged before being loaded with the atmospheric particulate sample 6.

[0038] The first automatic conveying mechanism 9 is used to transport the plurality of thermal desorption tube components 4 to the thermal desorption system, so that the thermal desorption tube components 4 can be heated in the thermal desorption system to allow the atmospheric particulate sample 6 to react with the saturated vapor of the derivatization reagent to obtain the target substance. In some embodiments, the first automatic conveying mechanism 9 includes: a movable support tray for loading the thermal desorption tube components 4, a second moving mechanism connected to the sample carrier, and a second drive motor that is driveably connected to the second moving mechanism. The second moving mechanism can be implemented with reference to the first moving mechanism described above, and can be a single-dimensional or multi-dimensional sliding mechanism, rotating mechanism, or robotic arm, etc., for delivering each of the thermal desorption tube components 4 into the thermal desorption system. The thermal desorption system may include a desorption heating chamber 5 and a first temperature control unit 51 for heating the desorption heating chamber 5. The heating area is used to receive each of the thermal desorption tube components 4. In some embodiments, the first automatic conveying mechanism 9 can batch-feed multiple thermal desorption tube components 4 into the desorption heating chamber 5, or it can feed them sequentially, for example, feeding the next thermal desorption tube component 4 after the previous one has been heated. Regardless of the conveying method, the entire process is automated by the first automatic conveying mechanism 9. Exemplarily, the first temperature control unit 51 can execute a gradient heating program to rapidly derivatize the atmospheric particulate sample 6 in the heating chamber 5 online. Exemplarily, the carrier gas carrying the saturated vapor of the derivatizing reagent can be heated by a third heating unit (not shown) before entering the thermal desorption tube component to improve reaction efficiency; or, the carrier gas carrying the saturated vapor of the derivatizing reagent can also be fed into the thermal desorption tube component located in the thermal desorption system and heated by the first heating unit 51.

[0039] In some embodiments, the number of carrier trays included in the first automatic conveying mechanism 9 can be one or more. For example, if there are multiple carrier trays, they can move in parallel to transport each thermal desorption tube component 4 into and out of the thermal desorption system sequentially or in batches. Alternatively, in the case of a single carrier tray, each thermal desorption tube component 4 can be transported into and out of the thermal desorption system one by one.

[0040] In a possible example, the device further includes a second automated conveying mechanism 10 for loading each loaded atmospheric particulate sample 6 into each of the thermal desorption tube components 4. In some embodiments, the second automated conveying mechanism 10, for loading each loaded atmospheric particulate sample 6 into each of the thermal desorption tube components 4, includes: a movable atmospheric particulate sample 6 carrier for loading the atmospheric particulate sample 6, a second moving mechanism connected to the sample carrier, and a second drive motor tractably connected to the second moving mechanism; the second drive motor is communicatively connected to and controlled by the control unit 11. Exemplarily, the atmospheric particulate sample 6 carrier may be movable and have sample introduction capability, or it may be used in conjunction with a sample introduction tool. The atmospheric particulate sample 6 carrier includes, but is not limited to, a tray, a clamp (or a robotic arm), a suction tip, etc., and the atmospheric particulate sample 6 carrier can deliver the atmospheric particulate sample 6 by tilting, releasing, or inserting. The first moving mechanism includes, but is not limited to, a sliding mechanism (e.g., a slider and a slide rail working together, which can be two-dimensional or three-dimensional sliding), a rotating mechanism, a robotic arm, etc. The first drive motor can be connected to the first moving mechanism through a transmission method such as a sprocket structure or a gear structure, so as to transmit the kinetic energy of its output shaft to the first moving mechanism, thereby driving the atmospheric particulate sample 6 carrier to move close to the thermal desorption tube component 4, and sending the atmospheric particulate sample 6 into the thermal desorption tube component 4.

