Method for detecting content of benzoquinone compounds in wood

Abstract

The application discloses a method for detecting the content of benzoquinone compounds in wood and relates to the technical field of chemical analysis. The method comprises the following steps: adding a wood sample to be detected into a toluene solvent for extraction to obtain a benzoquinone compound extraction liquid; and performing gas chromatography-mass spectrometry detection on the benzoquinone compound extraction liquid obtained in step S1, wherein the detected benzoquinone compounds are 2,3-dimethoxy-5-methyl-1,4-benzoquinone and / or 2,6-dimethoxy-1,4-benzoquinone. The detection limit of 2,3-dimethoxy-5-methyl-1,4-benzoquinone is as low as 0.0883 mg / kg, and the standard addition recovery rate is 97.6% to 103.7%; the detection limit of 2,6-dimethoxy-1,4-benzoquinone is as low as 0.0888 mg / kg, and the standard addition recovery rate is 99.8% to 101.3%.

Description

Technical Field

[0001] This invention relates to the field of chemical analysis technology, and more specifically, to a method for detecting the content of benzoquinone compounds in wood. Background Technology

[0002] Benzoquinones are compounds commonly found in plants. Studies have shown that these compounds possess strong antimicrobial activity and play an important role in plant defense against pathogens and termites. In 1972, Hausen et al. detected benzoquinones in various commercial woods already identified as potential causative agents of contact dermatitis. Other reports indicate that X-ray analysis of benzoquinone compounds in sensitizing Australian black locust wood identified two as 2,6-dimethoxy-1,4-benzoquinone and 2,3-dimethoxy-5-methyl-1,4-benzoquinone. Sensitization experiments in guinea pigs revealed that both of these benzoquinone compounds in the wood could induce contact dermatitis. Furthermore, in cases of contact dermatitis caused by 21 different commercially valuable woods, no other contact allergens besides benzoquinones were detected, suggesting that these substances can be considered pathogens. Therefore, determining the content of benzoquinone compounds in wood is of significant importance for the prevention of contact dermatitis.

[0003] Existing technologies disclose the isolation, identification, and content determination of benzoquinone compounds in starfruit roots; these methods employ high-performance liquid chromatography (HPLC) for quantitative analysis of benzoquinone compounds in starfruit roots. However, the benzoquinone compounds studied in these methods differ from the 2,6-dimethoxy-1,4-benzoquinone and 2,3-dimethoxy-5-methyl-1,4-benzoquinone studied in this project, and their detection areas are different. Current research on 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone primarily focuses on synthesis and characterization, with no reports found regarding their content detection. Therefore, there is a need to develop a simple, accurate, and highly sensitive method for determining 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone from wood. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem that the existing technology cannot accurately and effectively determine the content of benzoquinone compounds in wood, and to provide a method for detecting the content of benzoquinone compounds in wood.

[0005] The above-mentioned objective of this invention is achieved through the following technical solution:

[0006] This invention protects a method for detecting the content of benzoquinone compounds in wood, comprising the following steps:

[0007] S1, the wood sample to be tested is added to toluene solvent for extraction to obtain benzoquinone compound extract;

[0008] S2, the benzoquinone compound extract obtained in step S1 is subjected to gas chromatography-mass spectrometry for detection, and the detected benzoquinone compounds are 2,3-dimethoxy-5-methyl-1,4-benzoquinone and / or 2,6-dimethoxy-1,4-benzoquinone;

[0009] The gas chromatography conditions are as follows:

[0010] Column: DB-5HT, length 30m, film thickness 0.25μm, inner diameter 0.25mm; injection port temperature: 275~285℃; injection mode: splitless; column flow rate: 1.0~1.4mL / min;

[0011] Mass spectrometry conditions are:

[0012] Ion source temperature: 225~235℃; ionization method: electron impact ionization; quadrupole temperature: 145~155℃; acquisition mode: full scan mode and selected ion scan mode, the full scan mode range: 50~500m / z.

