Method for detecting content of catechol and pyrogallic phenol in cosmetics

Abstract

The invention provides a method for detecting the content of catechol and pyrogallic phenol in cosmetics, and belongs to the technical field of analytical chemistry. According to the method for detecting the content of catechol and pyrogallol in cosmetics, sodium chloride is added into the extraction solvent, osmotic pressure and ionic strength in the extraction solution are adjusted, separation of catechol and pyrogallol in cosmetics is promoted, and the method has high extraction efficiency, especially extraction of low-concentration catechol and pyrogallol; according to the method, catechol and pyrogallic acid are used as raw materials, then an extraction column with polystyrene-divinyl benzene as filler is used for solid-phase extraction, and methanol is used for elution, so that catechol and pyrogallic acid are enriched and separated from various organic matters, the detection accuracy is improved, and low-concentration detection is realized. According to the detection method provided by the invention, the detection limit of the catechol and the pyrogallic phenol is 0.01 mg / kg, and the quantitation limit is 0.03 mg / kg.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical chemistry, and in particular relates to a method for detecting the contents of catechol and pyrogallol in cosmetics. Background Art

[0002] Catechol, also known as catechol, has strong reducing properties and is an important chemical intermediate. It can be used as a rubber hardener, skin preservative and bactericide, etc. On October 27, 2017, the World Health Organization's International Agency for Research on Cancer published the "Preliminary Reference List of Carcinogens". Catechol is on the list of Class 2B carcinogens, with an acute toxicity LD50 of 260 mg / kg (rat oral). Pyrogallol, also known as pyrogallol, has strong reducing properties and can be used for leather coloring, dyeing of fur, hair, etc., as an intermediate for medicines and dyes, etc. It is extremely irritating to the skin and mucous membranes. There have been cases of poisoning and death through skin absorption. When swallowed, it can damage the digestive organs, liver, and kidneys, causing hemolysis, lethargy, collapse, and even death. The acute toxicity LD50 is 789 mg / kg (rat oral). my country's "Technical Specifications for Safety of Cosmetics" (2015 Edition) and the EU Cosmetics Regulation CE1223 / 2009 clearly stipulate that catechol and pyrogallol are prohibited from being used in cosmetics.

[0003] With the development of online shopping and purchasing agents, foreign cosmetics have entered the domestic market in large quantities. In order to ensure the quality and safety of cosmetics, it is necessary to monitor the content of catechol and pyrogallol in cosmetics. At present, the only method for detecting the content of catechol and pyrogallol in cosmetics is liquid chromatography, which uses a mixed solution of sodium bisulfite aqueous solution and methanol and formic acid to pretreat the sample. Its extraction efficiency is poor, resulting in low test results and low accuracy, especially for the extraction and detection of low-concentration catechol and pyrogallol, which can no longer meet the detection needs. Summary of the invention

[0004] The purpose of the present invention is to provide a method for detecting the content of catechol and pyrogallol in cosmetics. The detection method provided by the present invention has high extraction rate and high accuracy, and meets the trace detection requirements of catechol and pyrogallol in cosmetics.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for detecting the contents of catechol and pyrogallol in cosmetics, comprising the following steps:

[0007] 1) Mixing the sample to be tested with an extraction solvent, extracting the mixture, and then performing solid-liquid separation to obtain a clarified solution; the extraction solvent is a mixture of an organic solvent, sodium chloride and water; the organic solvent includes methanol, ethanol, formic acid or acetic acid;

[0008] 2) subjecting the clarified liquid obtained in step 1) to solid phase extraction and then eluting with methanol to obtain an eluate as a test liquid; the filler of the solid phase extraction is polystyrene-divinylbenzene;

[0009] 3) The test solution obtained in step 2) is subjected to high performance liquid chromatography-tandem mass spectrometry to obtain the contents of catechol and pyrogallol in the cosmetics.

[0010] Preferably, the mass concentration of sodium chloride in the extraction solvent in step 1) is 5-10%.

[0011] Preferably, the concentration of the organic solvent in the extraction solvent in step 1) is 0.05-0.1 mol / L.

[0012] Preferably, in step 1), the mass ratio of the sample to be tested to the extraction solvent is 1:(5-20).