[0041] The control unit 11 is communicatively connected to and controls the first automatic conveying mechanism 9. Optionally, if a second automatic conveying mechanism 10 is present, the control unit 11 is also communicatively connected to and controls the second automatic conveying mechanism 10. Specifically, the control unit 11 is electrically connected to and controls the operation of the first drive motor. In some embodiments, the control unit 11 may include a PLC, MCU, or SoC, etc. In some embodiments, the control unit 11 can control the actions of the second automatic conveying mechanism 10 and the first automatic conveying mechanism 9 according to a trigger signal. The actions of the control unit 11 on the second automatic conveying mechanism 10 and the first automatic conveying mechanism 9 can be sequential or parallel. Taking the sequential process as an example, when the first trigger signal is received, the control unit 11 controls the second automatic conveying mechanism 10 to obtain the atmospheric particulate sample 6 from the preset position and send it into the thermal desorption tube component 41, thermal desorption tube component 42 and thermal desorption tube component 43 respectively. When the second trigger signal indicating that the atmospheric particulate sample 6 has been placed is received, the thermal desorption tube component 41, thermal desorption tube component 42 and thermal desorption tube component 43 are sent into the thermal desorption system together or in batches for heating, and then removed.

[0042] In a possible example, the generation of the first trigger signal can be achieved through a preset instruction generator, such as a switch, button, voice recognition, image recognition, or other human-computer interaction module. When the input meets a preset condition, such as when a user presses a button, the first trigger signal is generated and transmitted to the control unit 11. It is possible that the control unit 11 can be directly electrically connected to the preset instruction generator, or the two can be connected via a wireless communication device.

[0043] In possible examples, the generation of the second trigger signal can be achieved by using sensing devices such as photoelectric sensors, magnetic sensors, cameras, lidar, and ultrasonic radar to detect the state of the second automatic conveying mechanism 10. When an event indicating sample introduction completion is detected, a second trigger signal is generated and sent to the control unit 11. Similarly, the sensing device can be connected to the control unit 11 via wired or wireless means. In possible examples, the event indicating sample introduction completion could be, for example, the second automatic conveying mechanism 10 returning to its original position after delivering the atmospheric particulate sample 6, which is detected by the sensing device during this process; alternatively, the event indicating sample introduction completion could be identified by an image captured by a camera, showing that the atmospheric particulate sample 6 has entered the cavity of the thermal desorption tube component 4; or alternatively, the event indicating sample introduction completion could be detected by a sensing device, such as a photoelectric sensor or magnetic sensor, at a specific position when the robotic arm in the second automatic conveying mechanism 10 places the atmospheric particulate sample 6 into the thermal desorption tube component 4, thereby generating the second trigger signal.

[0044] Alternatively, there are other ways to implement it, which will not be elaborated here.

[0045] The thermal desorption tube component 4, containing atmospheric particulate sample 6 in its lumen, is fed into the thermal desorption system for desorption. A second delivery line introduces a carrier gas carrying saturated vapor of a derivatizing reagent into the thermal desorption tube component 4 from the third input end. Under the heating condition of the thermal desorption system, the saturated vapor of the derivatizing reagent reacts with the atmospheric particulate sample 6, specifically derivatizing the polar organic compounds in the atmospheric particulate sample 6. The carrier gas carrying the target substance can be output from the third output end for mass spectrometry analysis. The target substance includes derivatized substances of weakly polar target substances and non-polar target substances, such as nonpolar organic compounds (NPOCs) and weakly polar organic compounds (POCs).

[0046] In some embodiments, the third output terminal may be connected to a gas chromatography-mass spectrometry (GC-MS) device. The GC-MS device includes a nonpolar gas chromatography column 7 and an analysis system 8 arranged in front and rear stages.

[0047] The nonpolar gas chromatographic column 7 includes a fourth input end and a fourth output end. The fourth input end is connected to the third output end of the thermal desorption tube component 4 to obtain the target substance. In some embodiments, when the third output end outputs a carrier gas carrying the target substance to the fourth input end, the temperature at which the nonpolar gas chromatographic column 7 collects the derivatized substances of the weakly polar target substance and the nonpolar target substance can be much lower than the heating temperature of the thermal desorption tube component 4, so that the target substance condenses on the surface of the nonpolar gas chromatographic column 7, such as at the column head, forming a semi-volatile target substance.

[0048] The mass spectrometry (MS) analysis system, connected to the fourth output terminal, is used to collect the target substance and perform mass spectrometry analysis. In some embodiments, the online pretreatment device for atmospheric particulate samples may further include a second heating unit 12 for heating the non-polar gas chromatography column 7, so that the condensed semi-volatile target substance is heated and converted into a gaseous state, which is then carried into the analysis system 8 by the carrier gas. Optionally, the second heating unit 12 may also be communicatively connected to and controlled by the control unit 11, or it may be controlled by other controllers.

