Method for detecting 32 pesticides in fresh Chinese prickly ash based on improved rapid filtration type purification technology

Abstract

The invention provides a method for detecting 32 pesticides in fresh Chinese prickly ash based on an improved rapid filtration type purification technology, which comprises the following steps: (1) sample preparation: crushing a sample after sampling, (2) sample extraction and purification: pre-treating the sample by using a rapid filtration type purification column integrating drying and purification to obtain a purified sample supernatant after extraction; (3) confirming conditions of an ultra-high performance liquid chromatography and a quadrupole time-of-flight mass spectrometer; and (4) determining the sample: quantitatively determining the extracted supernatant of the purified sample. According to the present invention, the improved rapid filtration type purification column integrating drying and purification is applied to the fresh zanthoxylum bungeanum maxim pretreatment process, such that the subsequent quantitative analysis detection of 32 pesticides in the fresh zanthoxylum bungeanum maxim is convenient, the method is simple, convenient and rapid, the accuracy and the sensitivity are high, the detection limit is as low as 0.1 [mu] g / kg, the quantification limit is as low as 0.3 [mu] g / kg, the standard addition recovery rate is 70.3-118%, the RSD is less than 10%, and the method is suitable for industrial production. A means is provided for rapid detection of various pesticides in the fresh Chinese prickly ash.

Description

Technical Field

[0001] The invention belongs to the technical field of food detection, and in particular relates to a method for detecting 32 kinds of pesticides in fresh pepper based on an improved rapid filtration purification technology. Background Art

[0002] Fresh peppercorns are loved by consumers for their unique flavor and health value. At the same time, fresh peppercorns are also of great significance in promoting agricultural economic development and international trade cooperation. With the rapid development of the spice economy market and the continuous improvement of consumers' food safety awareness, people are increasingly concerned about the problem of pesticide residues in fresh peppercorns. In the process of pepper cultivation, in order to ensure its quality and yield, different types of pesticides are often sprayed to prevent pests and diseases. However, improper use of pesticides can lead to pesticide residue problems, posing a threat to human health and the environment. The pepper matrix is ​​complex and rich in oils, pigments, vitamins, alkaloids, amides, lignans, coumarins and other minerals. These substances are not only very easy to cause matrix interference during pesticide detection, affecting the response intensity and accuracy of pesticide detection, but also damage the detection instrument and affect the service life of the instrument. In addition, there are many types of pesticides used in the cultivation and production of pepper, and the level of pesticide residues is often low, which further increases the difficulty of pepper pesticide detection. At the same time, the current research on pepper at home and abroad mainly focuses on breeding, cultivation, nutritional components and pharmacological effects, while there are relatively few studies on the detection of pesticide residues in pepper. Therefore, it is crucial to develop suitable sample pretreatment technology and instrumental analysis methods for pepper pesticide detection. QuEChERS technology is widely used in the detection of pesticide residues in agricultural products because of its rapid, simple, economical, efficient, durable and safe characteristics. The rapid filtration purification technology is a rapid and efficient sample pretreatment purification technology further developed on the basis of the QuEChERS method. Although the rapid filtration purification technology has shown a certain efficiency improvement compared with the traditional QuEChERS method, most rapid filtration purification technologies still need to add different QuEChERS salt packages to dry the extract separately before sample purification, and then transfer the supernatant to the rapid filtration purification column for subsequent purification operations after vortexing, centrifugation and other steps. Therefore, the traditional rapid filtration purification technology has the problem that the operation process needs to be further simplified and the detection efficiency still needs to be improved, which also limits its further development and application in the field of rapid pesticide detection. In the prior art, due to the complexity of the matrix and the types of pesticides, there are few studies on the detection of pesticide residues in fresh pepper. At the same time, the research on the simultaneous detection of multiple pesticides in fresh pepper is also limited to the application of traditional QuEChERS technology, and there is almost no research on rapid filtration purification technology. Therefore, it is of great significance to develop an accurate, simple, fast and safe analytical method for the simultaneous detection of multiple pesticides in fresh pepper. The method provided by the present invention innovatively applies the improved rapid filtration purification column integrating drying and purification in the fresh pepper pretreatment process, so that the sample drying and purification are carried out simultaneously, on the basis of effectively reducing the interference of the complex matrix of fresh pepper on pesticide detection, the steps such as centrifugation are omitted, the operation process is further simplified, the detection efficiency is improved, and the detection of 32 kinds of pesticides in fresh pepper is realized at the same time, with the characteristics of high detection efficiency, good purification effect, high-throughput detection, and economic and environmental protection. Summary of the invention