[0013] Preferably, the HPLC conditions for HPLC-tandem mass spectrometry detection in step 3) include: the chromatographic column is a C18 chromatographic column, the mobile phase is formic acid aqueous solution-methanol, the elution method is gradient elution, the flow rate is 0.2-0.5 mL / min, the column temperature is 20-40°C, and the injection volume is 5-20 μL.

[0014] Preferably, the mass percentage of formic acid in the formic acid aqueous solution is 0.05-0.2%.

[0015] Preferably, the tandem mass spectrometry detection conditions of the high performance liquid chromatography-tandem mass spectrometry detection in the step 3) include: the ion source is an electrospray ion source, the scanning mode is negative ion scanning, the cone voltage is 15-25V, the ion source temperature is 120-220°C, the desolvation temperature is 500-650°C, the capillary voltage is 1.5-3.0V, and the scanning mode is multiple reaction monitoring.

[0016] Preferably, the standard solution used in the high performance liquid chromatography-tandem mass spectrometry detection in step 3) is a mixed solution of catechol standard substance and pyrogallol standard substance.

[0017] Preferably, the solvent of the standard solution includes methanol, ethanol, formic acid or acetic acid.

[0018] Preferably, the solid-liquid separation in step 1) is carried out by centrifugal separation, and the rotation speed of the centrifugal separation is 8000-12000 r / min.

[0019] The invention provides a method for detecting the contents of catechol and pyrogallol in cosmetics, comprising the following steps: 1) mixing a sample to be tested with an extraction solvent and performing solid-liquid separation to obtain a clarified liquid; the extraction solvent is a mixed liquid of an organic solvent and a sodium chloride aqueous solution; the organic solvent comprises methanol, ethanol, formic acid or acetic acid; 2) performing solid phase extraction on the clarified liquid obtained in the step 1) and then eluting with methanol to obtain an eluate as a test liquid; the filler of the solid phase extraction is polystyrene-divinylbenzene; 3) performing high performance liquid chromatography-tandem mass spectrometry detection on the test liquid obtained in the step 2) to obtain the contents of catechol and pyrogallol in the cosmetics. The present invention promotes the separation of catechol and pyrogallol in cosmetics by adding sodium chloride to the extraction solvent, adjusting the osmotic pressure and ionic strength in the extraction solution, and has a high extraction efficiency, especially for the extraction of low-concentration catechol and pyrogallol; then, a solid phase extraction is performed on an extraction column filled with polystyrene-divinylbenzene, and methanol is used for elution, so that catechol and pyrogallol are enriched and separated from a variety of organic matter, thereby improving the accuracy of detection and realizing the detection of low-concentration catechol and pyrogallol. The results of the embodiment show that the detection method provided by the present invention has a detection limit of 0.01 mg / kg and a quantitative limit of 0.03 mg / kg for catechol and pyrogallol. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the total ion current diagram of the catechol and pyrogallol standard substances in Example 1 of the present invention, wherein 1 is catechol and 2 is pyrogallol;

[0021] Figure 2 The standard curve of catechol drawn in Example 1 of the present invention;

[0022] Figure 3 is the standard curve of pyrogallol drawn in Example 1 of the present invention;

[0023] Figure 4 It is the total ion current diagram of catechol and pyrogallol in the sample to be tested, where 1 is pyrogallol and 2 is catechol. DETAILED DESCRIPTION

[0024] All raw materials of the present invention have no particular limitation on their sources and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0025] The present invention provides a method for detecting the contents of catechol and pyrogallol in cosmetics, comprising the following steps:

[0026] 1) Mixing the sample to be tested with an extraction solvent, extracting the mixture, and then performing solid-liquid separation to obtain a clarified solution; the extraction solvent is a mixture of an organic solvent, sodium chloride and water; the organic solvent includes methanol, ethanol, formic acid or acetic acid;

[0027] 2) subjecting the clarified liquid obtained in step 1) to solid phase extraction and then eluting with methanol to obtain an eluate as a test liquid; the filler of the solid phase extraction is polystyrene-divinylbenzene;

[0028] 3) The test solution obtained in step 2) is subjected to high performance liquid chromatography-tandem mass spectrometry to obtain the contents of catechol and pyrogallol in the cosmetics.

