Method for determining phenolic antioxidants in heated cigarette filter

Abstract

The invention relates to a method for determining phenolic antioxidants in a heated cigarette filter, and belongs to the technical field of tobacco analysis. According to the method for determining the phenolic antioxidant in the heated cigarette filter, the heated cigarette filter to be detected is subjected to oscillation extraction by adopting the organic solution containing the internal standard substance to obtain the liquid to be detected, the method has the advantage of simple treatment process, then the liquid to be detected is subjected to gas chromatography-mass spectrometry analysis and detection, and the detection accuracy is high. The phenolic antioxidant can be well separated, and the detection sensitivity and the detection result accuracy are improved. An internal standard method is adopted for quantification, and the influence of operation conditions on analysis results is eliminated. When the filter tip containing the phenolic antioxidant is measured by adopting the method disclosed by the invention, the detection limits of 2, 6-di-tert-butyl p-methylphenol, 2, 4-di-tert-butyl phenol and 2, 2-methylene bis (4-methyl-6-tert-butyl phenol) are 0.05 mu g / mL, 0.07 mu g / mL and 0.11 mu g / mL respectively.

Description

Technical Field

[0001] The invention relates to a method for determining phenolic antioxidants in a heated cigarette filter, belonging to the technical field of tobacco analysis. Background Art

[0002] Heated cigarettes are a new type of tobacco product that produces smoke by low-temperature distillation of tobacco core sheets under heating without burning conditions. The filter rods of heated cigarettes require the use of hot melt adhesive for cigarettes during the molding process, and a certain amount of antioxidants are often added in the production of hot melt adhesives to enhance the stability of the product. In addition, a certain proportion of adhesives are added to the core sheets of heated cigarettes during the preparation process to increase the tensile strength of the sheets. These adhesives usually add a certain amount of antioxidants to increase the strength and toughness of the adhesive. The various components in the core sheets of heated cigarettes can be converted into smoke aerosols after being atomized by heated cigarette smoking utensils, and enter the human body after being inhaled by smokers. The filter tip serves as a bridge between the smoker and the cigarette smoke. It can not only intercept the smoke components, but also some components in the filter tip can be brought into the smoker's mouth with the smoke. Therefore, accurate measurement of antioxidants in the filter tip is of great significance for studying the filter tip's filtering and intercepting effect on antioxidants. At present, domestic and international laws and regulations and standards on food contact materials stipulate the permitted antioxidants and usage requirements, but there is no exact limit on the content of phenolic antioxidants in heated cigarette filters. These situations will pose safety risks to heated cigarette products.

[0003] Commonly used phenolic antioxidants in heated cigarettes include 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). At present, the analysis methods for 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2'-methylenebis(4-methyl-6-tert-butylphenol) at home and abroad are mainly concentrated in the sample detection of food, chemical industry and other industries. The commonly used methods are mainly high performance liquid chromatography, colorimetry, ultraviolet spectrometry, gas chromatography and gas chromatography-mass spectrometry. Chinese patent documents CN103115971A, CN104198605A and CN114235986A all use liquid chromatography to separate phenolic antioxidants in hot melt adhesives, water-based adhesives or tobacco flavors and fragrances. The liquid chromatography test relies on retention time to perform qualitative analysis on the sample content, which may result in false positives for complex sample matrices, has low detection sensitivity, and has large errors in the test results.

[0004] At present, there is no research report on the analytical method of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2'-methylenebis(4-methyl-6-tert-butylphenol) in heated cigarette filters. In view of the widespread use of phenolic antioxidants in heated cigarettes and their potential health risks to the human body, it is very necessary to provide a method for the determination of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2'-methylenebis(4-methyl-6-tert-butylphenol) in heated cigarette filters with high sensitivity and high detection accuracy. Summary of the invention

[0005] The purpose of the present invention is to provide a method for determining phenolic antioxidants in heated cigarette filters, which can solve the problem of low sensitivity in the current detection of phenolic antioxidants in tobacco products.

[0006] In order to achieve the above objectives, the technical solution adopted by the method for determining the phenolic antioxidant in the heated cigarette filter of the present invention is:

[0007] A method for determining phenolic antioxidants in heated cigarette filters comprises the following steps: subjecting the heated cigarette filters to be detected to oscillation extraction using an organic solution containing an internal standard to obtain an extract, and then subjecting the extract to gas chromatography-mass spectrometry analysis and detection, and using an internal standard method to determine the content of the phenolic antioxidants in the heated cigarette filters to be detected; the stationary phase in the chromatographic column used in the gas chromatography analysis is 35% phenylmethylpolysiloxane, and the mass spectrometry analysis adopts a full scan and selected ion monitoring simultaneous mode.