[0049] In some embodiments, regarding the specific morphology of the atmospheric particulate sample 6, the atmospheric particulate sample 6 can be processed into an elongated shape adapted to the lumen of the thermal desorption tube component 4. For example, a filter membrane containing atmospheric particulate matter of a certain area is first taken, cut into 1cm*1cm pieces, and then divided into three equal parts to form thin strip-shaped atmospheric particulate matter samples, each atmospheric particulate sample 6 having a size of approximately 0.3cm*1cm. The thin strip-shaped atmospheric particulate matter samples are then loaded into a pre-aged empty thermal desorption tube component, and the third output end of the thermal desorption tube component (i.e., Figure 1 The lower end of the middle section is filled with quartz gaskets, stainless steel mesh gaskets, or silanized glass wool.

[0050] In some embodiments, in order to further improve the efficiency of the entire online pretreatment device in processing various atmospheric particulate samples, for example, the transit time of the target substance generated from one atmospheric particulate sample into the gas chromatography-mass spectrometry device can at least partially cover the heating of the next atmospheric particulate sample in the thermal desorption system or the condensation before entering the gas chromatography-mass spectrometry device, i.e., time reuse, so that the total processing time of two atmospheric particulate samples is effectively shortened compared to the total processing time of waiting for one sample to be completely analyzed by mass spectrometry and then waiting for the next sample, which greatly improves the work efficiency.

[0051] Therefore, it is possible to Figure 2 The diagram shown illustrates the structure of an online pretreatment device for atmospheric particulate samples in yet another embodiment of this disclosure.

[0052] In this embodiment, the first delivery line 1, the derivatization reagent container 2, the second delivery line, the control valve, the thermal desorption tube assembly 4, the thermal desorption system 5, the atmospheric particulate sample 6, the non-polar chromatographic column 7, and the mass spectrometry analysis device 8, etc., can be connected with... Figure 1 As in the previous embodiment, the first automatic conveying mechanism 9, the second automatic conveying mechanism 10, and the control unit 11 have already been explained in principle, so they will not be shown in this embodiment.

[0053] Specifically, the thermal desorption system has a target substance adsorption storage device 13 connected to one side near the third output end, such as a packed tube (made of quartz), containing a commonly used broad-spectrum adsorbent such as Tenax TA. The target substance adsorption storage device 13 has a fifth input end and a fifth output end. The fifth input end is used to connect to the third input end of the thermal desorption tube component entering the thermal desorption system, and the fifth output end is used to connect to a gas chromatography-mass spectrometry device.

[0054] The target substance adsorption and storage device 13 is used to be cooled to trap and temporarily store the target substance and to allow carrier gas to pass through, or heated to release the target substance, so as to temporarily store the target substance of the next sample when the target substance of the previous sample is in the gas chromatography-mass spectrometry device. Exemplarily, the target substance is adsorbed by the adsorbent in the packed tube to achieve trapping, and cooling and heating can be achieved by installing a cold trap 14 and a heater 15 outside the packed tube, which operate alternately. When the target substance of the previous sample is in the non-polar chromatographic column 7, it requires carrier gas to propel it. The carrier gas passes through the target substance adsorption and storage device 13 and is blown into the gas chromatography-mass spectrometry device (e.g., into the non-polar chromatographic column 7) to carry the target substance of the previous sample. The cold trap 14 can be activated, so the target substance of the next sample is heated in the thermal desorption system 5 in sync with the movement of the target substance of the previous sample and can be adsorbed and trapped in the cold trap 14, preventing it from entering the gas chromatography-mass spectrometry device and thus not affecting the target substance of the previous sample. Subsequently, after the mass spectrometry analysis of the target substance of the previous sample is completed or during the mass spectrometry analysis process, the cold trap 14 can stop working, and the heater 15 can be activated to heat and de-adsorb the target substance of the next sample, allowing it to enter the gas chromatography-mass spectrometry device. For example, the cooling temperature of the cold trap 14 can be 40°C, and the heating temperature of the heater 15 can be between 250°C and 310°C or 320°C.

[0055] This shows that the target substances of the previous sample and the target substances of the next sample overlap in processing time, thereby improving efficiency.

