Method for analyzing and identifying squalene ozonation gas phase and particle phase products

Abstract

The invention belongs to the technical field of biomedicine in the aspect of human health, and particularly relates to a method for analyzing and identifying squalene ozonation gas-phase and particle-phase products. The method specifically comprises the following steps: firstly, introducing ozone with a certain concentration into a sampling bag, and then injecting a squalene standard solution, so that squalene reacts with the ozone; then, a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) is used for collecting and analyzing the composition and concentration of a gas phase product of the reaction, and an aerosol chemical component real-time analysis sample introduction system (CHARON) is used for collecting and analyzing the composition and concentration of a particle phase product of the reaction in combination with the PTR-TOF-MS. According to the method, the gas-solid distribution characteristic research of the squalene ozonation product can be perfected, and a reference basis is provided for the research of indoor peculiar smell and indoor environment health effect.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical technology in the field of human health, and more specifically, relates to a method for analyzing and identifying gas phase and particle phase products of squalene ozone oxidation. Background Art

[0002] Ozone is one of the common pollutants in the atmospheric environment. It can enter the indoor environment from the outdoors through ventilation. Due to the large specific surface area and many reactive substances in the indoor environment, ozone is more likely to react and release some volatile organic products or particulate organic products, which seriously affect the indoor air quality. There are a large number of unsaturated compounds in human skin oil, such as squalene, sterols, unsaturated fatty acids, wax esters, triglycerides, etc. Among them, squalene is the most abundant component in human skin oil and is also the main reactant of indoor ozone. The reaction between human skin oil and ozone will produce gas phase products and particulate phase products. Among them, the gas phase products mainly include 6-methyl-5-heptene-2-one (6-MHO) and 4-oxopentanal (4-OPA), which will irritate the human skin and respiratory system; the particulate phase products include 4-methyl-4-octene-1,8-diol (4-MOD) and 4-methyl-8-oxo-4-nonenal (4-MON), etc., which will increase the incidence of lung diseases and cardiovascular diseases, greatly endangering human health and indoor air quality. However, there are few studies on the products generated by the reaction between skin oil (mainly squalane) and ozone, the gas-solid distribution characteristics are still unclear, and the specific reaction mechanism and reaction products are not clearly understood, which is very unfavorable for indoor air treatment.

[0003] Therefore, identifying the products of the reaction between squalane and ozone plays an important role in improving the mechanism of ozonation reaction and is of great significance to the control of air pollution. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of the prior art and provide a method for analyzing and identifying the gas phase and particle phase products of squalene ozone oxidation.

[0005] The object of the present invention is to provide application of the method in indoor air quality monitoring.

[0006] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for analyzing and identifying gas phase and particle phase products of squalene ozone oxidation, comprising the following steps:

[0008] S1. Sampling bag to collect gas phase products and particle phase products of the reaction between squalene and ozone;

[0009] S2. Proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) collects and analyzes the composition and concentration of gas phase products in the S1 sampling bag;

[0010] S3. Aerosol chemical composition real-time analysis sampling system combined with proton transfer reaction time-of-flight mass spectrometer to collect and analyze the composition and concentration of particle phase products in the S1 sampling bag;

[0011] Among them, the mass-to-charge ratio m / z of the proton transfer reaction time-of-flight mass spectrometer is 27-400; the detection limit of the proton transfer reaction time-of-flight mass spectrometer is <10pptv; and the thermal desorption temperature of the aerosol chemical composition real-time analysis injection system is 80-150°C.

[0012] The present invention utilizes a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) and an aerosol chemical composition real-time analysis sampling system combined with a proton transfer reaction time-of-flight mass spectrometer (CHARON-PTR-TOF-MS) system, which can simultaneously detect particle phase products and gas phase products generated by the reaction of ozone and squalane, and identify changes in compound concentrations in different phases of ozone and squalane during the reaction process through a mass spectrum, thereby analyzing and identifying products that only exist in the gas phase, products that only exist in the particle phase, and products that exist in both phases, and further clarifying the product distribution and composition of the ozone and squalane oxidation reaction.

[0013] Preferably, the gas phase product and the particle phase product are prepared according to the following steps: 80-200 ppb of ozone is introduced into a sampling bag, and then 100-300 μL of squalene is injected into the sampling bag to allow the ozone to react with the squalene.

