Method for detecting quality stability of natural perfume for cigarettes

Abstract

The invention relates to the field of quality stability of natural flavors for cigarettes, in particular to a method for detecting batch stability and storage stability of natural flavors for cigarettes. The method for detecting the batch stability and the storage stability of the natural perfume for the cigarettes comprises the following steps: 1) determining natural perfume samples for the cigarettes in different batches or in different storage times or the natural perfume samples for the cigarettes and standard substances thereof by utilizing an online thermal cracking-gas chromatography-mass spectrometry analysis technology; and 2) data analysis and detection: comparing the determination results of the tobacco natural perfume samples of different batches or different storage times, or comparing the determination results of the tobacco natural perfume samples and the standard substances thereof, if the comparison results are consistent, determining that the quality stability is good, and if the comparison results are inconsistent, determining that the quality stability is poor. The method provided by the invention can be used for determining volatile components in the natural perfume for cigarettes, can also be used for determining the components after high-temperature combustion of non-expandable components in the natural perfume for cigarettes, can be used for comprehensively and effectively detecting the components of the natural perfume for cigarettes, and comprehensively reflects the aroma quality stability after the natural perfume is applied to cigarettes; therefore, the quality stability of cigarette products can be guaranteed.

Description

Technical Field

[0001] This invention relates to the field of quality stability of natural flavorings for tobacco, and in particular to a method for detecting the quality stability of natural flavorings for tobacco. Background Technology

[0002] Users of tobacco flavorings generally attach great importance to the stability of flavorings, because if the flavorings are unstable, it will lead to the instability of the aroma of the flavoring products, which in turn will affect the instability of the aroma of the cigarette products, resulting in a decrease in consumer acceptance.

[0003] The stability of tobacco flavorings is generally characterized by physicochemical indicators such as density, refractive index, color, acid value, and optical rotation, as well as sensory evaluation methods (olfactory methods). However, these indicators and characterization methods are only applicable to synthetic flavoring products and cannot fully reflect the quality stability of natural tobacco flavorings such as essential oils, absolutes, extracts, resins, and balms. Firstly, in addition to volatile components, natural tobacco flavorings also contain some non-volatile substances, making it difficult to evaluate their intrinsic quality using the aforementioned indicators and methods. Secondly, the chemical composition of natural flavorings is affected by various factors such as origin, year, and processing methods, causing fluctuations in the product's composition. Changes in volatile chemical components ultimately lead to unstable aroma. Thirdly, the non-volatile chemical components in natural tobacco flavorings may degrade during cigarette combustion, causing changes in the aroma of the cigarette product. Consistent aroma composition after smoking more accurately reflects the stability of natural tobacco flavorings.

[0004] Considering the above influencing factors, some researchers use gas chromatography, liquid chromatography, and near-infrared spectroscopy to evaluate and determine the stability of natural flavorings for tobacco products. Tong Lin et al. invented a method for evaluating the quality stability of natural tobacco flavorings using chromatographic similarity (CN 201510206249.2), disclosing a method for evaluating the quality stability of natural tobacco flavorings using chromatographic similarity. This invention first pre-treats the natural tobacco flavoring, then uses gas chromatography-mass spectrometry (GC-MS) or liquid chromatography to pre-treat and chromatographically analyze standard samples and samples of natural tobacco flavoring to be evaluated, respectively, to obtain chromatograms of the standard samples and the samples of natural tobacco flavoring to be evaluated. Finally, the chromatograms of the standard samples and the samples of natural tobacco flavoring to be evaluated are compared and judged using degree similarity to determine the stability of the samples of natural tobacco flavoring to be evaluated. This invention uses multiple pre-treatment methods to process complex natural flavoring samples. During the processing, hydrolysis, alcoholysis, or filtration to remove insoluble components may occur, therefore it cannot truly and comprehensively reflect the true quality and stability of the product. Gao Li et al. invented "A Method for Rapidly Evaluating the Quality Consistency of Volatile Tobacco Flavorings and Fragrances Using HS-IMR-MS (Application No. CN201611026536.6)," disclosing a method for rapidly evaluating the quality consistency of volatile tobacco flavorings and fragrances using HS-IMR-MS. This method utilizes a headspace sampler and IMR-MS to obtain the response values ​​of each volatile compound ion in the flavorings and fragrances, plots a mass spectrometry fingerprint, and combines this with similarity analysis to achieve rapid detection of the quality consistency of tobacco flavorings and fragrances. However, this method, using a headspace sampler, can only collect individual volatile compounds and is ineffective for non-volatile substances in natural flavorings. Therefore, it cannot comprehensively characterize the product quality, as non-volatile components can also affect the aroma of cigarette products. Huang Shansong et al. invented "A Method and Procedure for Rapid Analysis of the Quality Stability of Flavors and Fragrances" (CN201710124560.1), which discloses a method for rapidly analyzing the quality stability of flavors and fragrances. This method uses a near-infrared spectrometer to scan the spectra of flavors and fragrances produced by the same manufacturer and brand at different times. Principal component analysis (PCA) is performed on the scanned spectra, and the features of each spectrum are extracted using weighted correlation coefficients. Then, all near-infrared spectra are arranged row-wise to obtain a data matrix. Weighted correlation coefficients are applied to the matrix, and principal components are calculated using eigenvectors. By calculating the weighted correlation coefficients, the stability identification interval is determined, and a rapid WCC analysis model for that brand of flavor and fragrance is established. However, near-infrared spectroscopy requires modeling and maintenance, and its sensitivity to complex natural flavor samples is insufficient. Trace amounts of low-threshold aroma components can sometimes contribute significantly to the aroma of natural flavors, sometimes even determining it. Therefore, near-infrared spectroscopy has significant drawbacks.

[0005] Given the problems mentioned above, there is an urgent need to establish some rapid, efficient and simple analytical methods for the detection and control of flavoring quality stability. In particular, it is essential to establish a method for detecting the quality stability of natural flavorings for tobacco by measuring the consistency of components of natural flavorings after being heated at high temperatures. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for detecting the quality stability of natural flavorings for tobacco, in order to solve the problems in the prior art.

[0007] To achieve the above and other related objectives, the present invention provides a method for detecting the quality stability of natural flavorings for tobacco products, the method comprising the following steps:

[0008] 1) The samples of natural tobacco flavorings from different batches or stored for different times, or the samples of natural tobacco flavorings and their standards, were analyzed using online pyrolysis-gas chromatography-mass spectrometry.

[0009] 2) Data analysis and testing: Compare the test results of different natural flavoring samples for tobacco, or compare the test results of natural flavoring samples for tobacco and their standards. If the comparison results are consistent, the quality stability is considered to be good.

[0010] If the comparison results are inconsistent, the quality stability is considered poor.