[0013] The structural formula of 2,3-dimethoxy-5-methyl-1,4-benzoquinone is shown in Formula I; the structural formula of 2,6-dimethoxy-1,4-benzoquinone is shown in Formula II.

[0014]

[0015] This invention employs gas chromatography-mass spectrometry (GC-MS) for the qualitative and quantitative detection of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone. By optimizing GC conditions, column selection, and mass spectrometry conditions, GC-MS chromatograms were obtained. Qualitative analysis was performed using peak elution time, and quantitative analysis was performed using peak area (response value), thus enabling rapid detection of the content of these two benzoquinone compounds. The results show that, in the linear range of sample concentration from 1.0 mg / L to 50.0 mg / L, both 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone exhibit excellent linearity, with correlation coefficients of 0.9997 and 0.9992, respectively. The detection limit for 2,3-dimethoxy-5-methyl-1,4-benzoquinone is as low as 0.0883 mg / kg, and the quantitation limit is as low as 0.294 mg / kg. The spiked recovery rate was 97.6%–103.7% at 4 mg / kg, with a standard deviation of recovery rate not exceeding 3.7%. The detection limit for 2,6-dimethoxy-1,4-benzoquinone was as low as 0.0888 mg / kg, and the quantitation limit was as low as 0.2961 mg / kg, with a spiked recovery rate of 99.8%–101.3% and a standard deviation of recovery rate not exceeding 2.8%. This demonstrates that the detection method of the present invention has the characteristics of low detection limit, high sample spiked recovery rate, and high precision and accuracy.

[0016] Preferably, in step S1, the extraction temperature is 40–60°C.

[0017] Preferably, in step S1, the extraction is performed under ultrasonic conditions, and the ultrasonic extraction time is 15 to 60 minutes.

[0018] Preferably, the extraction temperature is 45–55°C, and the ultrasonic extraction time is 25–35 min. By optimizing the temperature and extraction time, the extraction efficiency is significantly improved.

[0019] Preferably, in step S1, the mass-to-volume ratio of the wood sample to the toluene solvent is (0.5-2) g : (5-30) mL.

[0020] Preferably, step S1 further includes a filtration process, wherein the filtration process involves filtering the extracted benzoquinone compound extract using a 0.2-0.5 μm filter membrane.

[0021] Preferably, in step S2, the gas chromatography conditions are programmed temperature rise, specifically: initial temperature 95-105℃, held for 0-2 min, then increased to 215-230℃ at a heating rate of 15-25℃ / min, and held for 0-2 min.

[0022] Preferably, in step S2, the gas chromatography conditions are as follows:

[0023] Column: DB-5HT, length 30m, membrane thickness 0.25μm, inner diameter 0.25mm;

[0024] Inlet temperature: 280℃;

[0025] Carrier gas: Helium, purity ≥ 99.999%;

[0026] Injection mode: Splitless;

[0027] Column flow rate: 1.2 mL / min;

[0028] Temperature program: Initial temperature 100℃, hold for 0 min, increase temperature to 220℃ at 20℃ / min, hold for 0 min.

[0029] Preferably, in the selected ion scanning mode of step S2, the qualitative ions of 2,3-dimethoxy-5-methyl-1,4-benzoquinone are 68 m / z, 83 m / z, 137 m / z, and 182 m / z, and the quantitative ion is 137 m / z; the qualitative ions of 2,6-dimethoxy-1,4-benzoquinone are 53 m / z, 69 m / z, 80 m / z, and 168 m / z, and the quantitative ion is 69 m / z.