[0003] Technical problem to be solved: In view of the above technical problem, the purpose of the present invention is to provide a method for detecting 32 kinds of pesticides in fresh pepper based on an improved rapid filtration purification technology, the steps of which are as follows: (1) sample preparation: crush the sample after sampling, (2) sample extraction and purification: use a rapid filtration purification column integrating drying and purification to pre-treat the sample to obtain a purified sample supernatant after extraction; (3) ultra-high performance liquid chromatography and quadrupole time-of-flight mass spectrometer condition confirmation, (4) sample determination: quantitative determination of the purified sample supernatant after extraction. In the present invention, the improved rapid filtration purification column integrating drying and purification is applied to the pre-treatment process of fresh pepper, which is convenient for subsequent quantitative analysis and detection of 32 kinds of pesticides in fresh pepper. The method is simple, fast, accurate and sensitive, with a detection limit as low as 0.1μg / kg, a quantitative limit as low as 0.3μg / kg, a spike recovery rate of 70.3%-118%, and RSDs less than 10%, providing a means for rapid detection of multiple pesticides in fresh pepper.

[0004] Technical solution: A method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology, comprising the following steps: S1. Fresh pepper is evenly crushed, and the extraction solvent is directly added and vortexed to extract to obtain a pretreated fresh pepper extract; S2. The pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified sample was obtained through the filter membrane; S3. The purified samples were tested by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry to obtain the absorption peak areas of 32 pesticides, and then the contents of 32 pesticides in fresh pepper were obtained according to the standard curve. The detection flow chart is as follows: Figure 1 shown. Furthermore, it is characterized in that: the extraction solvent in step S1 is a combination of acetonitrile and formic acid. Furthermore, in step S1, the ratio of acetonitrile to formic acid is 99:(0.9-1). Furthermore, the vortex oscillation time in step S1 is 1-2 minutes. Furthermore, the improved rapid filtration purification column in step S2 is filled with a purifier and a desiccant. Furthermore, the purifier is a combination of PSA+C18+GCB, and the ratio of the purifier to the purified sample to be tested is 25:25:10:1. Furthermore, the desiccant is a combination of anhydrous sodium sulfate and sodium chloride, and the ratio of the desiccant to the purified sample to be tested is 1:2:1. Furthermore, the chromatographic conditions of the ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometer in step S3 are: chromatographic column Agilent Poroshell 120C18 column, chromatographic column specifications 1.9 μm, 2.1×100 mm, column temperature 40°C, flow rate 0.3 mL / min, injection volume 5 μL; mass spectrometry conditions of the ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometer: ionization mode is electrospray ionization positive ion mode, capillary voltage is 4500 V, nebulization gas pressure is 2 Bar, drying gas flow rate is 8 L / min, and drying temperature is 220°C. Further, the 32 kinds of pesticides in step S4 include propamocarb, dinotefuran, thiamethoxam, imidacloprid, clothianidin, dimethoate, dichlorvos, methyl thiophanate, fenthion sulfoxide, fenthion sulfone, metalaxyl, promethazine, flumorph, myclobutanil, boscalid, malathion, dimethomorph, cyproconazole, triadimefon, myclobutanil, chlorfenapyr, triazophos, triadimenol, flusilazole, idemetonitrile, kresoxim-methyl, tebuconazole, phoxim, cadusafosfo, indoxacarb, chlorpyrifos, and pyraclostrobin. Beneficial effects: 1. The present invention adopts an improved rapid filtration purification technology, fills the rapid filtration purification technology with a purifier and a desiccant, enables the purification and drying of fresh pepper samples to be carried out simultaneously, omits the steps of activation, equilibration, elution, centrifugation, separate drying, etc., not only simplifies the method to the greatest extent, but also can greatly improve the detection efficiency, shorten the purification cycle of fresh pepper, and realize the simultaneous detection of 32 kinds of pesticides in fresh pepper, and has the characteristics of high detection efficiency, good purification effect, high-throughput detection, economy and environmental protection. 2. The purifiers used in the improved rapid filtration purification technology of the present invention are PSA, C18 and GCB, among which PSA can effectively remove components such as organic acids and fatty acids, C18 has a good removal effect on non-polar compounds such as lipids, and GCB has a good adsorption effect on pigments and planar compounds. The desiccant is anhydrous sodium sulfate and sodium chloride, which have good water removal properties and can promote full contact between the purifier and the fresh pepper extract, avoiding the disadvantages of easy heat release and agglomeration of the traditional desiccant anhydrous magnesium sulfate, and can effectively reduce the interference of the complex matrix in the fresh pepper on the pesticide detection, effectively improve the matrix removal efficiency of the fresh pepper sample, and realize the effective removal of the matrix of the fresh pepper sample, which is convenient for the subsequent determination of pesticides in the fresh pepper. 