Method for detecting trigonellin in a beverage
By using a gas chromatography-mass spectrometry (GC-MS) system with pH-adjusted ethanol-water solution and self-made silica gel packing material in alcoholic beverages, the complexity and inaccuracy of fenugreek lactone detection in alcoholic beverages were solved, achieving detection results with high sensitivity and low detection limit.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JING BRAND
- Filing Date
- 2026-03-11
- Publication Date
- 2026-06-19
AI Technical Summary
In the existing technology, the detection methods for fenugreek lactone in alcoholic beverages are complex and not accurate enough, making it difficult to effectively analyze its content at low concentrations.
An ethanol-water solution with adjusted pH was used as a simulated matrix. A liquid-liquid microextraction and thermal desorption-large volume cold trap injection system was combined with a gas chromatography-mass spectrometry system filled with self-made Silica unbonded silica gel packing material to detect the matrix interference by enriching and releasing fenugreek lactone.
It improves the accuracy and sensitivity of detection, with a detection limit of 0.42 μg/L for fenugreek lactone. It has the advantages of wide applicability, low detection limit and high specificity.
Smart Images
Figure CN122238518A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of liquor testing technology, and in particular to a method for detecting fenugreek lactone in alcoholic beverages. Background Technology
[0002] Fenugreek lactone (4-hydroxy-2,5-dimethyl-3(2H)-furanone, commonly known as HDMF) is a chiral lactone compound with a strong aroma, widely found in food and alcoholic beverages. It has a low aroma threshold (9 μg / L), exhibiting caramel and soy sauce aroma characteristics at low concentrations, and curry aroma characteristics at higher concentrations. Multiple studies have shown that fenugreek lactone is a hallmark compound of aging aromas in baijiu, wine, and huangjiu, and has a significant impact on the flavor of alcoholic beverages.
[0003] Due to its high polarity, poor thermal stability, and low content in alcoholic beverages, the accurate analysis and detection of fenugreek lactone presents significant challenges. Currently reported methods for determining fenugreek lactone include solid-phase extraction combined with microtube large-volume injection and gas chromatography-mass spectrometry (GC-MS) for quantification. However, these methods involve complex pretreatment processes and the use of large amounts of solvents. Chinese Invention Application 202211100015.6 discloses a method for the quantitative analysis of fenugreek lactone in rice wine, which involves first extracting and concentrating the rice wine sample, then removing impurities using thin-layer chromatography, and finally performing quantitative analysis using UHPLC-DAD. This method also suffers from complex pretreatment issues.
[0004] Therefore, how to accurately and conveniently detect the content of fenugreek lactone in alcoholic beverages has become one of the urgent technical problems to be solved. Summary of the Invention
[0005] The purpose of this invention is to provide a method for detecting fenugreekine in alcoholic beverages, aiming to improve the accuracy of fenugreekine detection in alcoholic beverages.
[0006] The technical solution of this invention is implemented as follows:
[0007] A method for detecting fenugreek lactone in alcoholic beverages includes the following steps: Step 1: Prepare an ethanol solution with a volume fraction close to that of the wine sample by dissolving anhydrous ethanol in it. Adjust the pH to 3-4 with lactic acid to prepare a simulated matrix. Then, use the simulated matrix to prepare a standard solution. Step 2: Perform liquid-liquid microextraction and concentration on the sample to be tested and the standard prepared with the simulated matrix to obtain the sample test solution and the standard test solution. Step 3: The sample solution and the standard solution were measured using a thermal desorption-large volume cold trap injection system-gas chromatography-mass spectrometry.
[0008] In some embodiments, the preparation method of the standard series solutions includes preparing an ethanol solution with a volume fraction of 50% to 60% by adding anhydrous ethanol and purified water, adjusting the pH to 3-4 with lactic acid to obtain a simulated matrix, adding fenugreek lactone standard stock solution to the simulated matrix, and then diluting the simulated matrix stepwise by 2.5 times to obtain the standard series solutions.