[0011] As described above, the method for detecting the quality stability of natural flavorings for tobacco products of the present invention has the following beneficial effects:

[0012] (1) This invention innovatively provides a method using online pyrolysis-gas chromatography-mass spectrometry to detect the stability of natural flavorings for tobacco by measuring and comparing the consistency of components after being heated at high temperatures. In particular, it measures the stability between different batches and the stability over different storage times. This method changes the traditional limitations of using physicochemical indicators such as density, refractive index, color, acid value, and optical rotation, as well as sensory detection methods (olfactory method) to characterize the stability of the quality of natural flavorings for tobacco.

[0013] (2) The present invention does not pre-treat the natural fragrances, thus avoiding human error caused by pre-treatment.

[0014] (3) This invention can measure both the volatile components in natural flavorings for tobacco and the components of non-volatile components after high-temperature combustion. It can comprehensively and effectively detect the components of natural flavorings for tobacco, fully reflect the aroma quality stability after their application in cigarettes, and thus ensure the quality stability of cigarette products.

[0015] (4) The present invention can accurately, quickly, efficiently and easily determine and detect the stability between different batches and the stability at different storage times of natural flavorings for tobacco. Attached Figure Description

[0016] Figure 1 The diagram shown illustrates the batch stability of lemon oil pyrolysis according to the present invention.

[0017] Figure 2 The diagram shows the batch stability of the jujube tincture pyrolysis according to the present invention.

[0018] Figures 2-1 to 2-5 for Figure 2 A magnified view of a portion of the image.

[0019] Figure 3 The diagram shown illustrates the batch stability of apple juice pyrolysis according to the present invention.

[0020] Figures 3-1 to 3-4 for Figure 3 A magnified view of a portion of the image.

[0021] Figure 4 The diagram shows the storage stability of lemon oil according to the present invention.

[0022] Figures 4-1 to 4-5 for Figure 4 A magnified view of a portion of the image. Detailed Implementation

[0023] This invention addresses the problems of existing methods for detecting the stability of natural flavorings in tobacco products, such as complex operation, incomplete reflection, and low sensitivity. It provides a method for detecting the quality stability of natural flavorings in tobacco products, comprising the following steps:

[0024] 1) Different samples of natural tobacco flavorings or samples of natural tobacco flavorings and their standards were analyzed using online pyrolysis-gas chromatography-mass spectrometry.

[0025] 2) Data Analysis and Testing: Compare the test results of natural flavoring samples for tobacco from different batches or with different storage times, or compare the test results of natural flavoring samples for tobacco with their standards. If the comparison results are consistent,

[0026] If the comparison results are inconsistent, the quality stability is considered good; if the comparison results are inconsistent, the quality stability is considered poor.

[0027] In some embodiments of the present invention, the different natural tobacco flavoring samples mentioned in step 1) are natural tobacco flavoring samples from different batches or natural tobacco flavoring samples with different storage times.

[0028] In some embodiments of the present invention, the natural flavoring sample for tobacco use in step 1) is a liquid natural flavoring sample for tobacco use. The liquid natural flavoring sample for tobacco use is selected from one or more of essential oils, absolute oils, tinctures, and fruit juices.

[0029] In some other embodiments of the present invention, the natural flavoring sample for tobacco use in step 1) is a paste-like natural flavoring sample for tobacco use. The paste-like natural flavoring sample for tobacco use is selected from extracts or pastes.

[0030] In some embodiments of the present invention, step 1) further includes sample pretreatment. The sample pretreatment method involves transferring the natural tobacco flavoring sample onto quartz wool, wherein the quartz wool is pre-filled onto a quartz pyrolysis rod, and the quartz pyrolysis rod is pre-filled into a quartz pyrolysis tube. In some embodiments of the present invention, the quartz wool is pesticide residue grade quartz wool. The mass of the quartz wool is 1–3 mg. The mass of the quartz wool is selected from any of the following ranges: 1–2 mg, 2–3 mg.

[0031] In some embodiments of the present invention, in step 1), when the natural flavoring sample for tobacco is in liquid state, the natural flavoring sample for tobacco is transferred by using a syringe or pipette. The volume of the natural flavoring sample for tobacco is 1-5 μL. The volume of the natural flavoring sample for tobacco is selected from any of the following ranges: 1-2 μL, 2-3 μL, 3-4 μL, 4-5 μL.

[0032] In some other embodiments of the present invention, in step 1), when the natural flavoring sample for tobacco is in paste form, the sample is weighed first and then transferred. The mass of the natural flavoring sample for tobacco is 1–3 mg. The mass of the natural flavoring sample for tobacco is selected from any of the following ranges: 1–1.5 mg, 1.5–2 mg, 2–2.5 mg, 2.5–3 mg.

[0033] In some embodiments of the present invention, in step 1), when the natural flavoring sample for tobacco is in paste form, the method further includes filling the natural flavoring sample for tobacco onto quartz wool on a quartz pyrolysis rod and then covering the natural flavoring sample for tobacco with quartz wool.

[0034] In some embodiments of the present invention, step 1) further includes preparing a blank sample. The method for preparing the blank sample is the same as that for preparing natural flavoring samples for tobacco, but without adding the sample to be tested.

[0035] In some embodiments of the present invention, the pyrolysis gas of the pyrolysis apparatus is a nitrogen-oxygen mixture or air with oxygen comprising 8.5% to 9.5%. The oxygen percentage in the nitrogen-oxygen mixture is selected from any of the following ranges: 8.5% to 8.7%, 8.7% to 8.9%, 8.9% to 9.1%, 9.1% to 9.3%, and 9.3% to 9.5%.

[0036] In some embodiments of the present invention, the gas flow rate of the pyrolysis gas is 40–100 mL / min. The flow rate is selected from any of the following ranges: 40–50 mL / min, 50–60 mL / min, 60–70 mL / min, 70–80 mL / min, 80–90 mL / min, 90–100 mL / min.

[0037] In some embodiments of the present invention, the pyrolysis temperature rise program of the pyrolysis apparatus is as follows: initial temperature 100–300°C, held for 5–60 s, then increased to 400–900°C at a rate of 10–30°C / s, and held for 5–300 s. The initial temperature is selected from any of the following ranges: 100–150°C, 150–200°C, 200–250°C, or 250–300°C. The holding time at the initial temperature of 100–300°C is any of the following ranges: 5–10 s, 10–20 s, 20–30 s, 30–40 s, 40–50 s, or 50–60 s. The temperature is increased to 400–900°C at any of the following rates: 10–15°C / s, 15–20°C / s, 20–25°C / s, or 25–30°C / s. Increase the temperature at a rate of 10–30℃ / s to any of the following ranges: 400–500℃, 500–600℃, 600–700℃, 700–800℃, or 800–900℃. The holding time at 400–900℃ is selected from any of the following ranges: 5–50s, 50–100s, 100–150s, 150–200s, 200–250s, or 250–300s.

[0038] In some embodiments of the present invention, after pyrolysis is completed, helium purging is switched on, and the post-pyrolysis operation is maintained for 0.5 to 1.5 min. The operation time is selected from any of the following ranges: 0.5 to 0.7 min, 0.7 to 0.9 min, 0.9 to 1.1 min, 1.1 to 1.3 min, and 1.3 to 1.5 min.

