An aerosol trapping device and a method for detecting benzene series in aerosol

Abstract

The application provides an aerosol trapping device and a method for detecting benzene series in aerosol. The aerosol trapping device comprises a suction module, a low-temperature circulation module, a collection module and a flow calibration module. The suction module is used for providing a negative pressure airflow. The collection module is internally filled with an absorption medium for dissolving or intercepting aerosol. The low-temperature circulation module is provided with a cooling pool. The flow calibration module is used for balancing the flow range of each aerosol trapping process. The collection module can be detachably arranged in the cooling pool to cool the absorption medium. The collection module is connected between the suction module and an aerosol generator. In this way, the aerosol sequentially passes through the aerosol generator, the collection module and the suction module under the negative pressure airflow. The absorption medium can effectively absorb various benzene series in the aerosol. Both particulate matter and gaseous matter can be dissolved or intercepted by the absorption medium. The low-temperature circulation module can cool the absorption medium, reduce the volatilization loss of benzene series and improve the detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of aerosol physicochemical detection technology, and in particular to an aerosol collection device and a method for detecting benzene series compounds in aerosols. Background Technology

[0002] Aerosols are colloidal dispersion systems formed by the dispersion and suspension of tiny solid or liquid particles in a gaseous medium. They are widely present in the atmosphere, industrial production, and everyday life. Clouds, fog, dust, and pollen in the sky; smoke from unburned fuel in industrial boilers and various engines; and solid dust generated during mining, stone processing, and food processing all fall under the category of aerosols. Aerosol particles are typically extremely small in size, can remain suspended in the air for extended periods, and are characterized by easy diffusion, inhalability, and high stability.

[0003] Aerosols contain a variety of harmful components, with wide-ranging and complex compositions. For example, aerosols generated in various scenarios such as industrial production, transportation, and environmental emissions widely contain volatile organic compounds (VOCs) and heavy metals; while aerosols generated during fuel combustion and mining processes can accumulate fine particulate matter, carbon monoxide, nitrogen oxides, sulfur oxides, dust, and other toxic and harmful substances. These harmful components pose potential threats to human health and the environment. Among these, benzene compounds are common harmful substances in aerosols. Aerosols generated from vehicle exhaust, fuel evaporation and incomplete combustion, industrial coating, petrochemicals, and fuel storage and transportation often contain benzene, toluene, xylene, ethylbenzene, and other benzene compounds. These compounds easily enter the human body through respiration in the form of volatile organic compounds, exhibiting irritant and neurotoxic properties. Benzene, in particular, is a confirmed carcinogen, and long-term inhalation can damage the hematopoietic, respiratory, and nervous systems. Therefore, the capture and accurate determination of benzene compound content in aerosols is of great significance.

[0004] Current methods for determining benzene compounds in aerosols suffer from low accuracy. For example, one method involves collecting aerosols using a Cambridge filter followed by solution extraction, and then analyzing the extract using GC-QTOF-MS (Gas Chromatography-Quadrupole Time-of-Flight Mass Spectrometry). However, aerosols consist of particulate and gaseous phases. The Cambridge filter can only capture benzene and its compounds in the particulate phase, failing to detect the benzene and its compounds in the gaseous phase, leading to inaccurate determination of benzene content in aerosols. Benzene compounds are volatile, and improper aerosol collection makes accurate determination difficult. To better study aerosol safety, a method for accurately determining benzene compounds in aerosols is needed, which can effectively capture aerosols. Summary of the Invention

[0005] This invention provides an aerosol collection device and a method for detecting benzene series compounds in aerosols, thereby solving the problem of low accuracy in the detection of benzene series compounds in aerosols in the prior art.

[0006] To address the aforementioned technical problems, one objective of this invention is to provide an aerosol capture device for capturing aerosols generated by an aerosol generator. The aerosol capture device includes a suction module, a collection module, a cryogenic circulation module, and a flow calibration module. The suction module provides a negative pressure airflow. The collection module has a first end and a second end, and its interior is filled with an absorption medium for dissolving or trapping aerosols. The cryogenic circulation module is equipped with a cooling pool. The flow calibration module balances the flow rate range for each aerosol capture process. The collection module is detachably placed within the cooling pool, where the absorption medium is cooled by the cryogenic environment. The first end is in fluid communication with the suction module, and the second end is in fluid communication with the aerosol generator, allowing the negative pressure airflow to sequentially pass through the aerosol generator and the collection module before entering the suction module.

[0007] According to one embodiment, the collection module includes at least two collectors connected in series; wherein the first end is located in the rear collector and the second end is located in the front collector.

[0008] According to one embodiment, the aerosol trapping device further includes a clamping module for fixing the aerosol generator.

[0009] According to one embodiment, the aerosol collection device further includes a heat insulation module for covering the collection module.