[0030] Preferably, in step S2, the mass spectrometry conditions are as follows:

[0031] Ion source temperature: 230℃;

[0032] Ionization method: Electron bombardment ionization;

[0033] Quadrupole temperature: 150℃;

[0034] Acquisition modes: Full scan mode and selective ion scan mode;

[0035] Full scan mode range: 50–500 m / z;

[0036] The ions selected for the ion scanning mode are: 53 m / z, 68 m / z, 69 m / z, 80 m / z, 83 m / z, 137 m / z, 168 m / z, and 182 m / z.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] This invention provides a method for detecting benzoquinone compounds, which can simultaneously determine the content of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone in wood. The method has a low detection limit, high sample spike recovery rate, and high precision and accuracy. In the detection method of this invention, 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone exhibit good linearity within a sample concentration range of 1.0 mg / L to 50.0 mg / L, with correlation coefficients of 0.9997 and 0.9992, respectively. The detection limit for 2,3-dimethoxy-5-methyl-1,4-benzoquinone is as low as 0.0883 mg / kg, the quantitation limit is as low as 0.2944 mg / kg, the spiked recovery rate is 97.6% to 103.7%, and the standard deviation of the recovery rate is not greater than 3.7%. The detection limit for 2,6-dimethoxy-1,4-benzoquinone is as low as 0.0888 mg / kg, the quantitation limit is as low as 0.2961 mg / kg, the spiked recovery rate is 99.8% to 101.3%, and the standard deviation of the recovery rate is not greater than 2.8%. Attached Figure Description

[0039] Figure 1 This is a GC-MS chromatogram of a wood sample tested in Example 1 of the present invention.

[0040] Figure 2 This is the mass spectrum of 2,3-dimethoxy-5-methyl-1,4-benzoquinone in Example 1 of the present invention.

[0041] Figure 3 This is the mass spectrum of 2,6-dimethoxy-1,4-benzoquinone in Example 1 of the present invention.

[0042] Figure 4 The GC-MS chromatogram was obtained by testing a DB-5HT-15m chromatographic column in the column optimization experiment of this invention.

[0043] Figure 5 The GC-MS chromatogram was obtained by testing with a DB-5MS column in the column optimization experiment of this invention.

[0044] Figure 6 The GC-MS chromatogram was obtained by testing a DB-5HT-30m chromatographic column in the column optimization experiment of this invention.

[0045] Figure 7 This is a graph showing the relationship between the effects of different extraction solvents on extraction efficiency in the optimization experiment of the extraction solvent of this invention.

[0046] Figure 8 This is a graph showing the relationship between different extraction temperatures and extraction efficiency in the optimization experiment of the extraction temperature of this invention.

[0047] Figure 9 This is a graph showing the effect of different ultrasonic times on extraction efficiency in the optimization experiment of extraction time according to the present invention. Detailed Implementation

[0048] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0049] Example 1

[0050] A method for detecting the content of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone, comprising the following steps:

[0051] 1. Preparation of the test sample solution: Take a representative commercial wood sample, cut it into small pieces no larger than 1mm*1mm. Accurately weigh 1g of sample (accurate to 0.1mg) and place it in a sample bottle, then add 10mL of toluene. Tighten the cap and place the sample bottle in an ultrasonic cleaner, sonicate at 50℃ for 30min. After cooling to room temperature, take 1mL of the extracted solution and filter it through a 0.45μm filter membrane to obtain the test sample solution.

[0052] 2. Gas Chromatography-Mass Spectrometry (GC-MS) Detection: The sample solution was analyzed using a gas chromatography-mass spectrometry (GC-MS) instrument. The instrument conditions were as follows:

[0053] (1) Gas chromatography conditions

[0054] Column: DB-5HT (30m length, 0.25μm film thickness, 0.25mm inner diameter); Injector temperature: 280℃; Carrier gas: Helium (99.999% purity); Injection mode: Splitless; Column flow rate: 1.2mL / min; Temperature program: Initial temperature 100℃ (hold for 0min), increase to 220℃ at 20℃ / min (hold for 0min).

[0055] (2) Mass spectrometry conditions:

[0056] Electron impact ion source (EI); Ion source temperature: 230°C; Quadrupole temperature: 150°C; Scan range m / z: 50–500; Selective ion (SIM) (2.5 min to end): 53 m / z, 68 m / z, 69 m / z, 80 m / z, 83 m / z, 137 m / z, 168 m / z, 182 m / z.

