Filter enrichment detection device and detection method for cigarette aerosol

Abstract

The application discloses a filter enrichment detection device, which comprises a filter enrichment device and a detection device. The filter enrichment device comprises a multi-stage filter device (11), an enrichment diffusion resolution device (12) and a suction pump (13). The detection device comprises a single-photon ionization time-of-flight mass spectrometer (21) and an orbitrap mass spectrometer. The application also discloses a detection method for cigarette aerosol by using the device. The device can accurately determine the content of harmful substances and main components in the cigarette aerosol.

Description

A filtration enrichment detection device and a method for detecting cigarette aerosols. Technical Field

[0001] This invention belongs to the field of tobacco technology, specifically relating to a filter enrichment detection device and a method for detecting cigarette aerosols. Background Technology

[0002] The composition of cigarette aerosols is extremely complex, typically including organic compounds such as hydrocarbons, aldehydes, ketones, and heterocyclic compounds; inorganic gases such as carbon dioxide, carbon monoxide, and nitrogen oxides; and particulate matter. To date, more than 5,000 components have been detected in cigarette aerosols, and their types and quantities continue to increase over time. The aerosols produced by cigarette combustion damage the respiratory system of smokers, becoming one of the leading causes of lung cancer and chronic obstructive pulmonary disease. Long-term inhalation of large amounts of secondhand smoke can also easily lead to various health problems, such as weakened immune function and endocrine disorders.

[0003] The compounds in cigarette aerosols possess certain unique characteristics and have low sample throughput, requiring detection technologies with high sensitivity and selectivity. Existing conventional detection and analysis techniques for cigarette aerosols include chromatography and mass spectrometry. Among these, gas chromatography and liquid chromatography-mass spectrometry (LC-MS) are two commonly used methods for detecting compounds in aerosols. However, due to the complex composition and low concentration of aerosol samples, it is often necessary to combine these methods with other pretreatment methods during instrumental analysis to extract the components as completely as possible and improve the method's sensitivity. Commonly used pretreatment methods include liquid-liquid extraction and solid-phase microextraction, but these methods generally suffer from cumbersome procedures and long processing times, making rapid sample analysis difficult.

[0004] In the analysis of cigarette aerosol components, current research focuses primarily on the determination of individual organic compounds, inorganic substances, or particulate matter size distribution, lacking a device capable of comprehensively and effectively analyzing all aerosol components. Single-photon ionization mass spectrometry (SPES) is an online monitoring technique for volatile organic compounds based on photoionization technology. This technique boasts advantages such as broad-spectrum soft ionization, fewer fragment peaks, high sensitivity, and short response time, enabling real-time online detection of complex samples. However, currently, there is no device available for processing aerosols at the front end of a real-time online SPES sample introduction system. Such a device could collect, transmit, filter, and detect aerosols generated from the natural combustion of cigarettes, providing a rapid, accurate, and effective method for accurately determining the content of harmful substances and their main components in cigarette aerosols. Meanwhile, single-photon ionization mass spectrometry can only detect and analyze volatile organic compounds with ionization energies less than 10.6 eV. However, cigarette aerosol contains more than 5,000 components. Therefore, using only single-photon ionization mass spectrometry cannot completely detect all the components in cigarette aerosol, and it is necessary to combine it with other instruments for detection.

[0005] This invention is proposed for this purpose. Summary of the Invention

[0006] This invention discloses a filtration enrichment detection device and a method for detecting cigarette aerosols. The device of this invention uses a multi-layer membrane filtration system to collect, transport, filter, and detect cigarette aerosols generated by the natural combustion of cigarettes.

[0007] The technical solution of the present invention is as follows:

[0008] The first aspect of the present invention discloses a filtration enrichment detection device, which includes a filtration enrichment device and a detection device.

[0009] The filtration and enrichment device includes: a multi-stage filtration device 11, an enrichment diffusion desorption device 12, and an air pump 13.

[0010] The detection apparatus includes a single-photon ionization time-of-flight mass spectrometer 21 and an orbital trap mass spectrometer.