[0010] One objective of this invention is to provide a method for detecting benzene compounds in aerosols, the method comprising the following steps: Aerosol capture: The aerosol generated by the aerosol-generating product to be tested is drawn and captured using the capture device described in any of the above embodiments. For the detection of benzene series compounds, gas chromatography-tandem mass spectrometry was used to perform qualitative and quantitative analysis of benzene series compounds in the captured aerosol samples to obtain the types and corresponding contents of benzene series compounds contained in the aerosol generated by the aerosol product to be tested.

[0011] According to one embodiment, the aerosol capture step includes the following steps: Connect the aerosol collection device to the aerosol generator, start the suction module and the aerosol generator, the aerosol generating product in the aerosol generator is atomized and generates aerosols, and the aerosols are partially or completely collected by the absorption medium as they pass through the collection module with the negative pressure airflow.

[0012] According to one embodiment, the method further includes a flow calibration step, which is performed before each sample collection to ensure that the aerosol flow rate is a preset value.

[0013] According to one embodiment, the absorption medium is selected from ethanol, isopropanol, methanol, and carbon disulfide.

[0014] According to one embodiment, during the aerosol capture process, the cooling temperature of the cooling pool is -60°C to -20°C.

[0015] Compared to existing technologies, this invention offers the following advantages: The aerosol collection device provided in this application uses a suction module to draw aerosols generated in an aerosol generator, and the absorption medium in the collection module effectively absorbs various benzene compounds in the aerosols. Both particulate and gaseous phases can be absorbed by the absorption medium, achieving accurate collection of benzene compounds from the aerosols. Subsequent chromatographic analysis can then precisely detect the type and content of benzene compounds. Secondly, a low-temperature circulation module cools the absorption medium in the collection module, maintaining the collected benzene compounds in a low and stable low-temperature environment, reducing the volatilization loss of benzene compounds, maintaining the collection efficiency, improving detection accuracy, and reducing detection errors. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A three-dimensional structural diagram of the aerosol collection device provided in the embodiments of this application; Figure 2 A three-dimensional structural diagram of the aerosol capture device provided in the embodiments of this application, viewed from another perspective. Figure 3 yes Figure 2 A magnified view of a portion of position A in the middle.

[0018] The following are the labeling elements in the figure: 1-Suction module; 2-Low temperature circulation module; 3-Collection module; 31-Collector; 4-Aerosol generator; 5-Clamping module; 51-Base; 52-Support part; 521-Support rod; 53-Clamping part; 531-Threaded rod; 5311-Turning handle; 532-Clamping plate. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] like Figure 1 As shown, this invention provides an aerosol capture device for capturing aerosols generated by an aerosol generator 4. The aerosol capture device includes a suction module 1, a cryogenic circulation module 2, a collection module 3, and a flow calibration module. The suction module 1 provides a negative pressure airflow. The collection module 3 has a first end and a second end, and its interior is filled with an absorption medium for dissolving or trapping aerosols. The cryogenic circulation module 2 is equipped with a cooling pool. The flow calibration module is used to balance the flow range for each aerosol capture process. The collection module 3 is detachably placed in the cooling pool, where the absorption medium is cooled by a cryogenic environment. Its first end is fluidly connected to the suction module 1, and its second end is fluidly connected to the aerosol generator 4, allowing the airflow to sequentially pass through the aerosol generator 4 and the collection module 3 before entering the suction module 1.

[0023] Specifically, the aerosol generator 4 refers to a specialized device that uses physical means to disperse liquids and solids (such as powders or precursors) into tiny particles and suspend them in a carrier gas (usually air) to form a stable and controllable aerosol. The suction module 1 is a device used to provide negative pressure airflow; for example, a vacuum pump, diaphragm pump, smoke extractor, or negative pressure suction device can all provide negative pressure and can be flexibly selected according to different aerosol types and actual application scenarios to achieve aerosol suction. The collection module 3 can be a collector, various types of samplers, etc. The collection module 3 is connected between the aerosol generator 4 and the suction module 1. When the suction module 1 starts working, the aerosol generated by the aerosol generator 4 forms an airflow that passes through the aerosol generator 4 and the collection module 3 into the suction module 1. The collection module 3 dissolves or traps the aerosol through its built-in absorption medium, thereby achieving aerosol collection. The cryogenic circulation module 2 is equipped with a cooling pool, which can maintain a continuously low-temperature environment through its own cryogenic circulation system. The collection module 3 is placed in a cooling pool to achieve low-temperature cooling, maintaining the absorption medium and collected aerosols in the collection module 3 at a low temperature. This minimizes the loss of volatile substances in the aerosols, improves collection efficiency, and reduces detection errors. The flow calibration module, which can be various types of flow meters, volumetric calibrators, dynamic flow calibration systems, etc., is used to detect and calibrate the airflow rate, ensuring that the airflow rate remains within a preset range during each aerosol collection process.