[0057] Chromatography Figure 1As shown, under optimized chromatographic conditions, the chromatographic peaks of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone eluted at 4.100 min and 5.035 min, respectively. At this time, the chromatographic peaks of the analytes were sharp and symmetrical, and there were no impurity peaks interfering with them near their retention times.

[0058] Mass spectrometry, such as Figure 2-3 As shown, the mass spectra of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone exhibit high response, few impurity peaks, and low interference.

[0059] Example 2

[0060] Optimization experiments of gas chromatography-mass spectrometry conditions:

[0061] 1. Preparation of standard solutions

[0062] Standard stock solution: Accurately weigh 5 mg of the standard substance (accurate to 0.1 mg), wherein the standard substance is 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone in a mass ratio of 1:1, dissolve in toluene and dilute to a volumetric flask of 10 mL to obtain a 500 mg / L stock solution of the standard substance, and store in a refrigerator at 2-8 °C protected from light.

[0063] Standard working solutions: The standard stock solution was serially diluted with toluene to obtain a series of standard working solutions with concentrations of 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, 20.0 mg / L, and 50.0 mg / L.

[0064] 2. Optimization of chromatographic columns

[0065] The standard working solutions of 2,3-dimethoxy-5-methyl-1,4-benzoquinone (mass concentration of 50.0 mg / L) were used to obtain the total ion chromatogram by full scanning in the range of 50–500 m / z. The characteristic fragment ions of the analytes were selected as the target monitoring ions for qualitative and quantitative analysis: the fragment ions of 2,3-dimethoxy-5-methyl-1,4-benzoquinone at 68 m / z, 83 m / z, 137 m / z, and 182 m / z were used as qualitative ions, of which fragment ion at 137 m / z was used as the quantitative ion; the fragment ions of 2,6-dimethoxy-1,4-benzoquinone at 53 m / z, 69 m / z, 80 m / z, and 168 m / z were used as qualitative ions, of which fragment ion at 69 m / z was used as the quantitative ion.

[0066] This embodiment found that the fragment ions described above have a high mass-to-charge ratio and high response value, are not easily interfered with, and have a high detection limit. Meanwhile, the screened quantitative ions exhibit excellent response values ​​and anti-interference properties, with extremely high detection limits.

[0067] 3. Optimization of chromatographic columns

[0068] In this embodiment, DB-624, DB-5HT-15m, DB-5HT-30m, and DB-5MS columns were used to test the standard working solutions of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone. The results are as follows: Figure 4-6 As shown.

[0069] Since the DB-624 column (60m in length, 250μm in film thickness, and 1.4μm in inner diameter) is a medium to strong polarity column, and the analyte is weakly polar, no chromatographic peak of the analyte was detected when using this column for detection.

[0070] like Figure 4 As shown, when using a DB-5HT-15m column (length 15m, film thickness 250μm, inner diameter 0.1mm), the two analytes elute at 5.7min and 6.9min respectively. However, the peak shapes are asymmetrical and there is obvious tailing, which makes it impossible to separate the two substances well and cannot be improved by changing the chromatographic conditions.

[0071] like Figure 5 As shown, when using a DB-5MS column (30m in length, 250μm in film thickness, and 0.25mm in inner diameter), the peak shape and response of 2,3-dimethoxy-5-methyl-1,4-benzoquinone are good, but the peak response of 2,6-dimethoxy-1,4-benzoquinone is significantly weaker and shows tailing.

[0072] like Figure 6 As shown, when using a DB-5HT-30m column (30m in length, 250μm in film thickness, and 0.25mm in inner diameter), the two analytes were well separated, with both exhibiting symmetrical peak shapes and high response. Therefore, the DB-5HT-30m column was ultimately selected for the experiment. Under optimized chromatographic conditions, the chromatographic peaks of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone eluted at 4.100 min and 5.035 min, respectively. At these times, the chromatographic peaks of the analytes were sharp and symmetrical, and there were no interfering impurity peaks near their retention times.

