A method for determining the authenticity and percentage content of Torreya grandis seed oil based on 24-aldehyde characteristics

Abstract

The invention relates to the technical field of quality control of Torreya grandis seed oil, and discloses a method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetradecanoic acid characteristics. By analyzing the presence and content of tetradecanoic acid in vegetable oil, the Torreya grandis seed oil is qualitatively determined and quantitatively analyzed. At the same time, gel permeation chromatography purification-online concentration and constant volume treatment, solid phase extraction purification and gas chromatography-mass spectrometry detection and other technologies are adopted to extract, purify and determine tetradecanoic acid in vegetable oil. The presence and content of tetradecanoic acid in vegetable oil indicate the authenticity and content of Torreya grandis seed oil. The method is simple and feasible, has good reproducibility, can realize accurate identification and content analysis of Torreya grandis seed oil, and has good application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of quality control of Torreya grandis seed oil, and in particular to a method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetradecanoic aldehyde characteristics. Background Art

[0002] Torreya grandis, also known as Torreya grandis, fine Torreya grandis, Chinese Torreya grandis, etc., is the fruit of Torreya grandis (Torreyagrandis), a plant of Taxaceae. Torreya grandis is mainly produced in Zhejiang Province. There are about 25 counties (cities) in the province with wild Torreya grandis trees, with a total resource of more than 600,000 trees, including more than 480,000 large trees and more than 50,000 century-old Torreya grandis trees. Torreya grandis is the main source of income for Torreya grandis farmers, an important resource for revitalizing the regional economy of Zhejiang, and the main variety for the development of agricultural and forestry economy. According to statistics, the output of Torreya grandis in Zhejiang Province reached 1,000 tons in 2006. With the guidance and promotion of local policies such as "Southern Expansion of Torreya Grandis" and "Western Expansion of Torreya Grandis", the research and development of cultivation scientific research projects, and the selection and breeding of new varieties and improved varieties, the cultivation area of ​​Torreya grandis has increased to the current 800,000 mu, and the output has increased sharply, exceeding 8,000 tons in 2020. However, since Torreya grandis products are mainly "fried Torreya grandis" for edible seeds, and the processing methods are old-fashioned and single, the industry has already shown an oversupply situation. The price of finished Torreya grandis seeds has dropped from a peak of 300 yuan per catty to 50 yuan in 2020. Increasing production without increasing income has become a dilemma for the development of the industry, and most of the newly added Torreya grandis forests are saplings. The production of Torreya grandis nut is expected to increase in future years. The supply and demand dilemma will become more and more severe, and high-value utilization and research and development of healthy products may become a new path for the sustainable development of the Torreya grandis industry.

[0003] Torreya grandis is a treasure, and its comprehensive development and utilization technology has been continuously presented. In order to meet market demand, Torreya grandis seed oil came into being, and its output is increasing. Torreya grandis kernels have an oil content of up to 42-61%, and the quality is excellent. Unsaturated fatty acids account for more than 80%, of which the content of succinic acid (5,11,14-eicosatrienoic acid) is 4.3-12.3%. Studies have shown that Torreya grandis oil can significantly reduce serum total cholesterol (TC), triglycerides (TG) and atherosclerosis index (AI) in experimental Wistar rats, and has significant functional development value. It is precisely because of these excellent qualities of Torreya grandis seed oil that its product price has been above 600 yuan / kg. However, since there is no clear Torreya grandis seed oil quality standard on the market, it can only be managed in accordance with the "Sanitary Standards for Edible Vegetable Oils" (GB2716-2018). Driven by high profits, the risk of adulteration of Torreya grandis seed oil is inevitable.