[0029] The present invention mixes the sample to be tested with the extraction solvent, extracts the mixture, and then separates the solid and the liquid to obtain a clear solution.

[0030] The present invention has no special requirements on the type of the sample to be tested, and any type of cosmetics can be used for the detection method of the present invention. As an embodiment of the present invention, the sample to be tested can be powder, hair care or hair dye.

[0031] In the present invention, the extraction solvent is a mixture of an organic solvent, sodium chloride and water; the organic solvent includes methanol, ethanol, formic acid or acetic acid. The extraction solvent extracts and separates catechol and pyrogallol in the sample to be tested. The present invention can effectively extract catechol and pyrogallol in the sample to be tested by selecting and preparing the extraction solvent, thereby improving the accuracy of detection.

[0032] In the present invention, the mass concentration of sodium chloride in the extraction solvent is preferably 5-10%, more preferably 6-8%. As an embodiment of the present invention, the mass concentration of sodium chloride in the extraction solvent can be 5%, 6%, 7%, 8%, 9% or 10%. The present invention adds sodium chloride to the extraction solvent to adjust the osmotic pressure and ionic strength in the solution. The concentration of sodium chloride is within the above range, which is conducive to further improving the extraction efficiency of catechol and pyrogallol.

[0033] In the present invention, the concentration of the organic solvent in the extraction solvent is preferably 0.05-0.1 mol / L, more preferably 0.06-0.08 mol / L. As an embodiment of the present invention, the mass concentration of the organic solvent in the extraction solvent can be 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L or 0.1 mol / L. The concentration of the organic solvent within the above range is conducive to further improving the extraction efficiency of catechol and pyrogallol.

[0034] In the present invention, the mass ratio of the sample to be tested to the extraction solvent is preferably 1:(5-20), more preferably 1:(7-18), and further preferably 1:(10-15). The mass ratio of the sample to be tested to the extraction solvent within the above range is conducive to further improving the extraction efficiency of catechol and pyrogallol.

[0035] The present invention has no particular requirements for the specific manner of mixing, and any mixing manner known to those skilled in the art may be used. In an embodiment of the present invention, vortex mixing is used, and the mixing time is 1 min.

[0036] In the present invention, the extraction is preferably ultrasonic extraction; the ultrasonic extraction time is preferably 15 to 25 minutes. The present invention has no special requirements for other parameters of the ultrasonic extraction, and conventional ultrasonic parameters in the art can be used. The present invention is conducive to the separation of catechol and pyrogallol from the sample to be tested by ultrasonic extraction of the mixed system.

[0037] In the present invention, the solid-liquid separation method is preferably centrifugal separation, and the rotation speed of the centrifugal separation is preferably 8000-12000 r / min, more preferably 9000-11000 r / min. The time of the centrifugal separation is preferably 8-15 min, more preferably 10-12 min. The centrifugal separation of the present invention is beneficial to further improve the extraction efficiency of catechol and pyrogallol.

[0038] After obtaining the clarified liquid, the present invention performs solid phase extraction on the clarified liquid and then elutes it to obtain the eluate as the test liquid.

[0039] In the present invention, the filler of the solid phase extraction is polystyrene-divinylbenzene. The present invention uses polystyrene-divinylbenzene as the filler of the solid phase extraction, which can effectively adsorb catechol and pyrogallol in the solution, which is beneficial to improve the accuracy of detection.

[0040] The present invention has no special requirements for the specific operation of the solid phase extraction, and the operation method familiar to those skilled in the art can be used. As an embodiment of the present invention, the operation of the solid phase extraction can be: transfer 5 mL of the clarified liquid to the solid phase extraction column, rinse with 5 mL of deionized water, and drain under reduced pressure.

[0041] In the present invention, the eluent used for elution is methanol. The present invention has no special requirements for the specific operation of the elution, and the conventional operation in the art can be adopted. As an embodiment of the present invention, the amount of the methanol is 50% of the clarified solution, and the flow rate of the elution is 1 mL / min.

[0042] After the elution is completed, the present invention preferably performs microporous membrane filtration on the solution obtained by the elution to obtain an eluate as a test liquid. As an embodiment of the present invention, the microporous membrane can use a 0.2 μm microporous membrane. The present invention removes impurities such as suspended particles and microorganisms in the test liquid through a microporous membrane, which is conducive to further improving the accuracy of the detection.