[0008] The method for determining phenolic antioxidants in heated cigarette filters of the present invention comprises the following steps: ultrasonically extracting the heated cigarette filters to be detected using an organic solution containing an internal standard to obtain a test liquid, which has the advantage of a simple processing process; then the test liquid is subjected to gas chromatography-mass spectrometry analysis and detection, which can better separate phenolic antioxidants and improve detection sensitivity and accuracy of detection results. At the same time, the present invention adopts an internal standard method for quantification, which eliminates the influence of operating conditions on the analysis results compared to the external standard method, thereby improving the accuracy of the determination results. When the method of the present invention is used to determine the filter containing phenolic antioxidants, the detection limits of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) are 0.05 μg / mL, 0.07 μg / mL and 0.11 μg / mL, respectively. The method for determining the phenolic antioxidant in the heated cigarette filter of the present invention has high precision and recovery rate, stable determination results, simple pretreatment, and is suitable for simultaneous rapid quantitative detection of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) in large batches of samples.

[0009] Preferably, the phenolic antioxidant is one, two or three of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol).

[0010] Preferably, the organic solution containing the internal standard consists of an internal standard and an organic solvent, the internal standard is D8-acetophenone, the organic solvent is dichloromethane or methyl tert-butyl ether, and the concentration of the internal standard is 3-5 μg / mL.

[0011] Preferably, the method for calculating the content of phenolic antioxidants in the heated cigarette filter to be tested by the standard curve method is as follows: first, standard solutions of different concentrations are subjected to gas chromatography-mass spectrometry analysis and detection to obtain mass spectra of each standard solution, and then the concentration ratio of the phenolic antioxidant and the internal standard in the standard solution and the ratio of the quantitative ion peak areas of the phenolic antioxidant and the internal standard in the mass spectrum of the standard solution are linearly fitted to obtain the regression equation of the standard curve, and then the ratio of the quantitative ion peak areas of the phenolic antioxidant and the internal standard in the mass spectrum of the extract is substituted into the regression equation of the standard curve to calculate the content of the phenolic antioxidant in the heated cigarette filter to be tested; the standard solution is composed of an organic solvent, an internal standard and a phenolic antioxidant, the internal standard is D8-acetophenone, the organic solvent is dichloromethane or methyl tert-butyl ether, and the concentration of the internal standard is 3-5 μg / mL.

[0012] Preferably, the chromatographic column for gas chromatography analysis is a VF-35MS capillary column, the carrier gas flow rate is 1.2-1.8 mL / min, the injection port temperature is 250-280°C, the injection volume is 1-2 μL, the split ratio is 10:1, and the heating process is: the initial temperature is 60-100°C and maintained for 3-5 minutes, then heated to 160-200°C at a rate of 2-4°C / min, and then heated to 260-290°C at a rate of 15-20°C / min and maintained for 10-20 minutes.

[0013] Preferably, the solvent delay time during mass spectrometry analysis is 7 to 9 minutes, the ion source temperature is 230 to 250° C., the transmission line temperature is 250 to 280° C.; and the scanning range of the full scan is 35 amu to 350 amu.

[0014] Preferably, in the selected ion monitoring mode, two ions are selected for monitoring of the phenolic antioxidant and the internal standard respectively; the phenolic antioxidants are 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol); the quantitative ion of 2,6-di-tert-butyl-p-methylphenol is 205, and the qualitative ion is 220, the quantitative ion of 2,4-di-tert-butylphenol is 206, and the qualitative ion is 191, and the quantitative ion of 2,2-methylenebis(4-methyl-6-tert-butylphenol) is 177, and the qualitative ion is 340; the internal standard is D8-acetophenone, and the quantitative ion of D8-acetophenone is 110, and the qualitative ion is 128.

[0015] Preferably, the oscillation extraction is ultrasonic oscillation or mechanical oscillation.

[0016] Preferably, the ultrasonic frequency during ultrasonic oscillation is 40 to 60 kHz, and the time is 20 to 30 min; the stirring rate during mechanical oscillation is 150 to 200 r / min, and the time is 60 to 120 min.

