A detection method for 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one

Abstract

The present invention belongs to the technical field of antioxidant detection and analysis, and specifically relates to a detection method for 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one. The present invention establishes a method for rapid determination of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one by gas chromatography-mass spectrometry, and the target compound determined by this method shows a good linear relationship within a certain range; the detection limit and quantitative limit are both low, and the sensitivity is high; the relative standard deviation and the spiked recovery rate meet the test requirements, and the precision and accuracy are high; and the method is simple and efficient to operate, and can provide technical and data support for the safe use of plastic packaging materials and the quality control of products by manufacturers.

Description

Technical Field

[0001] The present invention belongs to the technical field of antioxidant detection and analysis, and more specifically, relates to a detection method for 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one. Background Art

[0002] As a material in daily life, plastics have a wide range of applications. Among them, plastics have become the main packaging material due to their good barrier properties, high strength, transparency, and light weight. However, polymer materials are prone to oxidation reactions, which can cause the materials to fade, yellow, crack, harden, lose gloss or transparency, and then lead to a significant decrease in physical properties such as impact strength, flexural strength, tensile strength, and elongation, affecting the normal use of plastic products. At present, the more appropriate measures to delay the oxidation of polymers include improving the chemical structure of polymers, deactivating and stabilizing active end groups, and adding antioxidants. Among them, adding antioxidants is the simplest and most common method for polymer stabilization. Antioxidants are additives that inhibit or delay the degradation of polymers by oxygen or ozone in the atmosphere, and are the most widely used additives in plastics. Although antioxidants can slow down the aging of materials, excessive addition can be harmful to the human body. Toxicological experiments have shown that synthetic antioxidants (the most commonly used are BHA and BHT) have significant toxic side effects and have adverse effects on the human liver, spleen, lungs, etc. Countries around the world have successively promulgated standard requirements for packaging materials that come into direct contact with food, and there is an urgent need to establish a method for quickly determining the content of antioxidants in packaging materials.

[0003] At present, in order to control the amount of antioxidants added, the commonly used detection methods for antioxidants mainly include: liquid chromatography, gas chromatography, gas chromatography-mass spectrometry and infrared spectroscopy, etc. 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one (antioxidant HP-136) is often added to plastic packaging materials as an antioxidant and also needs to be strictly monitored. However, to date, the research on 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one (antioxidant HP-136) has mainly focused on the fields of synthesis and application, and there are few reports on the detection of its content in plastic packaging materials. Wang Yong et al. disclosed a method for determining the antioxidant HP-136 component in composite plastics by liquid chromatography-PDA detection method, but the analysis cost, instrument price and daily maintenance cost of the method are relatively high (Wang Yong, Hu Cuilan. Determination of active ingredients in composite plastic additives (9M) [C] / / . Proceedings of the 15th National Chromatography Academic Conference (Volume 2)., 2005: 99-100.). Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of the prior art method for determining 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one, and to provide a detection method with high sensitivity, fast detection speed, high detection accuracy and precision, and simple operation.

[0005] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0006] A method for detecting 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one comprises the following steps:

[0007] S1. Prepare a standard solution and a test solution, wherein the test solution is prepared by crushing the sample, adding an organic solvent, fully extracting at 25 to 40°C, filtering the extract, and testing the resulting filtrate;

[0008] S2. Use gas chromatography-mass spectrometry for detection and analysis, wherein the gas chromatography conditions are: use DB-5HT or DB-5MS; set the injection port temperature: 240-300°C; the injection mode is splitless; the chromatographic column flow rate is 0.8-1.5mL / min; the gas chromatography heating program is: set the initial temperature to 80-120°C, increase the temperature to 310-320°C at 20-30°C / min, and maintain for 3-5min;

[0009] The mass spectrometry conditions are as follows: ion source: EI source; ionization energy: 70 eV; ion source temperature: 220-240°C; quadrupole temperature: 140-160°C; solvent delay: 3-5 min; acquisition mode: sim and scan; quantitative ion (m / z): 307, qualitative ion (m / z): 308, 350, 335; wherein, m / z is the ratio of the number of protons to the number of charges.

[0010] Furthermore, the detection method further comprises the following steps:

[0011] (1) Draw a standard curve: Draw a standard working curve with concentration as the horizontal axis X and peak area as the vertical axis Y;

[0012] (2) Calculate the content of the target substance: Substitute the peak area of ​​5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one obtained from the test into the standard working curve to obtain the concentration of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one in the test solution. Then, calculate the residual amount of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one in the sample based on the sample mass corresponding to the test solution.