[0024] For example, in this embodiment, the aerosol capturing device is used to capture benzene compounds in heated cigarette aerosol. Heated cigarettes, also known as heated non-combustible cigarettes (HNB), are a new type of tobacco product combining a heating device and a cartridge. The heating temperature of HNB is generally below 350°C, and it mainly generates aerosol through distillation and simple pyrolysis reactions. This significantly reduces harmful components produced by high-temperature combustion while largely preserving the flavor, taste, and throat hit of traditional tobacco, providing smokers with a smoking experience most similar to traditional cigarettes. Benzene compounds in heated cigarette aerosol refer to harmful benzene-based components including benzene, toluene, ethylbenzene, p / m-xylene, and o-xylene. Accurately measuring the benzene content in mainstream HNB smoke is of great significance. It should be noted that in this embodiment, the aerosol generator 4 is a heating device in an HNB (Heated Tobacco Unit), and the aerosol forming substance is an HNB cartridge. Since the device and the cartridge are detachable, the aerosol collection device is connected to the cartridge, specifically to the cartridge's outlet end. In other embodiments, the aerosol generating product is housed inside the aerosol generator, forming an integrated device, and the aerosol collection device is connected to the outlet end of the aerosol generator.

[0025] In one embodiment, to ensure that aerosols are fully captured, the collection module 3 includes at least two collectors 31, which are connected in series; wherein the first end is located in the rear collector 31 and the second end is located in the front collector 31.

[0026] In this embodiment, the collection module 3 includes two collectors 31, which are connected in series via silicone tubes and placed in the cooling pool of the cryogenic circulation module 2. One collector 31 is connected to the suction module 1 via a silicone tube, and the other collector 31 is connected to the aerosol generator 4 via a silicone tube. That is, both the suction module 1 and the aerosol generator 4 are connected to the collection module 3 via silicone tubes, thus forming a connected and sealed gas suction path from the aerosol generator 4, the two collectors 31, and then to the suction module 1.

[0027] In other embodiments, the number of collectors 31 in the collection module 3 may be two or more, such as three or four, with all collectors 31 connected in series to form the overall collection module 3. The first end of the collection module 3 is located at the rear collector 31, that is, at the rear end of the suction path and connected to the suction module 1. Here, "rear" refers to the rear end of the suction path; when the aerosol capture device is working, the aerosol suction path is from the aerosol generator 4, through the collection module 3, and then to the suction module 1. Therefore, the collector 31 at the rear end of the suction path is also the collector 31 closest to the suction module 1. The second end of the collection module 3 is located at the front collector 31, that is, at the front end of the suction path and connected to the aerosol generator 4. Here, "front" refers to the front end of the suction path, that is, the collector 31 closest to the aerosol generator 4.

[0028] By setting multiple collectors 31 in series to absorb benzene compounds in aerosols, multi-stage collection of benzene compounds can be achieved, ensuring that benzene compounds are fully absorbed and avoiding low detection results due to incomplete absorption in a single absorption or the absorption medium reaching saturation capacity during a single absorption, thereby improving the accuracy and reliability of the detection results. Secondly, compared with the scheme of using a "single collector with a larger volume of absorption medium", the method of using multiple collectors 31 in series results in more uniform and sufficient heat dissipation in the low temperature cycling module 2, making it easier to achieve uniform cooling.

[0029] In one embodiment, the flow calibration module is a soap film flow meter, which is connected in the gas path of the aerosol trapping device consisting of the suction module 1, the cryogenic circulation module 2, the collection module 3, and the aerosol generator 4. For example, the soap film flow meter can be connected between the aerosol generator 4 and the collection module 3. Since the suction flow rate of the suction module 1 changes after the collection module 3 is added, the suction flow rate of the suction module 1 needs to be calibrated every time the collection module 3 is changed for suction. In actual operation, the collection module 3 containing the absorption medium is placed in the cooling tank of the cryogenic circulation module 2, and after the temperature of the cryogenic circulation module 2 stabilizes, the flow rate of the suction module 1 can be calibrated using the soap film flow meter.

[0030] In one embodiment, the aerosol capture device further includes a clamping module 5 for fixing the aerosol generator 4. The clamping module 5 can be installed beside the cooling pool of the cryogenic circulation module 2 and is used to fix and support the aerosol generator 4, thereby increasing the stability of the aerosol generator 4.

[0031] For example, such as Figure 3 As shown, in this embodiment, the clamping module 5 includes a base 51, a support 52, and a clamping part 53. The base 51 is disposed beside the cooling pool of the low-temperature circulation module 2. The support 52 is fixed on the base 51 and is used to install the clamping part 53. Specifically, the support 52 includes two support rods 521, which are spaced apart and parallel to each other on the base 51. The clamping part 53 is installed on the support 52 and is used to clamp the aerosol generator 4. The clamping part 53 includes two threaded rods 531 and two clamping pieces 532. Each of the two threaded rods 531 has a screw handle 5311 at one end, which is threaded through the top of the two support rods 521. The screw handles 5311 at the ends of the two threaded rods 531 are located on opposite sides of the two support rods 521, and the other end of each of the two threaded rods 531 is provided with the clamping piece 532. Both clamping plates 532 are arc-shaped and located between the two support rods 521. The two clamping plates 532 are spaced apart and opposite to each other to clamp the two side walls of the aerosol generator 4 respectively. In use, the user can rotate the corresponding threaded rod 531 by turning the handle 5311 to adjust the distance between the two clamping plates 532, so as to clamp or remove the aerosol generator 4. In addition, the angle of the two clamping plates 532 can also be adjusted by turning the corresponding threaded rod 531 by turning the handle 5311, thereby changing the angle at which the aerosol generator 4 is clamped. For example, the aerosol generator 4 can be clamped vertically or at an angle.