3. The method provided by the present invention adopts a compound of acetonitrile and formic acid as the extraction solvent of fresh pepper, which can not only reduce the extraction of lipophilic substances, but also has the ability to efficiently extract molecules of different polarities, and can also promote chromatographic separation and enhance mass spectrometry ionization in ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry detection, thereby obtaining better analysis results and better peak response, and effectively improving the extraction efficiency of 32 pesticides in fresh pepper. 4. The sample pretreatment method for detecting pesticides in fresh pepper of the present invention can suppress the influence of the sample matrix, greatly reduce the interference of the complex matrix of fresh pepper on the detection of 32 pesticides, and is combined with the rapid filtration purification technology widely used in the determination of pesticide residues in various matrices. It has the characteristics of simple operation, rapidity, high efficiency, durability and safety, and has been used to detect 32 pesticides in fresh pepper. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is a flow chart for the detection of 32 pesticides in fresh pepper; Figure 2 is the recovery rate of Example 2, Comparative Example 1 and Comparative Example 2; Figure 3 It is the recovery rate of Example 2 and Comparative Example 3; Figure 4 is the recovery rate of Example 2, Comparative Example 4 and Comparative Example 5; Figure 5 is the recovery rate of Example 2, Comparative Example 6 and Comparative Example 7; Figure 6 It is the recovery rate of Example 2 and Comparative Examples 8-15. DETAILED DESCRIPTION The present invention will be further described below in conjunction with embodiments, which are explanations of the present invention and are not limited to the following embodiments: Example 1 The detection method for drawing the standard curve of 32 pesticides in fresh pepper includes the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Table 1 Mobile phase gradient elution program The test results of the detection method for drawing the standard curve of 32 pesticides in fresh pepper are shown in Table 2. Table 2 Linear range and correlation coefficient (R) of 32 pesticides in fresh pepper 2 ), limit of detection (LOD) and limit of quantification (LOQ) As shown in Table 2, the R values ​​of the standard curves of 32 pesticides in fresh pepper are 2 All of them were greater than 0.99, indicating that the method had a good linear relationship, the detection limit of the method was 0.1-100.0μg / kg, and the quantification limit of the method was 0.3-300.0μg / kg. Example 2 A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Performance Testing (1) Spiked recovery rate Two different spike levels of 0.1 mg / kg and 0.2 mg / kg were selected, and the method of the present invention was used to pre-treat the fresh pepper samples, and then the spike recovery rates of 32 pesticides were determined. (2) Matrix effect The pretreatment method of the present invention is used to extract a blank matrix solution, and a standard curve is prepared. The matrix effect (ME) is evaluated by comparing the slope of the matrix matching standard curve and the slope of the organic solvent (acetonitrile) standard curve. The calculation formula is: ME (%) = (matrix matching standard curve slope / organic solvent standard curve slope-1) × 100%; when ME < 0, it is a matrix inhibition effect; ME > 0, it is a matrix enhancement effect; |ME| ≤ 20%, it is a weak matrix effect; 20% ≤ |ME| ≤ 50%, it is a medium matrix effect; |ME| > 50%, it is a strong matrix effect. The matrix effect of 32 pesticides is measured. Table 3 Recoveries, relative standard deviations and matrix effects of 32 pesticides spiked in fresh pepper As shown in Table 3, the recoveries of 32 pesticides in fresh pepper detected in Example 2 were within the range, and the intra-day RSD and inter-day RSD were both less than 10%; and both cymoxanil and pyraclostrobin showed matrix enhancement effect and weak matrix effect, while dimethoate, thiamethoxam, imidacloprid, clothianidin, dimethoate, dichlorvos, methyl thiophanate, fenthion sulfoxide, fenthion sulfone, metalaxyl, promethazine, flumorph, azoxystrobin, boscalid, malathion, dimethomorph, cyproconazole, triadimefon, myclobutanil, chlorfenapyr, triazophos, triadimenol, flusilazole, idemeton-butyl, kresoxim-butyl, tebuconazole, succinimide, chlorpyrifos ... chlorpyrifos, triazophos, triazophos, triazophos, triazophos, flusilazole, idemeton-butyl, kresoxim-butyl, tebuconazole, succinimide, chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorpyrifos, chlorpyrifos, Sulfate, cadusafosphos, indoxacarb