Detection method for rapidly screening 10 phenolic pollutants in cured products

Abstract

The invention provides a detection method for rapidly screening 10 phenolic pollutants in cured products, and belongs to the technical field of analysis and detection. The detection method comprises the following steps: step 1, preparing a mixed standard working solution; 2, pre-treating a sample to be detected; 3, testing the mixed standard working solution by using ultra-high performance liquid chromatography-quadrupole-electrostatic field orbital ion hydrazine high-resolution mass spectrometry to obtain a standard curve; and 4, separating the sample solution by using a chromatographic column, carrying out gradient elution by using an ammonia water solution-methanol acetonitrile solution mobile phase system, collecting data in a full-scanning negative ion mode, and quantifying by using a standard curve external standard method. The method disclosed by the invention is simple and convenient to operate, small in matrix interference, high in efficiency, high in flux and high in accuracy, and is suitable for rapidly screening the phenolic pesticide compounds in the cured meat products.

Description

Technical Field

[0001] This invention relates to the field of analytical testing technology, and provides a method for rapidly screening 10 phenolic contaminants in cured and preserved products. Background Technology

[0002] As a traditional food in my country, cured meat products involve the cutting, salting, air-drying, and smoking of raw meat. If raw meat, bamboo or wooden cutting boards, bamboo or wooden containers, or wood smoked during processing are contaminated with phenolic pesticides, these can all become important pathways for contamination. In recent years, safety control research on cured meat products has focused on pollutants such as nitrosamines, polycyclic aromatic hydrocarbons, and heavy metals, while systematic detection and migration mechanism research on phenolic pesticide compounds is relatively scarce.

[0003] Currently, the detection of phenolic pesticide compounds commonly employs pretreatment methods such as liquid-liquid extraction, solid-phase extraction, and QuEChERS combined with gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS / MS). However, liquid-liquid extraction consumes large amounts of organic solvents and is cumbersome. While solid-phase extraction achieves high enrichment rates, the packing material is prone to lipid blockage in high-fat, high-protein matrices such as cured meat products, leading to unstable recovery rates. GC-MS requires derivatization, which may introduce errors and prolong analysis time. Furthermore, low-resolution LC-MS / MS is susceptible to interference from isomers in the matrix, resulting in false positives or quantitative bias.

[0004] Therefore, establishing an efficient screening method for phenolic compounds in cured meat products is crucial for ensuring food safety. Summary of the Invention

[0005] To address the problems mentioned in the background, the main objective of this invention is to provide a rapid method for screening 10 phenolic contaminants in cured and preserved meat products. Employing QuEChERS pretreatment technology and based on ultra-high performance liquid chromatography-quadrupole-electrostatic field orbital ion hydrazine high-resolution mass spectrometry (UPLC-Q-Orbitrap HRMS), a rapid method for screening 10 phenolic contaminants in cured and preserved meat products is established. By optimizing the QuEChERS adsorbent combination, leveraging the ultra-high resolution and accurate mass numbers of Q-Orbitrap HRMS, and employing database identification processing, a rapid, efficient, and highly specific method for simultaneously determining 10 common phenolic compounds in cured and preserved meat products is established for the first time, providing technical support for risk assessment of phenolic pesticide contamination in cured and preserved meat products.

[0006] Firstly, a rapid screening method for 10 phenolic contaminants in cured and preserved products is provided, comprising the following steps:

[0007] Step 1: Preparation of a mixed standard working solution of 10 phenolic compounds;

[0008] Step 2: Sample pretreatment; After the sample is crushed, it is extracted with organic solvent, purified by enhanced lipid removal dispersant (EMR-Lipid), and then back-extracted and salted out to obtain the sample solution by MgSO4 and NaCl mixed powder.

[0009] Step 3: The mixed standard working solution was tested using ultra-high performance liquid chromatography-quadrupole-electrostatic field orbital ion hydrazine high-resolution mass spectrometry to obtain the standard curve;

[0010] Step 4: The sample solution was separated by a chromatographic column, and eluted with a gradient of ammonia solution-methanol-acetonitrile solution as the mobile phase. Data was acquired using full-scan negative ion mode, and quantified using the external standard method with a standard curve.