[0004] At present, the research on the use of characteristic components to identify the authenticity of Torreya grandis seed oil is much less than that of pecan seed oil and camellia oil. However, there are more studies on the use of characteristic components to identify the authenticity of plant oils. The main methods are chromatography (gas phase, liquid phase, such as a method for determining the fatty acid content of pecan by gas chromatography-mass spectrometry with the authorization announcement number CN105738504B), spectroscopy (such as infrared spectroscopy, fluorescence spectroscopy, ultraviolet-visible spectroscopy, atomic spectroscopy, low-field nuclear magnetic resonance), colorimetry (such as a simple method for identifying the authenticity of camellia oil with the authorization announcement number CN101893553B), chromatography-mass spectrometry, carbon isotope ratio mass spectrometry, electronic nose method, electronic tongue method, etc. These methods are all for qualitative and quantitative analysis of oil types based on the presence or content of functional groups or certain characteristic substances, and the samples are mainly virgin crude oil. However, Torreya grandis seed oil is usually refined oil as the main product, and its processing process is complex and changeable. In the finished oil, substances that can reflect the characteristics of the oil are either completely removed or the content is uncertain, and substances that can truly reflect the characteristics of the oil type itself are extremely scarce. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a gas chromatography-mass spectrometry method for determining the authenticity and content of Torreya grandis seed oil using tetradecene as an indicator, so as to solve the technical problem that the prior art lacks analysis of the Torreya grandis seed oil content in the finished product "Torreya grandis seed oil".

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetradecanoic acid characteristics, comprising the following steps:

[0008] A. Mix the vegetable oil sample evenly, weigh the vegetable oil sample and add it into a centrifuge tube;

[0009] B. Add cyclohexane-ethyl acetate to the centrifuge tube containing the vegetable oil sample, dissolve, vortex mix, and wait for purification;

[0010] C. After purification by gel permeation chromatography, the eluate is collected, and the eluate is fixed to volume by an online automatic concentration and volume fixing system, and then loaded into a chromatograph injection bottle, and then subjected to detection and analysis by a gas chromatography-mass spectrometer;

[0011] D. Establishment of a calibration curve for the percentage content of Torreya grandis seed oil: Weigh homemade, squeezed Torreya grandis seed oil, supplement less than 1g with vegetable oil to make up to 1g, and prepare Torreya grandis seed oil with mass fractions of 10%, 30%, 50%, 70%, and 100%, respectively, and analyze according to steps B to C simultaneously, and establish a calibration curve for the mass percentage concentration of Torreya grandis seed oil with the peak area of ​​24-aldehyde as the ordinate and the mass percentage of Torreya grandis seed oil as the abscissa;

[0012] E. Whether the sample contains Torreya grandis seed oil is verified by detecting the presence of tetracosaldehyde. The peak area of ​​tetracosaldehyde is substituted into the calibration curve established in step D to calculate the mass percentage concentration of Torreya grandis seed oil in the sample.

[0013] The present invention systematically screened the characteristic components of Torreya grandis seed oil products with different sources, oil extraction methods and processing degrees, and obtained a fatty aldehyde, namely "tetradecanoic acid" (C 24 H 48 O, cas number 57866-08-7), its mass spectrum is as follows Figure 1 As shown. This component only exists in Torreya grandis seed oil among common edible vegetable oils. By measuring 40 Torreya grandis seed oils processed in different ways, the results show that the deviation of tetradecanoic aldehyde content is only 4.5%, which shows that it has a relatively stable content in the crude oil, refined oil, extracted oil and pressed oil of Torreya grandis seed oil. The present invention conducts qualitative judgment and quantitative analysis on Torreya grandis seed oil by analyzing the presence and content of tetradecanoic aldehyde in vegetable oil.

[0014] Vegetable oil is a kind of oil mainly composed of fatty acid glycerides, rich in vitamins, pigments, proteins, terpenes, etc., and its composition is extremely complex. Unsatisfactory pre-treatment will directly affect the subsequent instrument detection results of tetradecanoic acid. Among them, degreasing treatment is extremely critical. This method uses gel permeation chromatography purification-online concentration and constant volume treatment to remove a large amount of impurities such as fatty acids, pigments, and protein whites to achieve an ideal purification effect.

[0015] Preferably, in step A, 0.5-1.5 g of the vegetable oil sample is weighed into a 10 ml centrifuge tube, and preferably the mass of the vegetable oil sample is 0.5 g.

[0016] Preferably, in step B, cyclohexane-ethyl acetate is mixed in a volume ratio of 1:1, the volume of hexane-ethyl acetate added is 10 ml, and the vortex time is 0.5 to 5 min, preferably the vortex time is 0.5 min.

[0017] Preferably, in step C, the gel permeation chromatography purification is performed with an injection volume of 5 ml, a mobile phase of a cyclohexane-ethyl acetate mixture in a volume ratio of 1:1, and a flow rate of 4.5 ml / min; and the eluent is collected for a period of 480 s to 1080 s.