[0014] Preferably, the sampling bag is square with a side length of 40 to 60 cm, and is sealed on three sides and open on one side.

[0015] Preferably, the sampling bag has at least three valves and one injection port; the distance between the valve and the upper and lower edges of the sampling bag is 5 to 15 cm, and the distance between the valve and the left and right edges of the sampling bag is 20 to 30 cm; the distance between the injection port and each side of the sampling bag is 20 to 30 cm.

[0016] Preferably, the response time of the proton transfer reaction time-of-flight mass spectrometer is <100 ms, and the mass resolution (FWHM) is >2000 m / Δm.

[0017] Preferably, the drift tube voltage of the proton transfer reaction time-of-flight mass spectrometer is 450-470 V, the drift tube pressure is 2.0-2.3 mbar, and the drift tube temperature is 100-115° C.

[0018] Preferably, the injection flow rate of the proton transfer reaction time-of-flight mass spectrometer is 95-100 mL / min; E / N (E is the electric field strength, N is the number density of the neutral gas 1TD = 10-17 V·cm 2 ) is 149TD.

[0019] Preferably, the time resolution of the proton transfer reaction time-of-flight mass spectrometer is 5000 Hz, that is, a set of data is collected every 1 s.

[0020] Preferably, the ion source of the proton transfer reaction time-of-flight mass spectrometer is H3O + .

[0021] Preferably, the thermal desorption temperature of the aerosol chemical composition real-time analysis sampling system is 150°C.

[0022] Preferably, the injection flow rate of the aerosol chemical composition real-time analysis injection system is 450-500 mL / min.

[0023] The present invention also protects the use of any of the methods described in indoor air quality monitoring.

[0024] The present invention has the following beneficial effects:

[0025] The present invention performs online sampling of ozone and squalane products, and combines PTR-TOF-MS and CHA RON-PTR-TOF-MS systems to simultaneously detect particle phase products and gas phase products generated by the reaction of ozone and squalane, and analyzes and distinguishes products that only exist in the gas phase, products that only exist in the particle phase, and products that exist in both phases based on changes in product concentrations, thereby further clarifying the distribution and composition of products of the ozone and squalane oxidation reaction.

[0026] The invention is simple to operate, rapid and highly accurate, and is conducive to in-depth exploration of the squalene ozone oxidation process and mechanism, while providing a reference basis for the study of indoor odor and indoor environmental health effects, playing an important role in the fields of environmental protection and human health. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Flow chart of the experimental steps of Examples 1, 2, and 3.

[0028] Figure 2 This is a graph showing the concentration changes of the product C3H2O detected in Example 1 in the gas phase and the particle phase.

[0029] Figure 3 This is a graph showing the concentration changes of the product C2H6O detected in Example 2 in the gas phase and particle phase.

[0030] Figure 4This is a graph showing the concentration changes of the product CH4O detected in Example 3 in the gas phase and the particle phase. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0032] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0033] Example 1

[0034] Before the experiment, in order to reduce the possible contaminants in the Teflon sampling bag, the opening of the Teflon sampling bag was sealed with a sealing strip and flushed repeatedly with high-purity nitrogen three times (after the Teflon sampling bag was filled with nitrogen, the gas inside was pumped out with a pump). In order to ensure the accuracy of the experimental data, nitrogen was passed into the cleaned Teflon sampling bag for 3 minutes, and then PTR-TOF-MS was used to detect the background value of contaminants in the Teflon sampling bag, and then the experimental steps were followed:

[0035] S1. After the background value is detected, the gas in the Teflon sampling bag is pumped out with a pump, and 165 ppb of ozone is introduced into the Teflon sampling bag until the Teflon sampling bag is filled with ozone; then 200 μL of squalene standard solution is injected into the injection port of the Teflon sampling bag to allow the squalene standard solution to react with ozone;

[0036] S2. Use PTR-TOF-MS to detect the composition and concentration of the gas phase products of the reaction: connect the PTR-TOF-MS to the valve on the sampling bag through a peek tube, and the gas phase products (VOCs) produced by the reaction of squalene solution and ozone enter the drift tube of the PTR-TOF-MS. The VOCs are ionized by the ion source of the PTR-TOF-MS to generate H3O + Proton transfer reaction occurs to form (VOC)H + , then enters the mass analyzer for separation, is detected by the ion detector, and is plotted as a mass spectrum and transmitted to the computer screen.

