Carbon component isotope fingerprint spectrum analysis method of atmospheric pollution source

Abstract

The invention discloses a carbon isotope fingerprint spectrum analysis method of an atmospheric pollution source, a thermal / optical carbon analysis method is optimized by adjusting a heating program, optical correction and other technologies so as to realize accurate separation of OC and EC, optimization and transformation are performed by combining low-temperature enrichment-normal-temperature purging, an analyzer interface, a connecting device and the like, and the carbon isotope fingerprint spectrum analysis method of the atmospheric pollution source is obtained. And automatic, continuous and accurate measurement of carbon components delta 13CEC and delta 13COC in tail gas of fossil fuel and biomass fuel is realized.

Description

Technical Field

[0001] This application relates to the field of atmospheric environmental monitoring technology, and in particular to a method for analyzing carbon component isotope fingerprint spectra of atmospheric pollution source samples. Background Technology

[0002] Fossil fuels and biomass fuels have wide applications in industrial energy, such as thermal power generation, metal smelting, seawater desalination, urban heating, lime production, industrial heating, and vehicle operation, with extremely broad application prospects. However, with the widespread use of fossil fuels and biomass fuels, the environmental hazards of exhaust gases produced after combustion are increasing year by year. For example, CO2 gas in exhaust gases can easily contribute to global warming and create the greenhouse effect; aerosols in exhaust gases are considered an important component of fine particulate matter under haze conditions, damaging the Earth's ecological environment.

[0003] Understanding the composition and sources of fuel exhaust gases is crucial for a scientific understanding of the formation mechanisms and climate effects of fossil fuels and biomass fuels, and also provides important reference for revealing the formation mechanism of atmospheric haze. With the development of isotope tracing technology, researchers are using stable isotopes of total carbon in particulate matter (…) 13 C) Abundance characteristics are used to determine the source of carbon aerosols or fine particulate matter in the atmosphere. δ¹⁸O₂ is found in organic carbon (OC) and elemental carbon (EC), water-soluble organic carbon (WSOC), and insoluble organic carbon (WINSOC). 13 C-to-total carbon (TC) provides more accurate source apportionment information. However, current techniques for determining OC / EC isotopes in carbon aerosols or fine particulate matter suffer from significant uncertainties due to limited testing accuracy; furthermore, there is a lack of research on techniques for determining OC / EC isotopes in fossil fuels and biomass fuels. Summary of the Invention

[0004] To address the aforementioned technical issues, this application discloses a carbon component isotope fingerprint analysis system and method for atmospheric pollution source samples. The atmospheric pollution source samples are derived from fuel exhaust gas. By establishing a carbon component isotope fingerprint spectrum, the types and quantities of carbon elements contained in the fuel exhaust gas can be comprehensively reflected, thereby enabling overall analysis and source tracing of the fuel composition.