[0032] Alternatively, in other embodiments, the base may be omitted, and the support 52 may be directly fixed to the side of the cooling pool of the low-temperature circulation module 2; the support 52 may also be a single vertical support rod 521, and the clamping part 53 may be a lever-type elastic clamp with two hinged arms, built-in torsion spring, which opens when pressed and closes when rebounded. The elastic clamp has a long handle that is fixedly installed to the top of the support rod 521.

[0033] By incorporating the clamping module 5, the aerosol generator 4 can be stably fixed, and its angle can be adjusted to facilitate the suction flow of negative pressure airflow. The clamping module 5 has a simple structure and is easy to operate.

[0034] In one embodiment, to maintain the cooling performance of the aerosol capture device, a heat insulation module is also included to cover the collection module 3. Specifically, in this embodiment, the heat insulation module is a wet towel, which covers the outer peripheral surface of the collector 31 of the collection module 3. Each collector 31 is covered with a wet towel, thereby insulating the collector 31 and further improving the cooling effect of the collector 31. In other embodiments, the heat insulation module can also be insulation cotton, heat insulation bag, sponge, foam board, etc.

[0035] In one embodiment, the aerosol generator 4 is a rechargeable heated aerosol generator. For example, in this embodiment, the aerosol generator 4 is a rechargeable heated smoking device in an HNB; the suction module 1 is a linear smoking machine, which is convenient to use.

[0036] According to another aspect of the present invention, the present invention also provides a method for detecting benzene series compounds in aerosols, the detection method comprising the following steps: Aerosol capture: The aforementioned aerosol capture device is used to extract and capture the generated aerosols from the aerosol-generating product. For the detection of benzene series compounds, gas chromatography-tandem mass spectrometry was used to perform qualitative and quantitative analysis of benzene series compounds in the captured aerosol samples to obtain the types and corresponding contents of benzene series compounds contained in the aerosol generated by the aerosol product to be tested.

[0037] Specifically, an aerosol generating product is loaded into aerosol generator 4. After aerosol generator 4 is started, the aforementioned aerosol trapping device is used to extract and trap the aerosols generated in aerosol generator 4 to prepare an aerosol sample. Then, gas chromatography-mass spectrometry (GC-MS) is used to perform chromatographic-mass spectrometric analysis on the standard working solution, aerosol sample, and blank control sample. The qualitative and quantitative detection of benzene series compounds in the aerosol sample by GC-MS mainly includes the key steps of chromatographic separation, mass spectrometry qualitative analysis, internal standard quantification, and blank control sample subtraction and correction. The standard working solutions contain known concentrations of various benzene compounds and a fixed concentration of internal standard. Standard working solutions of different concentration gradients are sequentially injected into the gas chromatography-mass spectrometry (GC-MS) instrument. Chromatographic conditions are set, and due to the different polarities and boiling points of the various benzene compounds and internal standard, their migration rates in the chromatographic column differ, resulting in peaks at different time points. Each benzene compound produces characteristic ion fragments after ionization. By comparing with a mass spectral library, the substance corresponding to each chromatographic peak can be identified. A standard curve is plotted using the known concentrations of the internal standard in the standard working solutions. Errors are eliminated using the peak area ratio of the target analyte to the internal standard, and background interference is subtracted through chromatographic analysis of a blank control sample. Finally, the types and corresponding contents of benzene compounds in the aerosol sample are calculated, yielding accurate and reliable results.

[0038] Compared with the prior art, the method for detecting benzene series compounds in aerosols provided in this application uses the absorption medium in the collection module 3 to capture benzene series compounds, which can simultaneously capture both gaseous and particulate benzene series compounds in aerosols, ensuring that benzene series compounds are fully absorbed and improving the capture efficiency. Secondly, the aerosol sample is cooled by the circulating cooling pool 2 to suppress the volatilization loss of benzene series compounds, thus solving the problem of incomplete capture and inaccurate detection structure caused by traditional methods.

[0039] In one embodiment, the aerosol capture step includes the following steps: Connect the aerosol collection device to the aerosol generator 4, start the suction module 1 and the aerosol generator 4, the aerosol generating product in the aerosol generator 4 is atomized and aerosol is generated, and the aerosol is partially or completely captured by the absorption medium as it passes through the collection module 3 with the negative pressure airflow.

