Method for simply extracting and accurately qualitatively and quantitatively analyzing micro-nano plastic in biological fluid

Abstract

The invention discloses a method for simply extracting and accurately determining and quantifying micro-nano plastic in biological fluid. The method comprises the following steps: heating and digesting the biological fluid by using a strong oxidant; after digestion, adding a moistening solution for ultrasonic treatment, collecting the treated solution, and detecting the particle size of particles in part of the mixed solution; and filtering the residual mixed solution to separate out the micro-plastics. Meanwhile, collecting a filtrate containing the nano plastic, and directly transferring the filtrate into a sample boat to be heated and concentrated until the filtrate is dry; and a thermal cracking / thermal desorption-gas chromatograph-mass spectrometer is used for detecting the types and contents of the medium-micro plastic and the nano plastic. According to the method, the micro-nano plastic in different biological fluids can be simply extracted, accurate qualitation and quantification can be realized, and the technical bottlenecks that the extraction of the micro-nano plastic in the biological fluids is tedious and the particle size of the micro-nano plastic particles and accurate qualitation and quantification cannot be considered at the same time at present are broken; and an available technical method is provided for comprehensively and deeply analyzing the in-vivo health risk of the micro-nano plastic.

Description

Technical Field

[0001] The present invention belongs to the technical field of micro-nano plastic detection, and specifically relates to a method for simply extracting and accurately qualitatively and quantitatively analyzing micro-nano plastics in biological fluids. Background Art

[0002] Microplastics are a new type of pollutant that has become popular in recent years. They have been frequently detected in environmental water, atmosphere, soil and other media. Microplastics in natural media can be ingested by various animals and even humans through diet, drinking water, breathing and other means. These microplastics that are accidentally ingested into the body will enter the internal circulation system from the digestive tract and respiratory tract and then be distributed in various tissues, organs and body fluids throughout the body. Microplastics that enter tissues and body fluids can cause inflammation, oxidative stress, metabolic disorders and many other toxic effects. Accurately qualitatively and quantitatively determining the content of microplastics in the body is the basic prerequisite for accurately assessing the potential health effects of microplastics in the body, and is also an important basis for further explaining the toxicity mechanism of microplastics and screening biomarkers in the future.

[0003] Despite this, the quantitative detection of micro-nano plastic content in organisms is a hot topic and difficulty in the current research field of microplastic analysis and health effects. The key core issues are: compared with common environmental media, the content of micro-nano plastics in organisms, especially in body fluids, is very low. How to construct a new method for extracting micro-nano plastics, reduce the loss of micro-nano plastics during the extraction process, and try to avoid introducing new pollution and improve the extraction efficiency of micro-nano plastics; in addition, the existing qualitative and quantitative methods of micro-nano plastics are difficult to solve the problem of accurately analyzing particle size distribution, type and quality at the same time.

[0004] Although there have been methods of using concentrated acid or alkali to digest animal and plant tissues to extract microplastics, these methods usually have disadvantages such as cumbersome methods and easy to be contaminated. So far, there is no method that can simultaneously and efficiently extract micro-nano plastics from biological fluids. On the other hand, micro-Raman spectroscopy or micro-infrared spectroscopy, as the current mainstream technologies for detecting micro-nano plastics, are semi-quantitative methods, which are difficult to accurately qualitatively and quantitatively identify microplastics with smaller particle sizes, especially nanoplastics. Traditional technical methods based on chromatography and mass spectrometry can alleviate the problem of accurate quantification of some micro-nano plastics to a certain extent, but they are not competent for the analysis of the morphology of micro-nano plastics, especially the particle size distribution, which deeply restricts the identification of the migration and transformation laws of micro-nano plastics in the body and the health hazards. Therefore, it is urgent to establish a simple, efficient and accurate technical method for extracting micro-nano plastics from biological fluids and accurately qualitatively and quantitatively. Summary of the invention

[0005] Purpose of the invention: In view of the fact that the prior art generally lacks technical methods for efficient extraction, identification and accurate quantification of micro-nano plastics in biological fluids, the present invention provides a method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids. The present invention innovatively solves the difficult problems of low extraction efficiency, easy contamination, and inaccurate qualitative and quantitative analysis of micro-nano plastics in biological fluids through oxidative digestion, ultrasonic fragmentation, trace concentration and thermal cracking / thermal desorption-gas chromatography-mass spectrometry technology, and provides key technical support for the subsequent accurate evaluation of the pollution status and health risk research of micro-nano plastics in organisms.