[0005] To achieve the above-mentioned objective, this application provides a method for analyzing the carbon component isotope fingerprint spectrum of atmospheric pollution sources, characterized in that the method includes the following steps: S1 Sample Collection and Preparation: The collected atmospheric pollution sources are prepared into sample quartz films. The sample quartz films are placed in the sample furnace. Before analyzing the sample quartz films, the optical / thermal analysis device is purged and preheated. S2 Thermal Desorption: When the oxidation furnace temperature reaches the preset temperature, the photothermal analysis device begins carbon analysis of the sample in the sample furnace. The sample furnace is heated in a helium environment. When the sample furnace reaches the first preset temperature, it is held at the temperature for a first preset time to obtain the gas from which OC in the sample is heated and volatilized. The sample furnace is then cooled in a helium environment. After reaching the second preset temperature, it is held at the temperature for a second preset time. The sample furnace is then programmed to heat up in an oxidation environment of a helium and oxygen mixture. When the sample furnace reaches the third preset temperature, it is held at the temperature for a third preset time to obtain the gas from which EC in the sample is heated and oxidized. During the thermal desorption process, the separation point between OC and EC is determined based on the change in laser light intensity. S3 calculates the component information of OC and EC: During the heating process in S2, the gas volatilized from OC in the sample is further oxidized to CO2 after passing through the oxidation furnace, and is discharged as the first tail gas after entering the NDIR detector; the gas oxidized from EC in the sample is passed through the oxidation furnace, enters the NDIR detector, and is discharged as the second tail gas; then, He / CH4 internal standard is introduced into the oxidation furnace, the internal standard is oxidized to CO2 after passing through the oxidation furnace, enters the NDIR detector, and is discharged as the third tail gas; the component information of OC and EC is calculated by the ratio of the CO2 peak area before and after the cutoff point determined in S2 to the peak area of ​​the internal standard. S4 measurement δ 13 C OC The first tail gas is enriched using a cold trap T1 in the pre-concentrator. Specifically, within a first preset time and at a first preset temperature, the OC in the sample is heated and volatilized, subsequently generating CO2 in the oxidation furnace. The first tail gas enriched and purified in the cold trap T1 is then purged into an isotope mass spectrometer for δ¹⁸O analysis. 13 C OC ; S5 measurement δ 13 C EC The second tail gas is enriched using the cold trap T2 in the pre-concentrator. During the third preset time period, EC in the sample is oxidized by heating in the sample furnace, and the CO2 extracted from the oxidation furnace is then used to purge the enriched and purified second tail gas in the cold trap T2 into an isotope mass spectrometer for δ¹⁴ spectroscopy. 13 C EC .

[0006] Preferably, step S2 further includes a fourth preset temperature. After a first preset time, the sample furnace is heated to the fourth preset temperature and protected for a fourth preset time. The fourth preset temperature is the temperature at which CC is decomposed and released.

[0007] Preferably, in the oxidizing environment of the helium and oxygen mixture, the concentration percentage of helium is 90-98%, and the concentration percentage of oxygen is 2-10%.

[0008] Preferred, S4 measurement δ 13 C OC When enriching and purifying the first tail gas, the cold trap 1 in the pre-concentrator is placed in liquid nitrogen, and then the cold trap 1 is lifted out of the liquid nitrogen. The first tail gas enriched in the cold trap 1 is then purged into the isotope mass spectrometer at room temperature. S5 measurement δ 13 C EC When enriching and purifying the second tail gas of EC, the cold trap 2 in the pre-concentrator is placed in liquid nitrogen, and then the cold trap 2 is lifted out of the liquid nitrogen. The second tail gas enriched in the cold trap 2 is then purged into the isotope mass spectrometer at room temperature.

[0009] Preferably, the method satisfies any of the following: The enrichment time of the first tail gas in the cold trap 1 is 15-20s; The enrichment time of the second tail gas in the cold trap 2 is 15-20s.

[0010] Preferably, the CO2 in the cold trap is first purged into the chromatographic column and then enters the isotope mass spectrometer.

[0011] Preferably, the air pollution source includes exhaust gas generated from the combustion of fossil fuels or biomass fuels.

[0012] Preferably, the method satisfies any of the following: The second preset temperature is lower than the first preset temperature and the third preset temperature; The first preset temperature is 600-700℃; The second preset temperature is 550-600℃; The third preset temperature is 650-900℃; The first preset time is 2-4 minutes; The second preset time is 2-3 minutes; The third preset time is 2-3 minutes; The heating process is a programmed heating process.

[0013] Preferably, the waste gas generated during the S2 thermal desorption is collected by a waste gas receiving device; the waste gas is gas other than CO2 generated in the oxidation furnace by the volatilization of OC in the sample and the CO2 generated by the oxidation of EC in the sample.

[0014] Preferably, both the cold trap T1 and the cold trap T2 are equipped with lifting and adjusting devices.

