A method for detecting phenolic compounds in soil

Abstract

The present invention relates to the technical field of soil detection, and specifically discloses a method for detecting phenolic compounds in soil. The soil sample is extracted with an acetonitrile-n-hexane-dichloromethane mixed solvent by ultrasonic oscillation, purified with an HLB solid phase extraction column, and detected by liquid chromatography / tandem mass spectrometry. The results show that the method has good linearity and the correlation coefficient R 2 The detection limit is greater than 0.995, and the detection limit is 0.2-2 μg / kg; the average recovery rate at 5, 20, and 100 μg / kg spiked levels is 61.0%-102.3%, and the relative standard deviation is 1.2%-11.5%. Therefore, the present invention can achieve simultaneous qualitative and quantitative detection of 10 phenolic compounds in soil in a simpler way, and provides a rapid, sensitive and efficient detection method for studying the pollution status of phenolic compounds in soil, and has a high application value in the detection of soil phenolic compounds.

Description

Technical Field

[0001] The present invention relates to the technical field of soil detection, and in particular to a method for detecting phenolic compounds in soil. Background Art

[0002] Phenolic compounds refer to compounds with hydroxyl groups on benzene rings or condensed rings. They are widely used in petrochemical, papermaking, pharmaceutical, pesticide and other fields. However, phenolic compounds are a class of highly toxic and carcinogenic organic pollutants. Industrially produced phenolic compounds can remain in the soil for a long time, causing soil environmental pollution and endangering human health through enrichment in the food chain. Countries around the world attach great importance to the environmental pollution of phenolic compounds. Phenol, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, 4-nitrophenol, 2-nitrophenol, 2,4-dinitrophenol, 2,4-dimethylphenol, 4-chloro-3-methylphenol, and 4,6-dinitro-4-methylphenol are listed in 129 environmental priority controlled organic pollutants. Therefore, it is of great significance to establish a highly sensitive, accurate and rapid analysis method for the above phenolic compounds in soil.

[0003] At present, the commonly used analytical methods for phenolic compounds in soil are gas chromatography, gas chromatography-mass spectrometry, and high performance liquid chromatography. Phenolic compounds are highly polar, have poor peak shapes in gas chromatography, and have low sensitivity. They generally require derivatization, but the derivatization method is cumbersome and time-consuming. High performance liquid chromatography can directly measure phenolic compounds without the need for derivatization reactions, but high performance liquid chromatography only relies on retention time for qualitative analysis, so its qualitative ability is poor. Therefore, it is necessary to provide a new method that is simple, convenient, sensitive, and accurate for detecting a variety of phenolic compounds in soil. Summary of the invention

[0004] In view of the problem that the prior art cannot rapidly, sensitively and accurately detect a variety of phenolic compounds in soil, the present invention provides a method for detecting phenolic compounds in soil.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] A method for detecting phenolic compounds in soil, wherein the phenolic compounds are 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-xylenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol, and the method is performed by high performance liquid chromatography-mass spectrometry, comprising the following steps:

[0007] (1) Preparation of test solution:

[0008] After dehydrating the soil sample, grind it, add it into a mixed solution of acetonitrile, n-hexane and dichloromethane, extract it by ultrasonic vibration for 2-3 times, combine the extracts, and concentrate them to obtain an extract;

[0009] The extract is transferred to an HLB solid phase extraction column, eluted with acetonitrile, the eluate is collected, concentrated, and fixed to volume to obtain a test solution;

[0010] (2) Testing the test solution, wherein the conditions of the high performance liquid chromatography are:

[0011] A C18 chromatographic column was used, with pure water as mobile phase A and methanol as mobile phase B, and gradient elution was performed;

[0012] The mass spectrometer adopts APCI ion source and negative ion detection mode, wherein the quantitative ion of phenol is: parent ion is 93.0m / z, daughter ion is 65.0m / z, declustering voltage is -60V, and collision voltage is -28V; the qualitative ion of phenol is: parent ion is 93.0m / z, daughter ion is 75.0m / z, declustering voltage is -60V, and collision voltage is -28V;

[0013] The quantitative ion of 4-nitrophenol is: the parent ion is 138.0 m / z, the daughter ion is 46.1 m / z, the declustering voltage is -70 V, and the collision voltage is -48 V. The qualitative ion of 4-nitrophenol is: the parent ion is 138.0 m / z, the daughter ion is 92.0 m / z, the declustering voltage is -60 V, and the collision voltage is -26 V.