[0011] Preferably, the multi-stage filtration device 11 comprises multiple filtration membrane devices connected in series. Each filtration membrane device includes a sheet membrane 111, a membrane support mesh 112, an O-ring 113, and a sealing plate 114. Each filtration membrane device is sealed except for one air inlet and one air outlet. The membrane support mesh 112 is formed by stacking multiple sheet membrane support meshes sequentially, and can hold one, two, or more sheet membranes 111, which can be freely combined as needed. The modular design facilitates the replacement of damaged particulate filter membranes. The membrane support mesh 112 increases the pressure difference that the sheet membranes 111 can withstand, preventing damage to the sheet membranes 111. A sealing O-ring 113 is provided on the sheet membrane 111, and the sealing O-ring 113 is fastened on top for sealing. A multi-stage membrane structure can be established according to actual conditions, which can be single-stage, two-stage, or even more stages.

[0012] Preferably, the air inlet of the first filter membrane device in the series of multiple filter membrane devices is an aerosol inlet 3 for the aerosol inlet of the cigarette sample 4. A carrier gas inlet 31 is provided on the side wall of the aerosol inlet 3. The carrier gas is helium or nitrogen. The carrier gas carries the sample gas to the surface of the sheet membrane 111. Finally, the sample gas diffuses into the mass spectrometer inlet after passing through the sheet membrane 111 for analysis. Excess sample gas is extracted and discharged through the aerosol outlet by the vacuum pump 13. The air outlet of the last filter membrane device in the series of multiple filter membrane devices is connected to the enrichment diffusion desorption device 12. One end of the enrichment diffusion desorption device 12 is connected to the vacuum pump 13, and the other end is connected to the single-photon ionization time-of-flight mass spectrometer 21.

[0013] Preferably, the enrichment diffusion desorption device 12 includes an organic semi-permeable membrane under vacuum; the organic semi-permeable membrane is one of polydimethylsiloxane membrane (PDMS), polytetrafluoroethylene membrane, cellulose membrane or polyethylene membrane, and can be selected according to the target molecule; generally, the membrane thickness is 0.05 mm.

[0014] Preferably, the sheet membrane 111 has a pore size of 0.01~10.0 μm and a thickness of 20-300 μm; the sheet membrane 111 is made of glass fiber, polytetrafluoroethylene, or other self-made composite fiber membranes, or other commercial membranes; the sheet membrane can filter ultrafine particles of 10 μm, 1 μm, 0.1 μm, and 0.01 μm in sequence.

[0015] Preferably, the carrier gas is helium, nitrogen, or a mixture of both; other inert gases may also be used.

[0016] Preferably, the flow rate of the air pump 13 is 30 mL / min ~ 40 mL / min.

[0017] A second aspect of this invention discloses a method for detecting cigarette aerosols, using the aforementioned apparatus, comprising the following steps:

[0018] The vacuum pump 13 is turned on; the cigarette sample 4 is ignited, and the generated aerosol enters through the aerosol inlet 3, while carrier gas is simultaneously introduced through the carrier gas inlet 31; the aerosol and carrier gas mixture enters the filter membrane device, and after being filtered by multiple filter membrane devices, the aerosol and carrier gas mixture is enriched by the organic semi-permeable membrane in the enrichment-diffusion-desorption device 12, and after diffusion and desorption, it enters the single-photon ionization time-of-flight mass spectrometer 21 for analysis; excess sample gas aerosol and carrier gas mixture are extracted and discharged by the vacuum pump; the ionization source of the single-photon ionization time-of-flight mass spectrometer 21 uses a vacuum ultraviolet krypton lamp with a single photon energy of 10.6 kilocalories. eV; The analyzer uses a vertically introduced reflective time-of-flight mass spectrometer; The single-photon ionization time-of-flight mass spectrometer 21 sample introduction process is as follows: The sample introduction process of an organic semi-permeable membrane such as PDMS membrane is divided into three steps: enrichment—diffusion—desorption; 1. The PDMS membrane selectively enriches the sample to be tested; 2. The sample to be tested diffuses into the membrane with a concentration gradient; 3. The sample to be tested desorbs and desorbs on the high vacuum side under the action of pressure difference; The PDMS membrane has a certain enrichment effect on sample molecules, which can ensure the high sensitivity of the mass spectrometer to a certain extent (generally tens to hundreds of times that of the injection injection method); During the diffusion process, different sample molecules have different solubilities in the membrane. Under the action of pressure difference on both sides of the membrane, the sample with high solubility is enriched on the high vacuum side, and then enters the mass spectrometer for ionization detection and analysis.