[0015] This application has the following beneficial effects: In the optical / thermal analysis device, the temperature program was adjusted to achieve accurate separation of OC and EC, avoiding interference from carbonate carbons CC and PC. Simultaneously, CO2 generated in the corresponding program was enriched and purified in the pre-concentration device. High-resolution mass spectrometry was then used to analyze the δ-fractions of the carbon components. 13 C EC and δ 13 C OC To achieve automatic and continuous accurate measurement, improve the accuracy and anti-interference ability of qualitative and quantitative analysis of carbon component isotopes in atmospheric pollution source samples, and enhance the automation and intelligence of sample analysis. Attached Figure Description

[0016] To more clearly illustrate the carbon isotope fingerprint analysis system and method for fuel exhaust gas described in this application, the accompanying drawings required for the embodiments 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 This is a schematic diagram of a photo / thermal analysis device according to this application; Figure 2 This is a flowchart of a carbon component isotope fingerprint analysis method for atmospheric pollution sources according to this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0019] As used herein, "an embodiment" or "an embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. The invention will be more readily understood by referring to the following detailed description of preferred embodiments and included examples. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, the definitions in this specification shall prevail.

[0020] For the purposes of the detailed description below, it should be understood that the invention may take various alternative variations and sequences of steps unless expressly stated otherwise. Furthermore, except in any operational instance, or otherwise indicated, all figures representing the amounts of ingredients used, for example, in the specification and claims, should be understood to be modified in all cases by the term “about.” Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations varying with the desired performance to be obtained according to the invention. It is not at all an attempt to limit the application of the doctrine of equivalents to the scope of the claims; each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying ordinary rounding techniques.

[0021] Although the numerical ranges and parameters illustrating the broad scope of the invention are approximate, the values ​​listed in the specific examples are reported as precisely as possible. However, any numerical value inherently contains some error that is necessarily caused by the standard deviation found in their respective test measurements.

[0022] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. For example, a specified range from “1 to 10” should be considered to include any and all subranges between the minimum value 1 and the maximum value 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0023] The carbon component isotope fingerprint analysis system used in this application is described below. Please refer to [link / reference]. Figure 1 , Figure 1 This is a schematic diagram of a carbon component isotope fingerprinting analysis system for fuel exhaust gas. It is understood that the reaction device structure shown in the diagram is merely a technical solution of one specific embodiment of this application, and the analysis system of this application may include fewer or more structural features, and is not intended to be a specific embodiment of this application. Figure 1 The structure of the proposed device is limited to what is described in the text.

[0024] The photothermal analysis device used in this application is for analyzing the carbon source in fuel exhaust gas samples. Specifically, it is a Model-4 semi-continuous organic carbon / elemental carbon aerosol analyzer manufactured by Sunset Laboratory Inc., which includes a sample furnace, an oxidation furnace, a laser emission device, a laser transmittance detector, and an NDIR detector. The oxidation furnace is a manganese dioxide oxidation furnace. The exhaust pipe of the photothermal analysis device is connected to the inlet of a pre-concentration device, and the outlet of the pre-concentration device is connected to the mass spectrometer via a proprietary "open-split" interface. The pre-concentration device separates and concentrates the carbon-containing gas obtained from the carbon source analysis, and the separated and concentrated carbon-containing gas is then analyzed by the mass spectrometer.