[0018] Preferably, in the automatic concentration and volume determination system in step C, the water bath temperature is 40°C, the vacuum degree of the first concentration step is 180 mbar, the vacuum degree of the second concentration step is 210 mbar, and the solvent during volume determination is a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and the volume is determined to 2 ml.

[0019] Preferably, the supplementary vegetable oil in step D is soybean oil.

[0020] The present invention has significant technical effects due to the adoption of the above technical solution:

[0021] The present invention is based on the fact that tetradecanoic aldehyde only exists in Torreya grandis seed oil among common edible vegetable oils, and the content of tetradecanoic aldehyde in Torreya grandis seed oil of different sources and processing stages is relatively stable. By analyzing the presence and content of tetradecanoic aldehyde in vegetable oil, the Torreya grandis seed oil is qualitatively determined and quantitatively analyzed. At the same time, the gel permeation chromatography purification-online concentration and constant volume treatment, solid phase extraction purification and gas chromatography-mass spectrometry detection and other technologies are adopted to extract, purify and measure the tetradecanoic aldehyde in the vegetable oil. The presence and content of tetradecanoic aldehyde in the vegetable oil indicate the authenticity and content of Torreya grandis seed oil. The method is simple and feasible, has good reproducibility, can realize the accurate identification and content analysis of Torreya grandis seed oil, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is the mass spectrum of tetradecanoaldehyde (cas number: 57866-08-7);

[0023] Figure 2 This is the total ion current chromatogram of the sample in Example 1 (including the "tetradecanoaldehyde" part).

[0024] Figure 3 The mass spectrum of tetracosaldehyde in the sample of Example 1 (the upper half is the sample spectrum, and the lower half is the spectrum of tetracosaldehyde in the NIST20 spectral library);

[0025] Figure 4 This is the selected ion spectrum of tetracosaldehyde in the sample of Example 1;

[0026] Figure 5 This is the total ion current chromatogram of the sample of Example 2 (including the "tetradecanoaldehyde" part);

[0027] Figure 6 The mass spectrum of tetracosaldehyde in the sample of Example 2 (the upper half is the sample spectrum, and the lower half is the spectrum of tetracosaldehyde in the NIST20 spectral library);

[0028] Figure 7 This is the selected ion spectrum of tetracosaldehyde in the sample of Example 2;

[0029] Figure 8 This is the total ion current chromatogram of the sample of Example 3 (including the "tetradecanoaldehyde" part);

[0030] Fig. 9 The mass spectrum of tetracosaldehyde in the sample of Example 3 (the upper half is the sample spectrum, and the lower half is the spectrum of tetracosaldehyde in the NIST20 spectral library);

[0031] Fig.10This is the selected ion spectrum of tetracosaldehyde in the sample of Example 3. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0033] Example 1

[0034] A method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetradecanoic acid characteristics, comprising the following steps:

[0035] A. Mix the vegetable oil sample evenly, weigh 0.5g of the vegetable oil sample and add it into a 10ml test tube;

[0036] B. Add 10 mL of cyclohexane-ethyl acetate (volume ratio of 1:1), dissolve, vortex mix for 0.5 min, and wait for purification;

[0037] C. Gel permeation chromatography was used for purification, with an injection volume of 5 ml, a mobile phase of a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and a flow rate of 4.5 ml / min; the eluent was collected for a period of 480 s to 1080 s;

[0038] The eluent is volume-fixed by an online automatic concentration and volume-fixing system. In the automatic concentration and volume-fixing system, the water bath temperature is 40°C, the vacuum degree of the first step of concentration is 180 mbar, and the vacuum degree of the second step of concentration is 210 mbar. The solvent for volume fixing is a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and the volume is fixed to 2 ml and loaded into a chromatograph injection bottle for detection and analysis by gas chromatography-mass spectrometry.

[0039] D. Establish a calibration curve for the percentage content of Torreya grandis seed oil. Weigh 0.10 g, 0.30 g, 0.50 g, 0.70 g, and 1.00 g of homemade and squeezed Torreya grandis seed oil in a 10 ml centrifuge tube, and make up to 1 g with soybean oil if it is less than 1 g, that is, the mass fraction of Torreya grandis seed oil is 10%, 30%, 50%, 70%, and 100%, respectively. Perform analysis simultaneously according to steps B to F, and establish a calibration curve for the mass percentage concentration of Torreya grandis seed oil with the peak area of ​​24-aldehyde as the ordinate and the mass percentage of Torreya grandis seed oil as the abscissa;

[0040] E. Whether the sample contains Torreya grandis seed oil is verified by detecting the presence of tetracosaldehyde. The peak area of ​​tetracosaldehyde is substituted into the calibration curve established in step D to calculate the mass percentage concentration of Torreya grandis seed oil in the sample.