[0039] In some embodiments of the present invention, the valve box temperature of the pyrolysis apparatus is 250–280°C. The valve box temperature is selected from any of the following ranges: 250–260°C, 260–270°C, or 270–280°C.

[0040] In some embodiments of the present invention, the transmission line temperature of the pyrolysis apparatus is 250–280°C. The transmission line temperature is selected from any of the following ranges: 250–260°C, 260–270°C, or 270–280°C.

[0041] In some embodiments of the present invention, the pyrolysis apparatus uses a -60°C liquid nitrogen cold trap, or a -60°C liquid nitrogen cold trap and the adsorbent TENAX for combined collection.

[0042] In some embodiments of the present invention, the desorption conditions of the pyrolysis apparatus are as follows: the temperature of the trapping cold trap is raised from -60°C to 250–280°C and held for 2–8 minutes for desorption. The temperature is raised from -60°C to any of the following ranges: 250–260°C, 260–270°C, or 270–280°C. The holding time at 250–280°C is selected from any of the following ranges: 2–3 minutes, 3–4 minutes, 4–5 minutes, 5–6 minutes, 6–7 minutes, or 7–8 minutes.

[0043] In some embodiments of the present invention, the gas chromatograph uses two 60m DB-WAX (polyethylene glycol) columns, or DB-5ms ((5% phenyl)-methylpolysiloxane) columns, or DB-1701 ((14% cyanopropyl-phenyl)-methylpolysiloxane) columns connected in series. The specifications of the columns are [60m (length) × 0.32mm (inner diameter) × 0.25μm (film thickness)] or [60m (length) × 0.25mm (inner diameter) × 0.25μm (film thickness)].

[0044] In some embodiments of the present invention, the carrier gas flow rate in the gas chromatograph is 1.5 to 3.0 mL / min. The flow rate is selected from any of the following ranges: 1.5 to 2.0 mL / min, 2.0 to 2.5 mL / min, and 2.5 to 3.0 mL / min.

[0045] In some embodiments of the present invention, the gas chromatograph uses a temperature gradient of 40°C held for 2–10 min, then increases to 240–280°C at a rate of 2–8°C / min and holds for 0–5 min, or a multi-gradient temperature gradient mode is determined based on the separation results. The initial temperature of 40°C is held for any of the following ranges: 2–4 min, 4–6 min, 6–8 min, or 8–10 min. The temperature is increased to 240–280°C at any of the following rates: 2–3°C / min, 3–4°C / min, 4–5°C / min, 5–6°C / min, 6–7°C / min, or 7–8°C / min. The temperature is increased to any of the following ranges at a rate of 2–8°C / min: 240–250°C, 250–260°C, 260–270°C, or 270–280°C. The holding time at 240–280°C is selected from any of the following ranges: 0–1 min, 1–2 min, 2–3 min, 3–4 min, or 4–5 min.

[0046] In some embodiments of the present invention, the mass spectrometer's mass transfer line temperature is 280°C.

[0047] In some embodiments of the present invention, the ion source temperature of the mass spectrometer is 230°C.

[0048] In some embodiments of the present invention, the quadrupole temperature of the mass spectrometer is 150°C.

[0049] In some embodiments of the present invention, the ionization mode of the mass spectrometer is EI.

[0050] In some embodiments of the present invention, the carrier gas of the mass spectrometer is helium.

[0051] In some embodiments of the present invention, the solvent delay time of the mass spectrometer is 4 to 8 minutes. The solvent delay time is selected from any of the following ranges: 4 to 5 minutes, 5 to 6 minutes, 6 to 7 minutes, and 7 to 8 minutes.

[0052] In some embodiments of the present invention, the split ratio of the mass spectrometer is (15–100):1. The split ratio is selected from any of the following ranges: (15–30):1, (30–45):1, (45–60):1, (60–75):1, (75–90):1, (90–100):1.

[0053] In some embodiments of the present invention, the mass spectrometer has a mass spectrometry scanning range of 10-450 amu.

[0054] In some embodiments of the present invention, parallel experiments are also included. When comparing a natural flavoring sample for tobacco with its standard, the standard is subjected to 5 parallel experiments. When comparing different natural flavoring samples for tobacco, each natural flavoring sample is subjected to 3 parallel experiments. In some embodiments of the present invention, in step 2), the data analysis method is qualitative analysis and / or semi-quantitative analysis.

[0055] The qualitative analysis involves comparing the types of pyrolysis compounds in natural tobacco flavoring samples from different batches or stored for different times, or comparing the types of pyrolysis compounds in natural tobacco flavoring samples with their standards. If the types of pyrolysis compounds are consistent, semi-quantitative analysis is performed; if the types of pyrolysis compounds are inconsistent, semi-quantitative analysis is not required. Consistent pyrolysis compound types mean that the types of pyrolysis compounds in the sample and its standard are 100% identical.

[0056] The method for comparing the types of pyrolytic compounds is to compare the matching degree of the detected mass spectra of each pyrolytic compound with the standard mass spectra. If the matching degree of the detected mass spectra of the pyrolytic compound with its standard mass spectra is greater than 80%, the detected pyrolytic compound is considered to be the same compound represented by the standard mass spectra; if the matching degree is less than 80%, the detected pyrolytic compound is considered to be an unknown substance.

[0057] The standard mass spectra are, for example, those of compounds in the Wiley and / or NIST libraries.

[0058] When both the sample and the standard contain unidentifiable unknowns, the mass-to-charge ratio of the unknowns is used to determine whether the two unknowns are the same compound. If the mass-to-charge ratios are exactly the same, they are considered the same compound; if they are different, they are considered different compounds.

[0059] In some embodiments of the present invention, the semi-quantitative analysis is performed by comparing the consistency of the peak area normalized percentage content of each pyrolysis compound in the tobacco flavoring sample. Specifically, this is achieved by: performing deconvolution integration on the sample detection spectrum to obtain the peak area of ​​each pyrolysis compound and the total integrated area of ​​the pyrolysis compounds in the tobacco flavoring sample; then calculating the peak area normalized percentage content of each pyrolysis compound using the following formula:

[0060] Xi = M i / ΣM i ×100%①

[0061] In the formula:

[0062] X i —The normalized percentage of peak area of ​​a certain pyrolysis compound;

[0063] M i —Peak area of ​​a certain pyrolysis compound;

[0064] ΣM i —Total integral area of ​​thermally decomposed compounds.

[0065] Specifically, the steps of the semi-quantitative analysis are as follows:

[0066] 2-1) Calculate the normalized percentage content of the peak area of ​​each pyrolysis compound in the natural flavoring sample for tobacco using formula ①, which is called the normalized percentage content of the actual peak area.