[0025] The following describes a carbon isotope fingerprint analysis method for atmospheric pollution sources used in this application, including the following steps: S1 Sample Collection and Preparation: The collected atmospheric pollution sources are prepared into sample quartz films. The sample quartz films are placed in the sample furnace. Before analyzing the sample quartz films, the optical / thermal analysis device is purged and preheated. S2 Thermal Desorption: When the oxidation furnace temperature reaches the preset temperature, the photothermal analysis device begins carbon analysis of the sample in the sample furnace. The sample furnace is heated in a helium environment. When the sample furnace reaches the first preset temperature, it is held at the temperature for a first preset time to obtain the gas from which OC in the sample is heated and volatilized. The sample furnace is then cooled in a helium environment. After reaching the second preset temperature, it is held at the temperature for a second preset time. The sample furnace is then programmed to heat up in an oxidation environment of a helium and oxygen mixture. When the sample furnace reaches the third preset temperature, it is held at the temperature for a third preset time to obtain the gas from which EC in the sample is heated and oxidized. During the thermal desorption process, the separation point between OC and EC is determined based on the change in laser light intensity. S3 calculates the component information of OC and EC: During the heating process in S2, the gas volatilized from OC in the sample is further oxidized to CO2 after passing through the oxidation furnace, and is discharged as the first tail gas after entering the NDIR detector; the gas oxidized from EC in the sample is passed through the oxidation furnace, enters the NDIR detector, and is discharged as the second tail gas; then, He / CH4 internal standard is introduced into the oxidation furnace, oxidized to CO2, and discharged as the third tail gas after entering the NDIR detector; the component information of OC and EC is calculated by the ratio of the CO2 peak area before and after the cutoff point determined in S2 to the peak area of ​​the internal standard; that is, the concentration information of OC and EC. S4 measurement δ 13 C OCThe first tail gas is enriched using a cold trap T1 in the pre-concentrator. Specifically, within a first preset time and at a first preset temperature, the OC in the sample is heated and volatilized, subsequently generating CO2 in the oxidation furnace. The first tail gas enriched and purified in the cold trap T1 is then purged into an isotope mass spectrometer for δ¹⁸O analysis. 13 C OC ; S5 measurement δ 13 C EC The second tail gas is enriched using the cold trap T2 in the pre-concentrator. During the third preset time period, EC in the sample is oxidized by heating in the sample furnace, and the CO2 extracted from the oxidation furnace is then used to purge the enriched and purified second tail gas in the cold trap T2 into an isotope mass spectrometer for δ¹⁴ spectroscopy. 13 C EC .

[0026] Specifically, the second preset temperature is lower than the first and third preset temperatures. The sample furnace is programmed to heat step-by-step in a helium environment, reaching the first preset temperature (600℃-700℃) for 2-4 minutes to allow complete volatilization of the gases generated by heating the OC in the sample. The second preset temperature is 550℃-600℃ for 2-3 minutes to allow time for exhaust gases to escape from the sample furnace. The sample furnace is then programmed to heat step-by-step in an oxidizing environment of helium and oxygen mixture, reaching the third preset temperature (650-900℃) for 2-3 minutes to allow complete exhaust of the gases generated by heating and oxidizing the EC in the sample. The decomposition products generated during the heating process are converted into CO2 by the carrier gas (He or He / O2) in the manganese dioxide oxidation furnace (MnO2) and then quantitatively analyzed by laser and non-dispersive infrared spectroscopy (NDIR).

[0027] The preset temperature of the oxidation furnace can be 800-900℃.

[0028] In some embodiments, if carbonate carbon (CC) is present, after a first preset time, the temperature inside the sample furnace is further increased to a fourth preset temperature above 890°C and maintained for a fourth preset time of 2 minutes to allow the carbonate carbon (CC) to decompose and release. The released waste gas is collected through a waste gas recovery device. Then, the temperature of the sample furnace is lowered to a second preset temperature, such as 550°C, and maintained for a second preset time, such as 2 minutes.

[0029] Specifically, the first preset time can be 2, 3, or 4 minutes, the second preset time can be 2 or 3 minutes, and the third preset time can be 2, 3, or 4 minutes.

[0030] In some embodiments, the third exhaust gas can be considered as waste gas and collected by a waste gas recovery device.

[0031] In some embodiments, in an oxidizing environment of a helium and oxygen mixture, the helium concentration percentage is 90-98%, and the oxygen concentration percentage is 2-10%. Specifically, when the helium concentration percentage is 90, 91, 92, 93, 94, 95, 96, 97, and 98%, the oxygen concentration percentage is 10, 9, 8, 7, 6, 5, 4, 3, 2, and 1%, respectively.