[0073] Example 3

[0074] Extraction condition optimization experiment:

[0075] 1. Optimization of extraction solvent

[0076] In this experiment, tetrahydrofuran, methanol, acetonitrile, acetone, and toluene were selected as extraction solvents to compare the extraction efficiencies of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone in the samples. The results are as follows: Figure 7 As shown.

[0077] exist Figure 7 Of the five extraction solvents, toluene had the highest extraction efficiency, with an average extraction efficiency of over 95% for both analytes. While acetonitrile and acetone achieved extraction efficiencies of 93-95% for 2,3-dimethoxy-5-methyl-1,4-benzoquinone, their efficiencies for 2,6-dimethoxy-1,4-benzoquinone were only 70-71%. Methanol's extraction efficiency was around 80%. Tetrahydrofuran had a lower extraction efficiency, with only about 35% for both analytes. Therefore, toluene was chosen as the extraction solvent in this embodiment.

[0078] 2. Optimization of extraction temperature

[0079] In this experiment, extraction temperatures of 40℃, 50℃, 60℃, and 70℃ were selected to compare the extraction efficiencies of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone in the samples.

[0080] like Figure 8 As shown, the recovery rate of the two analytes by ultrasonic extraction at 40℃ was around 85%, while the recovery rate of 2,3-dimethoxy-5-methyl-1,4-benzoquinone reached 90% and that of 2,6-dimethoxy-1,4-benzoquinone reached over 95% when ultrasonically extracted at 50℃. However, as the temperature increased, the extraction efficiency of 2,3-dimethoxy-5-methyl-1,4-benzoquinone did not increase significantly, while that of 2,6-dimethoxy-1,4-benzoquinone decreased significantly. Therefore, ultrasonic extraction at 50℃ was ultimately chosen as the extraction condition.

[0081] 3. Optimization of extraction time

[0082] In this experiment, extraction times of 15 min, 30 min, 45 min, 60 min, and 70 min were used to compare the extraction efficiencies of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone in the samples.

[0083] like Figure 9 As shown, the maximum extraction efficiency can be achieved after 30 minutes of ultrasonic treatment. The longer the ultrasonic treatment time, the lower the extraction efficiency. This is attributed to the semi-volatile nature of the sample. Therefore, the recovery rate decreases slightly with longer extraction time. Taking all factors into consideration, this embodiment ultimately selected 30 minutes of ultrasonic treatment as the extraction condition.

[0084] Performance testing

[0085] 1. Linear equation and detection limit

[0086] Standard working solutions of mixed 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone at concentrations of 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, 20.0 mg / L, and 50.0 mg / L were prepared.

[0087] Then, the content of 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone was detected using a method according to this embodiment. The sample solution was replaced with standard working solutions of different concentrations as described above. Under optimized gas chromatography-mass spectrometry conditions, the linear range and limit of detection for 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone were determined. A standard working curve was plotted with mass concentration X (mg / L) on the x-axis and peak area Y on the y-axis. The results are shown in Table 1.

[0088] Table 1. Linear equation, correlation coefficient, limit of detection, and limit of quantitation.

[0089]

[0090] Referring to Table 1, the experimental results show that 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone both exhibit good linearity within the linear range of 1.0 mg / L to 50.0 mg / L, with correlation coefficients of 0.9997 and 0.9992, respectively.

[0091] Based on this, the limits of detection (LOD) and limits of quantitation (LOQ) of the standard reference were determined by using a signal-to-noise ratio (S / N) of 3 and 10 times, respectively. The results showed that the method limits of detection were 0.0883 mg / kg and 0.0888 mg / kg, and the limits of quantitation were 0.2944 mg / kg and 0.2961 mg / kg, respectively.