[0009] In some embodiments, the liquid-liquid microextraction method includes taking 5-10 mL of wine sample, adding internal standard solution, diluting with saturated sodium chloride aqueous solution to an ethanol volume fraction of 10%-15%, then adding extraction solvent with a wine sample to extraction solvent volume ratio of 2:1, shaking for 10 min, letting stand for 1 h, transferring the organic phase to a 10 mL sample bottle, dehydrating with anhydrous Na2SO4 and blowing with nitrogen to 0.5-1 mL, to obtain sample test solution and standard test solution.
[0010] In some embodiments, the internal standard solution is prepared by dissolving anisylacetone in anhydrous ethanol, and the concentration of the internal standard solution is 100 mg / L.
[0011] In some embodiments, the fenugreek lactone standard stock solution is prepared by dissolving fenugreek lactone standard in anhydrous ethanol, and the concentration of the fenugreek lactone standard stock solution is 2.62-1279.80 mg / L.
[0012] In some embodiments, the extraction solvent is one or a mixture of two of ethyl acetate, anhydrous diethyl ether, and n-pentane, with ethyl acetate being preferred.
[0013] In some implementations, the thermal desorption (TDU) conditions are: initial temperature 50°C, held for 0.5 min, increased to 250°C at 300°C / min, held for 3 min, transfer line temperature 300°C, solvent evacuation mode, and time 0.5 min; the cold trap injection system (CIS) conditions are: initial temperature -120°C, held for 1.0 min, increased to 250°C at 12°C / s, and held for 3 min.
[0014] In some embodiments, 20-40 mg of adsorbent and 50-80 mg of glass wool are sequentially filled at the bottom of the liner.
[0015] In some embodiments, the adsorbent used is SiO2 unbonded silica gel filler.
[0016] In some embodiments, the gas chromatography conditions are as follows: a (50% phenyl)-50% dimethyl polysiloxane capillary column; solvent evacuation mode at the injection port with a flow rate of 40-50 mL / min; injection volume of 10-20 μL; and injection speed of 0.5-1.0 s. The carrier gas is high-purity He (purity ≥99.999%) in constant flow mode at a flow rate of 1.0 mL / min. The temperature program is as follows: initial temperature 60°C, hold for 2 min, increase to 160°C at 8°C / min, hold for 2 min, and then increase to 280°C at 30°C / min, hold for 10 min. The mass spectrometry conditions are: electron ionization (extractor); electron energy 70 eV; ion source temperature 230°C; quadrupole temperature 150°C; and mass transfer line temperature 280°C.
[0017] The present invention has the following advantages over the prior art: This invention uses an ethanol-water solution with adjusted pH as a simulated matrix to prepare a standard solution, and employs liquid-liquid microextraction for extraction. This avoids interference from other components in the beverage and effectively prevents detection errors caused by matrix effects.
[0018] When using large-volume injection, this invention employs a CIS-specific deactivated liner and a self-made unbonded silica gel packing material. This packing material is the most polar forward adsorbent with a very strong polar retention capacity. Trigonelline is also highly polar, and during injection, it is enriched by this adsorbent at low temperatures. Then, the temperature is gradually increased to release it into the chromatographic column. At the same time, solvent interference is reduced by purging the solvent, which greatly increases the mass spectrometry response to the trigonelline signal.
[0019] This invention employs liquid-liquid microextraction combined with nitrogen blowing concentration to increase the concentration of fenugreekine in the test solution. Further determination is performed using a thermal desorption-large-volume cold trap injection system-gas chromatography-mass spectrometry. Large-volume injection increases the mass spectrometry response value. Simultaneously, the adsorbent in the self-made liner enriches and releases fenugreekine, while also removing impurities from the beverage, significantly improving detection specificity and sensitivity.