[0017] Preferably, the volume of the organic solution containing the internal standard used for every 2 to 4 heated cigarette filters to be tested is 10 to 20 mL.

[0018] The heated cigarette filter to be tested in the present invention can be a heated cigarette filter before smoking, or can be a heated cigarette filter after smoking. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the mass spectrum peak spectrum of the standard solution in the embodiment of the present invention. DETAILED DESCRIPTION

[0020] The method for determining phenolic antioxidants in heated cigarette filters of the present invention is a pioneering invention. The method for determining phenolic antioxidants in heated cigarette filters of the present invention aims at the problem that the antioxidant content of cigarette filters is determined by liquid chromatography in the prior art, which has low sensitivity and large error in the detection results. A gas chromatography-mass spectrometry analysis and detection method is proposed, which has the advantages of high sensitivity and accurate results.

[0021] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0022] Example

[0023] The method for determining the phenolic antioxidant in the heated cigarette filter of this embodiment specifically comprises the following steps:

[0024] (1) Sample pretreatment

[0025] Take 2 commercially available heated cigarettes, and then use a heated cigarette smoking device to smoke the heated cigarettes, collect the filter after smoking, cut the filter longitudinally along the filter axis with a blade, and obtain the filter sample to be tested, place the filter sample to be tested in a 50mL centrifuge tube, and then add an organic solution containing an internal standard to the centrifuge tube for oscillation extraction. After the extraction is completed, let it stand for 10 minutes, and the upper clear liquid is the extract; the organic solution containing the internal standard is composed of an organic solvent and an internal standard, the organic solvent is dichloromethane, the internal standard is D8-acetophenone, the concentration of the internal standard in the organic solution containing the internal standard is 3μg / mL, and the volume of the organic solution containing the internal standard is 15mL. The oscillation extraction is ultrasonic oscillation extraction, the ultrasonic oscillation frequency is 60kHz, and the oscillation extraction time is 30min.

[0026] (2) Determination of standard working curve

[0027] A series of standard solutions were prepared. The standard solutions consisted of dichloromethane, internal standard substances and antioxidants. The antioxidants were 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol). The internal standard substance was D8-acetophenone. The concentration of the internal standard substance in the standard solution was 3 μg / mL. The concentration of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) in each series of standard solutions was 3 μg / mL. The concentrations of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) were the same, which were 0.2, 0.5, 1.0, 2.0, 5.0, 7.5 and 10.0 μg / mL respectively; each standard solution was then analyzed and detected by gas chromatography-mass spectrometry to obtain the mass spectrum peak spectra of each standard solution. The mass spectrum peak spectra of the standard solutions when the concentrations of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) were all 5.0 μg / mL were as follows: Figure 1 As shown, Figure 1 Here, 1 represents the internal standard D8-acetophenone, 2 represents the antioxidant 2,6-di-tert-butyl-p-methylphenol, 3 represents the antioxidant 2,4-di-tert-butylphenol, and 4 represents the antioxidant 2,2-methylenebis(4-methyl-6-tert-butylphenol).

[0028] Then, according to the mass spectrometry peak spectrum, the ratio of the quantitative ion peak area of ​​the antioxidant to the quantitative ion peak area of ​​the internal standard, and the ratio of the antioxidant concentration to the internal standard concentration are subjected to linear regression analysis to obtain a linear regression equation. In specific implementation, the ratio of the quantitative ion peak area of ​​the antioxidant to the quantitative ion peak area of ​​the internal standard is used as the ordinate, and the ratio of the antioxidant concentration to the internal standard concentration is used as the abscissa to draw the linear standard working curve of each antioxidant, that is, to obtain the linear regression equation of each antioxidant. The linear regression equation of each antioxidant, the linear concentration range of the linear regression equation, and the standard deviation R of the linear regression equation 2The detection limits and quantification limits of each antioxidant are shown in Table 1.

[0029] Table 1 Linear regression equations, linear concentration ranges, and R values ​​of each antioxidant 2 And the detection limit and quantification limit of each antioxidant

[0030]

[0031] As shown in Table 1, within the linear concentration range, the standard working curves of the three antioxidants are all linear and suitable for quantitative analysis. The detection limits of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) are 0.05 μg / mL, 0.07 μg / mL and 0.11 μg / mL, respectively, which can meet the detection requirements of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) in heated cigarette filters.