[0040] Specifically, the second end of the suction module 3 in the aerosol collection device is connected to the aerosol generator 4, forming a connected airflow path between the aerosol generator 4 and the aerosol collection device. The suction module 1 is turned on, and the suction parameters are set. The low-temperature circulation module 2 is turned on and the cooling temperature is set, ensuring the cooling pool temperature reaches the set value. The collection module 3, pre-filled with the absorption medium, is placed and fixed in the cooling pool. The aerosol generator 4 is started to preheat, and then the aerosol-generated product is installed into the aerosol generator 4. The heating switch of the aerosol generator 4 is activated to atomize the aerosol-generated product and generate aerosols. Then, the suction module 1 is activated to generate negative pressure, and the aerosols are collected by the absorption medium as they pass through the collection module 3 with the negative pressure airflow, obtaining an aerosol sample. After suction is complete, the aerosol generator 4 can be removed, and the aerosol-generated product can be taken out. Multiple aerosol-generated products can be repeatedly suctioned to obtain one aerosol sample, depending on actual needs.

[0041] For example, in this embodiment, the aerosol-generating product uses an HNB (Heated Tobacco Bulb) cartridge (hereinafter referred to as a cartridge). The aerosol is captured by the aerosol capturing device, and the types and contents of benzene compounds in the aerosol are detected. The specific process is as follows: First, turn on the suction module 1 and set the suction parameters, including suction capacity, suction duration, suction interval, number of suction ports, and suction waveform. Then, preheat the suction module 1 for a predetermined time, such as 30 minutes. Suction capacity refers to the standard volume of aerosol extracted by the suction module 1 during a single suction, and is a core parameter for measuring the amount of vapor produced per puff. Suction duration refers to the length of time from the start to the end of a single suction action, simulating the duration of human inhalation. Suction interval refers to the pause between two adjacent suction actions. Number of suction ports refers to the total number of suctions required to complete a single cartridge. Suction waveform is the curve showing the flow rate change over time during a single suction, simulating the airflow rate variation during human inhalation. Turn on the low-temperature circulation module 2, set the cooling temperature of the cooling pool, and wait for the temperature to stabilize at the set value and fluctuate by no more than 1°C. Two collectors 31 containing 10ml of absorption medium are connected in series with silicone tubes to form a collection module 3. The collection module 3 is placed in the cooling pool of the low-temperature circulation module 2 and fixed. The suction module 1 and one of the collectors 31 are connected with silicone tubes. The aerosol generator 4 and the other collector 31 are connected with silicone tubes. At this time, the temperature of the low-temperature circulation module 2 will change. It is necessary to wait for a period of time until the temperature of the low-temperature circulation module 2 stabilizes again. In addition, a damp towel can be covered around the collection module 3 for insulation.

[0042] Place the working aerosol generator 4 on the clamping module 5, turn on the aerosol generator 4 to preheat, and after the aerosol generator 4 has finished preheating, insert the test cartridge into the aerosol generator 4; start the suction module 1, and after the entire cartridge is sucked out, remove the remaining filter of the cartridge and replace it with a new cartridge. Repeat the suction steps 3-5 times, which is 3 times in this embodiment.

[0043] The aerosols from three e-cigarette cartridges were collected in a set of absorbers to create a single aerosol sample. This was done to avoid the benzene content in the aerosols from a single cartridge falling below the limit of quantification, which would prevent accurate quantification. Furthermore, the aerosol sample required further processing: first, the collection module 3 was removed, and the absorption medium from both collectors 31 was poured into a 50ml centrifuge tube and placed on a shaker to mix. For example, the shaker was set to 2500 rpm for 30 minutes to thoroughly mix the absorption medium. After mixing, the centrifuge tube was removed, and the absorption medium was transferred to a 2ml brown chromatographic vial and placed in a -20℃ refrigerator for analysis.

[0044] To ensure the accuracy and rigor of the test, it is necessary to repeat the aforementioned steps to prepare multiple parallel samples and one blank control sample. The blank control sample is prepared by starting the suction module 1 according to the aforementioned steps, but without heating the tobacco cartridge. In other words, the suction module 1 draws in ambient air, rather than the aerosol produced after heating the tobacco cartridge.

[0045] In one embodiment, the absorption medium is selected from ethanol, isopropanol, methanol, and carbon disulfide. The absorption medium should be a solvent with high aerosol absorption rate, ensuring that both gaseous and particulate matter in the aerosol can be effectively dissolved or retained by the absorption medium. Ethanol, isopropanol, methanol, and carbon disulfide all have good absorption effects on benzene compounds in aerosols. Among them, methanol and carbon disulfide, as solvents, show similar absorption rates for benzene compounds and are superior to isopropanol and ethanol. The selection of the solvent should follow the principles of environmental friendliness, non-toxicity, and easy availability; therefore, methanol, with relatively low toxicity, is chosen as the solvent.