[0013] Preferably, the gas chromatography conditions are: chromatographic column: DB-5HT (length 15m, inner diameter 0.25mm, film thickness 0.1μm), inlet temperature: 290°C, injection mode: non-divided flow, chromatographic column flow rate: 1.2mL / min, heating program: initial temperature 100°C, hold for 0min, heat to 320°C at 30°C / min, hold for 3min.

[0014] Preferably, the mass spectrometry conditions are: ion source: EI source, ionization energy: 70 eV, ion source temperature: 230°C, quadrupole temperature: 150°C, solvent delay: 3 min, acquisition mode: sim and scan, quantitative ion (m / z): 307, qualitative ion (m / z): 308, 350, 335.

[0015] Preferably, the organic solvent is methanol or toluene.

[0016] Most preferably, the organic solvent is toluene. When toluene is used as the solvent, the target object response value obtained is higher.

[0017] Preferably, the usage ratio of the sample to the organic solvent is 1 g: 10-50 mL.

[0018] Preferably, the method of sufficient extraction is ultrasound.

[0019] Preferably, the sufficient extraction time is 30 to 50 minutes.

[0020] Preferably, the pore size of the filter membrane used to filter the extract is 0.45 μm.

[0021] Furthermore, the detection limit of the detection method is 0.0061 mg / L.

[0022] Furthermore, the quantitative limit of the detection method is 0.0204 mg / L.

[0023] The present invention has the following beneficial effects:

[0024] (1) The present invention establishes a new detection method for 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one. By optimizing the instrument analysis parameters, a symmetrical chromatographic peak of the target compound 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one can be obtained within 6 minutes.

[0025] (2) The target compounds determined by this analytical test method show a good linear relationship within a certain range; the detection limit and quantitative limit are both low, with high sensitivity; the relative standard deviation and spike recovery rate are both within the test requirements, with high precision and accuracy; and the method is simple and efficient to operate, which can provide technical and data support for the safe use of plastic packaging materials and manufacturers' quality control of their products. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the chromatogram of a standard solution of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one prepared with toluene as solvent.

[0027] Figure 2 This is the mass spectrum of the standard solution of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one prepared with toluene as solvent.

[0028] Figure 3 The chromatograms are superimposed for the standard solutions of the same concentration corresponding to different solvents.

[0029] Figure 4 This is a graph showing the data of spike recovery corresponding to different extraction temperatures.

[0030] Figure 5 This is the data graph of the spike recovery corresponding to different extraction times.

[0031] Figure 6 This is the standard working curve of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one prepared with toluene as solvent. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0033] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0034] The information of 5,7-di-tert-butyl-3-(3,4-dimethylbenzyl)benzofuran-2(3H)-one is shown in Table 1:

[0035] Table 1 Basic information of 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)benzofuran-2(3H)-one

[0036]

[0037] Example 1 Determination of the Chromatogram and Mass Spectrum of 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)benzofuran-2(3H)-one

[0038] A method for detecting 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one, comprising the following steps:

[0039] 1. Experimental methods

[0040] S1. Preparation of standard solution

[0041] (1) Standard stock solution: Accurately weigh 10 mg of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one standard using a 100,000 grade analytical balance, dissolve it in toluene and make up to volume in a 10 mL volumetric flask to obtain a 1000 mg / L stock solution of the standard substance, which was stored in a refrigerator at 4°C away from light.

[0042] (2) Standard working solution: Dilute the standard stock solution stepwise with toluene to obtain a series of mixed standard working solutions of 0.1 mg / L, 0.5 mg / L, 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, and 10.0 mg / L.

[0043] S2. Detection and analysis The standard working solution with a concentration of 0.5 mg / mL obtained in step S1 was measured by GC-MS coupling instrument;

[0044] (1) Gas chromatography conditions:

[0045] Chromatographic column: DB-5HT (length 15m, inner diameter 0.25mm, film thickness 0.1μm), injection port temperature: 290℃, injection mode: non-split, column flow rate: 1.2mL / min, heating program: initial temperature 100℃, increase to 320℃ at 30℃ / min, and hold for 3min.

[0046] (2) Mass spectrometry conditions:

[0047] Ion source: EI source, ionization energy: 70ev, ion source temperature: 230℃, quadrupole temperature: 150℃, solvent delay: 3min, acquisition mode: select full scan mode for qualitative analysis, select SIM mode for quantitative analysis, quantitative ion (m / z): 307, qualitative ion (m / z): 308, 350, 335.

[0048] 2. Experimental results.