[0032] (3) Determination of phenolic antioxidants in the extract

[0033] 1 mL of the extract obtained in step (1) is added to a 2 mL chromatographic bottle, and analyzed and detected by gas chromatography-mass spectrometry to obtain a mass spectrum peak spectrum of the extract, and then, based on the mass spectrum peak spectrum, the ratio of the quantitative ion peak area of ​​the phenolic antioxidant in the extract to the quantitative ion peak area of ​​the internal standard is obtained, and then the obtained ratio is substituted into the standard working curve (linear regression equation) in step (2) to obtain the ratio of the concentration of the phenolic antioxidant in the extract to the concentration of the internal standard, and then the concentration of the phenolic antioxidant in the extract is calculated according to the concentration of the internal standard in the extract, and finally, the content of the phenolic antioxidant in the filter tip sample to be tested is calculated according to the volume of the extract and the concentration of the phenolic antioxidant. In this embodiment, the measurement results are as follows: the contents of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) in the filter samples to be tested corresponding to 2 commercially available heated cigarettes are 0.95, 4.32 and 3.58 μg / cigarette, respectively.

[0034] In this embodiment, the detection conditions of gas chromatography-mass spectrometry in step (2) and step (3) are as follows:

[0035] Gas chromatography was performed using a gas chromatograph (GC), and the chromatographic column used was a VF-35MS capillary column (30 m long, 0.25 mm inner diameter, 1.0 μm film thickness); the carrier gas was helium, and the carrier gas flow rate was 1.8 mL / min; the injection port temperature was 280°C; the injection volume was 1 μL, split injection, and the split ratio was 10:1; the temperature was raised in a programmed temperature rise mode, and the heating process was as follows: the initial temperature was maintained at 100°C for 3 min, then the temperature was raised to 200°C at a rate of 4°C / min, and then the temperature was raised to 290°C at a rate of 20°C / min and then maintained for 10 min, and the total operating time was 42.5 min;

[0036] The mass spectrometer was detected by a mass spectrometer detector (MSD) with a solvent delay time of 7 min, an ionization voltage of 70 eV, an ion source temperature of 230 °C, a transfer line temperature of 280 °C, and a scanning mode of full scan and selected ion monitoring. In the full scan monitoring mode, the scanning range was 35 amu to 350 amu. In the selected ion monitoring mode (SIM), the quantitative ion of 2,6-di-tert-butyl-p-methylphenol was 205, the qualitative ion was 220, and the retention time was 23.8 min. The quantitative ion of 2,4-di-tert-butylphenol was 206, the qualitative ion was 191, and the retention time was 24.1 min. The quantitative ion of 2,2-methylenebis(4-methyl-6-tert-butylphenol) was 177, the qualitative ion was 340, and the retention time was 37.3 min. The quantitative ion of D8-acetophenone was 110, the qualitative ion was 128, and the retention time was 11.4 min.

[0037] In other embodiments, the dichloromethane in step (1) and step (2) is replaced by methyl tert-butyl ether; or the concentration of the internal standard in the organic solution containing the internal standard is adjusted from 3 μg / mL to 5 μg / mL; or the concentration of the internal standard in the standard solution is adjusted from 3 μg / mL to 5 μg / mL; or the carrier gas flow rate during gas chromatography analysis is adjusted to 1.2 mL / min, the injection port temperature is adjusted to 250°C, the injection volume is adjusted to 2 μL, and the heating process is adjusted to: the initial temperature is 60°C and maintained for 5 min, the temperature is increased to 160°C at a rate of 2°C / min, and then the temperature is increased to 260°C at a rate of 15°C / min and maintained for 20 min; or the solvent delay time during mass spectrometry analysis is adjusted to 9 min, the ion source temperature is adjusted to 250°C, and the transmission line temperature is adjusted to 250°C; or ultrasonic oscillation is replaced by mechanical stirring, the stirring rate is 150-200 r / min, and the time is 60-120 min.

[0038] Experimental Example 1

[0039] The same brand and specification of heated cigarette smoking utensils and cigarettes were selected and smoked according to the Canadian deep smoking mode, and the filter tips after smoking were collected. Then, the content of the phenolic antioxidant in the filter tips was determined according to the method of the embodiment, and the intra-day precision of the determination method was investigated by performing 5 parallel smoking and experiments in one day, and the inter-day precision of the determination method was investigated by performing 1 parallel smoking and experiment every day for 5 consecutive days. The experimental results of intra-day precision are shown in Table 2, and the experimental results of inter-day precision are shown in Table 3.