[0011] In some embodiments, the phenolic compound is 2,4-dimethylphenol, 4-chloro-3-methylphenol, 2-nitrophenol, dichlorophenol, chlorpyrifos, 2,4,6-trichlorophenol, 2,3,4,5-tetrachlorophenol, 2,3,4,6-tetrachlorophenol, 2,3,5,6-tetrachlorophenol, and pentachlorophenol.

[0012] In some embodiments, the mixed standard working solution preparation process involves taking 10 phenolic compounds, dissolving them in acetonitrile, and then gradually diluting them with acetonitrile to prepare a series of mixed standard working solutions of different concentrations.

[0013] In some embodiments, the concentration of the mixed standard working solution is 2.0–200 ng / mL.

[0014] In some embodiments, the sample includes at least one of cured sausage, cured pork, cured fish, and cured duck.

[0015] In some embodiments, the organic solvent is selected from at least one of 2wt% ammonia-acetonitrile, acetonitrile, and 2wt% formic acid-acetonitrile.

[0016] In some embodiments, the mass ratio of MgSO4 and NaCl mixed powder is 4:1.

[0017] In some embodiments, the chromatographic conditions for testing in step 3 are as follows: the chromatographic column is a Waters BEH C 18 The column was 1.7 μm long and 2.1 mm × 50 mm. The column temperature was 40 °C and the sample chamber temperature was 5 °C. The injection volume was 2 μL and the flow rate was 0.3 mL / min. The mobile phase consisted of mobile phase A and mobile phase B.

[0018] The gradient elution program was as follows: 0 to 1.0 min, mobile phase B: 5%; 1.0 to 10.0 min, mobile phase B: 5% → 50%; 10.0 to 11.0 min, mobile phase B: 50%; 11.0 to 11.1 min, mobile phase B: 50% → 5%; 11.1 to 13.0 min, mobile phase B: 5%.

[0019] In some embodiments, mobile phase A is at least one of ammonia solution and ammonium acetate-ammonia solution; mobile phase B is at least one of acetonitrile and methanol-acetonitrile solution.

[0020] In some embodiments, the pH of the ammonia solution is 9-11, preferably 9.0, 10.0, or 11.0.

[0021] In some embodiments, the volume ratio of methanol to acetonitrile in the methanol-acetonitrile solution is 3:1.

[0022] In some embodiments, the mass spectrometry conditions tested in step 3 are as follows: lens voltage (RF) 60.0 V, ion transmission tube temperature 320°C, auxiliary heating gas temperature 350°C, auxiliary gas flow rate 10 Arb, sheath gas flow rate 30 Arb; scanning mode: negative ion full scan; scanning range 50–300 m / z, resolution 70,000, maximum IT 30 ms, maximum AGC target 1e. 6 .

[0023] In some embodiments, the ion source parameters in the mass spectrometry conditions are selected from negative ion mode (APCI). - ) or electrospray ionization source negative ion mode (ESI) - The preferred mode is the spray ionization source negative ion mode, with a voltage of 3.5 kV.

[0024] In some embodiments, the standard curve equation in step 3 is as follows:

[0025] Beneficial effects

[0026] (1) This invention provides a rapid screening method for detecting 10 phenolic contaminants in cured and preserved products. The 10 phenolic compounds show good linearity in the mass concentration range of 2.0–200 ng / mL (correlation coefficient (r)). 2 The average recovery rate at low, medium, and high spiking levels was 86.6%–104.5%, with a relative standard deviation (RSD) ≤7.8% and a limit of quantitation (LOQ) of 5.0–10 μg / kg. Pentachlorophenol was detected in 3 out of 125 batches of cured meat products on the market.

[0027] (2) The method of the present invention is simple to operate, has little matrix interference, high efficiency, high throughput and high accuracy, and is suitable for rapid screening of phenolic pesticide compounds in cured meat products. Attached Figure Description

[0028] Figure 1 This is the extracted ion chromatogram of the 10 phenolic pollutants detected in Example 1. Terminology Explanation

[0029] Certain embodiments of the invention will now be described in detail, examples of which are illustrated by the accompanying structural and chemical formulas. The invention is intended to cover all alternatives, modifications, and equivalents, all of which are included within the scope of the invention as defined in the claims. Those skilled in the art will recognize that many similar or equivalent methods and materials can be used to practice the invention. The invention is by no means limited to the methods and materials described herein. In the event that one or more of the incorporated documents, patents, and similar materials differ from or contradict this application (including, but not limited to, defined terminology, application of terminology, described techniques, etc.), this application shall prevail.