[0067] 2-2) Using the normalized percentage of actual peak area obtained in step 2-1) and the normalized percentage of peak area of ​​the corresponding thermally decomposed compound of the standard, calculate the average value of the normalized percentage of actual peak area of ​​each thermally decomposed compound and the normalized percentage of peak area of ​​the standard, as well as the SD and RSD.

[0068] 2-3) Determine the quality stability of the sample according to the following testing requirements: When the average value of the normalized percentage content of the peak area obtained in step 2-2) is greater than 10%, the RSD should be less than 10%; when the average value of the normalized percentage content of the peak area obtained in step 2-2) is greater than 2% but not greater than 10%, the RSD should be less than 20%; when the average value of the normalized percentage content of the peak area obtained in step 2-2) is not greater than 2%, the SD should be less than 1%.

[0069] If the above testing requirements are met, it indicates that the normalized percentage content of each pyrolysis compound in the tobacco natural flavoring sample and its standard has small fluctuations, and the quality stability of the tobacco natural flavoring sample is good. If the requirements are not met, it indicates that the normalized percentage content of each pyrolysis compound in the tobacco natural flavoring sample and its standard has large fluctuations, and the quality stability of the tobacco natural flavoring sample is poor.

[0070] The actual peak area normalized percentage content can be the average value obtained from multiple measurements.

[0071] For example, step 2-1 is as follows: use formula ① to calculate the peak area normalized percentage content (A1, B1, C1) of thermally pyrolyzed compound 1 obtained from three parallel experiments of natural flavoring sample X for tobacco, calculate the arithmetic mean of A1, B1, and C1, and obtain TS1 as shown in Table 2, which is the actual peak area normalized percentage content in step 2-1).

[0072] Step 2-2 involves merging TS1 into the corresponding thermally decomposed compounds obtained from the five pyrolysis experiments of the standard in Table 1, and calculating the average normalized percentage content of the peak area (F1±SD1) and RSD(J1) of the six groups of peak areas from the pyrolysis experiments of the sample and the standard (as shown in Table 3). Similarly, the average normalized percentage content of the peak area, SD, and RSD of each thermally decomposed compound are calculated.

[0073] If H1, H2, H3, H4…Hn in Table 1 and J1, J2, J3, J4…Jn in Table 3 all meet the testing requirements, then the quality stability of the tested natural flavoring sample for tobacco is consistent with that of its standard, and the quality stability of the natural flavoring sample for tobacco is good; otherwise, the quality stability of the tested natural flavoring sample for tobacco is poor.

[0074] Table 1 Results of five pyrolysis experiments on standard samples of natural flavorings for tobacco.

[0075]

[0076] Table 2 Results of three pyrolysis experiments on natural flavoring samples for tobacco products

[0077]

[0078] Table 3. Results of six pyrolysis experiments on standard tobacco natural flavorings and test samples.

[0079]

[0080] Specifically, the steps of the semi-quantitative analysis are as follows:

[0081] 2-4) Use formula ① to calculate the normalized percentage content of peak area of ​​each pyrolysis compound in natural tobacco flavoring samples from different batches or with different storage times;

[0082] 2-5) Calculate the average value of the peak area normalized percentage content of each thermally decomposed compound, as well as the SD and RSD;

[0083] 2-6) Determine the quality stability of the sample according to the following testing requirements: When the average value of the normalized percentage content of the peak area obtained in step 2-5) is greater than 10%, the RSD should be less than 10%; when the average value of the normalized percentage content of the peak area obtained in step 2-5) is greater than 2% but not greater than 10%, the RSD should be less than 20%; when the average value of the normalized percentage content of the peak area obtained in step 2-5) is not greater than 2%, the SD should be less than 1%.

[0084] If the above testing requirements are met, it indicates that the normalized percentage content of each pyrolysis compound in the tobacco natural flavoring sample fluctuates little between different batches or different storage times, and the quality stability of the tobacco natural flavoring sample is good; if not, it indicates that the normalized percentage content of each pyrolysis compound in the tobacco natural flavoring sample fluctuates greatly between different batches or different storage times, and the quality stability of the tobacco natural flavoring sample is poor.

[0085] For example, using formula ①, the peak area normalized percentage content of pyrolysis compound 1 obtained from three parallel experiments of natural tobacco flavoring samples 1 and 2 after different batches or storage times is calculated. The peak area normalized percentage content of pyrolysis compound 1 of sample 1 is A1, B1, and C1, respectively, and the peak area normalized percentage content of pyrolysis compound 1 of sample 2 is D1, E1, and F1, respectively. The arithmetic mean of A1, B1, C1, D1, E1, and F1 is calculated, and the average peak area normalized percentage content (L1±SD1) and RSD (K1) are obtained as shown in Table 4. Similarly, the average peak area normalized percentage content, SD, and RSD of each pyrolysis compound from different batches or storage times are calculated.

[0086] If K1, K2, K3, K4...Kn in Table 4 all meet the testing requirements, then the stability of the natural flavoring samples for tobacco products from different batches or stored for different times is good; otherwise, the quality stability of the natural flavoring samples for tobacco products is poor.

[0087] Table 4. Results of pyrolysis experiments on samples from different batches or at different storage times.

[0088]

[0089] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0090] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention; in the specification and claims of the present invention, unless otherwise expressly stated in the text, the singular forms "a", "an" and "this" include the plural forms.

[0091] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0092] Example 1: Stability of *Pyrophora flavescens* absolute oil was determined using pyrolysis-gas chromatography-mass spectrometry (GC-MS).

[0093] 1. Loading of *Symplocos edulis* oil sample: Place a quartz pyrolysis rod in a quartz pyrolysis tube, and fill the center of the quartz pyrolysis rod with approximately 1-2 mg of pesticide residue-grade quartz wool from bottom to top. Use a 5 μL microsyringe to accurately transfer 2 μL of *Symplocos edulis* oil sample and *Symplocos edulis* oil standard for subsequent thermal pyrolysis analysis experiments.

[0094] 2. Stability analysis experiment of lemon oil solution using thermal pyrolysis technology

[0095] 2.1 Conditions for the pyrolysis apparatus:

[0096] Pyrolysis atmosphere: 9% nitrogen-oxygen mixture, gas flow rate of 40 mL / min;

[0097] Pyrolysis heating program: Initial temperature 100℃ and hold for 60s, then increase to 400℃ at 10℃ / s and hold for 300s;

[0098] Post-pyrolysis purging: After pyrolysis is completed, switch to helium purging and maintain post-pyrolysis operation for 1 minute;

[0099] Valve box temperature: 280℃;

[0100] Transmission line temperature: 280℃;

[0101] Collection conditions: -60℃ liquid nitrogen cold trap and adsorbent TENAX are used for collection;

[0102] Desorption conditions: Raise the temperature of the cold trap from -60℃ to 280℃ and hold for 2 minutes to carry out desorption.