[0046] In one embodiment, during the aerosol collection step, the cooling temperature of the cooling pool is between -60°C and -20°C. Different temperatures have different effects on the collection of benzene compounds. When the cooling temperature in the cooling pool is set to between -60°C and -20°C, the collection efficiency of benzene compounds is high and the detection results are accurate.

[0047] In one embodiment, the method for preparing the standard working solution used in the gas chromatography-tandem mass spectrometry analysis during the benzene series compound detection step is as follows: (1) Accurately weigh 0.05 g of benzene-d6 as an internal standard into a 100 mL volumetric flask, accurate to 0.0001 g, and dissolve and dilute with methanol to prepare a 500 mg / L benzene-d6 internal standard stock solution; (2) Transfer 100 μL of benzene-d6 internal standard stock solution to a 100 mL glass volumetric flask and dilute to the mark with methanol to obtain an extraction solution with a concentration of 0.5 mg / L; (3) Accurately transfer 500 μL of benzene series standards dissolved in methanol and mixed with benzene, toluene, ethylbenzene, p / m-xylene and o-xylene into a 10 mL volumetric flask, dilute to the mark with extraction solution, and then transfer to a 10 mL capped brown storage bottle to obtain mixed standard stock solution. (4) The mixed standard stock solution was gradually diluted with the extraction solution to obtain an intermediate stock solution with a concentration of 1.0 mg / L. 50 μL, 100 μL, 200 μL, 500 μL and 1000 μL of the intermediate stock solution were accurately transferred to 10 mL volumetric flasks, and the volume was adjusted to the mark with the extraction solution. The mixture was mixed evenly to obtain 5 standard working solutions with different concentrations. The 5 different concentration values ​​were used as curve points to plot the standard working curve.

[0048] This application uses benzene-d6 as an internal standard, which is structurally similar and has close physicochemical properties to the target benzene series compounds (benzene, toluene, ethylbenzene, p / m-xylene, o-xylene), effectively offsetting systematic errors in sample pretreatment (such as shake extraction and transfer) and instrumental analysis. Benzene series standards are first prepared into a mixed standard stock solution, and then serially diluted with the extraction solution to obtain five different concentration curve points, providing a wide concentration coverage (gradual distribution from low to high), ensuring the linear correlation of the standard curve and meeting the quantitative requirements for different concentrations of benzene series compounds.

[0049] In one embodiment, in the benzene series compound detection step, the chromatographic analysis conditions are as follows: using a DB-624 column with dimensions of 30m × 250μm × 1.4μm, an injection port temperature of 250℃, an injection volume of 1μL, helium as the carrier gas, and split injection with a split ratio of 10:1. The column oven uses a programmed temperature rise method: the initial temperature is 50℃, held for 3 minutes; then it is raised to 100℃ at a rate of 10℃ / min, held for 2 minutes; then it is raised to 250℃ at a rate of 15℃ / min, held for 2 minutes.

[0050] Specifically, the DB-624 column (30m×250μm×1.4μm) was selected. It is designed specifically for the separation of volatile organic compounds (VOCs). Its stationary phase characteristics are highly matched with the physicochemical properties of benzene series compounds (benzene, toluene, ethylbenzene, etc.), which can effectively solve the separation problem caused by the similar structure and boiling point of the six benzene series compounds, ensuring that the peaks of each component are clear and non-overlapping, providing a basis for quantitative analysis.

[0051] The column oven employs a programmed temperature ramp, with an initial temperature of 50℃ held for 3 minutes to allow for the complete vaporization and initial separation of low-boiling-point components (such as benzene), avoiding peak overlap of early-eluting components. The temperature is then ramped up to 100℃ at a rate of 10℃ / min and held for 2 minutes to specifically separate medium-boiling-point toluene and ethylbenzene, balancing separation efficiency and analysis speed. Finally, the temperature is ramped up to 250℃ at a rate of 15℃ / min and held for 2 minutes to rapidly elute high-boiling-point impurities, preventing residual contamination of the column and shortening subsequent detection time. This entire temperature ramp program ensures complete separation of the six benzene compounds while keeping the total analysis time within a reasonable range, balancing separation quality and detection efficiency.

[0052] In one embodiment, in the benzene series compound detection step, the mass spectrometry analysis conditions are as follows: the ion source is an EI (Electron Impact Ionization Source) source, with a temperature of 230°C, an ionization energy of 70 eV, a quadrupole temperature of 150°C, and a transfer line temperature of 250°C. The mass spectrometry is performed in segmented scanning mode using SIM (Selected Ion Monitoring) to quantitatively analyze characteristic ions. The characteristic ion information for the six benzene series compounds is shown in Table 1. Table 1 Characteristic ion information of target compounds An EI (electron impact ionization) source was selected, with an ionization energy set to 70 eV, which is the standard ionization condition for organic compound mass spectrometry analysis. This energy ensures sufficient ionization of the six benzene series compounds (benzene, toluene, etc.) to generate characteristic fragment ions, while avoiding cluttered ion peaks caused by over-ionization, facilitating the identification of characteristic ions. The ion source temperature was set at 230℃, the quadrupole temperature at 150℃, and the transfer line temperature at 250℃. This parameter combination is reasonable; the high-temperature transfer line prevents condensation of sample components during transmission, the quadrupole temperature environment reduces noise interference, and the ion source temperature is adapted to the volatility of benzene series compounds, ensuring stable ionization efficiency and improving the detection signal intensity.