[0032] In some embodiments, S4 measures δ 13 C OC When enriching and purifying the first tail gas, i.e. CO2 converted by the OC reaction, the cold trap 1 in the pre-concentrator is placed in liquid nitrogen for 15-20 seconds. Then, the cold trap 1 is lifted out of the liquid nitrogen, and the first tail gas enriched in the cold trap 1 is purged at room temperature and entered into the isotope mass spectrometer. S5 measurement δ 13 C EC When enriching and purifying the second tail gas, i.e. CO2 converted from EC, the cold trap 2 in the pre-concentrator is placed in liquid nitrogen for 15-20 seconds. Then, the cold trap 2 is lifted out of the liquid nitrogen, and the second tail gas enriched in the cold trap 2 is purged into the isotope mass spectrometer at room temperature.

[0033] Specifically, the enrichment time can be 15, 16, 17, 18, 19, or 20 seconds.

[0034] In some embodiments, the cold trap device is equipped with a lifting and adjusting mechanism. Different cold trap devices are switched via two three-way valves at both ends to collect the first and second tail gases, i.e., CO2 gases formed by the oxidation of OC and EC, respectively. The cold trap is raised from liquid nitrogen temperature to room temperature to release CO2, which is then allowed to enter the mass spectrometer for detection. The cold trap can then be returned to liquid nitrogen, awaiting the next heating cycle.

[0035] Specifically, isotope mass spectrometry controls the enrichment times of cold traps T1 and T2 in the pre-concentrator to match the heating times of the first and third preset temperatures in the OC / EC online analyzer program. It then sequentially measures the CO2 released after pre-concentration in the pre-concentrator during both heating cycles, thereby obtaining the δ¹⁴ ... 13 C OC and δ 13 C EC information.

[0036] In practical applications, the source of air pollution is fuel exhaust, including exhaust generated from the combustion of fossil fuels or biomass fuels. Specifically, fossil fuels can be the combustion of substances such as coal and oil, while biomass fuels can be the combustion of substances such as natural gas, and are commonly used in automobiles, urban heating, and industrial heating.

[0037] The following specific embodiments illustrate the carbon component isotope fingerprint analysis method of this application. When testing samples, the laser value is not less than 5000.

[0038] Example 1: S1: Sample collection and preparation: The collected vehicle exhaust sample is prepared into a sample quartz film using a dilution channel sampler. The sample quartz film is placed in the sample furnace. Before analyzing the sample quartz film, the optical / thermal analysis device is purged and preheated.

[0039] S2 Thermal Desorption: When the manganese dioxide oxidation furnace reaches 800℃, the photothermal analysis device begins sampling and analyzing the carbon in the sample quartz film. The sample on the quartz film is gradually heated in a non-oxidizing helium (He) environment, reaching the first preset temperature of 600℃, causing OC to volatilize. This temperature is maintained for 2 minutes to extend the interval between OC and CC reaching the detector, ensuring sufficient time for separate enrichment of OC in the next step. The temperature is then raised to the fourth preset temperature of 890℃ and maintained for 2 minutes to allow complete release of carbonate carbon (CC). The furnace is then cooled in a helium environment to the second preset temperature of 550℃ and maintained for 2 minutes. Next, the sample is gradually heated in an oxidizing environment of helium and oxygen (98%He + 2%O2) to the third preset temperature of 650℃. During this heating process, EC is oxidized and decomposed into gaseous oxides, and the temperature is maintained for 2 minutes. The separation point between OC and EC can be determined based on the change in laser intensity during the thermal desorption process.

[0040] S3 calculates the component information of OC and EC: During the heating process in S2, the gas volatilized by heating in the sample is further oxidized to CO2 after passing through the oxidation furnace, and then discharged as the first tail gas to the pre-concentration device after entering the NDIR detector; the gas oxidized by heating in the sample passes through the oxidation furnace, enters the NDIR detector, and is discharged as the second tail gas to the pre-concentration device; after thermal desorption, the He / CH4 internal standard gas enters the pipeline through the quantitative loop, is oxidized to CO2 in the oxidation furnace, enters the NDIR detector, and is discharged as the third tail gas to the waste gas receiving device; the concentration information of OC and EC components is calculated by the ratio of the peak area of ​​CO2 before and after the split point to the peak area of ​​the internal standard.