[0030] It should be further appreciated that certain features of the invention, for clarity, have been described in multiple independent embodiments, but may also be provided in combination in a single embodiment. Conversely, various features of the invention, for brevity, have been described in a single embodiment, but may also be provided individually or in any suitable sub-combination.

[0031] Unless otherwise stated, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. All patents and publications related to this invention are incorporated herein by reference in their entirety.

[0032] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0033] In the following content, all numbers disclosed herein, whether or not they use words such as "approximately" or "about," are approximate values. The value of each number may vary by 1%, 2%, 5%, 7%, 8%, 10%, 15%, or 20%. Whenever a number with a value of N is disclosed, any numbers with values ​​of N+ / -1%, N+ / -2%, N+ / -3%, N+ / -5%, N+ / -7%, N+ / -8%, N+ / -10%, N+ / -15%, or N+ / -20% will be explicitly disclosed, where "+ / -" indicates addition or subtraction. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of this disclosure. Such structures and techniques have also been described in many publications.

[0035] All reagents used in this invention can be purchased commercially or prepared by the methods described in this invention. Example 1

[0036] 1. Instruments and Materials

[0037] 1.1 Instruments

[0038] Vanquish UHPLC-Q Exactive Focus ultra-high performance liquid chromatography / electrostatic field orbital ion trap high-resolution mass spectrometer (HESI ion source) (equipped with TraceFinder data processing system) (Thermo Fisher Scientific, USA); BSA223S 0.1 ppm electronic balance (Sartorius, Germany); BC-1000 multi-tube vortex mixer (Shenzhen DouDian Biotechnology Co., Ltd.); Sorvall St16R high-speed refrigerated centrifuge (Thermo Fisher Scientific, USA); ELMAP120H ultrasonic cleaner (ELMA, Germany); Severn Excellence pH meter (Mettler Toledo, Switzerland); Lecht GM200 sample pulverizer (Lecht, Germany); Milli-Q Reference ultrapure water generator (Merck, Germany).

[0039] 1.2 Medicines and Reagents

[0040] A mixed standard solution of 10 phenolic compounds in methanol (concentrations of 991.5 μg / mL to 1004.1 μg / mL (see Table 1), Beijing Zhenxiang Technology Co., Ltd.); methanol, acetonitrile, and formic acid (chromatographic grade, Merck AG, Germany); ammonium acetate (chromatographic grade, Shandong Xiya Chemical Industry Co., Ltd.); ammonia water (chromatographic grade, Tianjin Kemeio Chemical Reagent Co., Ltd.); a purification tube of enhanced lipid removal dispersant (EMR-Lipid) (1 g, 15 mL), a 15 mL back-extraction tube containing 2 g of MgSO4 and NaCl mixed powder (4:1) (Agilent Technologies, USA), and ultrapure water (18.2 MΩ·cm, 25℃, Merck AG, Germany).

[0041] 1.3 Sample

[0042] 125 batches of cured meat product samples.

[0043] 2 Methods

[0044] 2.1 Preparation of standard solutions

[0045] Mixed standard working solution of 10 phenolic compounds: Accurately transfer an appropriate amount of mixed standard solution of 10 phenolic compounds (concentration of 991.5 μg / mL to 1004.1 μg / mL), dilute stepwise with acetonitrile, and prepare a series of mixed standard working solutions of different concentrations as needed.