[0014] The quantitative ion of 3-methylphenol is: the parent ion is 106.9m / z, the daughter ion is 92.0m / z, the declustering voltage is -90V, and the collision voltage is -27V. The qualitative ion of 3-methylphenol is: the parent ion is 106.9m / z, the daughter ion is 105.8m / z, the declustering voltage is -90V, and the collision voltage is -27V.

[0015] The quantitative ion of 2-chlorophenol is: the parent ion is 127.0 m / z, the daughter ion is 35.0 m / z, the declustering voltage is -30 V, and the collision voltage is -20 V. The qualitative ion of 2-chlorophenol is: the parent ion is 127.0 m / z, the daughter ion is 91.0 m / z, the declustering voltage is -30 V, and the collision voltage is -20 V.

[0016] The quantitative ion of the 2-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 115.0 m / z, the declustering voltage is -80 V, and the collision voltage is -56 V. The qualitative ion of the 2-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 65.0 m / z, the declustering voltage is -80 V, and the collision voltage is -56 V.

[0017] The quantitative ion of the 1-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 115.0 m / z, the declustering voltage is -80 V, and the collision voltage is -34 V. The qualitative ion of the 1-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 40.9 m / z, the declustering voltage is -80 V, and the collision voltage is -34 V.

[0018] The quantitative ion of the 2,4-dimethylphenol is: the parent ion is 121.1 m / z, the daughter ion is 119.4 m / z, the declustering voltage is -50 V, and the collision voltage is -30 V. The qualitative ion of the 2,4-dimethylphenol is: the parent ion is 121.1 m / z, the daughter ion is 94.2 m / z, the declustering voltage is -50 V, and the collision voltage is -30 V.

[0019] The quantitative ion of the 2,4-dichlorophenol is: the parent ion is 160.9 m / z, the daughter ion is 125.0 m / z, the declustering voltage is -80 V, and the collision voltage is -44 V. The qualitative ion of the 2,4-dichlorophenol is: the parent ion is 160.9 m / z, the daughter ion is 89.0 m / z, the declustering voltage is -80 V, and the collision voltage is -20 V.

[0020] The quantitative ion of 2,4,6-trichlorophenol is: the parent ion is 195.0 m / z, the daughter ion is 35.0 m / z, the declustering voltage is -60 V, and the collision voltage is -50 V. The qualitative ion of 2,4,6-trichlorophenol is: the parent ion is 195.0 m / z, the daughter ion is 159.0 m / z, the declustering voltage is -60 V, and the collision voltage is -30 V.

[0021] The quantitative ion of pentachlorophenol is: the parent ion is 264.8m / z, the daughter ion is 35.0m / z, the declustering voltage is -110V, and the collision voltage is -59V. The qualitative ion of pentachlorophenol is: the parent ion is 264.8m / z, the daughter ion is 37.0m / z, the declustering voltage is -92V, and the collision voltage is -59V.

[0022] The soil sample matrix is ​​complex and the content of phenolic compounds is very low. The peak shape and stability of underivatized phenol in gas chromatography are poor, and the sensitivity is low. The derivatization method is complicated and time-consuming.

[0023] Compared with the prior art, the detection method of phenolic compounds in soil provided by the present invention adopts a C18 chromatographic column, a specific mobile phase, a gradient elution mode, and a specific mass spectrometry condition to achieve accurate detection of 8 priority controlled phenolic compounds and two naphthols in soil. And the method provided by the present invention is studied and verified by methodologies such as precision, accuracy, and sensitivity, and it is found that the method provided by the present invention is sensitive, accurate, and has good reproducibility, and can achieve simultaneous qualitative and quantitative detection of 10 phenolic compounds in soil in a simpler method, providing a rapid, sensitive, and efficient detection method for studying the pollution status of phenolic compounds in soil, and has a high application value in the detection of phenolic compounds in soil.