[0041] GC-MS Chromatographic Conditions:

[0042] Inlet: 250℃;

[0043] Injection volume: 1 μl, splitless injection;

[0044] Chromatographic column: HP-5MS 5% Phenyl Methyl Silox (30m×0.25mm, 0.25μm);

[0045] Carrier gas: He, flow rate 1 ml / min;

[0046] Program temperature rise: 50℃ for 0.5min, 5℃ / min to 250℃ for 5min, 10℃ / min to 280℃ for 10min;

[0047] Auxiliary heating zone (MSD transfer line): 280°C;

[0048] Mass spectrometry acquisition mode: full scan (scan), mass number 50.0-430, for qualitative analysis; selected ion scan (sim), mass number 82, dwell 40ms, mass number 96, dwell 100ms, mass number 334, dwell 40ms, mass number 352, dwell 40ms, for quantitative analysis;

[0049] Solvent delay: 3.0min;

[0050] Ion source: 230℃;

[0051] MS quadrupole: 150 °C.

[0052] Test results:

[0053] Figure 2 , Figure 3 , Figure 4 They are the total ion current chromatogram of the sample (including the "twenty-tetradecaldehyde" part), the mass spectrum of twenty-tetradecaldehyde in the sample and the selected ion spectrum of twenty-tetradecaldehyde in the sample.

[0054] Figure 2 , Figure 3 This indicates that the sample contains Torreya grandis seed oil. Figure 4 The peak area of ​​the quantitative ion (96) was 23579, and the calibration curve (y = 244.8631x + 78.9180, R 2 =0.9998), and the calculated content of Torreya grandis seed oil in the sample was 96.0%.

[0055] Conclusion: The content of Torreya grandis seed oil in this sample is 96.0%±4.5%, which is pure Torreya grandis seed oil.

[0056] Example 2

[0057] A method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetradecanoic acid characteristics, comprising the following steps:

[0058] A. Mix the vegetable oil sample evenly, weigh 0.5g of the vegetable oil sample and add it into a 10ml test tube;

[0059] B. Add 10 mL of cyclohexane-ethyl acetate (volume ratio of 1:1), dissolve, vortex mix for 0.5 min, and wait for purification;

[0060] C. Gel permeation chromatography was used for purification, with an injection volume of 5 ml, a mobile phase of a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and a flow rate of 4.5 ml / min; the eluent was collected for a period of 480 s to 1080 s;

[0061] The eluent is volume-fixed by an online automatic concentration and volume-fixing system. In the automatic concentration and volume-fixing system, the water bath temperature is 40°C, the vacuum degree of the first step of concentration is 180 mbar, and the vacuum degree of the second step of concentration is 210 mbar. The solvent for volume fixing is a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and the volume is fixed to 2 ml and loaded into a chromatograph injection bottle for detection and analysis by gas chromatography-mass spectrometry.

[0062] D. Establish a calibration curve for the percentage content of Torreya grandis seed oil. Weigh 0.10 g, 0.30 g, 0.50 g, 0.70 g, and 1.00 g of homemade and squeezed Torreya grandis seed oil in a 10 ml centrifuge tube, and make up to 1 g with soybean oil if it is less than 1 g, that is, the mass fraction of Torreya grandis seed oil is 10%, 30%, 50%, 70%, and 100%, respectively. Perform analysis simultaneously according to steps B to F, and establish a calibration curve for the mass percentage concentration of Torreya grandis seed oil with the peak area of ​​24-aldehyde as the ordinate and the mass percentage of Torreya grandis seed oil as the abscissa;

[0063] E. Whether the sample contains Torreya grandis seed oil is verified by detecting the presence of tetracosaldehyde. The peak area of ​​tetracosaldehyde is substituted into the calibration curve established in step D to calculate the mass percentage concentration of Torreya grandis seed oil in the sample.