[0056] Alternatively, in some embodiments, the heater 15 may be omitted, and a three-way valve may be added instead. The fourth output of the target substance adsorption temporary storage device 13 is connected to the first input port of the three-way valve, and the first output port of the three-way valve is connected to an exhaust channel, which can be used to discharge part of the carrier gas that is cooled during the cooling operation of the cold trap 14. The second output port of the three-way valve is connected to a gas chromatography-mass spectrometry (GC-MS) apparatus. The three-way valve controls the connection between the first input port and the second output port, so as to block the entry of the target substance of the next sample into the GC-MS apparatus when the target substance of the previous sample is in the GC-MS apparatus.

[0057] like Figure 3 The diagram shown illustrates a flowchart of an online analysis method for atmospheric particulate matter samples according to an embodiment of this disclosure. This online analysis method for atmospheric particulate matter samples can be applied to… Figure 1 An online pretreatment device for atmospheric particulate matter samples.

[0058] The online analysis method for atmospheric particulate samples includes:

[0059] Step S301: Send each atmospheric particulate sample into the cavity of each thermal desorption tube component.

[0060] Optionally, the atmospheric particulate sample 6 can be fed into the cavity of the thermal desorption tube component 4 by the second automatic conveying mechanism 10.

[0061] Step S302: Each thermal desorption tube component is fed into the thermal desorption system via the first automatic conveying mechanism;

[0062] Step S303: By manipulating the flow regulating valve, the carrier gas carrying the saturated vapor of the derivatizing reagent is introduced into the cavity of the thermal desorption tube component through the second delivery pipeline, so that the carrier gas carrying the saturated vapor of the derivatizing reagent is heated and reacts with the weakly polar target in the atmospheric particulate sample to form a derivatized substance that can be used for gas chromatography-mass spectrometry classification. The derivatized substance and the non-polar target in the atmospheric particulate sample are used as target substances.

[0063] Step S304: The target substance is output to a nonpolar gas chromatography column through a thermal desorption tube component to form gaseous semi-volatile nonpolar target substances and weakly polar target substances based on the target substance.

[0064] Before entering the gas chromatograph, the target substance may be temporarily stored in the target substance adsorption storage device 13.

[0065] Step S305: The gaseous semi-volatile nonpolar target analytes and the derivatized substances of the weakly polar target analytes are simultaneously fed into a gas phase nonpolar chromatographic column by a carrier gas, and are heated in the nonpolar chromatographic column to form a separation.

[0066] The separation is based on the different boiling points of the different compounds and is achieved through heating.

[0067] Step S306: The gaseous semi-volatile nonpolar target analytes and the derivatives of weakly polar target analytes are sent into a mass spectrometry analyzer for simultaneous mass spectrometry analysis.

[0068] As can be seen from the above, this disclosure addresses the technical problems of complex pretreatment of polar organic compounds (POCs) and the need for separate pretreatment from NPOCs in existing offline analysis methods. The embodiments provide an online pretreatment device and online analysis method for atmospheric particulate samples, enabling a fully automated process from automatic online derivatization of POCs in atmospheric particulate sample 6 to automatic injection along with NPOCs and automatic detection and analysis. Furthermore, this device employs a combined pretreatment method of online derivatization and automatic injection via the thermal desorption tube component 4, making it more efficient and convenient.

[0069] The following correspondence Figure 3 The online analysis method described herein can provide a specific implementation example of the process. For the sake of simplicity, the content of the material buffer device 15 has not been included.

[0070] The process is as follows:

[0071] 1. Take a certain area of ​​atmospheric particulate matter sample 6, cut it into 1cm*1cm pieces, and then cut it into 2 or 3 equal parts to obtain fine strip-shaped filter membrane samples. Place the fine strip-shaped filter membrane samples into a pre-aged air-thermal desorption tube component 4. The lower end of the thermal desorption tube component 4 is filled with a quartz gasket, a stainless steel mesh gasket, or silanized glass wool. Exemplarily, the fabrication of the fine strip-shaped filter membrane samples can also be automatically completed by an automated mechanical mechanism.

[0072] 2. Place each thermal desorption tube component 4 into the atmospheric particulate sample tray 6, and sequentially enter the thermal desorption system to perform the thermal desorption step according to the batch processing program.

[0073] 3. When each atmospheric particulate sample 6 enters the thermal desorption step, the carrier gas of high-purity helium passes through the first passivated delivery pipeline 1 and enters the derivatization reagent container 2 below the liquid surface of the derivatization reagent. Then, carrying the carrier gas saturated with the derivatization reagent vapor, it enters the thermal desorption tube component 4 carrying the atmospheric particulate sample 6 under the action of the flow regulating valve 3, ready to be thermally desorbed in the desorption heating chamber 5 of the thermal desorption system.