[0040] Table 2 Experimental results of intra-day precision

[0041]

[0042] Table 3 Experimental results of inter-day precision

[0043]

[0044]

[0045] Experimental Example 2

[0046] On the basis of the precision experiment of the test results of the same heated cigarette sample, a recovery experiment was conducted by matrix spike addition. The recovery experiment method is as follows: 36 commercially available heated cigarettes were taken, and the heated cigarettes were smoked using a heated cigarette smoking device, and the filter tips after smoking were collected. Each filter tip was cut longitudinally along the filter tip axis with a blade to obtain the filter tip samples to be tested, a total of 36 filter tip samples to be tested; then, 4 filter tip samples to be tested were added with an equal amount of high-content 2,6-di-tert-butyl-p-methylphenol standard solution, 4 filter tip samples to be tested were added with an equal amount of medium-content 2,6-di-tert-butyl-p-methylphenol standard solution, 4 filter tip samples to be tested were added with an equal amount of low-content 2,6-di-tert-butyl-p-methylphenol standard solution, 4 filter tip samples to be tested were added with an equal amount of high-content 2,4-di-tert-butylphenol standard solution, 4 filter tip samples to be tested were added with an equal amount of medium-content 2,4-di-tert-butylphenol standard solution, and 4 filter tip samples to be tested were added with an equal amount of An equal amount of low-content 2,4-di-tert-butylphenol standard solution was added to 4 filter samples to be tested, an equal amount of high-content 2,2-methylenebis(4-methyl-6-tert-butylphenol) standard solution was added to 4 filter samples to be tested, an equal amount of medium-content 2,2-methylenebis(4-methyl-6-tert-butylphenol) standard solution was added to 4 filter samples to be tested, and an equal amount of low-content 2,2-methylenebis(4-methyl-6-tert-butylphenol) standard solution was added to 4 filter samples to be tested, thereby obtaining 9 groups of experimental samples, each group of experimental samples having 4 filter tips; finally, each experimental sample was subjected to the determination of phenolic antioxidants according to the method of the embodiment, and then the antioxidant content contained in the sample before the standard solution was added was subtracted from the determination result to obtain the detection value of the added antioxidant, and then the antioxidant content added to the sample and the antioxidant detection value were used to calculate the recovery rate, and the results are shown in Table 4. In this experimental example, after the high-content standard solution was added to the filter sample to be tested, the content of antioxidant in the filter sample was 3 times that before the addition of the standard solution. After the medium-content standard solution was added to the filter sample to be tested, the content of antioxidant in the filter sample was 2 times that before the addition of the standard solution. After the low-content standard solution was added to the filter sample to be tested, the content of antioxidant in the filter sample was 1.5 times that before the addition of the standard solution.

[0047] Table 4 Filter sample spike recovery test results

[0048]

[0049] As can be seen from Table 4, when the determination method of the present invention is used to determine the content of phenolic antioxidants in the filter tip, the spiked recoveries of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol) are between 92.5% and 98.3%, 92.7% and 97.6%, and 95.3% and 96.7%, respectively.

[0050] Experimental Example 3

[0051] According to the determination method of the embodiment, the three antioxidants in the filters of 10 domestic heated cigarettes and 5 foreign brand heated cigarettes were determined. The three phenolic antioxidants were detected in the filters of the selected heated cigarettes. The content ranges of the three antioxidants in the filters are shown in Table 5.

[0052] Table 5 Antioxidant content range in different heated cigarettes

[0053] Phenolic antioxidants Content range (μg / vial) 2,6-Di-tert-butyl-p-methylphenol 0.42～2.88 2,4-Di-tert-butylphenol 1.51～18.32 2,2-Methylenebis(4-methyl-6-tert-butylphenol) 1.26～11.43

[0054] As shown in Table 5, the three phenolic antioxidants were detected in the heated cigarette filters, among which 2,4-di-tert-butylphenol was detected in the filter at the highest level, which was 18.32 μg / cigarette, and 2,6-di-tert-butyl-p-methylphenol was detected in a relatively small amount, which was 0.42 μg / cigarette.

Claims

1. A method for determining phenolic antioxidants in heated cigarette filters, characterized in that: The following steps are involved: The heated cigarette filter to be tested is subjected to oscillation extraction using an organic solution containing an internal standard to obtain an extract, which is then subjected to gas chromatography-mass spectrometry analysis and detection, and the content of phenolic antioxidants in the heated cigarette filter to be tested is determined using the internal standard method; the stationary phase in the chromatographic column used in the gas chromatography analysis is 35% phenylmethylpolysiloxane, and the full scan and selected ion monitoring modes are used simultaneously in the mass spectrometry analysis.