[0041] S4 measurement δ 13 C OC The first exhaust gas from the NDIR detector enters the gas pre-concentrator. During the heating phase when the sample furnace reaches the first preset temperature, the cold trap T1 is placed in liquid nitrogen to enrich and purify the CO2 converted from organic carbon (OC). After 15 seconds of enrichment, the cold trap T1 is lifted, and the focused CO2 is purged into the chromatographic column at room temperature, and then subjected to isotope mass spectrometry for δ-ray diffraction. 13C OC， The measured isotopic abundance of the first exhaust gas sample was -26.8‰ to 23‰, thus determining the contribution of fossil fuel combustion. This was mainly based on the response abundance comparison with the isotopic fingerprint spectral library, namely coal combustion (δ¹²⁻¹). 13 C: -25‰ to 21‰), vehicle exhaust (δ) 13 C: -27.8‰ to 26‰), C3 plants (δ 13 C: -13‰ to 11.4‰) and C4 plant emissions (δ 13 C: -32‰ to 29‰, etc.

[0042] S5 measurement δ 13 C EC The second tail gas emitted from the NDIR detector enters the gas pre-concentrator. In the sample furnace, under an oxidizing environment of helium and oxygen mixture, a third, preset temperature-raising stage is performed. The cold trap T2 is placed in liquid nitrogen to enrich and purify the CO2 converted from inorganic carbon (EC). After 15 seconds of enrichment, the cold trap T2 is lifted, and the CO2 converted from EC is purged at room temperature and subjected to isotope mass spectrometry for δ¹⁸O analysis. 13 C EC， The measured isotopic abundance of the second exhaust gas sample was -26.4‰ to 23.2‰, thus determining the contribution of fossil fuel combustion. This was mainly based on the response abundance comparison with the isotopic fingerprint spectral library, namely, coal combustion (δ¹²⁻¹). 13 C: -25‰ to 21‰), vehicle exhaust emissions (δ) 13 C: -27.8‰ to 26‰, etc.

[0043] It should be noted that the selection of materials and experimental parameters involved in the above embodiments are only for the purpose of obtaining better control experimental results and better demonstrating the beneficial effects of the OC, EC separation, concentration and isotope detection methods provided in this application. They are only as specific and feasible embodiments. The materials and parameters that can actually be implemented in this application are not limited to those in the embodiments, and can be referred to the specific scope of the implementation.

[0044] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A method for analyzing the carbon component isotope fingerprint of air pollution sources, characterized in that, The method includes the following steps: S1 Sample Collection and Preparation: The collected atmospheric pollution sources are prepared into sample quartz films. The sample quartz films are placed in the sample furnace. Before analyzing the sample quartz films, the optical / thermal analysis device is purged and preheated. S2 Thermal Desorption: When the oxidation furnace temperature reaches the preset temperature, the photothermal analysis device begins carbon analysis of the sample in the sample furnace. The sample furnace is heated in a helium environment. When the sample furnace reaches the first preset temperature, it is held at the temperature for a first preset time to obtain the gas from which OC in the sample is heated and volatilized. The sample furnace is then cooled in a helium environment. After reaching the second preset temperature, it is held at the temperature for a second preset time. The sample furnace is then programmed to heat up in an oxidation environment of a helium and oxygen mixture. When the sample furnace reaches the third preset temperature, it is held at the temperature for a third preset time to obtain the gas from which EC in the sample is heated and oxidized. During the thermal desorption process, the separation point between OC and EC is determined based on the change in laser light intensity. S3 calculates the component information of OC and EC: During the heating process in S2, the gas volatilized from OC in the sample is further oxidized to CO2 after passing through the oxidation furnace, and is discharged as the first tail gas after entering the NDIR detector; the gas oxidized from EC in the sample is passed through the oxidation furnace, enters the NDIR detector, and is discharged as the second tail gas; then, He / CH4 internal standard is introduced into the oxidation furnace, the internal standard is oxidized to CO2 after passing through the oxidation furnace, enters the NDIR detector, and is discharged as the third tail gas; the component information of OC and EC is calculated by the ratio of the CO2 peak area before and after the cutoff point determined in S2 to the peak area of ​​the internal standard. S4 measurement δ 13 C OC Using the cold trap T1 set in the pre-concentrator, the first tail gas is enriched, and the first tail gas enriched and purified in the cold trap T1 is purged into the isotope mass spectrometer for determination. S5 measurement δ 13 C EC The second tail gas is enriched using the cold trap T2 in the pre-concentrator. The enriched and purified second tail gas in the cold trap T2 is then purged into an isotope mass spectrometer for δ-ray diffraction. 13 C EC .