[0046] 2.2 Sample Pretreatment

[0047] Weigh 5.00 g of the pulverized and thoroughly mixed sample and place it in a 50 mL polypropylene stoppered centrifuge tube. Add 10.0 mL of acetonitrile solution and vortex for 2 min. Centrifuge at 9500 r / min for 5 min. Let the supernatant stand at room temperature for later use. Add 5 mL of water to a 15 mL dSPE EMR-Lipid purification tube and vortex for 1 min to activate it. Transfer 5 mL of the supernatant after extraction to the activated EMR-Lipid purification tube and vortex for 1 min. Centrifuge at 8000 r / min for 3 min. Transfer all the supernatant after centrifugation to a 15 mL back-extraction tube containing 2 g of salt (MgSO4:NaCl = 4:1) and vortex immediately for 1 min. Centrifuge at 8000 r / min for 3 min. Take the upper acetonitrile solution after salting out the layers after centrifugation and filter it through a microporous membrane (0.22 µm, PTFE). Use the filtrate for UPLC-Q-Orbitrap analysis. A reagent blank solution should be prepared simultaneously, following the same procedure as the sample extraction step, except that the sample is not weighed. Depending on the concentration of the analyte in the sample solution, it can be gradually diluted with acetonitrile solution to the range of the standard curve for quantitative determination.

[0048] 2.3 Analysis Conditions

[0049] 2.3.1 Chromatographic conditions Waters BEH C 18 The chromatographic column (1.7 µm, 2.1 mm × 50 mm) was used at a column temperature of 40 °C and a sample chamber temperature of 5 °C. The injection volume was 2 μL. Mobile phase A was ammonia solution (pH 10.0 ± 0.1), and mobile phase B was methanol-acetonitrile solution (3:1). The flow rate was 0.3 mL / min, and the gradient elution program was as follows: 0 to 1.0 min, B: 5%; 1.0 to 10.0 min, B: 5% → 50%; 10.0 to 11.0 min, B: 50%; 11.0 to 11.1 min, B: 50% → 5%; 11.1 to 13.0 min, B: 5%.

[0050] 2.3.2 Mass Spectrometry Conditions: Ion source parameters: spray voltage 3.5 kV (negative ions), lens voltage (RF) 60.0 V, ion transmission tube temperature 320℃, auxiliary heating gas temperature 350℃, auxiliary gas flow rate 10 Arb, sheath gas flow rate 30 Arb; Mass spectrometry parameters: scan mode: negative ion full scan; scan range 50–300 m / z, resolution 70000, maximum IT 30 ms, maximum AGC target 1e. 6 Information on the 10 phenolic compounds is shown in Table 1.

[0051] 2.3.3 Screening and Confirmation Criteria In the TraceFinder data processing software, the molecular formula, addition method, retention time, and precise mass number of the primary precursor ion were input to construct a qualitative screening method database for 10 phenolic pollutants (see Table 1). The following qualitative screening matching parameters were set in the software: primary mass precision deviation less than 5 ppm, retention time deviation less than ±30 s, and isotope abundance matching threshold not less than 90%. If a target compound in the sample solution meets all three conditions simultaneously when compared with data in the database, the substance is considered detected.

[0052] Table 1. Basic information and mass spectrometry analysis parameters of 10 phenolic contaminants.

[0053]

[0054] 3 Results and Discussion

[0055] 3.1 Optimization of the mobile phase system

[0056] Phenolic compounds are well-suited for negative ion acquisition. In this study, five mobile phase systems with different pH values ​​were selected: ammonia solution (pH=9.0, 10.0, 11.0)-acetonitrile, 2 mmol ammonium acetate-ammonia solution (pH=10.0)-acetonitrile, and ammonia solution (pH=10.0)-methanol-acetonitrile (3:1) to investigate the chromatographic peak shape and response intensity of each compound. Comparing ammonia-acetonitrile mobile phase systems with different pH values, it was found that the higher the pH of the ammonia solution in the mobile phase, the earlier the retention times of each chromatographic peak tended to be. This was not conducive to the chromatographic separation of the three tetrachlorophenol isomers. Furthermore, when the pH of the ammonia solution reached 11.0, 2-nitrophenol underwent cleavage, forming multiple chromatographic peaks. Conversely, at lower pH values, the peaks eluted later, prolonging the analysis time. Adding 2 mmol of ammonium acetate to the ammonia solution (pH=10.0) reduced the overall response value of phenolic compounds by four times, and broadened the peaks of several compounds, such as tetrachlorophenol, making it difficult to separate the isomers effectively. Adding an appropriate amount of methanol to the acetonitrile organic phase could balance the extensibility of each compound in both methanol and acetonitrile, thus facilitating their separation. In conclusion, the ammonia solution (pH 10.0)-methanol:acetonitrile (3:1) mobile phase system was ultimately selected. The chromatograms of each compound are shown in [reference needed]. Figure 1 .