[0103] 2.2 Gas chromatograph conditions:

[0104] Chromatographic columns: Two 60m DB-5 columns in series; Single column specifications: [60m (length) × 0.32mm (inner diameter) × 0.25μm (film thickness)];

[0105] Carrier gas flow rate: 1.5 mL / min;

[0106] Temperature gradient: 40℃ for 8 min, then increase to 280℃ at a rate of 8℃ / min and hold for 5 min.

[0107] 2.3 Mass Spectrometer Conditions

[0108] Mass spectrometer transfer line temperature: 280℃;

[0109] Ion source temperature: 230℃;

[0110] Quadrupole temperature: 150℃;

[0111] Ionization mode: EI;

[0112] Carrier gas: Helium;

[0113] Solvent delay time: 5 min;

[0114] Flow split ratio: 100:1;

[0115] Mass spectrometry scanning range: 10-450 amu.

[0116] 3. Sample Testing: The absolute oil samples and their standards were tested. The absolute oil standards were tested in 5 parallel experiments, and the absolute oil samples were tested in 3 parallel experiments. Before analyzing the experimental samples, a blank sample was prepared to confirm that there were no residual compounds in the instrument system before formal sample testing began.

[0117] 4. Data Analysis and Testing

[0118] 4.1 Qualitative Analysis: The detection spectra of each pyrolytic compound in the *Pyrrosia lingua* absolute oil sample and its standard were compared with the standard spectra in the Wiley and NIST libraries to determine the types of pyrolytic compounds. Since the types of pyrolytic compounds in the *Pyrrosia lingua* absolute oil sample and its standard were consistent, semi-quantitative analysis was performed.

[0119] 4.2 Semi-quantitative analysis: The sample detection spectrum was integrated using deconvolution integration, and semi-quantitative analysis was performed using peak area normalization. The results were calculated using the following formula:

[0120] Xi = M i / ΣM i ×100% ①

[0121] In the formula:

[0122] X i —The normalized percentage of peak area of ​​a certain pyrolysis compound;

[0123] M i —Peak area of ​​a certain pyrolysis compound;

[0124] ΣM i —Total integral area of ​​thermally decomposed compounds.

[0125] Specifically, the semi-quantitative analysis steps are as follows:

[0126] The normalized percentage content of the peak area of ​​each thermally decomposed compound was calculated in three parallel experiments of the *Symplocos edulis* oil sample using formula ①, and the arithmetic mean of the normalized percentage content of the peak area of ​​each decomposed compound was calculated.

[0127] The peak area normalized percentage content of the standard of *Symplocos edulis* oil was determined in 5 parallel experiments, and the average peak area normalized percentage content of each thermally decomposed compound was determined in 3 parallel experiments of *Symplocos edulis* oil samples. The average peak area normalized percentage content of each thermally decomposed compound, as well as the SD and RSD, were calculated.

[0128] When the peak area normalization percentage of each thermally decomposed compound is greater than 10%, the maximum relative standard deviation is 6.951%, which is less than 10%; when the area normalization percentage is greater than 2% but not greater than 10%, the maximum relative standard deviation is 8.424%, which is less than 20%; when the area normalization percentage is not greater than 2%, the maximum standard deviation is 0.235%, which is less than 1%.

[0129] If the types of thermally decomposed compounds in the *Symplocos edulis* oil sample and its standard are consistent, and the normalized percentage content of each thermally decomposed compound in the tobacco natural flavoring sample and its standard fluctuates little, then the quality stability of the tobacco natural flavoring sample is good.

[0130] Table 5. Pyrolysis test results of *Symplocos edulis* oil samples and its standards.

[0131]

[0132]

[0133] Note: Due to the large number of types of thermally decomposed compounds and the large amount of data, only a portion of the decomposition data is shown.

[0134] Example 2: Study on batch stability of lemon oil using pyrolysis-gas chromatography-mass spectrometry.

[0135] 1. Lemon oil solution loading: Take a quartz pyrolysis rod and place it in a quartz pyrolysis tube. Fill the center of the quartz pyrolysis rod with about 1-2 mg of pesticide residue grade quartz wool from bottom to top. Use a 5 μL microsyringe to accurately transfer 2 μL of the above two different batches of lemon oil samples for subsequent thermal pyrolysis analysis experiments.

[0136] 2. Stability analysis experiment of lemon oil solution using thermal pyrolysis technology

[0137] 2.1 Conditions of the pyrolysis apparatus

[0138] Pyrolysis atmosphere: 9% nitrogen-oxygen mixture, gas flow rate of 70 mL / min;

[0139] Pyrolysis heating program: Initial temperature 150℃ and hold for 15s, then increase to 400℃ at 30℃ / s and hold for 60s;

[0140] Post-pyrolysis purging: After pyrolysis is completed, switch to helium purging and maintain post-pyrolysis operation for 1 minute;

[0141] Valve box temperature: 250℃;

[0142] Transmission line temperature: 250℃;

[0143] Collection conditions: -60℃ liquid nitrogen cold trap;

[0144] Desorption conditions: Raise the temperature of the cold trap from -60℃ to 250℃ and maintain it for 8 minutes to carry out desorption.

[0145] 2.2 Gas Chromatograph Conditions

[0146] Chromatographic column: 2 60m DB-WAX columns in series; single column specifications: [60m (length) × 0.32mm (inner diameter) × 0.25μm (film thickness)];

[0147] Carrier gas flow rate: 2.0 mL / min;

[0148] Temperature gradient: Hold at 40℃ for 2 min, increase to 180℃ at 2℃ / min, then increase to 240℃ at 8℃ / min and hold for 5 min.

[0149] 2.3 Mass Spectrometer Conditions

[0150] Mass spectrometer transfer line temperature: 280℃;

[0151] Ion source temperature: 230℃;

[0152] Quadrupole temperature: 150℃;

[0153] Ionization mode: EI;

[0154] Carrier gas: Helium;

[0155] Solvent delay time: 8 min;

[0156] Flow split ratio: 100:1;

[0157] Mass spectrometry scanning range: 10-450 amu.

[0158] 3. Sample Testing: Two batches of lemon oil samples were tested, with each sample measured in triplicate. Before analyzing the experimental samples, a blank sample was prepared to confirm that there were no residual compounds in the instrument system before formal sample testing began.

[0159] 4. Data Analysis and Testing

[0160] 4.1 Qualitative Analysis: The spectra of each pyrolytic compound in the two batches of lemon oil samples were compared with standard spectra in the Wiley and NIST libraries to determine the types of pyrolytic compounds. The comparison of the types of pyrolytic compounds showed significant inconsistencies, thus semi-quantitative analysis was unnecessary.

[0161] If the types of thermally decomposed compounds are inconsistent between two batches of lemon oil samples, the quality stability of the lemon oil is poor.

[0162] Table 6. Results of pyrolysis experiments on two batches of lemon oil samples.

[0163]

[0164]

[0165] In the table, the contents in parentheses after the unknown, such as (43,59,81,99,152), represent the mass-to-charge ratio of fragment particles of the thermally decomposed compound.