[0006] Technical solution: To achieve the above-mentioned purpose of the invention, the method of the present invention for simple extraction and accurate quantitative analysis of micro-nano plastics in biological fluids comprises the following steps:

[0007] (1) Oxidative digestion of biological fluid samples: using strong oxidants to heat and digest biological fluids;

[0008] (2) ultrasonically treating the digestion solution: after the digestion in step (1), heat and evaporate to dryness, add a rinse solution and perform ultrasonic treatment;

[0009] (3) Detection of micro-nano plastic particle size: taking a portion of the solution in step (2) and analyzing the micro-nano plastic particle size distribution therein;

[0010] (4) Separating microplastics: filtering the remaining solution in step (2) to separate the microplastics, and collecting the filtrate;

[0011] (5) Concentrating and enriching the nanoplastics: heating and volatilizing the filtrate in the above step (4) to dryness;

[0012] (6) Qualitative and quantitative analysis of micro-nano plastic content: Use pyrolysis / thermal desorption-gas chromatography-mass spectrometry to detect the type and quality of microplastics in the above step (4) and nanoplastics in step (5).

[0013] The biological fluid in step (1) includes human or animal blood, semen, follicular fluid, cerebrospinal fluid, saliva, digestive fluid, urine or sweat.

[0014] Wherein, the strong oxidant in step (1) is a mixed liquid of one or more of hydrogen peroxide, nitric acid, sulfuric acid or Fenton's reagent.

[0015] The heating digestion condition in step (1) is 60 to 100° C., the volume ratio of the strong oxidant to the biological liquid is 1:3-1:5; and the digestion is terminated by heating and evaporating after the digestion liquid becomes clear and transparent.

[0016] Wherein, the rinse solution in step (2) is one or more of ethanol, isopropanol, and pure water.

[0017] The amount of the rinse solution added in step (2) is 1 to 10 times the volume of the initial biological fluid; the ultrasonic treatment conditions are: ultrasonic treatment at 100-500w for 10-20min; and the ultrasonic treatment step needs to be repeated 3-4 times.

[0018] The laser particle size analyzer used to analyze the particle size distribution in step (3) is a particle size analyzer covering the nanometer and micrometer detection range.

[0019] Wherein, the filter membrane in step (4) is a glass fiber membrane or a metal membrane with a pore size of 1-5000 μm. The filter membrane needs to be heated at 500° C. in a muffle furnace for 2-4 hours before use.

[0020] In step (5), the filtrate is directly transferred to the sample boat to avoid damage to the intermediate nanoplastics and the introduction of new contamination to the greatest extent; the sample boat is made of quartz or metal; and the heating volatilization condition is 100-150°C.

[0021] Wherein, the thermal cracking / thermal desorption-gas chromatography-mass spectrometry detection conditions in step (6) are as follows:

[0022] Pyrolysis conditions: starting temperature 50-60°C, ending temperature 600-700°C, hold 10-15min, 10-15°C / min heating rate, nitrogen flow rate 100-120mL / min;

[0023] Thermal desorption conditions: 250-350℃; adsorption tube desorption time: 10-15min; nitrogen blowing flow rate: 40-60mL / min; desorption flow rate: 40-60mL / min; cold trap purge time: 1-2min; cold trap purge flow rate: 50mL / min; cold trap low temperature: 25-35℃; cold trap high temperature: 300-400℃; cold trap desorption time: 3-5min; split ratio: 10:1 to 100:1, split rate: 30mL / min;

[0024] Gas phase conditions: injection port temperature: 100-130°C, splitless injection; column flow rate: 1.2-1.5 mL / min; program temperature rise: initial temperature 30-35°C, hold for 5-10 min, increase to 260-300°C at a rate of 8-10°C / min, hold for 10-15 min; transfer line temperature: 260-300°C; carrier gas: He;

[0025] Mass spectrometry conditions: ion source temperature: 220-250°C; quadrupole temperature: 150°C; voltage: 70 eV; data acquisition mode: full scan (Scan), scanning range: 30-400 amu.