[0020] The method of the present invention has a detection limit of 0.42 μg / L for fenugreek lactone, and has the advantages of wide applicability, low detection limit, high specificity and high accuracy. Attached Figure Description
[0021] Figure 1 The selected ion mass spectra of fenugreek lactone and internal standard in Example 1 are shown. Figure 2 This is the standard curve of fenugreek lactone in Example 1; Figure 3Selected ion mass spectrum of the light-aroma baijiu sample in Example 1; Figure 4 The selected ion mass spectrum is shown in Example 1 for the recovery experiment of the light-aroma baijiu sample. Figure 5 Selected ion mass spectrum of the strong-aroma baijiu sample in Example 2; Figure 6 The selected ion mass spectrum of the Maotai-flavor liquor sample in Example 3; Figure 7 Selected ion mass spectra of the wine sample in Example 4; Figure 8 Selected ion mass spectra of the rice wine sample in Example 5; Figure 9 Selected ion mass spectra of the light-aroma baijiu sample in Comparative Example 2. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this invention pertain. If any definition stated in this section is contrary to or otherwise inconsistent with a definition stated in a patent, patent application, published patent application, or other publication incorporated herein by reference, the definitions listed here shall prevail over those incorporated herein by reference.
[0024] Unless otherwise specified, the methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials, reagents, and instruments used are conventional materials, reagents, and instruments in the art, and can be obtained commercially by those skilled in the art.
[0025] Example 1 This embodiment provides a method for detecting the fenugreek lactone content in light-aroma baijiu, as detailed below: 1. Reagents: Anhydrous ethanol and ethyl acetate were of chromatographic grade; lactic acid, anhydrous Na₂SO₄, and NaCl were of analytical grade; water was ultrapure water. Simulated matrix: Transfer 50 mL of anhydrous ethanol to a 100 mL volumetric flask, add about 0.2 mL of lactic acid aqueous solution (60.0 g / L), and dilute to the mark with ultrapure water to make the pH = 3~4.
[0026] 2. Sample to be tested and fenugreek lactone standard The light-aroma baijiu has an alcohol content of 53.5% vol. Trigonelline and anisylacetone, with a purity greater than 97.8%, were purchased from Shanghai Anpu Experimental Technology Co., Ltd.
[0027] 3. Preparation of standard solutions 3.1 Trigonelline Standard Stock Solution and Working Solution Accurately weigh an appropriate amount of fenugreek lactone standard into a 10 mL volumetric flask, dissolve it in anhydrous ethanol and dilute to the mark to obtain fenugreek lactone standard stock solution with a concentration of 12798 mg / L, labeled as SS-1, and store at -20 ℃ protected from light.
[0028] Accurately pipette 0.01 mL of the standard stock solution (SS-1) into a 10 mL volumetric flask, dissolve it in anhydrous ethanol and dilute to the mark to obtain the fenugreek lactone standard stock solution with a concentration of 12.798 mg / L, labeled as SS-2, and store at -20 ℃ protected from light.
[0029] 3.2 Standard series solutions Accurately pipette 0.05 mL of fenugreek lactone standard stock solution (SS-1) into a 50 mL volumetric flask, and dilute to the mark with a simulated matrix to obtain the fenugreek lactone standard solution, labeled BY1. Subsequently, BY1 is serially diluted 2.5 times with a simulated matrix to obtain BY2 to BY8, thus obtaining a series of fenugreek lactone standard solutions. Store at 4°C protected from light, with a shelf life of 1 month.
[0030] 3.3 Internal Standard Solution Weigh 1.0 mg of anethole acetone standard into a 10 mL volumetric flask, dissolve and dilute to the mark with anhydrous ethanol to obtain a 100 mg / L internal standard solution, and store at -20 ℃ protected from light.
[0031] 4. Sample processing procedure Accurately transfer 10 mL of light-aroma baijiu sample and the standard series solutions (BY1~BY8) from step 3.2 into 100 mL centrifuge tubes. Add 10 μL of internal standard solution and 50 mL of saturated sodium chloride solution. Add 5 mL of ethyl acetate to the centrifuge tubes, shake for 10 min, and let stand for 1 h. Transfer the organic phase to a 10 mL sample bottle, dehydrate with anhydrous Na2SO4 and blow with nitrogen to 1 mL. Use the obtained sample solution for GC-MS analysis.