[0024] Preferably, the elution procedure of the gradient elution is as follows:

[0025] 0 min, 70% mobile phase A, 30% mobile phase B;

[0026] 7 min, 50% mobile phase A, 50% mobile phase B;

[0027] 10 min, 10% mobile phase A, 90% mobile phase B;

[0028] 16 min, 10% mobile phase A, 90% mobile phase B;

[0029] 18 min, 100% mobile phase B;

[0030] 18.1 min, 70% mobile phase A, 30% mobile phase B;

[0031] 20 min, 70% mobile phase A, 30% mobile phase B.

[0032] The preferred gradient elution sequence can improve the separation between phenolic compounds and the detection sensitivity, making the detection results quantitatively accurate and highly precise.

[0033] Preferably, the scanning mode of the mass spectrometer is multiple reaction monitoring, the needle current is 3 mA, the ionization temperature is 550° C., the collision gas pressure is 48 KPa, the curtain gas pressure is 276 KPa, the inlet voltage is -10 V, the collision chamber outlet voltage is -14 V, and the nebulizer gas pressure is 276 KPa.

[0034] Under the optimal mass spectrometry analysis conditions, the accuracy and sensitivity of the determination of various phenolic compounds in the soil can be maximized.

[0035] Preferably, the volume ratio of acetonitrile, n-hexane and dichloromethane is 1:2:4.

[0036] Preferably, the specification of the chromatographic column is 3.0 mm*100 mm, and the filler diameter is 2.6 μm.

[0037] Further preferably, the chromatographic column is Kinetex C18, 3.0 mm*100 mm, 2.6 μm.

[0038] The optimal chromatographic column specifications can make the peak shape, separation and detection sensitivity of each component excellent, and the baseline interference is small, which is conducive to the detection of various phenolic compounds in soil, and the results are accurate, reliable and reproducible.

[0039] Preferably, the column temperature is 28°C-32°C, and the flow rate is 0.18 mL / min-0.22 mL / min.

[0040] More preferably, the column temperature is 30° C. and the flow rate is 0.2 mL / min.

[0041] Preferably, the injection volume is 20 μL.

[0042] The preferred detection conditions are conducive to the effective detection of various phenolic compounds in the soil and improve the sensitivity of the detection, thereby achieving the purpose of effectively and accurately detecting the content of trace phenolic compounds in the soil.

[0043] Preferably, the preparation of the standard solution includes: taking 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-xylenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol standard substances, dissolving and diluting them with methanol, and then diluting them with acetonitrile-water mixed solution to prepare a mixed standard series solution.

[0044] Further preferably, the preparation of the mixed standard series solution comprises:

[0045] Prepare standard stock solution of phenolic compounds: ρ = 1000 mg / L. Prepare with 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-methylphenol, 2-chlorophenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol standard substances and dissolve in methanol.

[0046] Prepare mixed standard working solution of phenolic compounds: ρ = 10.0 mg / L. Take an appropriate amount of standard stock solution of phenolic compounds, dilute it with methanol, and prepare mixed standard working solution with the concentration of 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-xylenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol at 10.0 mg / L.

[0047] Pipette an appropriate amount of the mixed standard working solution of phenolic compounds and dilute it with a mixed solvent of acetonitrile-water (1:1, v / v). The mass concentrations of 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol in the standard solution are 10μg / L, 50.0μg / L, 100μg / L, 200μg / L, 500μg / L and 1000μg / L respectively. Pipette 1.0mL of the standard series solution into a brown injection bottle for testing.

[0048] The present invention adopts high performance liquid chromatography tandem mass spectrometry, and realizes accurate qualitative and quantitative detection of various phenolic compounds in soil by controlling detection conditions and extraction and purification parameters of phenolic compounds in soil. The method is applicable to complex soil sample matrices, does not require derivatization, is simple to operate, has high sensitivity, is suitable for practical application and promotion, and has broad application prospects in large-scale soil pollution investigations. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The total ion current diagram of the mixed standard solution with a concentration of 200.0 μg / L under Item 2.1 in Example 2; wherein, 1, phenol; 2,4-nitrophenol; 3,3-methylphenol; 4,2-chlorophenol; 5,2,4-dimethylphenol; 6,2-naphthol; 7,1-naphthol; 8,2,4-dichlorophenol; 9,2,4,6-trichlorophenol; 10, pentachlorophenol;

[0050] Figure 2 is the total ion current diagram of positive sample 1 in Example 3;