2. The method for determining the phenolic antioxidant in the heated cigarette filter according to claim 1, characterized in that: The phenol antioxidant is one, two or three of 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol).

3. The method for determining the phenolic antioxidant in the heated cigarette filter according to claim 1, characterized in that: The organic solution containing the internal standard substance consists of the internal standard substance and an organic solvent. The internal standard substance is D8-acetophenone, the organic solvent is dichloromethane or methyl tert-butyl ether, and the concentration of the internal standard substance is 3-5 μg / mL.

4. The method for determining the phenolic antioxidant in the heated cigarette filter according to claim 1, characterized in that: The method for calculating the content of phenolic antioxidants in the heated cigarette filter to be tested by using the standard curve method is as follows: first, standard solutions of different concentrations are subjected to gas chromatography-mass spectrometry analysis to obtain mass spectra of each standard solution, and then the concentration ratio of the phenolic antioxidant and the internal standard in the standard solution and the quantitative ion peak area ratio of the phenolic antioxidant and the internal standard in the mass spectrum of the standard solution are linearly fitted to obtain the regression equation of the standard curve, and then the quantitative ion peak area ratio of the phenolic antioxidant and the internal standard in the mass spectrum of the extract is substituted into the regression equation of the standard curve to calculate the content of the phenolic antioxidant in the heated cigarette filter to be tested; the standard solution is composed of an organic solvent, an internal standard and a phenolic antioxidant, the internal standard is D8-acetophenone, the organic solvent is dichloromethane or methyl tert-butyl ether, and the concentration of the internal standard is 3-5 μg / mL.

5. The method for determining the phenolic antioxidant in the heated cigarette filter according to any one of claims 1 to 4, characterized in that: The chromatographic column used in gas chromatography analysis is a VF-35MS capillary column, the carrier gas flow rate is 1.2-1.8 mL / min, the injection port temperature is 250-280°C, the injection volume is 1-2 μL, the split ratio is 10:1, and the heating process is as follows: the initial temperature is 60-100°C and maintained for 3-5 min, then heated to 160-200°C at a rate of 2-4°C / min, and then heated to 260-290°C at a rate of 15-20°C / min and maintained for 10-20 min.

6. The method for determining the phenolic antioxidant in the heated cigarette filter according to any one of claims 1 to 4, characterized in that: The solvent delay time during mass spectrometry analysis was 7 to 9 minutes, the ion source temperature was 230 to 250°C, the transfer line temperature was 250 to 280°C; the scanning range of the full scan was 35 amu to 350 amu.

7. The method for determining the phenolic antioxidant in the heated cigarette filter according to any one of claims 1 to 4, characterized in that: In the selected ion monitoring mode, two ions were selected for monitoring of phenolic antioxidants and internal standards respectively; the phenolic antioxidants were 2,6-di-tert-butyl-p-methylphenol, 2,4-di-tert-butylphenol and 2,2-methylenebis(4-methyl-6-tert-butylphenol); the quantification ion of 2,6-di-tert-butyl-p-methylphenol was 205 and the qualifier ion was 220, the quantification ion of 2,4-di-tert-butylphenol was 206 and the qualifier ion was 191, the quantification ion of 2,2-methylenebis(4-methyl-6-tert-butylphenol) was 177 and the qualifier ion was 340; the internal standard was D8-acetophenone, the quantification ion of D8-acetophenone was 110 and the qualifier ion was 128.

8. The method for determining the phenolic antioxidant in the heated cigarette filter according to any one of claims 1 to 4, characterized in that: Oscillation extraction is ultrasonic oscillation or mechanical oscillation.

9. The method for determining the phenolic antioxidant in the heated cigarette filter according to claim 8, characterized in that: The ultrasonic frequency during ultrasonic oscillation is 40-60kHz, and the time is 20-30min; the stirring rate during mechanical oscillation is 150-200r / min, and the time is 60-120min.

10. The method for determining the phenolic antioxidant in the heated cigarette filter according to any one of claims 1 to 4, characterized in that: The volume of the organic solution containing the internal standard substance used for each of the 2 to 4 heated cigarette filters to be tested is 10 to 20 mL.

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