[0057] Figure 1 In the above, peak 1 is 2,4-dimethylphenol, peak 2 is 4-chloro-3-methylphenol, peak 3 is 2-nitrophenol, peak 4 is dichlorophenol, peak 5 is chlorpyrifos, peak 6 is 2,4,6-trichlorophenol, peak 7 is 2,3,4,5-tetrachlorophenol, peak 8 is 2,3,4,6-tetrachlorophenol, peak 9 is 2,3,5,6-tetrachlorophenol, and peak 10 is pentachlorophenol.

[0058] 3.2 Selection of Purifying Agent

[0059] Common adsorbents in the QuEChERS method, such as C18 and PSA, are suitable for samples with low fat content and high water content, such as fruits and vegetables. However, when used on oily, fatty samples like cured meat products, an additional step is required: liquid-liquid extraction of the oil with n-hexane followed by disposal. This significantly increases the complexity of the extraction process and the risk of target analyte loss. EMR-Lipid, a hydrophobically and sterically selective polymer, can selectively adsorb straight-chain hydrocarbons such as free fatty acids, triglycerides, cholesterol, and phospholipids after water activation. Therefore, it is widely used in the QuEChERS pretreatment of animal-derived meat products.

[0060] 3.3 Optimization of Extraction Solvent

[0061] Alcohols are generally not used as extraction solvents when using EMR-Lipid because they can partially dissolve EMR and salts, making it difficult to form a two-phase layer with water and thus reducing extraction efficiency. Acetonitrile is the preferred extraction solvent for EMR due to its wide range of extractant selectivity and good miscibility with water. Depending on the properties of the compounds, appropriate acid or alkaline solutions can be added to acetonitrile to enhance the extraction effect and ionization efficiency. This study used three extraction solvents—2% ammonia acetonitrile, acetonitrile, and 2% formic acid acetonitrile—to investigate their effects on the overall extraction efficiency and solvation effect of 10 phenolic pollutants. When 2% ammonia acetonitrile and acetonitrile were used as solvents, the overall chromatographic response values ​​of phenolic compounds did not differ significantly. However, 2-nitrophenol was broken down into three chromatographic peaks in alkaline acetonitrile solvent, affecting subsequent qualitative and quantitative analysis. When 2% formic acid acetonitrile was used as the solvent, although the overall chromatographic response value was twice that when acetonitrile was used, the recovery rate of some compounds was significantly lower, such as 2-nitrophenol with a recovery rate of less than 20% and acaricide with a recovery rate of less than 60%. Considering the above factors, acetonitrile was finally selected as the extraction solvent.

[0062] 3.4 Methodological Validation

[0063] 3.4.1 Limit of Quantification Baseline noise in Orbitrap high-resolution mass spectrometry is generally very low; therefore, relying on the signal-to-noise ratio of chromatographic peaks to determine the limit of detection or limit of quantification (LOQ) using traditional chromatographic analysis methods is inaccurate. This study used the following method to investigate the LOQ: A suitable amount of mixed standard solution was taken and diluted with a negative sample extract of cured meat products to prepare a series of spiked solutions. If a chromatographic peak signal at the lowest matrix concentration allowed for qualitative screening of a target compound, then the content of that target compound at three times that concentration in the cured meat product was the LOQ of that compound. Of the 10 phenolic contaminants, 4 had a LOQ of 5.0 μg / kg, and 6 had a LOQ of 10.0 μg / kg (see Table 2).

[0064] 3.4.2 Linearity Analysis Accurately transfer appropriate amounts of a mixed standard solution of 10 phenolic compounds and prepare a series of mixed standard solutions with concentrations ranging from 2.0 to 200 ng / mL using acetonitrile solution. The ordinate (Y) represents the peak area of ​​the extracted ion chromatogram, and the abscissa (X) represents the mass concentration (ng / mL). At least 5 concentration points were selected for linear fitting. The linear relationship of the 10 phenolic pollutants was good, r 2 >0.9993, see Table 2.