[0051] Figure 3 is the total ion current diagram of positive sample 2 in Example 3;

[0052] Figure 4 This is the total ion current diagram of positive sample 3 in Example 3. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] Example 1

[0055] 1.1 Preparation of test solution:

[0056] Remove foreign matter from the soil sample, weigh 10g of soil sample, add anhydrous sodium sulfate, grind and homogenize into quicksand, add into a 150mL stoppered conical flask, add 5mL of acetonitrile, 10mL of n-hexane and 20mL of dichloromethane mixed solvent, oscillate for 5min, ultrasonicate for 5min, control the temperature during extraction not to exceed 40℃, extract twice, combine the extracts, concentrate the extracts to about 1mL using a parallel concentrator, and obtain the extract;

[0057] Fix the HLB solid phase extraction column (6mL, 500mg) on ​​the extraction device, activate it with 10mL acetonitrile to ensure that the column head is infiltrated, transfer the above extract to the extraction column, and transfer all the eluent that infiltrates the concentration tube to the extraction column, elute with 10mL acetonitrile, receive the eluent in the collection tube, concentrate it to 0.5mL by parallel concentrator, make up to 1.0mL with pure water, mix well and place in a brown injection bottle for testing.

[0058] The blank samples were prepared in the same manner as above, using quartz sand instead of soil samples.

[0059] Take another 10g soil sample and determine the dry matter according to the "Gravimetric method for determination of soil dry matter and moisture" (HJ 613-2011).

[0060] 1.2 Detection method of phenolic compounds in soil:

[0061] Chromatographic column: Kinetex C18, 3.0mm*100mm, 2.6μm;

[0062] Mobile phase A: pure water;

[0063] Mobile phase B: methanol;

[0064] Flow rate: 0.2 mL / min;

[0065] Injection volume: 20 μL;

[0066] Column temperature: 30°C;

[0067] Gradient elution, the elution program is as follows:

[0068] Table 1

[0069] Time (min) Mobile phase A (%) Mobile phase B (%) 0.0 70 30 7.0 50 50 10.0 10 90 16.0 10 90 18.0 0 100 18.1 70 30 20.0 70 30

[0070] Mass spectrometry conditions: APCI ion source, negative ion detection mode, multiple reaction monitoring (MRM) scanning mode, needle current of 3 mA, ionization temperature of 550 ° C, collision gas pressure of 48 KPa, curtain gas pressure of 276 KPa, inlet voltage of -10 V, collision chamber outlet voltage of -14 V, nebulizer gas pressure of 276 KPa, detection ion pairs, declustering voltage and collision voltage (CE) are shown in Table 2 below.

[0071] Table 2

[0072]

[0073]

[0074] Note 1: The one with * is the quantitative daughter ion of the secondary mass spectrometry, and the other one is the qualitative daughter ion.

[0075] Example 2

[0076] Methodological validation:

[0077] 2.1 Detection limit

[0078] 2.1.1 Preparation of mixed standard series working solution

[0079] Prepare standard stock solution of phenolic compounds: ρ = 1000 mg / L. Prepare with 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-methylphenol, 2-chlorophenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol standard substances and dissolve in methanol.

[0080] Prepare mixed standard working solution of phenolic compounds: ρ = 10.0 mg / L. Take an appropriate amount of standard stock solution of phenolic compounds, dilute it with methanol, and prepare mixed standard working solution with the concentration of 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-xylenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol at 10.0 mg / L.

[0081] Pipette an appropriate amount of the mixed standard working solution of phenolic compounds and dilute it with a mixed solvent of acetonitrile-water (1:1, v / v). The mass concentrations of 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol in the standard solution are 10μg / L, 50.0μg / L, 100μg / L, 200μg / L, 500μg / L and 1000μg / L respectively. Pipette 1.0mL of the standard series solution into a brown injection bottle for testing.

[0082] According to the conditions under 1.2 of Example 1, the mixed standard series working solutions were injected in order from low concentration to high concentration, and the concentration of the target component in the mixed standard series solution was used as the horizontal axis and the corresponding peak area was used as the vertical axis to establish the linear regression equation of the standard curve. Among them, the total ion current of the mixed standard working solution with a concentration of 200.0 μg / L is as follows Figure 1 shown.