[0064] GC-MS Chromatographic Conditions:

[0065] Inlet: 250℃;

[0066] Injection volume: 1 μl, splitless injection;

[0067] Chromatographic column: HP-5MS 5% Phenyl Methyl Silox (30m×0.25mm, 0.25μm);

[0068] Carrier gas: He, flow rate 1 ml / min;

[0069] Program temperature rise: 50℃ for 0.5min, 5℃ / min to 250℃ for 5min, 10℃ / min to 280℃ for 10min;

[0070] Auxiliary heating zone (MSD transfer line): 280°C;

[0071] Mass spectrometry acquisition mode: full scan (scan), mass number 50.0-430, for qualitative analysis; selected ion scan (sim), mass number 82, dwell 40ms, mass number 96, dwell 100ms, mass number 334, dwell 40ms, mass number 352, dwell 40ms, for quantitative analysis;

[0072] Solvent delay: 3.0min;

[0073] Ion source: 230℃;

[0074] MS quadrupole: 150 °C.

[0075] Test results

[0076] Figure 5 , Figure 6 , Figure 7 They are the total ion current chromatogram of the sample (including the "twenty-tetradecaldehyde" part), the mass spectrum of twenty-tetradecaldehyde in the sample and the selected ion spectrum of twenty-tetradecaldehyde in the sample.

[0077] Figure 5 , Figure 6 This indicates that the sample contains Torreya grandis seed oil. Figure 7 The peak area of ​​the quantitative ion (96) was 24459, and the calibration curve (y = 244.8631x + 78.9180, R 2 =0.9998), and the calculated content of Torreya grandis seed oil in the sample is 99.6%.

[0078] Conclusion: The content of Torreya grandis seed oil in the sample is 99.6%±4.5%, which is pure Torreya grandis seed oil.

[0079] Example 3

[0080] A method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetradecanoic acid characteristics, comprising the following steps:

[0081] A. Mix the vegetable oil sample evenly, weigh 0.5g of the vegetable oil sample and add it into a 10ml test tube;

[0082] B. Add 10 mL of cyclohexane-ethyl acetate (volume ratio of 1:1), dissolve, vortex mix for 0.5 min, and wait for purification;

[0083] C. Gel permeation chromatography was used for purification, with an injection volume of 5 ml, a mobile phase of a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and a flow rate of 4.5 ml / min; the eluent was collected for a period of 480 s to 1080 s;

[0084] The eluent is volume-fixed by an online automatic concentration and volume-fixing system. In the automatic concentration and volume-fixing system, the water bath temperature is 40°C, the vacuum degree of the first step of concentration is 180 mbar, and the vacuum degree of the second step of concentration is 210 mbar. The solvent for volume fixing is a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and the volume is fixed to 2 ml and loaded into a chromatograph injection bottle for detection and analysis by gas chromatography-mass spectrometry.

[0085] D. Establish a calibration curve for the percentage content of Torreya grandis seed oil. Weigh 0.10 g, 0.30 g, 0.50 g, 0.70 g, and 1.00 g of homemade and squeezed Torreya grandis seed oil in a 10 ml centrifuge tube, and make up to 1 g with soybean oil if it is less than 1 g, that is, the mass fraction of Torreya grandis seed oil is 10%, 30%, 50%, 70%, and 100%, respectively. Perform analysis simultaneously according to steps B to F, and establish a calibration curve for the mass percentage concentration of Torreya grandis seed oil with the peak area of ​​24-aldehyde as the ordinate and the mass percentage of Torreya grandis seed oil as the abscissa;

[0086] E. Whether the sample contains Torreya grandis seed oil is verified by detecting the presence of tetracosaldehyde. The peak area of ​​tetracosaldehyde is substituted into the calibration curve established in step D to calculate the mass percentage concentration of Torreya grandis seed oil in the sample.

[0087] GC-MS Chromatographic Conditions:

[0088] Inlet: 250℃;

[0089] Injection volume: 1 μl, splitless injection;

[0090] Chromatographic column: HP-5MS 5% Phenyl Methyl Silox (30m×0.25mm, 0.25μm);

[0091] Carrier gas: He, flow rate 1 ml / min;

[0092] Program temperature rise: 50℃ for 0.5min, 5℃ / min to 250℃ for 5min, 10℃ / min to 280℃ for 10min;

[0093] Auxiliary heating zone (MSD transfer line): 280°C;

[0094] Mass spectrometry acquisition mode: full scan (scan), mass number 50.0-430, for qualitative analysis; selected ion scan (sim), mass number 82, dwell 40ms, mass number 96, dwell 100ms, mass number 334, dwell 40ms, mass number 352, dwell 40ms, for quantitative analysis;

[0095] Solvent delay: 3.0min;

[0096] Ion source: 230℃;

[0097] MS quadrupole: 150 °C.