[0074] 4. The carrier gas carrying the saturated vapor of the derivatizing reagent is rapidly heated in the thermal desorption zone of the thermal desorption tube component 4, rising from 40°C to 280-300°C. The polar substances in the atmospheric particulate sample 6 undergo a full and rapid derivatization reaction with the derivatizing reagent and enter the non-polar chromatographic column 7.

[0075] 5. At this time, the column temperature of the nonpolar chromatographic column 7 is 40℃, and all the gaseous semi-volatile target substances after thermal desorption condense at the column head of the nonpolar chromatographic column 7.

[0076] 6. After the thermal desorption procedure is completed, the gaseous semi-volatile target substance is carried into the non-polar chromatographic column 7 along with the carrier gas. The chromatographic column 7 is heated at a rate of 5-12℃ / s to 310℃ and held for 5 min before entering the mass spectrometry (MS) analysis system 8.

[0077] 7. After the analysis of the previous atmospheric particulate sample 6 is completed, the next atmospheric particulate sample 6 is automatically sent into the deheating chamber 5 for desorption, and the above analysis process is repeated.

[0078] In some examples, the carrier gas is an inert gas, typically 99.999% high-purity helium. The derivatives of the weakly polar target and non-polar target can be thermally desorbed at 200°C to 310°C.

[0079] In some examples, the derivatizing reagent reaches gas-liquid equilibrium in a sealed container 2 at room temperature. The carrier gas, carrying the saturated vapor of the derivatizing reagent, passes through the sealed container 2 and enters the thermal desorption tube component 4 in the deheating chamber 5. The amount of saturated vapor added can be controlled by the flow regulating valve 3 by controlling the carrier gas flow rate and the heating time in the deheating chamber 5. The derivatizing reagent container 2 is made of quartz glass or high-purity glass with a polytetrafluoroethylene cap. The first delivery line 1 is made of stainless steel or brass, with its inner surface pre-passivated. The first delivery line 1, the derivatizing reagent container 2, the flow control valve, the thermal desorption tube component 4, and other pipelines and containers 2 before them do not require heating or cooling; they can be kept at room temperature in the laboratory. The first output end of the first delivery line 1 must be inserted below the surface of the derivatizing reagent liquid. The derivatizing reagent container 2 can retain approximately 1 / 2 to 1 / 4 of its space above the liquid surface to ensure sufficient carrier gas carrying the saturated vapor of the derivatizing reagent in the upper space. The second input end of the second delivery pipeline is above the liquid surface, ensuring that the derived vapor reagent and carrier gas enter the thermal desorption tube component 4 along the second delivery pipeline.

[0080] The apparatus in this embodiment enables the introduction of derivatization reagents in a closed state, facilitating rapid derivatization reactions and automating the processing of atmospheric particulate samples 6 (including the added derivatization reagents and atmospheric filter membrane) in the thermal desorption atmospheric particulate sample 6 injection system. This new method effectively improves instrument operation and human efficiency, reduces differences between batches of atmospheric particulate samples 6 caused by manual operation, and allows for the continuous analysis of multiple atmospheric particulate samples 6 in a single operation (e.g., triggering the insertion of the sample into the thermal desorption tube component 4 via a trigger signal). It boasts high derivatization efficiency and a simple and easy-to-operate structure. Simultaneously, it avoids the switching of the six-way valve and the heating, cooling, and reheating steps required in conventional secondary thermal desorption methods, reducing instrument construction and requirements for instrument sealing, insulation, and heating / cooling efficiency.

[0081] In summary, this disclosure provides an online pretreatment device and analysis method for atmospheric particulate samples. The device includes: a first delivery line, a derivatization reagent container, a second delivery line, a thermal desorption tube assembly, a second automatic delivery mechanism, a first automatic delivery mechanism, and a control unit. The first delivery line leads to a solvent container, and the carrier gas it carries passes through the derivatization reagent in the derivatization reagent container to generate saturated vapor of the derivatization reagent. The second automatic delivery mechanism automatically delivers each atmospheric particulate sample into the cavity of each thermal desorption tube assembly. The first automatic delivery mechanism delivers each thermal desorption tube assembly in batches or sequentially to the thermal desorption system for heating, while the second delivery line collects the saturated vapor of the derivatization reagent and delivers it into the cavity, allowing the atmospheric particulate sample in the cavity to react with the saturated vapor of the derivatization reagent to obtain the target substance, which is then output for mass spectrometry analysis. This disclosure achieves the introduction of the derivatization reagent in a closed state of the thermal desorption tube assembly, enabling rapid derivatization reactions. It also automates the entire atmospheric particulate sample processing process, improving instrument operation and personnel efficiency.