[0083] 2.1.2 Qualitative analysis

[0084] According to the parent ions and daughter ions determined in Table 2, the absolute value of the relative deviation between the retention time of the target in the sample and the retention time of the target in the standard sample should be less than 2.5%; and the relative abundance of the qualitative and quantitative daughter ions of the target to be measured in the sample (Ksam, Formula 1) is compared with the relative abundance of the qualitative and quantitative daughter ions of the corresponding target in the standard solution with similar concentration (Kstd, Formula 2). The obtained deviation should be within the maximum allowable deviation range specified in Table 3, then it can be determined that the target exists in the sample.

[0085] Ksam=A2 / A1×100………………………………(1)

[0086] Where:

[0087] Ksam—relative abundance of a certain component in the sample, %;

[0088] A2—peak area (or peak height) of the secondary mass spectrometric qualitative product ion of a component in the sample;

[0089] A1—The peak area (or peak height) of the secondary mass spectrometry product ion of a component in the sample.

[0090] Kstd=Astd2 / Astd1×100…………………………(2)

[0091] Where:

[0092] Kstd—Relative abundance of a certain component qualitative ion in the standard sample, %;

[0093] Astd2—peak area (or peak height) of the secondary mass spectrometry qualitative product ion of a component in the standard sample;

[0094] Astd1—The peak area (or peak height) of the secondary mass spectrometry quantification product ion of a component in the standard sample.

[0095] Table 3 Maximum allowable deviation of relative ion abundance for qualitative confirmation

[0096] <![CDATA[K std / %]]> <![CDATA[K sam Permissible deviation / %]]> <![CDATA[K std >50]]> ±20 <![CDATA[20<K std ≤50]]> ±25 <![CDATA[10<K std ≤20]]> ±30 <![CDATA[K std ≤10]]> ±50

[0097] 2.1.3 Quantitative analysis

[0098] The content of target compounds in soil was calculated by external standard method, and the content of phenolic compounds in soil (μg / kg) was calculated according to formula (3).

[0099] ω i =(ρ i ×V) / (m×w dm ) (3)

[0100] Where: i —Content of target compound in the sample, μg / kg;

[0101] ρ i —Mass concentration of target compound calculated from the calibration curve, μg / L;

[0102] V—sample fixed volume, mL;

[0103] m—soil sample mass (wet weight), g;

[0104] w dm —Dry matter content of soil sample, %.

[0105] 2.1.3 Calibration curve and detection limit

[0106] The concentration of the target component in the standard series solution is used as the horizontal coordinate, and the corresponding peak area is used as the vertical coordinate to establish the linear regression equation of the standard curve. 7 blank quartz sand spiked samples are analyzed continuously, and their standard deviation s is calculated. According to the Technical Guidelines for the Development of Environmental Monitoring Analysis Methods (HJ 168-2020), MDL = S × t (n-1,0.99) (Wherein: MDL is the method detection limit; n is the number of parallel determinations of the sample; t is the t distribution value when the degree of freedom is n-1 and the confidence level is 99%; S is the standard deviation of n parallel determinations) Calculate the method detection limit. The linear regression equation, correlation coefficient and method detection limit of phenolic compounds are shown in Table 4.

[0107] Table 4 Calibration curve and detection limit

[0108]

[0109]

[0110] Note: - indicates that this compound is not tested in this standard

[0111] It can be seen from the above table that the linear correlation coefficients of each component are all above 0.995, and the method detection limits of 10 phenolic compounds are 0.2μg / kg~2μg / kg, which are much smaller than the detection limits of target compounds in "Gas Chromatography for Determination of Phenolic Compounds in Soil and Sediment" (HJ703-2014) and "Gas Chromatography-Mass Spectrometry for Determination of Semi-volatile Organic Compounds in Soil and Sediment" (HJ 834-2017), which can fully meet the detection requirements of phenolic compounds in soil.

[0112] 2.2 Precision and Accuracy

[0113] The spiked recoveries of 10 phenolic compounds at three addition levels of 5 μg / kg, 20 μg / kg and 100 μg / kg in actual soil samples were investigated. The experimental method was used for six parallel determinations. The results are shown in Table 5.