[0053] In one embodiment, the detection method further includes a flow calibration step, which is performed before each sample collection to ensure that the aerosol flow rate is a preset value.

[0054] Because the suction flow rate of suction module 1 changes after the addition of collection module 3, the suction flow rate of suction module 1 needs to be calibrated every time collection module 3 is replaced for suction. In actual operation, collection module 3, which contains the absorption medium, is placed in the cooling tank of cryogenic circulation module 2. After the temperature of cryogenic circulation module 2 stabilizes again, the flow calibration module is used to calibrate the flow rate of suction module 1 so that the aerosol flow rate reaches the preset value. The preset value can be determined according to the suction standard adopted.

[0055] Specifically, in this embodiment, after the two collectors 31 of the collection module 3 are placed in the cooling pool, when the temperature of the low temperature circulation module 2 stabilizes again to the set value and the fluctuation does not exceed 1°C, the flow rate of the suction module 1 is calibrated using a soap film flow meter so that the aerosol flow rate is the preset 55mL.

[0056] In one embodiment, in the aerosol capture step, after each aerosol-generated product is extracted, the aerosol-generated product is removed from the aerosol generator 4 and weighed. The aerosol generator 4 is then charged and cooled down so that the aerosol generator 4 is fully charged and at room temperature when each aerosol product is extracted.

[0057] For example, in this embodiment, after each cartridge is smoked, it is removed from the aerosol generator 4 and weighed. This allows the accuracy of the final benzene content test result to be verified by the change in the weight of the cartridge. After each cigarette is smoked, the aerosol generator 4 is charged and cooled to room temperature. This ensures that the aerosol generator 4 operates well and consistently each time it is smoked, thereby eliminating operational errors in the detection process.

[0058] Example 1 A method for detecting benzene series compounds in aerosols, comprising: Step 1), turn on suction module 1, set suction parameters including suction capacity, suction duration, suction interval, number of suction ports and suction waveform, and preheat suction module 1 for 30 minutes. Step 2), turn on the low temperature circulation module 2, set the cooling temperature to -20℃, and wait for the temperature value to stabilize and fluctuate by no more than 1℃. Step 3) Connect the two collectors 31 containing 10 mL of absorption medium in series with silicone tubes, place them in the cooling pool of the low temperature circulation module 2 and fix them in place, and cover the collectors 31 with wet towels to keep them warm. Step 4) Connect one of the collectors 31 of the suction module 1 and the collection module 3 with a silicone tube; Step 5): After the temperature of the low-temperature circulation module 2 stabilizes again, calibrate the aerosol flow rate using a soap film flow meter. Step 6): Weigh the HNB cartridge to be tested and insert it into the aerosol generator 4. Connect the cartridge on the aerosol generator 4 to another collector 31 in the collection module 3 using a silicone tube. Step 7) Turn on the aerosol generator 4 to preheat. Once the aerosol generator 4 has finished preheating, immediately start the suction button on the suction module 1, and then place the working aerosol generator 4 on the clamping module 5. Step 8): After vaping the HNB cartridge, remove the aerosol generator 4 from the collection module 3, weigh the HNB cartridge, charge and cool the aerosol generator 4 to ensure that the aerosol generator 4 is fully charged and at room temperature before each vaping step. Step 9), repeat steps 7) and 8), inhale 3 HNB cartridges to complete the collection of one HNB aerosol sample; Step 10): Remove the collection module 3, pour all the absorption medium in the collector 31 into a 50 mL centrifuge tube, place it on a shaker and shake at 2500 r / min for 30 min. After completion, remove the centrifuge tube and put the absorption medium into a 2 mL brown chromatographic bottle to obtain an aerosol sample. Step 11): Under this cooling temperature (-20℃) condition, the low-temperature cycling module 2 prepares 3 parallel samples and one blank control sample by suction. Step 12): Perform chromatographic-mass spectrometric analysis on the standard working solution, parallel samples, and blank control samples using a gas chromatography-mass spectrometry system. Step 13), standard curve plotting and result calculation.

[0059] Example 2 Compared with Example 1, the difference in Example 2 is that in steps 2) and 11), the cooling temperature of the low-temperature circulation module 2 is set to -40°C.

[0060] Example 3 Compared with Example 1, the difference in Example 3 is that in steps 2) and 11), the cooling temperature of the low-temperature circulation module 2 is set to -60°C.

[0061] Example 4 Compared with Example 1, the difference in Example 4 is that in steps 2) and 11), the cooling temperature of the low-temperature circulation module 2 is set to -80°C.