[0037] S3. Use CHARON combined with PTR-TOF-MS to detect the composition and concentration of the particle phase products of the reaction: CHARON is connected to the valve of the sampling bag through a conductive silicone tube, the gas phase filter efficiently filters the gas phase organic gas, and the particulate matter is enriched through an aerodynamic lens. The organic chemical composition in the particulate matter is then heated and converted into the gas phase through a thermal desorber and loaded into the drift tube of the PTR-TOF-MS. The organic chemical composition is then ionized by the ion source and the H3O +A proton transfer reaction occurs to form protonated organic components, which then enter the mass analyzer for separation and are detected by the ion detector. The components are plotted as a mass spectrum and transmitted to the computer screen.

[0038] S4. Repeat the above operation and conduct three parallel experiments. Then compare the concentration change diagrams of the gas phase and the particle phase of different products. According to the real-time changes in concentration, screen out the products that only exist in the gas phase.

[0039] PTR-TOF-MS test conditions: The ion source used for PTR-TOF-MS is H3O + , mass resolution (FWHM)>2000m / Δm; scanning range is mass-to-charge ratio (m / z)=27~400; drift tube voltage is 460V; drift tube pressure is 2.3mbar; drift tube temperature is 110℃; injection flow rate: 100mL / min; E / N (E is the electric field strength, N is the number density of neutral gas 1TD=10~17V·cm 2 ) is 149TD; the time resolution is 5000Hz, that is, a set of data is collected every 1s.

[0040] The specific parameters of CHARON combined with PTR-TOF-MS are as follows: the thermal desorption temperature of CHARON is 150°C, and the ion source used for PTR-TOF-MS is H3O + , mass resolution (FWHM)>2000m / Δm; scanning range is mass-to-charge ratio (m / z)=27~400; drift tube voltage is 460V; drift tube pressure is 2.3mbar; drift tube temperature is 110℃; injection flow rate: 500mL / min; E / N (E is the electric field strength, N is the number density of neutral gas 1TD=10~17V·cm 2 ) is 149TD; the time resolution is 5000Hz, that is, a set of data is collected every 1s.

[0041] The experiment screened out 20 products that only exist in the gas phase. Taking the concentration change of C3H2O in the gas phase and particle phase as an example, Figure 2 This is a graph showing the concentration changes of the product C3H2O, which only exists in the gas phase, in the gas phase detection and the particle phase detection. It can be seen from the figure that the concentration of the compound remains basically unchanged in the particle phase, while the concentration gradually increases in the gas phase. This is because as the reaction time of ozone and squalane increases, the reaction products also gradually increase, while the concentration of C3H2O in the particle phase remains basically unchanged, indicating that it is a product that only exists in the gas phase.

[0042] Example 2

[0043] Before the experiment, in order to reduce the possible contaminants in the Teflon sampling bag, the opening of the Teflon sampling bag was sealed with a sealing strip and flushed repeatedly with high-purity nitrogen three times (after the Teflon sampling bag was filled with nitrogen, the gas inside was pumped out with a pump). In order to ensure the accuracy of the experimental data, nitrogen was passed into the cleaned Teflon sampling bag for 3 minutes, and then PTR-TOF-MS was used to detect the background value of contaminants in the Teflon sampling bag, and then the experimental steps were followed:

[0044] S1. After the background value is detected, the gas in the Teflon sampling bag is pumped out with a pump, and 165 ppb of ozone is introduced into the Teflon sampling bag until the Teflon sampling bag is filled with ozone; then 200 μL of squalene standard solution is injected into the injection port of the Teflon sampling bag to allow the squalene standard solution to react with ozone;

[0045] S2. Use PTR-TOF-MS to detect the composition and concentration of the gas phase products of the reaction: connect the PTR-TOF-MS to the valve on the sampling bag through a peek tube, and the gas phase products (VOCs) produced by the reaction of squalene solution and ozone enter the drift tube of the PTR-TOF-MS. The VOCs are ionized by the ion source of the PTR-TOF-MS to generate H3O + Proton transfer reaction occurs to form (VOC)H + , then enters the mass analyzer for separation, is detected by the ion detector, and is plotted as a mass spectrum and transmitted to the computer screen.