[0026] Preferably, the thermal desorption-gas chromatography-mass spectrometry detection conditions are as follows:

[0027] Pyrolysis conditions: starting temperature 60°C, ending temperature 600°C, hold 10-15 min, 15°C / min heating rate, nitrogen flow rate 120 mL / min;

[0028] Thermal desorption conditions: 300℃; adsorption tube desorption time: 10 -15min; nitrogen blowing flow rate: 40-60mL / min; desorption flow rate: 40-60mL / min; cold trap purge time: 1-2min; cold trap purge flow rate: 50mL / min; cold trap low temperature: 30℃; cold trap high temperature: 300℃; cold trap desorption time: 4min; split ratio: 10:1 to 100:1, split rate: 30mL / min;

[0029] Gas phase conditions: injection port temperature: 120°C, splitless injection; column flow rate: 1.5 mL / min; program temperature rise: initial temperature 35°C, hold for 5 min, increase to 260°C at a rate of 10°C / min, hold for 10 min; transfer line temperature: 260°C; carrier gas: He;

[0030] Mass spectrometry conditions: ion source temperature: 220-250°C; quadrupole temperature: 150°C; voltage: 70 eV; data acquisition mode: full scan (Scan), scanning range: 30-400 amu.

[0031] The present invention provides a technical method for simply extracting micro-nano plastics from biological fluids and accurately determining the quality and quantity. The method is a technical method for realizing efficient extraction of trace micro-nano plastics in biological fluid samples and high-precision qualitative and quantitative determination, and belongs to the field of environmental analysis and health. The steps are: using a strong oxidant to heat and digest the biological fluid; after the digestion is completed, adding a rinse solution to the obtained digestion solution for ultrasonic treatment, and collecting the treated mixed solution. Using a laser particle size analyzer to detect the particle size of particulate matter in part of the mixed solution; filtering the remaining mixed solution to separate microplastics. At the same time, the filtrate containing nanoplastics is collected, and the filtrate is directly transferred to a sample boat, heated and concentrated to dryness; using a thermal cracking / thermal desorption-gas chromatography-mass spectrometry instrument to detect the types and contents of the above-mentioned microplastics and nanoplastics. This method can not only easily extract micro-nano plastics from different biological fluids and achieve qualitative and quantitative analysis, but also solve the current technical bottleneck of cumbersome extraction of micro-nano plastics from biological fluids and the inability to take into account the particle size of micro-nano plastics and accurate qualitative and quantitative analysis. It provides a usable technical method for accurately evaluating the current status of micro-nano plastic pollution in organisms and subsequently comprehensively and in-depth analyzing the health risks of micro-nano plastics in the body.

[0032] The present invention uses the least steps to simultaneously extract trace amounts of micro-nano plastics in biological fluids, and in particular, the rapid concentration and extraction of nanoplastics is not available in other existing methods. In addition, compared to existing methods, the present invention can not only analyze the type and quality of microplastics and nanoplastics, but also analyze the particle size of particulate matter, and can simultaneously provide data from three dimensions: morphology, type, and quality. The present invention can not only reduce the digestion reaction process and transfer steps in traditional methods, maximize the extraction efficiency of micro-nano plastics in biological fluids, but also minimize the possibility of introducing contamination in excessive reactions and transfer steps; it introduces morphological detection technology into existing quantitative methods, and provides important particle size distribution data while accurately analyzing the type and quality of micro-nano plastics.

[0033] The present invention proposes for the first time a one-time quick extraction of micro-nano plastics from biological fluids and accurate qualitative and quantitative analysis from three aspects: particle size, type and quality. The present invention simplifies the source digestion method to achieve the simultaneous extraction of micro-nano plastics from biological fluids and reduce pollution. It can not only provide the type and quality data of micro-nano plastics, but also provide the particle size data of micro-nano plastics. The present invention can detect plastic particles from nanometers to micrometers, with a detection limit of ng / L. The present invention effectively overcomes the problem that the existing methods have cumbersome extraction steps and cannot accurately extract nanoplastics. It also solves the problem that the existing methods cannot simultaneously provide the particle size distribution, type and quality results of micro-nano plastics.