[0166] Note: Due to the large number of types of thermally decomposed compounds and the large amount of data, only a portion of the decomposition data is shown.

[0167] Example 3: Study on batch stability of jujube tincture using pyrolysis-gas chromatography-mass spectrometry.

[0168] 1. Jujube tincture sample loading: Take a quartz pyrolysis rod and place it in a quartz pyrolysis tube. Fill the center of the quartz pyrolysis rod with about 1-2 mg of pesticide residue grade quartz wool from bottom to top. Use a 5 μL microsyringe to accurately transfer 2 μL of the above 3 different batches of jujube tincture for subsequent thermal pyrolysis analysis experiments.

[0169] 2. Stability analysis experiment of jujube tincture sample by thermal pyrolysis technique

[0170] 2.1 Conditions of the pyrolysis apparatus

[0171] Pyrolysis atmosphere: 9% nitrogen-oxygen mixture, gas flow rate of 100 mL / min;

[0172] Pyrolysis heating program: Initial temperature 300℃ and hold for 5s, then increase to 900℃ at 30℃ / s and hold for 5s;

[0173] Post-pyrolysis purging: After pyrolysis is completed, switch to helium purging and maintain post-pyrolysis operation for 1 minute;

[0174] Valve box temperature: 280℃;

[0175] Transmission line temperature: 280℃;

[0176] Collection conditions: -60℃ liquid nitrogen cold trap and adsorbent TENAX are used for collection;

[0177] Desorption conditions: Raise the temperature of the cold trap from -60℃ to 280℃ and maintain it for 5 minutes to carry out desorption.

[0178] 2.2 Gas Chromatograph Conditions

[0179] Chromatographic column: 2 DB-1701 columns of 60m in series; single column specifications: [60m (length) × 0.32mm (inner diameter) × 0.25μm (film thickness)];

[0180] Carrier gas flow rate: 3.0 mL / min;

[0181] Temperature gradient: 40℃ held for 10 min, then increased to 200℃ at 4℃ / min, then increased to 260℃ at 8℃ / min, and held for 2 min.

[0182] 2.3 Mass Spectrometer Conditions

[0183] Mass spectrometer transfer line temperature: 280℃;

[0184] Ion source temperature: 230℃;

[0185] Quadrupole temperature: 150℃;

[0186] Ionization mode: EI;

[0187] Carrier gas: Helium;

[0188] Solvent delay time: 4 min;

[0189] Flow split ratio: 15:1;

[0190] Mass spectrometry scanning range: 10-450 amu.

[0191] 3. Sample Testing: Three batches of lemon oil samples were tested, with each sample measured in triplicate. Before analyzing the experimental samples, a blank sample was prepared to confirm that there were no residual compounds in the instrument system before formal sample testing began.

[0192] 4. Data Analysis and Testing

[0193] 4.1 Qualitative Analysis: The spectra of each pyrolysis compound in the three batches of jujube tincture were compared with standard spectra in the Wiley and NIST libraries to determine the types of pyrolysis compounds. The types of pyrolysis compounds in the three batches of jujube tincture were consistent, and semi-quantitative analysis was performed.

[0194] 4.2 Semi-quantitative analysis: The sample detection spectrum was integrated using deconvolution integration, and semi-quantitative analysis was performed using peak area normalization. The results were calculated using the following formula:

[0195] Xi = M i / ΣM i ×100% ①

[0196] In the formula:

[0197] X i —The normalized percentage of peak area of ​​a certain pyrolysis compound;

[0198] M i —Peak area of ​​a certain pyrolysis compound;

[0199] ΣM i —Total integral area of ​​thermally decomposed compounds.

[0200] Specifically, the semi-quantitative analysis steps are as follows:

[0201] The normalized percentage content of peak area of ​​each thermally decomposed compound in the three batches of jujube tincture samples was calculated using formula ①.

[0202] Calculate the average value of the peak area normalized percentage content of each thermally decomposed compound in the jujube tincture sample, as well as the SD and RSD;

[0203] When the average normalized percentage content of peak area is greater than 10%, the RSD is less than 10%; when the average normalized percentage content of peak area is greater than 2% but not greater than 10%, the RSD is less than 20%; when the average normalized percentage content of peak area is not greater than 2%, the SD is less than 1%.

[0204] The fact that the jujube tincture sample meets the above testing requirements indicates that the normalized percentage content of each thermally decomposed compound fluctuates little across different batches, thus the jujube tincture sample has good quality stability.

[0205] Table 7. Pyrolysis test results of three batches of jujube tincture samples

[0206]

[0207]

[0208] Note: Due to the large number of types of thermally decomposed compounds and the large amount of data, only a portion of the decomposition data is shown.

[0209] Example 4: Study on batch stability of apple juice using pyrolysis-gas chromatography-mass spectrometry.

[0210] 1. Apple juice sample loading: Take a quartz pyrolysis rod and place it in a quartz pyrolysis tube. Fill the center of the quartz pyrolysis rod with about 1-2 mg of pesticide residue grade quartz wool from bottom to top. Use a 5 μL microsyringe to accurately transfer 2 μL of the above 3 different batches of apple juice for subsequent thermal pyrolysis analysis experiments.

[0211] 2. Stability analysis experiment of apple juice using thermal pyrolysis technology

[0212] 2.1 Conditions of the pyrolysis apparatus

[0213] Pyrolysis atmosphere: air, gas flow rate of 50 mL / min;

[0214] Pyrolysis heating program: Initial temperature 300℃ and hold for 5s, then increase to 900℃ at 20℃ / s and hold for 300s;

[0215] Post-pyrolysis purging: After pyrolysis is completed, switch to helium purging and maintain post-pyrolysis operation for 1 minute;

[0216] Valve box temperature: 280℃;

[0217] Transmission line temperature: 280℃;

[0218] Collection conditions: -60℃ liquid nitrogen cold trap collection;

[0219] Desorption conditions: Raise the temperature of the cold trap from -60℃ to 250℃ and maintain it for 5 minutes to carry out desorption.

[0220] 2.2 Gas Chromatograph Conditions

[0221] Chromatographic column: 2 DB-1701 columns of 60m in series; single column specifications: [60m (length) × 0.32mm (inner diameter) × 0.25μm (film thickness)];

[0222] Carrier gas flow rate: 1.5 mL / min;

[0223] Temperature gradient: 40℃ held for 2 min, then increased to 260℃ at a rate of 8℃ / min, and held for 0 min;

[0224] 2.3 Mass Spectrometer Conditions

[0225] Mass spectrometer transfer line temperature: 280℃;

[0226] Ion source temperature: 230℃;

[0227] Quadrupole temperature: 150℃;

[0228] Ionization mode: EI;

[0229] Carrier gas: Helium;

[0230] Solvent delay time: 4 min;

[0231] Flow split ratio: 15:1;

[0232] Mass spectrometry scanning range: 10-450 amu.