[0098] Test results:

[0099] Figure 8 , Fig. 9 , Fig.10 They are the total ion current chromatogram of the sample (including the "twenty-tetradecaldehyde" part), the mass spectrum of twenty-tetradecaldehyde in the sample and the selected ion spectrum of twenty-tetradecaldehyde in the sample.

[0100] Figure 8 , Fig. 9 This indicates that the sample contains Torreya grandis seed oil. Fig.10 The peak area of ​​the quantitative ion (96) was 23536, and the calibration curve (y = 244.8631x + 78.9180, R 2 =0.9998), and the calculated content of Torreya grandis seed oil in the sample was 95.8%.

[0101] Conclusion: The content of Torreya grandis seed oil in this sample is 95.8%±4.5%, which is pure Torreya grandis seed oil.

[0102] In conclusion, the above is only a preferred embodiment of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the patent of the present invention.

Claims

1. A method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetradecanoic acid characteristics, characterized in that: The following steps are involved: A. Mix the vegetable oil sample evenly, weigh the vegetable oil sample and add it into the centrifuge tube; B. Add cyclohexane-ethyl acetate to the centrifuge tube containing the vegetable oil sample, dissolve, vortex mix, and wait for purification; Wherein, cyclohexane-ethyl acetate is mixed in a volume ratio of 1:1; C. After purification by gel permeation chromatography, the eluate is collected, and after being fixed to volume by an online automatic concentration and volume fixing system, the eluate is loaded into the chromatograph injection bottle and then tested and analyzed by gas chromatography-mass spectrometry; The mobile phase for gel permeation chromatography purification was a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and the speed was 4.5 ml / min; the eluent was collected for a period of 480 s to 1080 s; D. Establish a calibration curve for the percentage content of Torreya grandis seed oil: Weigh homemade and pressed Torreya grandis seed oil, and make up to 1g with vegetable oil if it is less than 1g, and prepare Torreya grandis seed oil with mass fractions of 10%, 30%, 50%, 70%, and 100%, respectively. Perform analysis according to steps B to C simultaneously, and establish a calibration curve for the mass percentage concentration of Torreya grandis seed oil with the peak area of ​​24-aldehyde as the ordinate and the mass percentage of Torreya grandis seed oil as the abscissa; E. Whether the sample contains Torreya grandis seed oil is verified by whether tetracosaldehyde is detected. The peak area of ​​tetracosaldehyde is brought into the calibration curve established in step D to calculate the mass percentage concentration of Torreya grandis seed oil in the sample.

2. The method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetracosaldehyde characteristics according to claim 1, characterized in that: In step A, weigh 0.5-1.5 g of vegetable oil sample into a 10 ml centrifuge tube.

3. The method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetracosaldehyde characteristics according to claim 2, characterized in that: Weigh 0.5 g of the vegetable oil sample.

4. The method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetracosaldehyde characteristics according to claim 1, characterized in that: The volume of hexane-ethyl acetate added in step B is 10 ml, and the vortex time is 0.5~5 min.

5. The method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetracosaldehyde characteristics according to claim 4, characterized in that: The vortex time was 0.5 min.

6. The method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetracosaldehyde characteristics according to claim 1, characterized in that: The injection volume in step C was 5 ml.

7. The method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetracosaldehyde characteristics according to claim 1, characterized in that: In the automatic concentration and volume determination system in step C, the water bath temperature is 40° C., the vacuum degree of the first concentration step is 180 mbar, and the vacuum degree of the second concentration step is 210 mbar. The solvent for volume determination is a cyclohexane-ethyl acetate mixture with a volume ratio of 1:1, and the volume is determined to 2 ml.

8. A method for determining the authenticity and percentage content of Torreya grandis seed oil based on tetracosaldehyde characteristics according to any one of claims 1 to 7, characterized in that: The supplementary vegetable oil in step D is soybean oil.

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