[0065] 3.4.3 Recovery and Precision: Spiking experiments were conducted on negative samples of cured meat products at three concentration levels (1, 2, and 5 times the limit of quantitation). Quantification was performed using the external standard method with a standard curve. Six parallel experiments were conducted for each spiked concentration level. The results showed that the recoveries of the 10 phenolic contaminants ranged from 86.6% to 104.5%, with RSD < 7.8% (see Table 2).

[0066] Table 2. Retention time, linear equation, limit of quantitation, recovery rate, and precision of 10 phenolic contaminants (n=6)

[0067]

[0068] 3.5 Establishment of Screening Methods

[0069] Because phenolic pollutants have a stable benzene ring structure, they are used in atmospheric pressure chemical ionization source negative ion mode (APCI). - ) or electrospray ionization source negative ion mode (ESI) - When comparing samples with data in the database, it is difficult to generate stable secondary ion fragments with high response values. Therefore, secondary fragment ions are omitted as a screening criterion in this method's database. The following qualitative screening matching parameters are set in the software: primary quality accuracy deviation less than 5 ppm, retention time deviation less than ±30 s, and isotope abundance matching threshold not less than 90%. If a target compound in the sample solution meets all three conditions simultaneously when compared with data in the database, the substance is considered detected.

[0070] 3.6 Determination of actual samples

[0071] The method established in this study was used to test 125 batches of cured meat products. The sample categories included 35 batches of cured sausages, 35 batches of cured pork, 35 batches of cured fish, and 20 batches of cured duck. Three batches of pentachlorophenol were positive, with the contents measured as 9.7 μg / kg, 12 μg / kg, and 19 μg / kg, respectively.

[0072] 4. Conclusion

[0073] This study established a rapid detection method for simultaneously screening 10 phenolic contaminants in cured meat products based on UHPLC-Q-Orbitrap HMRRS and the QuEChERS pretreatment technique with EMR-Lipid for efficient impurity removal. A series of optimizations were performed on chromatographic and mass spectrometric conditions. This method is simple to operate, has minimal matrix interference, high efficiency, high throughput, and high accuracy. It is suitable for the rapid screening of phenolic pesticide contaminants in cured meat products, providing more comprehensive and reliable technical support and a cutting-edge monitoring direction for the quality and safety supervision of cured meat products.

[0074] The method of this invention has been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and applications described herein within the scope, spirit, and context of this invention to implement and apply the technology of this invention. Those skilled in the art can refer to the content herein to appropriately improve process parameters. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of this invention.

Claims

1. A rapid screening method for 10 phenolic contaminants in cured and preserved products, characterized in that, Includes the following steps: Step 1: Preparation of a mixed standard working solution of 10 phenolic compounds; Step 2: Sample pretreatment; After the sample is crushed, it is extracted with an organic solvent, purified by an enhanced lipid removal dispersant, and then back-extracted and salted out to obtain the sample solution by a mixture of MgSO4 and NaCl powder. Step 3: The mixed standard working solution was tested using ultra-high performance liquid chromatography-quadrupole-electrostatic field orbital ion hydrazine high-resolution mass spectrometry to obtain the standard curve; Step 4: The sample solution is separated by a chromatographic column, and eluted with a gradient of ammonia solution-methanol acetonitrile solution as the mobile phase. Data is acquired using full scan negative ion mode, and quantification is performed using the external standard method with a standard curve.

2. The detection method according to claim 1, characterized in that, The phenolic compounds are 2,4-dimethylphenol, 4-chloro-3-methylphenol, 2-nitrophenol, dichlorophenol, chlorpyrifos, 2,4,6-trichlorophenol, 2,3,4,5-tetrachlorophenol, 2,3,4,6-tetrachlorophenol, 2,3,5,6-tetrachlorophenol, and pentachlorophenol.