[0019] Organic compounds enriched on sheet membrane 111 were eluted using an organic solvent, and the eluent was analyzed using an orbital trap mass spectrometer to qualitatively determine the types of organic compounds in the eluent.

[0020] Preferably, the organic solvent is methanol, acetonitrile, or a mixture of both, and the eluent is filtered using a 0.22 μm filter membrane. A certain amount of organic solvent, such as methanol / acetonitrile, is used to ultrasonically extract the enriched sheet membrane 111 multiple times, and the extracts are combined. Nitrogen is blown to near dryness, and then organic solvent is added to dissolve the residue. The mixture is vortexed for 1 min and filtered using a 0.22 μm filter membrane. The filtered eluent is then used for analysis by an orbital trap mass spectrometer.

[0021] The beneficial effects of this invention are:

[0022] This invention relates to a filtration enrichment and detection device, which, in conjunction with the operating conditions of a real-time online single-photon ionization mass spectrometer, designs a multi-stage membrane device capable of collecting, transporting, and filtering aerosols generated from the natural combustion of cigarettes. This device effectively overcomes the problem of residue in the membrane sample introduction device of the single-photon ionization mass spectrometer caused by excessively high concentrations of cigarette aerosol particles. Simultaneously, by eluting the sheet-like membrane of this device with organic solvents and combining it with orbital trap mass spectrometry for detection, qualitative analysis of organic compounds in cigarette aerosols can be performed. This provides a rapid, accurate, and effective method for accurately determining the content of harmful substances and their main components in cigarette aerosols. The filtration enrichment and detection device of this invention introduces N2 / He into the multi-stage membrane device; N2 / He serves as both a carrier gas, carrying the aerosol into the sample introduction end of the single-photon ionization mass spectrometer, and also diluting the aerosol to a certain extent; simultaneously, as the aerosol passes through the surface of the multi-stage membrane, the membrane also enriches the components in the aerosol, further diluting it to the ppb level. Attached Figure Description

[0023] Figure 1 is a schematic diagram of the filtration enrichment detection device of the present invention.

[0024] Figure 2 is a schematic diagram of a single filter membrane device.

[0025] Figure 3 is a flowchart of the method for detecting cigarette aerosols using the apparatus of the present invention.

[0026] Figure 4 shows the detection results of cigarette aerosol using the device of the present invention in an embodiment.

[0027] The attached figures are labeled as follows: 11, multi-stage filtration device; 111, sheet membrane; 112, membrane support mesh; 113, O-ring; 114, sealing and fixing plate; 12, enrichment diffusion desorption device; 13, air pump; 21, single-photon ionization time-of-flight mass spectrometer; 3, aerosol inlet; 4, cigarette sample. Detailed Implementation

[0028] The present invention will be further described in detail below through specific embodiments, but it should not be construed as limiting the scope of the invention to the following examples. Various substitutions and modifications made based on ordinary technical knowledge and conventional methods in the art without departing from the above-described methodological spirit of the invention should be included within the scope of the invention.

[0029] As shown in Figure 1, the present invention provides a filtration enrichment detection device, which includes a filtration enrichment device and a detection device; the filtration enrichment device includes a multi-stage filtration device 11, an enrichment diffusion desorption device 12 and a vacuum pump 13; the detection device includes a single-photon ionization time-of-flight mass spectrometer 21 and an orbital trap mass spectrometer (not shown in the figure). The multi-stage filtration device 11 comprises multiple filtration membrane devices connected in series. Each filtration membrane device includes a sheet membrane 111, a membrane support mesh 112, an O-ring 113, and a sealing plate 114. Each filtration membrane device is sealed except for one air inlet and one air outlet. The membrane support mesh 112 is formed by stacking multiple sheet membrane support meshes sequentially, and can hold one, two, or more sheet membranes 111, which can be freely combined as needed. The modular design facilitates the replacement of damaged particulate filter membranes. The membrane support mesh 112 increases the pressure difference that the sheet membranes 111 can withstand, preventing damage to the sheet membranes 111. A sealing O-ring 113 is provided on the sheet membrane 111, and the sealing O-ring 113 is fastened on top for sealing. A multi-stage membrane structure can be set according to actual conditions, which can be single-stage, two-stage, or even more stages. This invention sets three filtration membrane devices, each containing one sheet membrane 111.