2. The method for analyzing carbon isotopic fingerprints of air pollution sources according to claim 1, characterized in that, The S2 also includes a fourth preset temperature. After the first preset time, the sample furnace is heated to the fourth preset temperature and protected for the fourth preset time. The fourth preset temperature is the temperature at which CC is decomposed and released.

3. The method for analyzing carbon isotope fingerprints of air pollution sources according to claim 1, characterized in that, In the oxidizing environment of the helium and oxygen mixture, the concentration percentage of helium is 90-98%, and the concentration percentage of oxygen is 2-10%.

4. The method for analyzing carbon isotope fingerprints of air pollution sources according to claim 1, characterized in that, S4 measurement δ 13 C OC When enriching and purifying the first tail gas, the cold trap 1 in the pre-concentrator is placed in liquid nitrogen, and then the cold trap 1 is lifted out of the liquid nitrogen. The first tail gas enriched in the cold trap 1 is then purged into the isotope mass spectrometer at room temperature. S5 measurement δ 13 C EC When enriching and purifying the second tail gas, the cold trap 2 in the pre-concentrator is placed in liquid nitrogen, and then the cold trap 2 is lifted out of the liquid nitrogen. The second tail gas enriched in the cold trap 2 is then purged at room temperature and introduced into the isotope mass spectrometer.

5. A method for analyzing carbon isotope fingerprints of atmospheric pollution sources according to any one of claims 1 or 4, characterized in that, The method satisfies any of the following: The enrichment time of the first tail gas in the cold trap 1 is 15-20s; The enrichment time of the second tail gas in the cold trap 2 is 15-20s.

6. A method for analyzing carbon isotope fingerprints of atmospheric pollution sources according to any one of claims 1 or 4, characterized in that, The CO2 in the cold trap is purged into the isotope mass spectrometer.

7. The method for analyzing carbon isotope fingerprints of air pollution sources according to claim 1, wherein the air pollution sources include exhaust gases generated from the combustion of fossil fuels or biomass fuels.

8. The method for analyzing carbon isotope fingerprints of air pollution sources according to claim 1, characterized in that, The method satisfies any of the following: The second preset temperature is lower than the first preset temperature and the third preset temperature; The first preset temperature is 600-700℃; The second preset temperature is 550-600℃; The third preset temperature is 650-900℃; The first preset time is 2-4 minutes; The second preset time is 2-3 minutes; The third preset time is 2-3 minutes; The heating process is a programmed heating process.

9. The carbon component isotope fingerprint analysis method for an atmospheric pollution source according to claim 1, wherein the waste gas generated in the S2 thermal desorption is collected by a waste gas receiving device; the waste gas refers to gases other than CO2 generated in the oxidation furnace by the volatilization of OC in the sample and CO2 generated by the oxidation of EC in the sample.

10. The method for analyzing carbon isotope fingerprints of atmospheric pollution sources according to claim 1, wherein both cold trap T1 and cold trap T2 are equipped with lifting and adjusting devices.

Images