[0032] 5. Sample Determination 5.1 Instrument Conditions Thermal desorption (TDU) conditions: initial temperature 50 ℃, held for 0.5 min, increased to 250 ℃ at 300 ℃ / min, held for 3 min, transfer line temperature 300 ℃, solvent evacuation mode, time 0.5 min.
[0033] Cold trap injection system (CIS) conditions: initial temperature -120 ℃, hold for 1.0 min, increase to 250 ℃ at 12 ℃ / s, hold for 3 min.
[0034] GC conditions: Gas chromatography conditions included a (50% phenyl)-50% dimethyl polysiloxane capillary column; the injection port mode was solvent evacuation mode with a solvent evacuation flow rate of 50 mL / min, the injection volume was 20 μL, and the injection rate was 0.7 μL / s; the carrier gas was high-purity He (purity ≥99.999%), in constant flow mode with a flow rate of 1.0 mL / min; the temperature program was as follows: initial temperature 60 ℃, hold for 2 min, increase to 160 ℃ at 8 ℃ / min, hold for 2 min, then increase to 280 ℃ at 30 ℃ / min, hold for 10 min.
[0035] MS conditions: electron ionization (extractor); electron energy 70 eV; ion source temperature 230 ℃; quadrupole temperature 150 ℃; mass transfer line temperature 280 ℃; GC-MS was first used for a full scan in SCAN mode (m / z 30-500) to obtain the full scan mass spectrum. Instrument parameters were then optimized to determine the retention times and characteristic ions of fenugreek lactone and the internal standard. Selected ion mode (SIM) scanning was then used for quantification using the internal standard method. The selected ion mass spectrometry information for fenugreek lactone and the internal standard is shown in Table 1, and the mass spectra are attached. Figure 1 .
[0036] Table 1. Quantitative information on fenugreek lactone and internal standard.
[0037] 5.2 Establishment of the Standard Curve Take the pretreated BY1~BY8 standard series solutions from step 3.2 and inject them sequentially into a GC-MS according to their concentration from low to high. Monitor the mass spectra of fenugreek lactone and the internal standard. Construct a standard curve with the peak area ratio of fenugreek lactone to the internal standard in the standard series solutions as the ordinate and the mass concentration of fenugreek lactone as the abscissa. The parameters of the fenugreek lactone standard curve are shown in Table 2. The fenugreek lactone standard curves are as follows: Figure 2 As shown.
[0038] Table 2. Parameters of the standard curve of fenugreek lactone
[0039] 5.3 Sample Determination The sample solution and standard solution were measured under the same detection conditions. The peak areas of fenugreek lactone and the internal standard were substituted into the standard curve to calculate the mass concentration of the corresponding fenugreek lactone in the sample. The chromatogram of the light-aroma baijiu sample to be tested is shown below. Figure 3 As shown.
[0040] 6. Precision test Take the pretreated BY3 solution from step 5.2 and inject it 6 times. Calculate the precision test RSD value based on the peak area ratio of fenugreek lactone and internal standard. All RSD values are less than 5%. The results are shown in Table 3.
[0041] Table 3 Results of the precision test of fenugreek lactone
[0042] 7. Repeatability Experiments Accurately transfer 10 mL of the sample to be tested into 100 mL centrifuge tubes, making a total of 6 aliquots, labeled S-1 to S-6. Process the sample solutions according to the above method, determine the content of fenugreek lactone, and calculate the repeatability of the fenugreek lactone determination results. The RSD values are all less than 5%, indicating that the method has good repeatability. The specific results are shown in Table 4.