[0030] The first filter membrane device in the series of multiple filter membrane devices has an air inlet 3 for the aerosol inlet of the cigarette sample 4. A carrier gas inlet 31 is provided on the side wall of the aerosol inlet 3. The carrier gas is helium or nitrogen. The carrier gas carries the sample gas to the surface of the sheet membrane 111. Finally, the sample gas diffuses into the mass spectrometer inlet after passing through the sheet membrane 111 for analysis. Excess sample gas is discharged through the aerosol outlet by the vacuum pump. The air outlet of the last filter membrane device in the series of multiple filter membrane devices is connected to the enrichment diffusion desorption device 12. One end of the enrichment diffusion desorption device 12 is connected to the vacuum pump 13, and the other end is connected to the single-photon ionization time-of-flight mass spectrometer 21. The filtration and detection device for cigarette aerosols of the present invention introduces N2 / He into a multi-stage membrane device; N2 / He serves as both a carrier gas, carrying the cigarette aerosols into the sample inlet of the single-photon ionization mass spectrometer, and also has a certain degree of dilution effect on the aerosols; at the same time, as the cigarette aerosols pass through the surface of the multi-stage membrane, the membrane also enriches the components in the aerosols, which also plays a dilution role, diluting them to the ppb level.

[0031] The enrichment diffusion desorption device 12 includes an organic semi-permeable membrane under vacuum; the organic semi-permeable membrane is one of polydimethylsiloxane membrane (PDMS), polytetrafluoroethylene membrane, cellulose membrane, or polyethylene membrane, and can be selected according to the target molecule; generally, the membrane thickness is 0.05 mm. This invention selects a PDMS membrane with a thickness of 0.05 mm as the organic semi-permeable membrane.

[0032] The sheet-like membrane 111 has a pore size of 0.01~10.0 μm and a thickness of 20-300 μm. The sheet-like membrane 111 is made of glass fiber, polytetrafluoroethylene (PTFE), other self-made composite fiber membranes, or other commercially available membranes. The sheet-like membrane can sequentially filter ultrafine particles of 10 μm, 1 μm, 0.1 μm, and 0.01 μm. In this invention, a polytetrafluoroethylene membrane is selected as the sheet-like membrane 111, with pore sizes of 10 μm, 1 μm, 0.1 μm, and 0.01 μm, and a thickness of 100 μm for each size.

[0033] The flow rate of the air pump 13 is 30 mL / min ~ 40 mL / min.

[0034] The method for detecting cigarette aerosols using the aforementioned filter enrichment detection device includes the following steps:

[0035] The vacuum pump 13 is turned on; the cigarette sample 4 is ignited, and the generated aerosol enters through the aerosol inlet 3, while carrier gas is simultaneously introduced through the carrier gas inlet 31; the aerosol and carrier gas mixture enters the filter membrane device, and after being filtered by multiple filter membrane devices, the aerosol and carrier gas mixture is enriched by the organic semi-permeable membrane in the enrichment-diffusion-desorption device 12, and after diffusion and desorption, it enters the single-photon ionization time-of-flight mass spectrometer 21 for analysis; excess sample aerosol and carrier gas mixture are extracted and discharged by the vacuum pump; the ionization source of the single-photon ionization time-of-flight mass spectrometer 21 uses a vacuum ultraviolet krypton lamp, and the single photon energy is 10.6 kilocalories. eV; The analyzer uses a vertically introduced reflective time-of-flight mass spectrometer; The single-photon ionization time-of-flight mass spectrometer 21 sample introduction process is as follows: The sample introduction process of an organic semi-permeable membrane, such as a PDMS membrane, is divided into three steps: enrichment—diffusion—desorption; First, the PDMS membrane selectively enriches the sample to be tested; Second, the sample to be tested diffuses into the membrane with a concentration gradient; Third, the sample to be tested desorbs and desorbs on the high vacuum side under the action of pressure difference; The PDMS membrane has a certain enrichment effect on sample molecules, which can ensure the high sensitivity of the mass spectrometer to a certain extent (generally tens to hundreds of times that of the injection injection method); During the diffusion process, different sample molecules have different solubilities in the membrane. Under the action of pressure difference on both sides of the membrane, the sample with high solubility is enriched on the high vacuum side, and then enters the mass spectrometer for ionization detection and analysis.