[0233] 3. Sample Testing: The prepared apple juice samples were tested, with each sample measured in triplicate. Before testing the experimental samples, a blank sample was prepared to confirm that there were no residual compounds in the instrument system before formal sample testing began.

[0234] 4. Data Analysis and Testing

[0235] 4.1 Qualitative Analysis: The spectra of each pyrolysis compound in the three batches of apple juice were compared with standard spectra in the Wiley and NIST libraries to determine the types of pyrolysis compounds. The types of pyrolysis compounds in the three batches of apple juice were consistent, and semi-quantitative analysis was performed.

[0236] 4.2 Semi-quantitative analysis: The sample detection spectrum was integrated using deconvolution integration, and semi-quantitative analysis was performed using peak area normalization. The results were calculated using the following formula:

[0237] Xi = M i / ΣM i ×100% ①

[0238] In the formula:

[0239] X i—The normalized percentage of peak area of ​​a certain pyrolysis compound;

[0240] M i —Peak area of ​​a certain pyrolysis compound;

[0241] ΣM i —Total integral area of ​​thermally decomposed compounds.

[0242] Specifically, the semi-quantitative analysis steps are as follows:

[0243] The normalized percentage content of peak area of ​​each thermally decomposed compound in apple juice samples from three batches was calculated using formula ①.

[0244] Calculate the average value of the peak area normalized percentage of each thermally decomposed compound in the apple juice sample, as well as the SD and RSD;

[0245] When the average normalized percentage content of peak area is greater than 10%, the RSD is less than 10%; when the average normalized percentage content of peak area is greater than 2% but not greater than 10%, the RSD is less than 20%; when the average normalized percentage content of peak area is not greater than 2%, the SD is less than 1%.

[0246] The fact that the apple juice sample met the above testing requirements indicates that the normalized percentage content of each pyrolysis compound fluctuated little across different batches, thus demonstrating good quality stability of the apple juice sample.

[0247] Table 8. Results of lysis experiments on three batches of apple juice samples.

[0248]

[0249] Note: Due to the large number of types of thermally decomposed compounds and the large amount of data, only a portion of the decomposition data is shown.

[0250] Example 5: Study on the storage stability of lemon oil using pyrolysis-gas chromatography-mass spectrometry.

[0251] 1. Lemon oil solution loading: Take a quartz pyrolysis rod and place it in a quartz pyrolysis tube. Fill the center of the quartz pyrolysis rod with about 1-2 mg of pesticide residue grade quartz wool from bottom to top. Use a 5 μL microsyringe to accurately transfer 2 μL of the above 3 lemon oil samples stored for 1 year and 2 fresh lemon oil samples for subsequent thermal pyrolysis analysis experiments.

[0252] 2. Stability analysis experiment of lemon oil solution using thermal pyrolysis technology

[0253] 2.1 Conditions of the pyrolysis apparatus

[0254] Pyrolysis atmosphere: 9% nitrogen-oxygen mixture, gas flow rate of 70 mL / min;

[0255] Pyrolysis heating program: Initial temperature 150℃ and hold for 15s, then increase to 400℃ at 30℃ / s and hold for 60s;

[0256] Post-pyrolysis purging: After pyrolysis is completed, switch to helium purging and maintain post-pyrolysis operation for 1 minute;

[0257] Valve box temperature: 250℃;

[0258] Transmission line temperature: 250℃;

[0259] Collection conditions: -60℃ liquid nitrogen cold trap;

[0260] Desorption conditions: Raise the temperature of the cold trap from -60℃ to 250℃ and maintain it for 8 minutes to carry out desorption.

[0261] 2.2 Gas Chromatograph Conditions

[0262] Chromatographic column: 2 60m DB-WAX columns in series; single column specifications: [60m (length) × 0.32mm (inner diameter) × 0.25μm (film thickness)];

[0263] Carrier gas flow rate: 2.0 mL / min;

[0264] Temperature gradient: Hold at 40℃ for 2 min, increase to 180℃ at 2℃ / min, then increase to 240℃ at 8℃ / min and hold for 5 min.

[0265] 2.3 Mass Spectrometer Conditions

[0266] Mass spectrometer transfer line temperature: 280℃;

[0267] Ion source temperature: 230℃;

[0268] Quadrupole temperature: 150℃;

[0269] Ionization mode: EI;

[0270] Carrier gas: Helium;

[0271] Solvent delay time: 8 min;

[0272] Flow split ratio: 100:1;

[0273] Mass spectrometry scanning range: 10-450 amu.

[0274] 3. Sample Testing: Three lemon oil samples stored for one year and two new lemon oil samples were tested, with each sample measured in triplicate. Before analyzing the experimental samples, a blank sample was prepared to confirm that there were no residual compounds in the instrument system before formal sample testing began.

[0275] 4. Analysis of Test Sample Results

[0276] Qualitative analysis: The spectra of various pyrolysis compounds in lemon oil samples stored for different times were compared with standard spectra in the Wiley and NIST libraries to determine the types of pyrolysis compounds. The comparisons of the types of pyrolysis compounds showed significant inconsistencies, thus semi-quantitative analysis was unnecessary.

[0277] The types of thermally decomposed compounds in lemon oil samples stored for different times are inconsistent, thus the quality stability of lemon oil is poor.

[0278] Table 9. Results of pyrolysis experiments on lemon oil samples stored for different times.

[0279]

[0280]

[0281] Note: The types of thermal cracking products of the three lemon oils stored for 1 year are consistent, and some data are listed with one as a representative.

[0282] Due to the large number of types of thermally decomposed compounds and the large amount of data, only a portion of the decomposition data is shown.

[0283] The above embodiments are for illustrating the implementation schemes disclosed in this invention and should not be construed as limiting the invention. Furthermore, various modifications and variations of the methods listed herein will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been specifically described in conjunction with various specific preferred embodiments, it should be understood that the invention should not be limited to these specific embodiments. In fact, various modifications as described above that are obvious to those skilled in the art to obtain the invention should be included within the scope of this invention.

Claims

1. A method for testing the quality stability of natural flavorings for tobacco, characterized in that, The detection method includes the following steps: 1) The samples of natural tobacco flavorings from different batches or stored for different times, or the samples of natural tobacco flavorings and their standards, were analyzed using online pyrolysis-gas chromatography-mass spectrometry. 2) Data analysis and testing: Compare the test results of natural flavoring samples for tobacco from different batches or with different storage times, or compare the test results of natural flavoring samples for tobacco with their standards. If the comparison results are consistent, the quality stability is considered good; if the comparison results are inconsistent, the quality stability is considered poor.

2. The method for testing the quality stability of natural flavorings for tobacco products according to claim 1, characterized in that, Step 1) includes one or more of the following conditions: 1) The natural flavoring sample for tobacco is a liquid natural flavoring sample for tobacco; preferably, the liquid natural flavoring sample for tobacco is selected from one or more of essential oils, absolute oils, tinctures, and fruit juices; 2) The natural flavoring sample for tobacco is a paste-like natural flavoring sample for tobacco. Preferably, the paste-like natural flavoring sample for tobacco is selected from extracts or extracts.