[0043] After obtaining the test liquid, the present invention performs high performance liquid chromatography-tandem mass spectrometry detection on the test liquid to obtain the contents of catechol and pyrogallol in the cosmetics.

[0044] In the present invention, the standard solution used in the HPLC-MS / MS detection is preferably a mixed solution of catechol standard substance and pyrogallol standard substance.

[0045] The present invention has no special requirements for the specific preparation process of the standard solution, and the preparation method commonly used by those skilled in the art can be adopted. As an embodiment of the present invention, the preparation process of the standard solution can be: accurately weigh 10 mg of catechol and pyrogallol standard substances, respectively, place them in 100 mL brown volumetric flasks, dissolve and fix the volume with methanol, and prepare a standard stock solution with a mass concentration of 100 μg / mL; accurately pipette 1 mL of catechol and pyrogallol standard stock solutions, respectively, place them in 100 mL brown volumetric flasks, dilute and fix the volume with methanol, and prepare a mixed standard intermediate solution with a mass concentration of 1 μg / mL; accurately pipette 1 mL of the mixed standard intermediate solution and place them in volumetric flasks of different specifications, dilute and fix the volume with methanol, and prepare a mixed standard series working solution with concentrations of 1 ng / mL, 2 ng / mL, 5 ng / mL, 10 ng / mL, and 20 ng / mL, respectively.

[0046] In the present invention, the HPLC conditions for HPLC-MS / MS detection preferably include: the chromatographic column is a C18 chromatographic column, the mobile phase is formic acid aqueous solution-methanol, the elution method is gradient elution, the flow rate is 0.2-0.5 mL / min, the column temperature is 20-40°C, and the injection volume is 5-20 μL.

[0047] In the present invention, the mass percentage of formic acid in the formic acid aqueous solution is preferably 0.05 to 0.2%, and more preferably 0.1 to 0.15%.

[0048] In the present invention, the gradient elution method is preferably performed according to Table 1.

[0049] Table 1 Mobile phase gradient elution table

[0050] Time (min) Flow rate mL / min Formic acid solution (mobile phase A) Methanol (mobile phase B) 0～6 0.2～0.5 90 5％～60％ 6～6.01 0.2～0.5 70 60％～5％ 6.01～10 0.2～0.5 70 5％

[0051] The present invention limits the conditions of high performance liquid chromatography to the above range, which is beneficial to further improve the accuracy of detection.

[0052] In the present invention, the tandem mass spectrometry detection conditions of the high performance liquid chromatography-tandem mass spectrometry detection preferably include: the ion source is an electrospray ion source, the scanning mode is negative ion scanning, the cone voltage is 15-25V, the ion source temperature is 120-220°C, the desolvation temperature is 500-650°C, the capillary voltage is 1.5-3.0V, and the scanning mode is multiple reaction monitoring.

[0053] In the present invention, the specific conditions of the multiple reaction monitoring are preferably carried out according to Table 2.

[0054] Table 2 Mass spectrometry parameters of catechol and pyrogallol

[0055]

[0056] The present invention limits the conditions for tandem mass spectrometry detection within the above range, which is beneficial to further improve the accuracy of detection.

[0057] The invention adds sodium chloride to the extraction solvent to adjust the osmotic pressure and ionic strength in the extraction solution, thereby promoting the separation of cosmetic catechol and pyrogallol, and has high extraction efficiency, especially for low-concentration extraction; then, an extraction column with polystyrene-divinylbenzene as a filler is used for solid phase extraction, and methanol is used for elution, so that catechol and pyrogallol are enriched and separated from various organic matters, thereby improving the accuracy of detection and realizing low-concentration detection.

[0058] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] Example 1

[0060] A method for detecting catechol and pyrogallol in cosmetics, comprising the following specific steps:

[0061] 1) Instruments and reagents

[0062] High performance liquid chromatography-tandem mass spectrometer: with electrospray ion source; ultrasonic cleaning machine; high-speed centrifuge: maximum speed 15000r / min; electronic analytical balance: sensitivity of 0.1mg and 0.001g; solid phase extraction instrument (with solid phase extraction column: filler is polystyrene-divinylbenzene, 500mg, 6mL); catechol and pyrogallol standards: purity greater than 99.5%; methanol (chromatographic grade); formic acid (chromatographic grade); glacial acetic acid (analytical grade); sodium chloride (analytical grade); ultrapure water (18.2MΩ·cm).