[0036] Organic compounds enriched on sheet membrane 111 were eluted using an organic solvent. The eluent was then analyzed using an orbital trap mass spectrometer to qualitatively determine the types of organic compounds in the eluent. The orbital trap mass spectrometer is not shown in the figure.

[0037] The organic solvents selected were methanol, acetonitrile, or a mixture of both. The eluent was filtered using a 0.22 μm filter membrane. A certain amount of organic solvent, such as methanol / acetonitrile, was used to ultrasonically extract the enriched sheet membrane 111 multiple times, and the extracts were combined. The membrane was purged with nitrogen until nearly dry, and then an organic solvent was added to dissolve the residue. The mixture was vortexed for 1 min and filtered using a 0.22 μm filter membrane. The filtered eluent was then used for analysis by an orbital trap mass spectrometer.

[0038] The device of this invention, combining a real-time online single-photon ionization mass spectrometer and an orbital trap mass spectrometer, can accurately determine the content of harmful substances and their main components in cigarette aerosol. The results are shown in Figure 4.

[0039] The embodiments described are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. 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.

Claims

1. A filtration enrichment detection device, characterized in that, It includes a filtration and enrichment device and a detection device; The filtration and enrichment device includes: a multi-stage filtration device (11), an enrichment diffusion desorption device (12), and a vacuum pump (13); the detection device includes a single-photon ionization time-of-flight mass spectrometer (21) and an orbital trap mass spectrometer; the multi-stage filtration device (11) consists of multiple filtration membrane devices connected in series, each filtration membrane device including a sheet membrane (111), a membrane support mesh (112), an O-ring (113), and a sealing plate (114); each filtration membrane device is sealed except for one air inlet and one air outlet; the sheet membrane (111) has a pore size of 0.01~10.0 μm and a thickness of 20-300 μm. μm; the sheet membrane (111) is made of glass fiber or polytetrafluoroethylene; the air inlet of the first filter membrane device in the series of multiple filter membrane devices is an aerosol inlet (3) for the aerosol inlet of the cigarette sample (4), and a carrier gas inlet (31) is provided on the side wall of the aerosol inlet (3); the air outlet of the last filter membrane device in the series of multiple filter membrane devices is connected to the enrichment diffusion desorption device (12), one end of the enrichment diffusion desorption device (12) is connected to the air pump (13), and the other end is connected to the single photon ionization time-of-flight mass spectrometer (21); the enrichment diffusion desorption device (12) includes an organic semi-permeable membrane in a vacuum state; the organic semi-permeable membrane is one of polydimethylsiloxane membrane, polytetrafluoroethylene membrane, cellulose membrane or polyethylene membrane.

2. The apparatus according to claim 1, characterized in that, The carrier gas is helium, nitrogen, or a mixture of both.

3. The apparatus according to claim 1, characterized in that, The flow rate of the air pump (13) is 30 mL / min ~ 40 mL / min.

4. A method for detecting cigarette aerosol, characterized in that, Using the apparatus according to any one of claims 1-3, the following steps are included: turning on the vacuum pump (13); igniting the cigarette sample (4), the generated aerosol enters through the aerosol inlet (3), and at the same time, carrier gas is introduced from the carrier gas inlet (31); the aerosol and carrier gas mixture enters the filter membrane device, and after being filtered by multiple filter membrane devices, the aerosol and carrier gas mixture is enriched by the organic semi-permeable membrane in the enrichment diffusion desorption device (12), and after diffusion and desorption, it enters the single photon ionization time-of-flight mass spectrometer (21) for analysis; excess sample gas aerosol and carrier gas mixture are discharged by the vacuum pump; the organic compounds enriched on the sheet membrane (111) are eluted using an organic solvent, and the eluent is measured using an orbital trap mass spectrometer to qualitatively determine the types of organic compounds in the eluent.

5. The detection method according to claim 4, characterized in that, The organic solvent is methanol, acetonitrile, or a mixture of both, and the eluent is filtered using a filter membrane with a pore size of 0.22 μm.

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