[0046] S3. Use CHARON combined with PTR-TOF-MS to detect the composition and concentration of the particle phase products of the reaction: CHARON is connected to the valve of the sampling bag through a conductive silicone tube, the gas phase filter efficiently filters the gas phase organic gas, and the particulate matter is enriched through an aerodynamic lens. The organic chemical composition in the particulate matter is then heated and converted into the gas phase through a thermal desorber and loaded into the drift tube of the PTR-TOF-MS. The organic chemical composition is then ionized by the ion source and the H3O + A proton transfer reaction occurs to form protonated organic components, which then enter the mass analyzer for separation and are detected by the ion detector. The components are plotted as a mass spectrum and transmitted to the computer screen.

[0047] S4. Repeat the above operation and conduct three parallel experiments. Then compare the concentration change diagrams of the gas phase and the particle phase of different products. According to the real-time changes in concentration, screen out the products that only exist in the particle phase.

[0048] PTR-TOF-MS test conditions: The ion source used for PTR-TOF-MS is H3O +, mass resolution (FWHM)>2000m / Δm; scanning range is mass-to-charge ratio (m / z)=27~400; drift tube voltage is 460V; drift tube pressure is 2.3mbar; drift tube temperature is 110℃; injection flow rate: 100mL / min; E / N (E is the electric field strength, N is the number density of neutral gas 1TD=10~17V·cm 2 ) is 149TD; the time resolution is 5000Hz, that is, a set of data is collected every 1s.

[0049] The specific parameters of CHARON combined with PTR-TOF-MS are as follows: the thermal desorption temperature of CHARON is 150°C, and the ion source used for PTR-TOF-MS is H3O + , mass resolution (FWHM)>2000m / Δm; scanning range is mass-to-charge ratio (m / z)=27~400; drift tube voltage is 460V; drift tube pressure is 2.3mbar; drift tube temperature is 110℃; injection flow rate: 500mL / min; E / N (E is the electric field strength, N is the number density of neutral gas 1TD=10~17V·cm 2 ) is 149TD; the time resolution is 5000Hz, that is, a set of data is collected every 1s.

[0050] The experiment screened out 20 products that only exist in the particle phase. Taking the concentration change of C2H6O in the gas phase and particle phase as an example, Figure 3 This is a graph showing the concentration changes of C2H6O, a product that only exists in the particle phase, in gas phase detection and particle phase detection. It can be seen from the figure that the concentration of C2H6O in the gas phase is very low and basically does not change with time, while the concentration of the product in the particle phase is maintained at a relatively high level, indicating that it is a product that only exists in the particle phase.

[0051] Example 3

[0052] Before the experiment, in order to reduce the possible contaminants in the Teflon sampling bag, the opening of the Teflon sampling bag was sealed with a sealing strip and flushed repeatedly with high-purity nitrogen three times (after the Teflon sampling bag was filled with nitrogen, the gas inside was pumped out with a pump). In order to ensure the accuracy of the experimental data, nitrogen was passed into the cleaned Teflon sampling bag for 3 minutes, and then PTR-TOF-MS was used to detect the background value of contaminants in the Teflon sampling bag, and then the experimental steps were followed:

[0053] S1. After the background value is detected, the gas in the Teflon sampling bag is pumped out with a pump, and 165 ppb of ozone is introduced into the Teflon sampling bag until the Teflon sampling bag is filled with ozone; then 200 μL of squalene standard solution is injected into the injection port of the Teflon sampling bag to allow the squalene standard solution to react with ozone;

[0054] S2. Use PTR-TOF-MS to detect the composition and concentration of the gas phase products of the reaction: connect the PTR-TOF-MS to the valve on the sampling bag through a peek tube, and the gas phase products (VOCs) produced by the reaction of squalene solution and ozone enter the drift tube of the PTR-TOF-MS. The VOCs are ionized by the ion source of the PTR-TOF-MS to generate H3O + Proton transfer reaction occurs to form (VOC)H + , then enters the mass analyzer for separation, is detected by the ion detector, and is plotted as a mass spectrum and transmitted to the computer screen.

[0055] S3. Use CHARON combined with PTR-TOF-MS to detect the composition and concentration of the particle phase products of the reaction: CHARON is connected to the valve of the sampling bag through a conductive silicone tube, the gas phase filter efficiently filters the gas phase organic gas, and the particulate matter is enriched through an aerodynamic lens. The organic chemical composition in the particulate matter is then heated and converted into the gas phase through a thermal desorber and loaded into the drift tube of the PTR-TOF-MS. The organic chemical composition is then ionized by the ion source and the H3O + A proton transfer reaction occurs to form protonated organic components, which then enter the mass analyzer for separation and are detected by the ion detector. The components are plotted as a mass spectrum and transmitted to the computer screen.