[0049] According to the above conditions, the standard solution was analyzed, the chromatogram and mass spectrum were recorded, and the chromatogram and mass spectrum of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one were obtained. The results were as follows: Figure 1and Figure 2 As shown. Figure 1 It can be seen that the chromatographic peak of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one is sharp and symmetrical, and the peak emerges within 5.5 minutes. Figure 2 It can be seen that ions 308, 335 and 350 are selected as the qualitative ions of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one; among them, ion 307 has the highest response value and is selected as the quantitative ion of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one.

[0050] Example 2 Selection of solvent

[0051] 1. Experimental methods

[0052] S1. Preparation of standard solution

[0053] (1) Standard stock solution: Accurately weigh 10 mg of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one standard using a 100,000 grade analytical balance, dissolve it in toluene, methanol and acetone as organic solvents respectively and make up to volume in a 10 mL volumetric flask to obtain a 1000 mg / L stock solution of the standard substance, which is stored in a refrigerator at 4°C away from light.

[0054] (2) Standard working solution: Use corresponding organic solvents to dilute the standard stock solution step by step to obtain a series of mixed standard working solutions of 0.1 mg / L, 0.5 mg / L, 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, and 10.0 mg / L.

[0055] S2. Detection and Analysis

[0056] The standard working solution with a concentration of 0.5 mg / mL obtained in step S1 was measured using a GC-MS instrument;

[0057] (1) Gas chromatography conditions:

[0058] Chromatographic column: DB-5HT (length 15m, inner diameter 0.25mm, film thickness 0.1μm), injection port temperature: 290℃, injection mode: non-split, column flow rate: 1.2mL / min, heating program: initial temperature 100℃, increase to 320℃ at 30℃ / min, and hold for 3min.

[0059] (2) Mass spectrometry conditions:

[0060] Ion source: EI source, ionization energy: 70ev, ion source temperature: 230℃, quadrupole temperature: 150℃, solvent delay: 3min, acquisition mode: select full scan mode for qualitative analysis, select SIM mode for quantitative analysis, quantitative ion (m / z): 307, qualitative ion (m / z): 308, 350, 335.

[0061] 2. Experimental results

[0062] Test according to the above conditions and record the chromatograms of standard working solutions prepared with different solvents. The results are as follows: Figure 3 As shown in the figure, the target response corresponding to acetone is very low, while the target response value corresponding to toluene is the highest. This is probably because 5,7-di-tert-butyl-3-(3,4-dimethylbenzene)benzofuran-2(3H)-one contains two benzene rings and an alkane structure, and the substance itself has a low polarity, resulting in its good solubility in toluene. According to the response value comparison results, toluene was selected as the extraction solvent.

[0063] Example 3 Optimization of extraction temperature

[0064] 1. Experimental methods

[0065] S1. Preparation of standard solution

[0066] (1) Standard stock solution: Accurately weigh 10 mg of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one standard using a 100,000 grade analytical balance, dissolve it in toluene and make up to volume in a 10 mL volumetric flask to obtain a 1000 mg / L stock solution of the standard substance, which was stored in a refrigerator at 4°C away from light.

[0067] (2) Standard working solution: Dilute the standard stock solution stepwise with toluene to obtain a series of mixed standard working solutions of 0.1 mg / L, 0.5 mg / L, 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, and 10.0 mg / L.

[0068] S2. Preparation of test solution and spike solution

[0069] (1) Preparation of test solution: Weigh 1 g (accurate to 0.1 mg) of a plastic film sample that does not contain the target product, cut it into pieces of 2 mm × 2 mm, place it in a sample bottle, and add 10 mL of an organic solvent.

[0070] (2) Preparation of spiked solution: Weigh 1 g (accurate to 0.1 mg) of a plastic film sample that does not contain the target product, cut it into pieces of 2 mm × 2 mm, place it in a sample bottle, add 9 mL of an organic solvent, and then add 1 mL of a standard working solution with a concentration of 20 mg / mL.

[0071] (3) The extraction temperature was set at 25°C, 40°C and 60°C respectively. The sample (test solution or spiked solution) solution was extracted by ultrasonic for 50 min under different temperature conditions. The extracted solution was filtered through a 0.45 μm filter membrane to obtain the test solution.

[0072] S3. Detection and analysis

[0073] The solutions obtained in step S1 and step S2 are measured by GC-MS;

[0074] (1) Gas chromatography conditions:

[0075] Chromatographic column: DB-5HT (length 15m, inner diameter 0.25mm, film thickness 0.1μm), injection port temperature: 290℃, injection mode: non-split, column flow rate: 1.2mL / min, heating program: initial temperature 100℃, increase to 320℃ at 30℃ / min, and hold for 3min.