[0114] Table 5 Precision and spike recovery test results of soil samples (n=6)

[0115]

[0116] The results showed that the average recoveries of the 10 phenolic compounds at three spike levels were 61.0% to 102.3%, and the relative standard deviations (RSDs) were 1.2% to 11.5%, which proved that the method had good accuracy and precision and could accurately determine the 10 phenolic compounds in soil.

[0117] Example 3 Sample Detection

[0118] The method provided by the present invention was used to test 20 soil samples from a chemical industry zone, and the results are shown in Table 6.

[0119] Table 6 Test results of positive soil samples (n=6)

[0120]

[0121]

[0122] Note: ND means the compound was not detected.

[0123] The results showed that 4 phenolic compounds, including phenol, 3-cresol, 2,4,6-trichlorophenol and 2-naphthol, were detected in 3 soil samples, with concentrations ranging from 0.53 to 21.21 μg / kg. No phenolic compounds were detected in the other 27 soil samples. The total ion current of the 3 positive samples is shown in the figure below. Figure 2-Figure 4 shown.

[0124] In summary, the present invention can directly determine phenolic compounds, which is simple and fast, solves the problems of poor peak shape and low sensitivity in gas chromatography, and complicated steps and long time consumption in derivatization-gas chromatography-mass spectrometry. The detection method of phenolic compounds in soil provided by the present invention has high sensitivity and qualitative and quantitative capabilities, solves the problem of poor qualitative ability of high performance liquid chromatography, is suitable for simultaneous and accurate determination of 10 phenolic compounds in soil, and has strong use value. According to the method provided by the present invention, the actual sample is measured, and the spike recovery rate is 61.0% to 102.3%, and the relative standard deviation (RSD, n=6) of the result is 1.2% to 11.5%, which proves that the method of the present invention can be successfully applied to the analysis of phenolic compounds in soil.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting phenolic compounds in soil, wherein the phenolic compounds are 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-xylenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol, characterized in that: The detection is performed by high performance liquid chromatography-mass spectrometry, including the following steps: (1) Preparation of test solution: After dehydrating the soil sample, grind it, add it into a mixed solution of acetonitrile, n-hexane and dichloromethane, extract it by ultrasonic vibration for 2-3 times, combine the extracts, and concentrate them to obtain an extract; The extract is transferred to an HLB solid phase extraction column, eluted with acetonitrile, the eluate is collected, concentrated, and fixed to volume to obtain a test solution; (2) Testing the test solution, wherein the conditions of the high performance liquid chromatography are: A C18 chromatographic column was used, with pure water as mobile phase A and methanol as mobile phase B, and gradient elution was performed; The elution procedure of the gradient elution is as follows: 0 min, 70% mobile phase A, 30% mobile phase B; 7 min, 50% mobile phase A, 50% mobile phase B; 10 min, 10% mobile phase A, 90% mobile phase B; 16 min, 10% mobile phase A, 90% mobile phase B; 18 min, 100% mobile phase B; 18.1 min, 70% mobile phase A, 30% mobile phase B; 20 min, 70% mobile phase A, 30% mobile phase B; The mass spectrometer adopts APCI ion source and negative ion detection mode, wherein the quantitative ion of phenol is: parent ion is 93.0m / z, daughter ion is 65.0m / z, declustering voltage is -60V, and collision voltage is -28V; the qualitative ion of phenol is: parent ion is 93.0m / z, daughter ion is 75.0m / z, declustering voltage is -60V, and collision voltage is -28V; The mass spectrometer was scanned in multiple reaction monitoring mode, with a needle current of 3 mA, an ionization temperature of 550°C, a collision chamber pressure of 48 KPa, a curtain gas pressure of 276 KPa, an inlet voltage of -10 V, a collision chamber outlet voltage of -14 V, and a nebulizer pressure of 276 KPa. The quantitative ion of 4-nitrophenol is: the parent ion is 138.0 m / z, the daughter ion is 46.1 m / z, the declustering voltage is -70 V, and the collision voltage is -48 V. The qualitative ion of 4-nitrophenol is: the parent ion is 138.0 m / z, the daughter ion is 92.0 m / z, the declustering voltage is -60 V, and the collision voltage is -26 V. The quantitative ion of 3-methylphenol is: the parent ion is 106.9m / z, the daughter ion is 92.0m / z, the declustering voltage is -90V, and the collision voltage is -27V. The qualitative ion of 3-methylphenol is: the parent ion is 106.9m / z, the daughter ion is 105.8m / z, the declustering voltage is -90V, and the collision voltage is -27V. The quantitative ion of 2-chlorophenol is: the parent ion is 127.0 m / z, the daughter ion is 35.0 m / z, the declustering voltage is -30 V, and the collision voltage is -20 V. The qualitative ion of 2-chlorophenol is: the parent ion is 127.0 m / z, the daughter ion is 91.0 m / z, the declustering voltage is -30 V, and the collision voltage is -20 V. The quantitative ion of the 2-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 115.0 m / z, the declustering voltage is -80 V, and the collision voltage is -56 V. The qualitative ion of the 2-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 65.0 m / z, the declustering voltage is -80 V, and the collision voltage is -56 V. The quantitative ion of the 1-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 115.0 m / z, the declustering voltage is -80 V, and the collision voltage is -34 V. The qualitative ion of the 1-naphthol is: the parent ion is 143.0 m / z, the daughter ion is 40.9 m / z, the declustering voltage is -80 V, and the collision voltage is -34 V. The quantitative ion of the 2,4-dimethylphenol is: the parent ion is 121.1 m / z, the daughter ion is 119.4 m / z, the declustering voltage is -50 V, and the collision voltage is -30 V. The qualitative ion of the 2,4-dimethylphenol is: the parent ion is 121.1 m / z, the daughter ion is 94.2 m / z, the declustering voltage is -50 V, and the collision voltage is -30 V. The quantitative ion of the 2,4-dichlorophenol is: the parent ion is 160.9 m / z, the daughter ion is 125.0 m / z, the declustering voltage is -80 V, and the collision voltage is -44 V. The qualitative ion of the 2,4-dichlorophenol is: the parent ion is 160.9 m / z, the daughter ion is 89.0 m / z, the declustering voltage is -80 V, and the collision voltage is -20 V. The quantitative ion of 2,4,6-trichlorophenol is: the parent ion is 195.0 m / z, the daughter ion is 35.0 m / z, the declustering voltage is -60 V, and the collision voltage is -50 V. The qualitative ion of 2,4,6-trichlorophenol is: the parent ion is 195.0 m / z, the daughter ion is 159.0 m / z, the declustering voltage is -60 V, and the collision voltage is -30 V. The quantitative ion of pentachlorophenol is: the parent ion is 264.8m / z, the daughter ion is 35.0m / z, the declustering voltage is -110V, and the collision voltage is -59V. The qualitative ion of pentachlorophenol is: the parent ion is 264.8m / z, the daughter ion is 37.0m / z, the declustering voltage is -92V, and the collision voltage is -59V.