[0034] The present invention innovatively solves the problems of low extraction efficiency, easy contamination, and inaccurate qualitative and quantitative analysis of micro-nano plastics in biological fluids through oxidative digestion, ultrasonic fragmentation, micro-concentration, and thermal cracking / thermal desorption-gas chromatography-mass spectrometry. Each technology works synergistically, and any single application cannot solve any problem.

[0035] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0036] (1) The present invention greatly simplifies the extraction method of micro-nano plastics in biological fluids, greatly improves the extraction efficiency, and reduces the problem of micro-nano plastic pollution introduced by excessive steps in previous methods.

[0037] (2) The present invention can not only extract microplastics and nanoplastics simultaneously, but also accurately and quantitatively detect the types, qualities and particle size ranges of microplastics and nanoplastics in biological fluids, providing key technical support for the subsequent accurate assessment of the pollution status and health risk research of microplastics and nanoplastics in organisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is the principle diagram of the method of the present invention;

[0039] Figure 2The particle size distribution, types and concentration diagram of microplastics and nanoplastics extracted and detected in human semen by the present invention;

[0040] Figure 3 The particle size distribution, types and concentration of microplastics and nanoplastics in human follicular fluid are extracted and detected for the present invention. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0042] Example 1

[0043] A simple method for extracting and accurately quantitatively analyzing micro-nanoplastics in biological fluids. The specific steps for extracting and quantitatively detecting microplastics and nanoplastics in animal semen are as follows:

[0044] (1) Oxidative digestion of human semen samples: accurately weigh 1 mL of semen, add 3 mL of hydrogen peroxide solution (30%, V / V), set the digestion condition at 65°C, digest until the digestion solution is clear, and then heat and evaporate to dryness.

[0045] (2) Ultrasonic treatment of digestion solution: After evaporation, add 5 mL of anhydrous ethanol, ultrasonicate at 200 W for 10 min, and collect the ultrasonicate solution. Repeat the above ultrasonic rinse process 3 times.

[0046] (3) Take 5 mL of the solution after ultrasound in step (2) and use a laser particle size analyzer to detect the particle size distribution range of the micro-nano plastic.

[0047] (4) Separation of microplastics: Use a glass fiber membrane with a pore size of 1 μm that has been heated in a muffle furnace at 500° C. for 3 h to filter the remaining solution that has been ultrasonically rinsed in step (2) to separate the microplastics, and collect the filtrate.

[0048] (5) Concentrating nanoplastics: Collect the filtrate in step (4) and gradually transfer it into a 15 mL quartz sample boat. After heating at 100° C. to evaporate to dryness, collect the quartz sample boat.

[0049] (6) Quantitative analysis of micro-nano plastic content: Use thermal desorption-gas chromatography-mass spectrometry to detect the microplastic content on the glass fiber membrane in step (4) and the nanoplastic content in the quartz sample boat in step (5).

[0050] Step (6) Specific testing conditions:

[0051] Cracking conditions: starting temperature of 60°C, ending temperature of 600°C, holding for 10 min, heating rate of 15°C / min, nitrogen flow rate of 120 mL / min.

[0052] Thermal desorption conditions: 300℃; adsorption tube desorption time: 10min; nitrogen blow flow: 40mL / min; desorption flow: 40mL / min; cold trap purge time: 1min; cold trap purge flow: 50mL / min; cold trap low temperature: 30℃; cold trap high temperature: 300℃; cold trap desorption time: 4min; split ratio: 10:1, split rate: 30mL / min.

[0053] Gas phase conditions: injection port temperature: 120°C, splitless injection; column flow rate: 1.5 mL / min; programmed temperature: initial temperature 35°C, hold for 5 min, increase to 260°C at a rate of 10°C / min, hold for 10 min; transfer line temperature: 260°C; carrier gas: He.

[0054] Mass spectrometry conditions: ion source temperature: 230°C; quadrupole temperature: 150°C; voltage: 70 eV. Data acquisition mode: full scan (Scan), scanning range: 35-350 amu.