[0056] S4. Repeat the above operation and conduct three parallel experiments. Then compare the concentration change diagrams of the gas phase and the particle phase of different products. According to the real-time changes in concentration, screen out the products that exist in both the gas phase and the particle phase.

[0057] PTR-TOF-MS test conditions: The ion source used for PTR-TOF-MS is H3O + , mass resolution (FWHM)>2000m / Δm; scanning range is mass-to-charge ratio (m / z)=27~400; drift tube voltage is 460V; drift tube pressure is 2.3mbar; drift tube temperature is 110℃; injection flow rate: 100mL / min; E / N (E is the electric field strength, N is the number density of neutral gas 1TD=10~17V·cm 2 ) is 149TD; the time resolution is 5000Hz, that is, a set of data is collected every 1s.

[0058] The specific parameters of CHARON combined with PTR-TOF-MS are as follows: the thermal desorption temperature of CHARON is 150°C, and the ion source used for PTR-TOF-MS is H3O +, mass resolution (FWHM)>2000m / Δm; scanning range is mass-to-charge ratio (m / z)=27~400; drift tube voltage is 460V; drift tube pressure is 2.3mbar; drift tube temperature is 110℃; injection flow rate: 500mL / min; E / N (E is the electric field strength, N is the number density of neutral gas 1TD=10~17V·cm 2 ) is 149TD; the time resolution is 5000Hz, that is, a set of data is collected every 1s.

[0059] The experiment screened out 20 products that exist in both the gas phase and the particle phase. Taking the concentration change of CH4O in the gas phase and the particle phase as an example, Figure 4 This is a graph showing the concentration variation of the product CH4O, which exists in both the gas phase and the particle phase, in the gas phase detection and the particle phase detection. It can be seen from the figure that CH4O has a high concentration in both the gas phase and the particle phase.

[0060] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for analyzing and identifying gas phase and particle phase products of squalene ozone oxidation, characterized in that: The following steps are involved: S1. Sampling bag to collect gas phase products and particle phase products of the reaction between squalene and ozone; S2. Proton transfer reaction time-of-flight mass spectrometer collects and analyzes the composition and concentration of gas phase products in the S1 sampling bag; S3. Aerosol chemical composition real-time analysis sampling system combined with proton transfer reaction time-of-flight mass spectrometer to collect and analyze the composition and concentration of particle phase products in the S1 sampling bag; The mass-to-charge ratio m / z of the proton transfer reaction time-of-flight mass spectrometer is 27-400, and the detection limit is <10pptv; the thermal desorption temperature of the aerosol chemical composition real-time analysis injection system is 80-150°C.

2. The method according to claim 1, characterized in that: The gas phase product and the particle phase product are prepared according to the following steps: 80-200 ppb of ozone is introduced into a sampling bag, and then 100-300 μL of squalene is injected into the sampling bag to allow the ozone to react with the squalene.

3. The method according to claim 1, characterized in that: The drift tube voltage of the proton transfer reaction time-of-flight mass spectrometer is 450-470V, the drift tube pressure is 2.0-2.3mbar, and the drift tube temperature is 100-115°C.

4. The method according to claim 1, characterized in that: The injection flow rate of the proton transfer reaction time-of-flight mass spectrometer is 95-100 mL / min.

5. The method according to claim 1, characterized in that: The response time of the proton transfer reaction time-of-flight mass spectrometer is <100 ms.

6. The method according to claim 1, characterized in that: The mass resolution FWHM of the proton transfer reaction time-of-flight mass spectrometer is >2000 m / Δm.

7. The method according to claim 1, characterized in that: The ion source of the proton transfer reaction time-of-flight mass spectrometer is H3O + .

8. The method according to claim 1, characterized in that: The time resolution of the proton transfer reaction time-of-flight mass spectrometer is 5000 Hz.

9. The method according to claim 1, characterized in that: The injection flow rate of the aerosol chemical composition real-time analysis injection system is 450-500 mL / min.

10. Application of the method according to any one of claims 1 to 9 in indoor air quality monitoring.

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