[0076] (2) Mass spectrometry conditions:

[0077] Ion source: EI source, ionization energy: 70ev, ion source temperature: 230℃, quadrupole temperature: 150℃, solvent delay: 3min, acquisition mode: select full scan mode for qualitative analysis, select SIM mode for quantitative analysis, quantitative ion (m / z): 307, qualitative ion (m / z): 308, 350, 335.

[0078] (3) Draw a standard curve: Draw a standard working curve with concentration as the horizontal axis X and peak area as the vertical axis Y.

[0079] (4) Calculation formula for spike recovery

[0080] P=(c 2 -c 1 ) / c 3 ×100%

[0081] Where, P is the spike recovery rate;

[0082] c 1 is the concentration of the target substance in the test solution, mg / L;

[0083] c 2 is the concentration of the target substance in the spiked solution, mg / L;

[0084] c 3 is the spiked amount, mg / L.

[0085] 2. Experimental results

[0086] The test data were used to obtain the concentration of the target product under each condition, and then the above calculation formula was used to obtain the test result of the spike recovery rate (the average value of the results of three parallel measurements was taken as the test result). The results are as follows: Figure 4 As shown in the figure, when the extraction temperature is 25℃, the average recovery rate of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one is the highest, higher than 95%. When the temperature is 40℃, its recovery rate is slightly lower than that of 25℃, but still higher than 95%. When the temperature is raised to 60℃, the recovery rate drops sharply, and the average recovery rate drops to about 86%, which may be due to the increase in temperature, which enhances the matrix interference and destroys the extraction balance. Comprehensive extraction factors and recovery results, the optimized extraction temperature is selected as 40℃.

[0087] Example 4 Optimization of extraction time

[0088] 1. Experimental methods

[0089] S1. Preparation of standard solution

[0090] (1) Standard stock solution: Accurately weigh 10 mg of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one standard using a 100,000 grade analytical balance, dissolve it in toluene and make up to volume in a 10 mL volumetric flask to obtain a 1000 mg / L stock solution of the standard substance, which was stored in a refrigerator at 4°C away from light.

[0091] (2) Standard working solution: dilute the standard stock solution with toluene step by step to obtain a series of mixed standard working solutions of 0.1 mg / L, 0.5 mg / L, 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, and 10.0 mg / L. S2. Preparation of test solution and spiked solution

[0092] (1) Preparation of test solution: Weigh 1 g (accurate to 0.1 mg) of a plastic film sample that does not contain the target product, cut it into pieces of 2 mm × 2 mm, place it in a sample bottle, and add 10 mL of an organic solvent.

[0093] (2) Preparation of spiked solution: Weigh 1 g (accurate to 0.1 mg) of a plastic film sample that does not contain the target product, cut it into pieces of 2 mm × 2 mm, place it in a sample bottle, add 9 mL of an organic solvent, and then add 1 mL of a standard working solution with a concentration of 20 mg / mL.

[0094] (3) The extraction time was set to 30 min, 50 min, 70 min, 90 min, and 110 min in sequence, and the extraction temperature was set to 40 °C. The sample solution (test solution or spiked solution) was ultrasonically extracted under different time conditions. The extracted solution was filtered through a 0.45 μm filter membrane to obtain the test solution.

[0095] S3. Detection and analysis

[0096] The solutions obtained in step S1 and step S2 are measured by GC-MS;

[0097] (1) Gas chromatography conditions:

[0098] Chromatographic column: DB-5HT (length 15m, inner diameter 0.25mm, film thickness 0.1μm), injection port temperature: 290℃, injection mode: non-split, column flow rate: 1.2mL / min, heating program: initial temperature 100℃, increase to 320℃ at 30℃ / min, and hold for 3min.

[0099] (2) Mass spectrometry conditions:

[0100] Ion source: EI source, ionization energy: 70ev, ion source temperature: 230℃, quadrupole temperature: 150℃, solvent delay: 3min, acquisition mode: select full scan mode for qualitative analysis, select SIM mode for quantitative analysis, quantitative ion (m / z): 307, qualitative ion (m / z): 308, 350, 335.

[0101] 2. Experimental results

[0102] Record the chromatogram and obtain the spiked recovery data results for different extraction times according to the calculation method of Example 3. The results are as follows: Figure 5 As shown in the figure, when the extraction time increases from 30min to 50min, the average recovery rate of the target product remains almost unchanged. When the extraction time increases from 50min to 70min, 90min and 110min, the recovery rate of the target product decreases. Considering the extraction factors and the recovery rate results, the optimal extraction time is 50min.