[0043] Table 4 Results of repeatability experiments with fenugreek lactone
[0044] 8. Limit of Detection (LOD) and Limit of Quantification (LOQ) The limit of detection (LOD) is the sample mass concentration corresponding to a signal intensity / baseline noise (S / N) ratio of 3:1; the limit of quantitation (LOQ) is the sample mass concentration corresponding to a signal intensity / baseline noise (S / N) ratio of 10:1.
[0045] In this embodiment, the limit of detection (LOD) for fenugreek lactone was 0.42 μg / L, and the limit of quantitation (LOQ) was 1.41 μg / L.
[0046] 9. Accuracy Experiment Accurately transfer 10 mL of the sample to be tested into a 100 mL centrifuge tube, and divide it into three groups: A, B, and C, with three aliquots in each group, for a total of nine aliquots. Label these as Group A (R1-1, R1-2, and R1-3), Group B (R2-1, R2-2, and R2-3), and Group C (R3-1, R3-2, and R3-3), respectively. Take 1 μL of fenugreek lactone standard stock solution (SS-2) from step 3.1, and add 25 μL of SS-2 to Group A, 50 μL of SS-2 to Group B, and 75 μL of SS-2 to Group C. Then, perform pretreatment as described in steps 4.1 and 4.2 to obtain the sample solutions for GC-MS analysis. The selected ion mass spectrum for the accuracy experiment of the test sample is shown below. Figure 4 As shown.
[0047] Substituting the peak areas of fenugreek and the internal standard into the standard curve, the content and recovery rate of each fenugreek were calculated. The recovery rate of fenugreek was greater than 85%, and the RSD value was less than 10%, indicating that the method has good accuracy. The specific calculation results are shown in Table 5.
[0048] Table 5. Results of the accuracy test for fenugreek lactone
[0049] Example 2 This embodiment provides a method for detecting the fenugreek lactone content in strong-aroma baijiu, as detailed below: 1. Reagents: Same as in Example 1.
[0050] 2. Samples to be tested and standards The sample to be tested was a strong-aroma baijiu with an alcohol content of 64.2% vol; the standard was the same as in Example 1.
[0051] 3. Preparation of standard solutions: Same as in Example 1.
[0052] 4. Sample processing procedure Accurately transfer 10 mL of strong-aroma baijiu sample and the standard series solutions (BY1~BY8) from step 3.2 into 100 mL centrifuge tubes, add 10 μL of internal standard solution and 60 mL of saturated sodium chloride solution, add 5 mL of ethyl acetate to the centrifuge tubes, shake for 10 min, let stand for 1 h, transfer the organic phase to a 10 mL sample bottle, dehydrate with anhydrous Na2SO4 and blow with nitrogen to 1 mL, and use the obtained sample solution for GC-MS analysis.
[0053] 5. Plotting the standard curve: Same as in Example 1.
[0054] 6. Sample Determination The determination conditions and methods were the same as in Example 1. The selected ion mass spectrum of the obtained strong-aroma baijiu sample is shown below. Figure 5 As shown in the figure. Substituting the peak areas of fenugreek and the internal standard into the standard curve, the content of each fenugreek in the strong-aroma baijiu sample was calculated to be 14.23 μg / L.
[0055] Example 3 This embodiment provides a method for detecting the fenugreek lactone content in Maotai-flavor liquor, as detailed below: 1. Reagents: Same as in Example 1.
[0056] 2. Samples to be tested and standards The sample to be tested was a sauce-flavored baijiu with an alcohol content of 53.2% vol; the standard was the same as in Example 1.
[0057] 3. Preparation of standard solutions: Same as in Example 1.
[0058] 4. Sample processing procedure Accurately transfer 10 mL of the Maotai-flavor liquor sample and the standard series solutions (BY1~BY8) from step 3.2 into 100 mL centrifuge tubes. Add 10 μL of internal standard solution and 50 mL of saturated sodium chloride solution. Add 5 mL of ethyl acetate to the centrifuge tubes, shake for 10 min, and let stand for 1 h. Transfer the organic phase to a 10 mL sample bottle, dehydrate with anhydrous Na2SO4 and blow with nitrogen to 1 mL. Use the obtained sample solution for GC-MS analysis.