[0055] like Figure 2 As shown, the present invention successfully extracted micro-nano plastics from human semen samples, and the particle size range of the micro-nano plastics in the sample was measured to be 5nm-20μm, of which the main particle size was between 5nm-1μm (accounting for up to 91%), and the main components were polystyrene, polyethylene, polypropylene, polyvinyl chloride, polylactic acid and polyethylene terephthalate. Among them, the content of polypropylene in micro-nano plastics was the highest, reaching 690 and 540ng / mL respectively.

[0056] Example 2

[0057] A simple method for extracting and accurately quantitatively analyzing micro-nanoplastics in biological fluids. The specific steps for extracting and quantitatively detecting microplastics and nanoplastics in animal follicular fluid are as follows:

[0058] (1) Oxidative digestion of human follicular fluid samples: Accurately weigh 1 mL of semen, add 5 mL of nitric acid solution (70%, V / V), set the digestion condition to 65°C, digest until the digestion solution is clear, and then heat and evaporate to dryness.

[0059] (2) Ultrasonic treatment of digestion solution: evaporate to dryness, add 7 mL of anhydrous ethanol, ultrasonicate at 200 W for 10 min, and collect the solution after ultrasonication. Repeat the above rinsing process 3 times.

[0060] (3) Take 5 mL of the ultrasonic solution and use a laser particle size analyzer to detect the particle size distribution range of the micro-nano plastic.

[0061] (4) Separation of microplastics: Use a glass fiber membrane with a pore size of 1 μm that has been heated in a muffle furnace at 500° C. for 3 h to filter the remaining solution that has been ultrasonically rinsed in step (2) to separate the microplastics, and collect the filtrate.

[0062] (5) Concentrating nanoplastics: Collect the filtrate in step (4) and gradually transfer it into a 15 mL quartz sample boat. After heating at 100° C. to evaporate to dryness, collect the quartz sample boat.

[0063] (6) Quantitative analysis of micro-nano plastic content: Use thermal desorption-gas chromatography-mass spectrometry to detect the microplastic content on the glass fiber membrane in step (4) and the nanoplastic content in the quartz sample boat in step (5).

[0064] Step (6) Specific testing conditions:

[0065] Cracking conditions: starting temperature of 60°C, ending temperature of 600°C, holding for 10 min, heating rate of 15°C / min, nitrogen flow rate of 120 mL / min.

[0066] Thermal desorption conditions: 300℃; adsorption tube desorption time: 10min; nitrogen blow flow: 40mL / min; desorption flow: 40mL / min; cold trap purge time: 1min; cold trap purge flow: 50mL / min; cold trap low temperature: 30℃; cold trap high temperature: 300℃; cold trap desorption time: 4min; split ratio: 10:1, split rate: 30mL / min.

[0067] Gas phase conditions: injection port temperature: 120°C, splitless injection; column flow rate: 1.5 mL / min; programmed temperature: initial temperature 35°C, hold for 5 min, increase to 260°C at a rate of 10°C / min, hold for 10 min; transfer line temperature: 260°C; carrier gas: He.

[0068] Mass spectrometry conditions: ion source temperature: 230°C; quadrupole temperature: 150°C; voltage: 70 eV. Data acquisition mode: full scan (Scan), scanning range: 35-350 amu.

[0069] The present invention successfully extracted micro-nano plastics from human follicular fluid samples, and the particle size range of the micro-nano plastics in the sample was measured to be 5nm-20μm, of which nano plastics with a main particle size between 500nm-1μm accounted for the largest proportion (27%), and the main components were polypropylene, polyvinyl chloride, polylactic acid and polyethylene terephthalate. Among them, the content of polyethylene terephthalate was the highest in micro-nano plastics, reaching 7.87 and 5.95ng / mL respectively.

[0070] like Figure 3As shown, the present invention successfully extracted micro-nano plastics from human follicular fluid samples, and the particle size range of the micro-nano plastics in the sample was measured to be 5nm-20μm, of which nano plastics with a main particle size between 500nm-1μm accounted for the largest proportion (27%), and the main components were polypropylene, polyvinyl chloride, polylactic acid and polyethylene terephthalate. Among them, the content of polyethylene terephthalate in micro-nano plastics was the highest, reaching 7.87 and 5.95ng / mL respectively.