[0103] Example 5 Determination of linear equation and detection limit

[0104] 1. Experimental methods

[0105] Referring to the preparation method of the standard solution in Example 1, standard working solutions of different concentrations were obtained. Referring to the GC-MS conditions in Example 1, the samples were injected respectively, the injection volume was 1uL, and the number of injections for each concentration was 3 times (the average value was taken at the end), and the average peak area of ​​each concentration was obtained. The standard working curve (such as Figure 6 shown).

[0106] 2. Experimental results

[0107] The linear regression equation and other parameters of the analyte are shown in Table 2.

[0108] Table 2 Regression equations and other parameters of target compounds

[0109]

[0110] Combining the data in Table 2 and Figure 6 It can be seen that within the linear range of 0.1 mg / L to 10.0 mg / L, the target compound showed a good linear relationship, and its detection limit and quantification limit were low, which were 0.0061 mg / L and 0.0204 mg / L, respectively.

[0111] Example 6 Precision and Accuracy Investigation

[0112] 1. Experimental methods

[0113] A plastic film sample that does not contain the target product was selected, and the extraction temperature was set to 40°C. Three spiked solutions with different spiked concentration levels (0.1 mg / L, 2.0 mg / L, and 10.0 mg / L) were prepared for precision and accuracy experiments. Each level was measured three times in parallel, and the average spiked recovery and precision were calculated. For other operations, refer to Example 3.

[0114] 2. Experimental results

[0115] The measurement results are shown in Table 3.

[0116] Table 3 Precision and accuracy test results

[0117]

[0118]

[0119] The results showed that the relative standard deviation was less than 3.4%, indicating that the test method had good repeatability and high precision. At three different spike levels, the spike recovery of the target substance was in the range of 95.3% to 105.0%, indicating that the method had high accuracy and could meet the test requirements.

[0120] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for detecting 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one, characterized in that: The following steps are involved: S1. Prepare a standard solution and a test solution, wherein the test solution is prepared by crushing the sample, adding an organic solvent, fully extracting at 25-40 °C, filtering the extract, and testing the resulting filtrate; S2. Gas chromatography-mass spectrometry was used for detection and analysis, wherein the gas chromatography conditions were as follows: DB-5HT or DB-5MS was used; the injection port temperature was set to 240-300 °C; the injection mode was splitless; the column flow rate was 0.8-1.5 mL / min; the gas chromatography temperature program was as follows: the initial temperature was set to 80-120 °C, and the temperature was increased to 310-320 °C at a rate of 20-30 °C / min, and maintained for 3-5 min; The mass spectrometry conditions were as follows: ion source: EI source; ionization energy: 70 eV; ion source temperature: 220-240 °C; quadrupole temperature: 140-160 °C; solvent delay: 3-5 min; acquisition mode: sim and scan; quantitative ion m / z: 307, qualitative ion m / z: 308, 350, 335; The organic solvent is methanol or toluene.

2. The detection method according to claim 1, characterized in that: The gas chromatography conditions are as follows: chromatographic column: DB-5HT, length 15 m, inner diameter 0.25 mm, film thickness 0.1 μm, injection port temperature: 290 °C, injection mode: splitless, chromatographic column flow: 1.2 mL / min, heating program: initial temperature 100 °C, hold for 0 min, heat to 320 °C at 30 °C / min, hold for 3 min.

3. The detection method according to claim 1, characterized in that: The mass spectrometry conditions are: ion source: EI source, ionization energy: 70 ev, ion source temperature: 230 °C, quadrupole temperature: 150 °C, solvent delay: 3 min, acquisition mode: sim and scan, quantitative ion m / z: 307, qualitative ion m / z: 308, 350, 335.

4. The detection method according to claim 1, characterized in that: The dosage ratio of the sample to the organic solvent is 1 g: 10-50 mL.

5. The detection method according to claim 1, characterized in that: The method of sufficient extraction is ultrasound.

6. The detection method according to claim 1, characterized in that: The sufficient extraction time is 30 to 50 min.

7. The detection method according to claim 1, characterized in that: The pore size of the filter membrane used to filter the extract is 0.45 μm.

8. The detection method according to claim 1, characterized in that: The detection limit of the detection method is 0.0061 mg / L.

9. The detection method according to claim 1, characterized in that: The limit of quantification of the detection method is 0.0204 mg / L.

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