3. The detection method according to claim 1, characterized in that, The preparation process of the mixed standard working solution is as follows: 10 phenolic compounds are dissolved in acetonitrile and then diluted stepwise with acetonitrile to prepare a series of mixed standard working solutions of different concentrations. Alternatively, the concentration of the mixed standard working solution is 2.0–200 ng / mL.

4. The detection method according to claim 1, characterized in that, The samples include at least one of cured sausage, cured pork, cured fish, and cured duck.

5. The detection method according to claim 1, characterized in that, The organic solvent is selected from at least one of 2wt% ammonia-acetonitrile, acetonitrile, and 2wt% formic acid-acetonitrile.

6. The detection method according to claim 1, characterized in that, The mass ratio of MgSO4 and NaCl in the mixed powder is 4:

1.

7. The detection method according to claim 1, characterized in that, In step 3, the chromatographic conditions for the test are as follows: the chromatographic column is a Waters BEH C2000L. 18 The column was 1.7 μm long and 2.1 mm × 50 mm. The column temperature was 40 °C and the sample chamber temperature was 5 °C. The injection volume was 2 μL and the flow rate was 0.3 mL / min. The mobile phase consisted of mobile phase A and mobile phase B. The gradient elution program was as follows: 0 to 1.0 min, mobile phase B: 5%; 1.0 to 10.0 min, mobile phase B: 5% → 50%; 10.0 to 11.0 min, mobile phase B: 50%. From 11.0 to 11.1 min, mobile phase B: 50% → 5%; from 11.1 to 13.0 min, mobile phase B: 5%.

8. The detection method according to claim 7, characterized in that, Mobile phase A is at least one of ammonia solution and ammonium acetate-ammonia solution; mobile phase B is at least one of acetonitrile and methanol-acetonitrile solution. The pH of an ammonia solution is 9-11; The volume ratio of methanol to acetonitrile in the methanol-acetonitrile solution is 3:

1.

9. The detection method according to claim 1, characterized in that, In step 3, the mass spectrometry conditions were as follows: lens voltage 60.0 V, ion transmission tube temperature 320 °C, auxiliary heating gas temperature 350 °C, auxiliary gas flow rate 10 Arb, sheath gas flow rate 30 Arb; scanning mode: negative ion full scan; scanning range 50–300 m / z, resolution 70,000, maximum IT 30 ms, maximum AGC target 1e. 6 ; In the mass spectrometry conditions, the ion source parameters are either negative ion mode or electrospray ionization source negative ion mode.

10. The detection method according to claim 1, characterized in that, The equation of the standard curve in step 3 is as follows: The curve regression equation for 2,4-dimethylphenol is Y = 2.312 × 10⁻⁶. 4 X +3.228×10 4 R 2 The value is 0.9995; the curve regression equation for 4-chloro-3-methylphenol is Y = 9.257 × 10⁻⁶. 4 X -4.354×10 4 R 2 The value is 0.9998; the curve regression equation for 2-nitrophenol is Y = 1.942 × 10⁻⁶. 5 X -3.945×10 4 R 2 The value is 0.9997; the curve regression equation for diphenhydramine is Y = 3.170 × 10⁻⁶. 5 X -8.949×10 5 R 2 The value was 0.9993; the curve regression equation for chlorfenapyr was Y = 2.707 × 10⁻⁶. 5 X +1.054×10 5 R 2 The value is 0.9999; the curve regression equation for 2,4,6-trichlorophenol is Y = 3.193 × 10⁻⁶. 4 X -1.445×10 4 R 2 The value is 0.9996; the curve regression equation for 2,3,4,5-tetrachlorophenol is Y = 4.722 × 10⁻⁶. 4 X -1.089×10 4 R 2 The value is 0.9995; the curve regression equation for 2,3,4,6-tetrachlorophenol is Y = 4.848 × 10⁻⁶. 4 X -3.206×10 4 R 2 The value is 0.9993; the curve regression equation for 2,3,5,6-tetrachlorophenol is Y = 6.205 × 10⁻⁶. 4 X -3.812×10 4 R 2 The value is 0.9995; the curve regression equation for pentachlorophenol is Y = 9.031 × 10⁻⁶. 4 X -4.653×10 4 R 2 It is 0.9997.

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