[0063] 2) Preparation of standard solution

[0064] Standard stock solution (100 μg / mL): Accurately weigh 10 mg (accurate to 0.1 mg) of catechol and pyrogallol standard substances respectively, place them in 100 mL brown volumetric flasks, dissolve them in methanol to the mark, and prepare standard stock solutions with a mass concentration of 100 μg / mL; store at -18 °C away from light.

[0065] Mixed standard intermediate solution (1.0 μg / mL): Accurately pipette 1 mL of catechol and pyrogallol standard stock solutions into a 100 mL brown volumetric flask, dilute to the mark with methanol to prepare a mixed standard intermediate solution with a mass concentration of 1 μg / mL; store at -18°C away from light.

[0066] Mixed standard series working solution: Accurately transfer an appropriate amount of the mixed standard intermediate solution, dilute with methanol and shake well to prepare the mixed standard series working solution. The mass concentrations of the components to be tested are 1ng / mL, 2ng / mL, 5ng / mL, 10ng / mL, and 20ng / mL, respectively. Prepare them before use.

[0067] 3) Preparation of test solution

[0068] Accurately weigh 1.0 g (accurate to 0.1 mg) of a certain imported hair dye cosmetic sample into a 50 mL polypropylene centrifuge tube, accurately add 10 mL of 0.05 mol / L acetic acid solution and 0.6 g of sodium chloride, vortex mix for 1 min, ultrasonically extract for 20 min, centrifuge at 10000 r / min for 10 min, take 5.0 mL of the clarified liquid and transfer it to a solid phase extraction column, rinse with 5 mL of deionized water, drain under reduced pressure, and elute with 2.5 mL of methanol. The flow rate of the entire elution process is controlled at 1 mL / min; the collected eluate is filtered through a 0.2 μm microporous membrane to obtain the test solution.

[0069] 4) High performance liquid chromatography-tandem mass spectrometry detection

[0070] The mobile phase was 0.1% formic acid solution-methanol for gradient elution, and the analysis was performed using a high performance liquid chromatography-tandem mass spectrometer with an electrospray ion source in multiple reaction monitoring (MRM) mode.

[0071] The chromatographic conditions of the HPLC were as follows: chromatographic column: C18 column, 100 mm × 2.1 mm (particle size 1.7 μm), mobile phase: 0.1% formic acid solution-methanol (gradient elution according to Table 1); flow rate: 0.3 mL / min; column temperature: 30°C; injection volume: 10 μL.

[0072] Tandem mass spectrometry conditions: ion source is electrospray ion source, scanning mode: negative ion scanning; cone voltage: 20 V; ion source temperature: 150 ° C; desolvation temperature: 600 ° C; capillary voltage: 2.0 V; scanning mode: multiple reaction monitoring (MRM), specific conditions are shown in Table 2.

[0073] 5) Qualitative and quantitative determination

[0074] Qualitative determination

[0075] The test solution and the mixed standard series working solution are tested. If the retention time of the chromatographic peak detected in the test solution is consistent with the retention time of a component peak in the mixed standard series working solution, and in the sample mass spectrum after background subtraction, the mass-to-charge ratios of the two selected pairs of ions (Table 2) are consistent, and when the relative abundance of the sample qualifier ion is compared with the relative abundance of the qualifier ion of the standard working solution with equivalent concentration, the relative deviation does not exceed the range specified in Table 3, then it can be determined that the component exists in the sample.

[0076] Table 3 Maximum allowable deviation of relative ion abundance in qualitative confirmation

[0077] Relative ion abundance / % ＞50 ＞20～50 ＞10～20 ≤10 Allowable relative deviation / % ±20 ±25 ±30 ±50

[0078] Quantitative determination

[0079] Preparation of standard curve: Inject the mixed standard series working solutions into the liquid chromatography-tandem mass spectrometer respectively, determine the corresponding measured components, and obtain the total ion flow diagram of the standard substances catechol and pyrogallol, such as Figure 1 shown.