[0062] Comparative Example 1 Compared with Example 1, the difference of Comparative Example 1 is that Comparative Example 1 does not have the low temperature cycle module 2 turned on.

[0063] Table 2 shows the determination results of benzene series compounds in aerosols in various embodiments and comparative examples of this application: Table 2. Results of benzene series compounds determination under different temperature conditions (unit: ng / vial) Analysis of the data in Table 2 shows that six benzene series compounds were detected in all samples. Compared with the room temperature collection conditions in Comparative Example 1, lowering the collection temperature resulted in the collection of more benzene series compounds. At -20℃, the detected benzene series compound content was significantly higher than at room temperature. When the temperature dropped to -40℃, the contents of toluene and ethylbenzene increased significantly, except for ethylbenzene, p / m-xylene, and o-xylene, which did not increase significantly. However, as the temperature continued to decrease, the benzene series compound content tended to decrease. Therefore, to reduce energy consumption and maintain maximum collection efficiency, a collection temperature range of -20℃ to -60℃ is preferable, with -40℃ being the optimal collection temperature.

[0064] To verify the precision of the test results under the conditions of Example 2 (i.e., the cooling temperature of the low-temperature cycling module 2 is -40°C), this application also prepared 6 parallel samples under the conditions of Example 2 and performed tests. The measured data and precision are shown in Table 3 below: Table 3. Data (ng / vial) and precision of 6 parallel determinations at -40℃. As shown in Table 3, when measured in parallel at -40℃ for 6 times, the RSD of each target compound was less than 5%, indicating good precision.

[0065] To verify the accuracy of the conditions and detection method in Example 2 above, standard working solutions with concentrations of 10 ng / mL, 50 ng / mL, and 100 ng / mL (low, medium, and high) were used as absorption media. Three spiked samples were aspirated and analyzed according to the detection method in Example 2 above. The recovery rates of various benzene series compounds are shown in Table 4 below: Table 4. Method recovery rate (%) As shown in Table 4, the recoveries of each target compound at low, medium, and high concentrations are all within the range of 90%-110%, which is within the acceptable range for trace organic compound detection. This indicates that the detection method of this application has high authenticity and the detection results are reliable.

[0066] The technical solution provided in this application enables aerosol collection under different low-temperature conditions, while ensuring more stable temperature during long-term aerosol collection, reducing errors in the detection process, and improving the accuracy of the detection results.

[0067] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. An aerosol collection device for collecting aerosols generated by an aerosol generator, characterized in that, include: The suction module is used to provide negative pressure airflow; The collection module has a first end and a second end, and the inside of the collection module is filled with an absorption medium for dissolving or trapping aerosols; the low-temperature circulation module is equipped with a cooling pool. A flow calibration module is used to balance the flow range for each aerosol capture process; The collection module is detachably placed in the cooling pool to cool the absorption medium in a low-temperature environment. The first end is in fluid communication with the suction module, and the second end is in fluid communication with the aerosol generator, so that the negative pressure airflow passes through the aerosol generator and the collection module in sequence and enters the suction module.

2. The collection device as described in claim 1, characterized in that, The collection module includes at least two collectors, which are connected in series; wherein the first end is located in the rear collector and the second end is located in the front collector.

3. The aerosol collection device as described in claim 1, characterized in that, The aerosol collection device also includes a clamping module for fixing the aerosol generator.

4. The aerosol collection device as described in claim 1, characterized in that, The aerosol collection device also includes a heat insulation module for covering the collection module.

5. A method for detecting benzene series compounds in aerosols, characterized in that, The detection method includes the following steps: Aerosol capture, wherein the aerosol generated by the aerosol-generating product of the aerosol under test is drawn and captured using the capture device as described in any one of claims 1-4; For the detection of benzene series compounds, gas chromatography-tandem mass spectrometry was used to perform qualitative and quantitative analysis of benzene series compounds in the captured aerosol samples to obtain the types and corresponding contents of benzene series compounds contained in the aerosol generated by the aerosol product to be tested.

6. The method for detecting benzene series compounds in aerosols as described in claim 5, characterized in that, The aerosol capture step includes the following steps: Connect the aerosol collection device to the aerosol generator, start the suction module and the aerosol generator, the aerosol generating product in the aerosol generator is atomized and generates aerosols, and the aerosols are partially or completely collected by the absorption medium as they pass through the collection module with the negative pressure airflow.

7. The method for detecting benzene series compounds in aerosols as described in claim 5, characterized in that, It also includes a flow calibration step, which must be performed before each sample collection to ensure that the aerosol flow rate is at a preset value.

8. The method for detecting benzene series compounds in aerosols as described in claim 5, characterized in that, The absorption medium is selected from one of ethanol, isopropanol, methanol, and carbon disulfide.

9. The method for detecting benzene series compounds in aerosols as described in claim 5, characterized in that, During the aerosol capture process, the cooling temperature of the cooling pool is -60℃ to -20℃.

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