[0059] 5. Plotting the standard curve: Same as in Example 1.
[0060] 6. Sample Determination The determination conditions and methods were the same as in Example 1. The selected ion mass spectrum of the obtained Maotai-flavor liquor sample is shown below. Figure 6 As shown in the figure. Substituting the peak areas of fenugreek and the internal standard into the standard curve, the content of fenugreek in the Maotai-flavor liquor sample was calculated to be 32.58 μg / L.
[0061] Example 4 This embodiment provides a method for detecting the fenugreek lactone content in wine, as detailed below: 1. Reagents: Same as in Example 1.
[0062] 2. Samples to be tested and standards The sample to be tested was wine with an alcohol content of 14.1% vol; the standard was the same as in Example 1.
[0063] 3. Preparation of standard solutions: Same as in Example 1.
[0064] 4. Sample processing procedure Accurately transfer 10 mL of wine sample and the series of standard solutions (BY1~BY8) from step 3.2 into 100 mL centrifuge tubes, add 10 μL of internal standard solution and 10 mL of saturated sodium chloride solution, add 5 mL of ethyl acetate to the centrifuge tubes, shake for 10 min, let stand for 1 h, transfer the organic phase to a 10 mL sample bottle, dehydrate with anhydrous Na2SO4 and blow with nitrogen to 1 mL, and use the obtained sample solution for GC-MS analysis.
[0065] 5. Plotting the standard curve: Same as in Example 1.
[0066] 6. Sample Determination The determination conditions and methods were the same as in Example 1, and the selected ion mass spectrum of the obtained wine sample is shown below. Figure 7 As shown in the figure. Substituting the peak areas of fenugreek and the internal standard into the standard curve, the content of fenugreek in the wine sample was calculated to be 45.3 μg / L.
[0067] Example 5 This embodiment provides a method for detecting the fenugreek lactone content in rice wine, as detailed below: 1. Reagents: Same as in Example 1.
[0068] 2. Samples to be tested and standards The sample to be tested was rice wine with an alcohol content of 11.2% vol; the standard was the same as in Example 1.
[0069] 3. Preparation of standard solutions: Same as in Example 1.
[0070] 4. Sample processing procedure Accurately transfer 10 mL of rice wine sample and the series of standard solutions (BY1~BY8) from step 3.2 into 100 mL centrifuge tubes, add 10 μL of internal standard solution and 10 mL of saturated sodium chloride solution, add 5 mL of ethyl acetate to the centrifuge tubes, shake for 10 min, let stand for 1 h, transfer the organic phase to a 10 mL sample bottle, dehydrate with anhydrous Na2SO4 and blow with nitrogen to 1 mL, and use the obtained sample solution for GC-MS analysis.
[0071] 5. Plotting the standard curve: Same as in Example 1.
[0072] 6. Sample Determination The determination conditions and methods were the same as in Example 1, and the selected ion mass spectrum of the obtained rice wine sample is shown below. Figure 8 As shown in the figure. Substituting the peak areas of fenugreek and the internal standard into the standard curve, the content of fenugreek in the rice wine sample was calculated to be 132.4 μg / L.
[0073] Comparative Example 1 This comparative example uses different standard test solutions to determine fenugreek lactone in light-aroma baijiu as a comparison method. The specific steps are as follows: A standard solution was prepared using a 50% ethanol solution as a simulated matrix (without using lactic acid to adjust the pH). The standard test solution was obtained by pretreatment using the same process as the test sample.
[0074] In Example 1, the recovery rate of fenugreek lactone was 85.13%–101.38%; in Comparative Example 1, the recovery rate of fenugreek lactone was 138.21%–164.32%, indicating that the accuracy and detection limit of the method provided by the present invention are superior to the comparative method.