[0092] 2. Recovery rate and precision

[0093] The recovery rate of this invention was determined by a blank matrix spiking experiment. A sample free of the analytes 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone was used as the blank matrix, and three different spiking concentration levels (1.0 mg / L, 5.0 mg / L, and 20.0 mg / L) were set. Each spiking level was tested in triplicate (n=3) for precision experiments. The results are shown in Table 2.

[0094] Table 2 Results of Recovery and Precision Tests

[0095]

[0096]

[0097] Table 2 shows that, at the three spiking levels, the recoveries of 2,3-dimethoxy-5-methyl-1,4-benzoquinone were 97.6%–103.7%, with a standard deviation of recovery of no more than 3.7%; the recoveries of 2,6-dimethoxy-1,4-benzoquinone were 99.8%–101.3%, with a standard deviation of recovery of no more than 2.8%. This indicates that the detection method of the present invention has high accuracy and can meet the testing requirements.

[0098] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for detecting the content of benzoquinone compounds in wood, characterized in that, Includes the following steps: S1, the wood sample to be tested is added to toluene solvent for extraction to obtain benzoquinone compound extract; S2, The benzoquinone compound extract obtained in step S1 was subjected to gas chromatography-mass spectrometry for detection. The detected benzoquinone compounds were 2,3-dimethoxy-5-methyl-1,4-benzoquinone and 2,6-dimethoxy-1,4-benzoquinone. The gas chromatography conditions are as follows: Column: DB-5HT, length 30m, film thickness 0.25μm, inner diameter 0.25mm; injection port temperature: 275~285℃; injection mode: splitless; column flow rate: 1.0~1.4mL / min; The gas chromatography conditions adopted a programmed temperature rise, specifically: an initial temperature of 95-105℃, held for 0-2 min, and then increased to 215-230℃ at a heating rate of 15-25℃ / min, held for 0-2 min. Mass spectrometry conditions are: Ion source temperature: 225~235℃; Ionization method: electron impact ionization; Quadrupole temperature: 145~155℃; Acquisition mode: full scan mode and selected ion scan mode, the range of the full scan mode: 50~500m / z; In the selected ion scanning mode, the qualitative ions of 2,3-dimethoxy-5-methyl-1,4-benzoquinone are 68 m / z, 83 m / z, 137 m / z, and 182 m / z, and the quantitative ion is 137 m / z; the qualitative ions of 2,6-dimethoxy-1,4-benzoquinone are 53 m / z, 69 m / z, 80 m / z, and 168 m / z, and the quantitative ion is 69 m / z.

2. The method for detecting the content of benzoquinone compounds in wood according to claim 1, characterized in that, In step S1, the extraction temperature is 40–60°C.

3. The method for detecting the content of benzoquinone compounds in wood according to claim 1, characterized in that, In step S1, the extraction is performed under ultrasonic conditions for a time of 15–60 min.

4. The method for detecting the content of benzoquinone compounds in wood according to claim 2 or 3, characterized in that, The extraction temperature was 45–55℃, and the ultrasonic extraction time was 25–35 min.

5. The method for detecting the content of benzoquinone compounds in wood according to claim 1, characterized in that, In step S1, the mass-to-volume ratio of the wood sample to the toluene solvent is (0.5-2) g : (5-30) mL.

6. The method for detecting the content of benzoquinone compounds in wood according to claim 1, characterized in that, Step S1 also includes a filtration process, wherein the filtration process involves filtering the extracted benzoquinone compound extract using a 0.2-0.5 μm filter membrane.

7. The method for detecting the content of benzoquinone compounds in wood according to claim 1, characterized in that, In step S2, the gas chromatography conditions are as follows: Inlet temperature: 280℃; Carrier gas: Helium, purity ≥ 99.999%; Column flow rate: 1.2 mL / min; Temperature program: Initial temperature 100℃, hold for 0 min, increase to 220℃ at 20℃ / min, hold for 0 min.

8. The method for detecting the content of benzoquinone compounds in wood according to claim 1, characterized in that, In step S2, the mass spectrometry conditions are as follows: Ion source temperature: 230℃; Quadrupole temperature: 150℃.

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