3. The method for testing the quality stability of natural flavorings for tobacco products according to claim 1, characterized in that, Step 1) involves using pyrolysis technology to degrade the natural flavoring sample for tobacco and then using gas chromatography-mass spectrometry to determine its composition. Step 2) involves testing the stability of the natural flavoring sample for tobacco based on the consistency of the pyrolysis products.

4. The method for testing the quality stability of natural flavorings for tobacco products according to claim 1, characterized in that, Step 1) further includes sample pretreatment; preferably, the sample pretreatment method is to transfer the tobacco natural flavoring sample onto quartz wool; preferably, the quartz wool is quartz wool pre-filled on a quartz pyrolysis rod; preferably, the quartz pyrolysis rod is a quartz pyrolysis rod pre-filled into a quartz pyrolysis tube.

5. The method for detecting the quality stability of natural flavorings for tobacco products according to claim 1, characterized in that, Step 1) The operating conditions for pyrolysis include one or more of the following conditions: 1) The pyrolysis gas is a mixture of nitrogen and oxygen or air; 2) The gas flow rate of the pyrolysis gas is 40–100 mL / min; 3) The pyrolysis heating program is as follows: initial temperature 100-300℃, hold for 5-60s, then increase to 400-900℃ at 10-30℃ / s, and hold for 5-300s; 4) After pyrolysis is complete, switch to helium purging and maintain post-pyrolysis operation; 5) Valve box temperature is 250~280℃; 6) The trapping conditions are to use a liquid nitrogen cold trap, or a combination of a liquid nitrogen cold trap and the adsorbent TENAX. 7) The desorption conditions are to raise the temperature of the cold trap to 250–280°C and hold it for 2–8 minutes; And / or, the operating conditions of the gas chromatograph include one or more of the following: 1) Two 60m DB-WAX (polyethylene glycol) columns, a DB-5ms ((5% phenyl)-methylpolysiloxane) column, or a DB-1701 ((14% cyanopropyl-phenyl)-methylpolysiloxane) column connected in series; preferably, the specifications of the columns are: [60m (length) × 0.32mm (inner diameter) × 0.25μm (film thickness)] or [60m (length) × 0.25mm (inner diameter) × 0.25μm (film thickness)]; 2) The carrier gas flow rate is 1.5–3.0 mL / min; 3) The temperature gradient is 40℃ and held for 2 to 10 minutes, then increased to 240 to 280℃ at a rate of 2 to 8℃ / min and held for 0 to 5 minutes, or a multi-gradient temperature gradient mode is proposed according to the separation situation; And / or, the operating conditions of the mass spectrometer include one or more of the following conditions: 1) The mass spectrometer transfer line temperature is 280℃; 2) The ion source temperature is 230℃; 3) The quadrupole temperature is 150℃; 4) Ionization mode is EI; 5) The carrier gas is helium; 6) Solvent delay time is 4–8 min; 7) The split ratio is (15~100):1; 8) The mass spectrometry scanning range is 10-450 amu.

6. The method for detecting the quality stability of natural flavorings for tobacco products according to claim 1, characterized in that, Step 2) describes a data analysis method that is qualitative and / or semi-quantitative.

7. The method for detecting the quality stability of natural flavorings for tobacco products according to claim 6, characterized in that, The qualitative analysis involves comparing the types of pyrolysis compounds in different natural tobacco flavoring samples, or comparing the types of pyrolysis compounds in natural tobacco flavoring samples and their standards. If the types of pyrolysis compounds match, then semi-quantitative analysis is performed; if the types of pyrolysis compounds do not match, then semi-quantitative analysis is not required.

8. The method for detecting the quality stability of natural flavorings for tobacco products according to claim 6, characterized in that, The semi-quantitative analysis was performed by comparing the peak area normalized percentage content of each pyrolysis compound in the natural flavoring sample for tobacco.

9. The method for detecting the quality stability of natural flavorings for tobacco products according to claim 8, characterized in that, The method for obtaining the peak area normalized percentage content is to perform integral processing on the sample detection spectrum using deconvolution integral method to obtain the peak area of ​​each pyrolysis compound and the total integral area of ​​pyrolysis compounds in the tobacco flavoring sample, and then calculate the peak area normalized percentage content of each pyrolysis compound according to the following formula: Xi=M i / ΣM i ×100%① In the formula: X i —The normalized percentage of peak area of ​​a certain pyrolysis compound; M i —Peak area of ​​a certain pyrolysis compound; ΣM i —Total integral area of ​​thermally decomposed compounds.

10. The method for detecting the quality stability of natural flavorings for tobacco products according to claim 9, characterized in that, When determining samples of natural flavorings for tobacco and their standards, the steps of the semi-quantitative analysis are as follows: 2-1) Calculate the normalized percentage content of the peak area of ​​each pyrolysis compound in the natural flavoring sample for tobacco using formula ①, which is called the normalized percentage content of the actual peak area. 2-2) Using the normalized percentage of actual peak area obtained in step 2-1) and the normalized percentage of peak area of ​​the corresponding thermally decomposed compound of the standard, calculate the average value of the normalized percentage of actual peak area of ​​each thermally decomposed compound and the normalized percentage of peak area of ​​the standard, as well as the SD and RSD. 2-3) Determine the sample's quality stability according to the following testing requirements: When the average normalized percentage content of peak area obtained in step 2-2) is greater than 10%, the RSD should be less than 10%; when the average normalized percentage content of peak area obtained in step 2-2) is greater than 2% but not greater than 10%, the RSD should be less than 20%; when the average normalized percentage content of peak area obtained in step 2-2) is not greater than 2%, the SD should be less than 1%. If the test requirements are met, the quality stability of the tested natural flavoring samples for tobacco is good; if not, the quality stability of the tested natural flavoring samples for tobacco is poor.

11. The method for detecting the quality stability of natural flavorings for tobacco products according to claim 9, characterized in that, When measuring different natural flavoring samples for tobacco, the steps of the semi-quantitative analysis are as follows: 2-4) Use formula ① to calculate the normalized percentage content of peak area of ​​each pyrolysis compound in natural tobacco flavoring samples from different batches or with different storage times; 2-5) Calculate the average value of the peak area normalized percentage content of each thermally decomposed compound, as well as the SD and RSD; 2-6) Determine the sample's quality stability according to the following testing requirements: When the average normalized percentage content of peak area obtained in step 2-5) is greater than 10%, the RSD should be less than 10%; when the average normalized percentage content of peak area obtained in step 2-5) is greater than 2% but not greater than 10%, the RSD should be less than 20%; when the average normalized percentage content of peak area obtained in step 2-5) is not greater than 2%, the SD should be less than 1%. If the test requirements are met, the quality stability of the tested natural flavoring samples for tobacco is good; if not, the quality stability of the tested natural flavoring samples for tobacco is poor.

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