[0080] With the concentration of the measured component as the horizontal axis and the chromatographic peak area of ​​the measured component as the vertical axis, a standard curve is drawn, such as Figure 2 , Figure 3 As shown, the linear regression equation of catechol is:

[0081] y1=8.94068x1+20.5876 formula (1);

[0082] The linear regression equation of pyrogallol was obtained as follows:

[0083] y2=22.5973x2-37.147 formula (2);

[0084] The detection limit of catechol and pyrogallol was 0.01 mg / kg, and the quantification limit was 0.03 mg / kg.

[0085] Determination of the test solution: Take the above sample test solution and inject it for determination to obtain the total ion flow diagram of catechol and pyrogallol in the sample, such as Figure 4According to the peak area measured by the software, the instrument automatically calculates the concentration of catechol and pyrogallol in the test solution according to the linear regression equation obtained above.

[0086] The contents of catechol and pyrogallol in the sample were calculated according to formula (3).

[0087]

[0088] Where:

[0089] Xi: the content of catechol and pyrogallol in the sample, in micrograms per kilogram (μg / kg);

[0090] Ci: The concentration of catechol and pyrogallol in the sample solution obtained from the standard curve, in micrograms per milliliter (μg / mL);

[0091] V: volume of the sample solution, in milliliters (mL);

[0092] m: sample mass, in grams (g);

[0093] b: Dilution multiple.

[0094] The content of catechol detected in the sample was 100μg / kg; the content of pyrogallol detected was 550μg / kg.

[0095] It can be seen from the above examples that the detection method provided by the present invention can detect catechol and pyrogallol at the microgram level in cosmetics, meeting the detection requirements.

[0096] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for detecting the content of catechol and pyrogallol in cosmetics, comprising the following steps: 1) Mixing the sample to be tested with an extraction solvent, extracting the mixture, and then performing solid-liquid separation to obtain a clarified solution; the extraction solvent is a mixture of an organic solvent, sodium chloride and water; the organic solvent includes methanol, ethanol, formic acid or acetic acid; 2) subjecting the clarified liquid obtained in step 1) to solid phase extraction and then eluting with methanol to obtain an eluate as a test liquid; the filler of the solid phase extraction is polystyrene-divinylbenzene; 3) The test solution obtained in step 2) is subjected to high performance liquid chromatography-tandem mass spectrometry to obtain the contents of catechol and pyrogallol in the cosmetics.

2. The detection method according to claim 1, characterized in that: The mass concentration of sodium chloride in the extraction solvent in step 1) is 5-10%.

3. The detection method according to claim 1, characterized in that: The concentration of the organic solvent in the extraction solvent in step 1) is 0.05-0.1 mol / L.

4. The detection method according to claim 1, 2 or 3, characterized in that: In the step 1), the mass ratio of the sample to be tested to the extraction solvent is 1:(5-20).

5. The detection method according to claim 1, characterized in that: The HPLC conditions for HPLC-MS / MS detection in step 3) include: a C18 chromatographic column, a formic acid aqueous solution-methanol mobile phase, a gradient elution method, a flow rate of 0.2-0.5 mL / min, a column temperature of 20-40° C., and an injection volume of 5-20 μL.

6. The detection method according to claim 5, characterized in that: The mass percentage of formic acid in the formic acid aqueous solution is 0.05-0.2%.

7. The detection method according to claim 1, characterized in that: The tandem mass spectrometry detection conditions of the high performance liquid chromatography-tandem mass spectrometry detection in the step 3) include: the ion source is an electrospray ion source, the scanning mode is negative ion scanning, the cone voltage is 15-25V, the ion source temperature is 120-220°C, the desolvation temperature is 500-650°C, the capillary voltage is 1.5-3.0V, and the scanning mode is multiple reaction monitoring.

8. The detection method according to any one of claims 1, 5 to 7, characterized in that: The standard solution used in the high performance liquid chromatography-tandem mass spectrometry detection in step 3) is a mixed solution of catechol standard substance and pyrogallol standard substance.

9. The detection method according to claim 8, characterized in that: The solvent of the standard solution includes methanol, ethanol, formic acid or acetic acid.

10. The detection method according to claim 1, characterized in that: The solid-liquid separation in step 1) is carried out by centrifugal separation, and the rotation speed of the centrifugal separation is 8000-12000 r / min.

Images