[0082] The above embodiments are merely illustrative of the principles and effects of this disclosure and are not intended to limit this disclosure. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this disclosure. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this disclosure should still be covered by the claims of this disclosure.

Claims

1. An online pretreatment device for atmospheric particulate samples, characterized in that, include: The first delivery pipeline includes a first input end and a first output end, wherein the first input end is used to supply carrier gas; A sealed derivatization reagent container is used to load the derivatization reagent; wherein, the first output end of the first delivery pipeline is connected to the derivatization reagent container to allow the carrier gas to flow in, so as to form a carrier gas carrying saturated vapor of the derivatization reagent; The second delivery pipeline includes a second input end and a second output end. The second input end is connected to the top of the derivatization reagent liquid surface in the derivatization reagent container to collect the carrier gas carrying the saturated vapor of the derivatization reagent. Multiple thermal desorption tube components; each thermal desorption tube component includes a third input end, a lumen, and a third output end connected in series; the second output end of the second delivery line is connected to the third input end for introducing the carrier gas carrying the saturated vapor of the derivatizing reagent into the lumen, and the lumen is provided to contain the atmospheric particulate sample and the carrier gas carrying the saturated vapor of the derivatizing reagent; A first automatic conveying mechanism is used to transport the plurality of thermal desorption tube components to the thermal desorption system, so that the thermal desorption tube components can be heated in the thermal desorption system to react the atmospheric particulate sample with the saturated vapor of the derivatization reagent to obtain the target substance; the target substance includes derivatizations of weakly polar target substances and non-polar target substances; the control unit is communicatively connected to and controls the first automatic conveying mechanism. A second automatic conveying mechanism is used to load each atmospheric particulate sample into each of the thermal desorption tube components; the second automatic conveying mechanism includes: a movable atmospheric particulate sample carrier for loading the atmospheric particulate sample, a second moving mechanism connected to the sample carrier, and a second drive motor that is tractably connected to the second moving mechanism; the second drive motor is communicatively connected to and controlled by the control unit; The thermal desorption system has a target substance adsorption and storage device connected to it on the side near the third output end. The target substance adsorption and storage device has a fifth input end and a fifth output end. The fifth input end is used to connect to the third input end of the thermal desorption tube component entering the thermal desorption system, and the fifth output end is used to connect to the gas chromatography-mass spectrometry device. The target substance adsorption and storage device can be cooled to retain and temporarily store the target substance and allow the carrier gas to pass through, or heated to release the target substance, so as to temporarily store the target substance of the next sample while the target substance of the previous sample is in the gas chromatography-mass spectrometry device. The target substance adsorption and storage device uses the adsorbent in the packed tube to adsorb the target substance to achieve retention, and uses a cold trap and a heater installed outside the packed tube to achieve cooling and heating respectively. The cold trap and the heater work alternately. The third output terminal is used to output carrier gas carrying the target substance, so as to perform simultaneous mass spectrometry analysis on the derivatives of the weakly polar target and the non-polar target.

2. The online pretreatment device for atmospheric particulate samples according to claim 1, characterized in that, The third output terminal is connected to a gas chromatography-mass spectrometry device; The gas chromatography-mass spectrometry apparatus includes: A nonpolar gas chromatographic column includes a fourth input end and a fourth output end; the fourth input end is connected to the third output end of a thermal desorption tube component to obtain the target substance; A mass spectrometry analysis device, connected to the fourth output terminal, is used to collect the target substance and perform mass spectrometry analysis.

3. The online pretreatment device for atmospheric particulate samples according to claim 2, characterized in that, The nonpolar gas chromatography column is heated at a temperature lower than that of the thermal desorption tube component when collecting the target substance, so that the target substance condenses on the surface of the gas chromatography column to form a semi-volatile target substance.