[0075] Comparative Example 2 This comparative example uses a split / splitless injection method to determine fenugreek lactone in light-aroma baijiu as a comparison method. The specific steps are as follows: In Example 1, the sample processed in step 4 was directly injected at a rate of 1 μL using a split / splitless injection port. Figure 9 As shown, fenugreek lactone has a low response value and significant background interference.
[0076] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for detecting fenugreek lactone in alcoholic beverages, characterized in that, Includes the following steps: Step 1: Prepare an ethanol solution with a volume fraction close to that of the wine sample by dissolving anhydrous ethanol in it. Adjust the pH to 3-4 with lactic acid to prepare a simulated matrix. Then, use the simulated matrix to prepare a standard solution. Step 2: Perform liquid-liquid microextraction and concentration on the sample to be tested and the standard prepared with the simulated matrix to obtain the sample test solution and the standard test solution. Step 3: The sample solution and the standard solution were measured using a thermal desorption-large volume cold trap injection system-gas chromatography-mass spectrometry.
2. The method according to claim 1, characterized in that, The preparation method of the standard series solutions includes: preparing an ethanol solution with a volume fraction of 50%~60% by adding anhydrous ethanol and purified water; adjusting the pH to 3-4 with lactic acid to obtain a simulated matrix; adding fenugreek lactone standard stock solution to the simulated matrix; and then diluting the simulated matrix stepwise by 2.5 times to obtain the standard series solutions.
3. The method according to claim 1, characterized in that, The liquid-liquid microextraction method includes taking 5-10 mL of wine sample, adding internal standard solution, diluting with saturated sodium chloride aqueous solution to an ethanol volume fraction of 10%-15%, then adding extraction solvent with a wine sample to extraction solvent volume ratio of 2:1, shaking for 10 min, letting stand for 1 h, transferring the organic phase to a 10 mL sample bottle, dehydrating with anhydrous Na2SO4 and blowing with nitrogen to 0.5-1 mL, to obtain the sample test solution and the standard test solution.
4. The method according to claim 3, characterized in that, The internal standard solution was prepared by dissolving anisylacetone in anhydrous ethanol, and the concentration of the internal standard solution was 100 mg / L.
5. The method according to claim 2, characterized in that, The fenugreek lactone standard stock solution is prepared by dissolving fenugreek lactone standard in anhydrous ethanol, and the concentration of the fenugreek lactone standard stock solution is 2.62-1279.80 mg / L.
6. The method according to claim 3, characterized in that, The extraction solvent is one or a mixture of two of ethyl acetate, anhydrous diethyl ether, and n-pentane, preferably ethyl acetate.
7. The method according to claim 1, characterized in that, The thermal desorption (TDU) conditions were: initial temperature 50℃, held for 0.5 min, increased to 250℃ at 300℃ / min, held for 3 min, transfer line temperature 300℃, solvent evacuation mode, and time 0.5 min; the cold trap injection system (CIS) conditions were: initial temperature -120℃, held for 1.0 min, increased to 250℃ at 12℃ / s, and held for 3 min.
8. The method according to claim 1, characterized in that, For large-volume injection, the liner used is a CIS 4 deactivated liner, with 20-40 mg of adsorbent and 50-80 mg of glass wool sequentially packed at the bottom of the liner.
9. The method according to claim 8, characterized in that, The adsorbent used is unbonded silica gel filler with SiO2.
10. The method according to claim 1, characterized in that, Gas chromatography conditions: 50% phenyl-50% dimethyl polysiloxane capillary column; solvent evacuation mode, solvent evacuation flow rate 40-50 mL / min, injection volume 10-20 μL, injection rate 0.5-1.0 s; carrier gas: He with purity ≥99.999%, constant flow mode, flow rate 1.0 mL / min; temperature program: initial temperature 60℃, hold for 2 min, increase to 160℃ at 8℃ / min, hold for 2 min, then increase to 280℃ at 30℃ / min, hold for 10 min; mass spectrometry conditions: electron ionization source; electron energy 70 eV; ion source temperature 230℃; quadrupole temperature 150℃; mass transfer line temperature 280℃.