Claims

1. A method for simply extracting and accurately qualitatively and quantitatively analyzing micro-nano plastics in biological fluids, characterized in that: The steps include: (1) Oxidative digestion of biological fluid samples: using strong oxidants to heat and digest biological fluids; (2) ultrasonically treating the digestion solution: after the digestion in step (1), evaporate to dryness, add a rinse solution and perform ultrasonic treatment; (3) Detection of micro-nano plastic particle size: taking a portion of the solution in step (2) and analyzing the micro-nano plastic particle size distribution therein; (4) Separating microplastics: filtering the remaining solution in step (2) to separate the microplastics, and collecting the filtrate; (5) Concentrating and enriching the nanoplastics: heating and volatilizing the filtrate in the above step (4) to dryness; (6) Qualitative and quantitative analysis of micro-nano plastic content: Use pyrolysis / thermal desorption-gas chromatography-mass spectrometry to detect the type and quality of microplastics in the above step (4) and nanoplastics in step (5).

2. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1 is characterized in that: The biological fluid in step (1) includes human or animal blood, semen, follicular fluid, cerebrospinal fluid, saliva, digestive fluid, urine or sweat.

3. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1 is characterized in that: The strong oxidant in step (1) is a mixed liquid of one or more of hydrogen peroxide, nitric acid, sulfuric acid or Fenton's reagent.

4. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1, characterized in that: The heating digestion conditions in step (1) are 60-100° C., and the volume ratio of the strong oxidant to the biological liquid is 1:3-1:5; and the digestion is terminated by heating and evaporating after the digestion liquid becomes clear and transparent.

5. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1 is characterized in that: The rinse solution in step (2) is one or more of ethanol, isopropanol, and pure water.

6. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1, characterized in that: The amount of the rinse solution added in step (2) is 1-10 times the volume of the initial biological fluid; the ultrasonic treatment conditions are: ultrasonic treatment at 100-500w for 10-20min; the ultrasonic treatment step needs to be repeated 3-4 times.

7. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1, characterized in that: The laser particle size analyzer used to analyze the particle size distribution in step (3) is preferably a particle size analyzer covering the nanometer and micrometer detection ranges.

8. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1, characterized in that: The filter membrane in step (4) is a glass fiber membrane or a metal membrane with a pore size of 1-5000 μm. The filter membrane needs to be heated at 500° C. for 2-4 hours before use.

9. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1, characterized in that: In step (5), the filtrate is directly transferred to a sample boat; the sample boat is made of quartz or metal; and the heating volatilization condition is 100-150°C.

10. The method for simple extraction and accurate qualitative and quantitative analysis of micro-nano plastics in biological fluids according to claim 1, characterized in that: The thermal cracking / thermal desorption-gas chromatography-mass spectrometry detection conditions in step (6) are as follows: Pyrolysis conditions: starting temperature 50-60°C, ending temperature 600-700°C, hold 10-15min, 10-15°C / min heating rate, nitrogen flow rate 100-120mL / min; Thermal desorption conditions: 250-350℃; adsorption tube desorption time: 10-15min; nitrogen blowing flow rate: 40-60mL / min; desorption flow rate: 40-60mL / min; cold trap purge time: 1-2min; cold trap purge flow rate: 50mL / min; cold trap low temperature: 25-35℃; cold trap high temperature: 300-400℃; cold trap desorption time: 3-5min; split ratio: 10:1 to 100:1, split rate: 30mL / min; Gas phase conditions: injection port temperature: 100-130°C, splitless injection; column flow rate: 1.2-1.5 mL / min; program temperature rise: initial temperature 30-35°C, hold for 5-10 min, increase to 260-300°C at a rate of 8-10°C / min, hold for 10-15 min; transfer line temperature: 260-300°C; carrier gas: He; Mass spectrometry conditions: ion source temperature: 220-250°C; quadrupole temperature: 150°C; voltage: 70 eV; data acquisition mode: full scan (Scan), scanning range: 30-400 amu.

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