4. The online pretreatment device for atmospheric particulate samples according to claim 3, characterized in that, include: The first heating unit, located in the thermal desorption system, is used to gradient heat the thermal desorption tube components to rapidly derivatize atmospheric particulate samples online. And / or a second heating unit for heating the nonpolar gas chromatography column so that the semi-volatile target substance condensed at the column head is heated and carried by the carrier gas through the nonpolar gas chromatography column into the mass spectrometry analysis device.

5. The online pretreatment device for atmospheric particulate samples according to claim 1, characterized in that, The second delivery pipeline is provided with a flow regulating valve between the second input end and the second output end; and / or, the first delivery pipeline is provided with a flow regulating valve between the first input end and the first output end.

6. The online pretreatment device for atmospheric particulate samples according to claim 1, characterized in that, The first automatic conveying mechanism includes: a movable support tray for loading the heat desorption tube component, a first moving mechanism connected to the support tray, and a first drive motor that is driveably connected to the first moving mechanism; the first drive motor is communicatively connected to and controlled by the control unit.

7. The online pretreatment device for atmospheric particulate samples according to claim 6, characterized in that, The first automatic conveying mechanism includes multiple carrier trays that can move in parallel, for conveying each thermal desorption tube component into the thermal desorption system sequentially or in batches.

8. The online pretreatment device for atmospheric particulate samples according to claim 1, characterized in that, At least one of the following situations exists: 1) The first delivery pipeline is a stainless steel or brass pipeline with a passivated inner surface; 2) The atmospheric particulate sample is processed into an elongated shape to fit the lumen of the thermal desorption tube component; 3) The size of the atmospheric particulate sample is based on 2 or 3 equal sections of 1 cm * 1 cm; 4) The derivatization reagent container includes: a bottle body made of quartz glass or high-purity glass, and a bottle cap made of polytetrafluoroethylene; 5) The derivatization reagent container has 1 / 2 to 1 / 4 of its space above the liquid surface; 6) The carrier gas is an inert gas with a purity of 99.99% to 99.999%; 7) The third output end of the thermal desorption tube component is filled with a quartz gasket, a stainless steel mesh gasket, or silanized glass wool; 8) The thermal desorption tube component is placed vertically during use, with the third input end at the top and the third output end at the bottom; 9) The derived substances and nonpolar target substances are target organic compounds; 10) The first output terminal is located below the liquid surface of the derivatizing reagent; 11) The thermal desorption tube component has undergone aging; The target substance adsorption and storage device is used to be cooled to retain and temporarily store the target substance and allow carrier gas to pass through, or heated to release the target substance, so as to temporarily store the target substance of the next sample when the target substance of the previous sample is in the gas chromatography-mass spectrometry device; or, the fourth output end of the target substance adsorption and storage device is connected to the first input valve port of a three-way valve, the first output valve port of the three-way valve is connected to the exhaust channel, the second output valve port of the three-way valve is connected to the gas chromatography-mass spectrometry device, and the three-way valve controls the connection between the first input valve port and the second output valve port, so as to block the target substance of the next sample from entering the gas chromatography-mass spectrometry device when the target substance of the previous sample is in the gas chromatography-mass spectrometry device.

9. An online analysis method for atmospheric particulate matter samples, applied to the online pretreatment device for atmospheric particulate matter samples as described in any one of claims 1 to 8, the method comprising: Each atmospheric particulate sample is delivered into the lumen of each thermal desorption tube component; Each thermal desorption tube component is fed into the thermal desorption system via a first automatic conveying mechanism; By manipulating the flow regulating valve, the carrier gas carrying the saturated vapor of the derivatizing reagent is introduced into the cavity of the thermal desorption tube component through the second delivery pipeline, so that the carrier gas carrying the saturated vapor of the derivatizing reagent is heated and reacts with the weakly polar target in the atmospheric particulate sample to form a derivatized substance for gas chromatography-mass spectrometry classification. The derivatized substance and the non-polar target in the atmospheric particulate sample are used as target substances. The target substance is output to a nonpolar gas chromatography column via a thermal desorption tube component, so as to form gaseous semi-volatile nonpolar target substances and weakly polar target substances based on the target substance; Gaseous semi-volatile nonpolar target analytes and derivatized substances of weakly polar target analytes are simultaneously fed into a gas-phase nonpolar chromatographic column by a carrier gas and heated in the nonpolar chromatographic column to achieve separation. Gaseous semi-volatile nonpolar target substances and derivatives of weakly polar target substances are fed into a mass spectrometry analyzer for simultaneous mass spectrometry analysis.

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