2. The method for detecting phenolic compounds in soil according to claim 1, characterized in that: The specification of the chromatographic column is 3.0mm*100mm, and the filler diameter is 2.6µm.

3. The method for detecting phenolic compounds in soil according to claim 2, characterized in that: The chromatographic column is Kinetex C18, 3.0 mm*100 mm, 2.6 µm.

4. The method for detecting phenolic compounds in soil according to claim 1, characterized in that: The column temperature was 28°C-32°C, and the flow rate was 0.18mL / min-0.22mL / min.

5. The method for detecting phenolic compounds in soil according to claim 4, characterized in that: The column temperature was 30°C and the flow rate was 0.2 mL / min.

6. The method for detecting phenolic compounds in soil according to claim 1, characterized in that: The injection volume was 20 µL.

7. The method for detecting phenolic compounds in soil according to claim 1, characterized in that: The preparation of the standard solution includes: taking 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-methylphenol, 2-chlorophenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol standard substances, dissolving and diluting them with methanol, and then diluting them with acetonitrile-water mixed solution to prepare a mixed standard series solution.

8. The method for detecting phenolic compounds in soil according to claim 7, characterized in that: In the mixed standard series solution, the concentrations of 1-naphthol, 2-naphthol, phenol, 4-nitrophenol, 3-cresol, 2-chlorophenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol are 10 μg / L, 50.0 μg / L, 100 μg / L, 200 μg / L, 500 μg / L and 1000 μg / L.

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