and chlorpyrifos all showed matrix inhibition effects of varying intensities. Among them, dinotefuran, thiamethoxam, imidacloprid, clothianidin, dimethoate, dichlorvos, fenthion sulfoxide, fenthion sulfone, metalaxyl, promethazine, flumorph, azoxystrobin, malathion, triadimefon, tebuconazole, cadusafosphos, indoxacarb and chlorpyrifos all showed weak matrix effects, methyl thiophanate, boscalid, dimethomorph, cyproconazole, myclobutanil and flusilazole all showed moderate matrix effects, while chlorfenapyr, triazophos, triadimenol, idemeton-butyl, kresoxim-methyl and phoxim all showed strong matrix effects. Comparative Example 1 The difference between this comparative example and Example 2 is that the extraction solvent in step S1 is a combination of acetonitrile and acetic acid, wherein acetonitrile:acetic acid=99:1. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile: acetic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 2 The difference between this comparative example and Example 2 is that the extraction solvent in step S1 is acetonitrile. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and crush it evenly into a 50mL centrifuge tube, directly add 15mL of acetonitrile solvent, and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Table 4 Recovery rates of Example 2, Comparative Example 1 and Comparative Example 2 Figure 2 Example 2 is recorded as 1% formic acid acetonitrile, Comparative Example 1 is recorded as 1% acetic acid acetonitrile, and Comparative Example 2 is recorded as acetonitrile. Figure 2 It can be seen that the recovery rates of 32 kinds of pesticides detected in fresh pepper in Example 1 are all higher than 70%, ranging from 71.05% to 99.19%, while in Comparative Example 1, the extraction solvent is a combination of acetonitrile and acetic acid, wherein acetonitrile: acetic acid = 99: 1, and the recovery rates of methyl thiophanate, boscalid, kresoxim-methyl, and chlorpyrifos are all lower than 70%, and the extraction effect of pesticides such as dinotefuran, flumorph, and dimethomorph is poor; in Comparative Example 2, the extraction solvent is acetonitrile, and the recovery rates of propamocarb, methyl thiophanate, and chlorpyrifos are all lower than 70%, and the extracted matrix interference is less, indicating that the 32 kinds of pesticides of different polarities in fresh pepper can be well dissolved in acetonitrile, and the addition of formic acid is beneficial to the chromatographic separation and ionization enhancement in the ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometer analysis to obtain better analysis results. Comparative Example 3 The difference between this comparative example and Example 2 is that anhydrous sodium sulfate is replaced by anhydrous magnesium sulfate in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Table 5 Recovery of Example 2 and Comparative Example 3 Figure 3 Example 2 is recorded as anhydrous sodium sulfate, and Comparative Example 3 is recorded as anhydrous magnesium sulfate. Figure 3 It can be seen that compared with Comparative Example 3, Example 2 has a higher recovery rate for 32 kinds of pesticides detected in fresh pepper, all higher than 70%, between 71.05-99.19%, while the recovery rates of boscalid and triazophos in Comparative Example 3 are both lower than 70%, and the recovery rate of dinotefuran is reduced. This is due to the strong adsorption effect of anhydrous magnesium sulfate, and anhydrous magnesium sulfate is very easy to agglomerate, and the phenomenon of agglomeration and wrapping the purifier is easy to occur during the drying process, resulting in the purifier being unable to fully contact with the extract. Comparative Example 4 The difference between this comparative example and Example 2 is that in step S2, the ratio of anhydrous sodium sulfate:sodium chloride is 4:1. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 532 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 5 The difference between this comparative example and Example 2 is that in step S2, the ratio of anhydrous sodium sulfate:sodium chloride is 1:1. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 266 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Table 6 Recovery of Example 2, Comparative Example 4 and Comparative Example 5 Figure 4 Example 2 is recorded as 0.266g Na2SO4+0.133g NaCl (combination A), Comparative Example 4 is recorded as 0.532g Na2SO4+0.133g NaCl (combination B), and Comparative Example 5 is recorded as 0.266g Na2SO4+0.266g NaCl (combination C). Figure 4 It can be seen that Example 2 has a high recovery rate for 32 kinds of pesticides detected in fresh pepper, all of which are higher than 70%, between 71.05-99.19%, while the recovery rate of pesticides such as dinotefuran, malathion, chlorfenapyr, demeton, and chlorpyrifos in Comparative Example 4 is significantly reduced, indicating that excessive addition of anhydrous sodium sulfate will produce competitive adsorption on some target pesticide molecules, thereby reducing the recovery rate, and the recovery rate of dinotefuran, thiamethoxam, dimethoate, malathion, and chlorpyrifos in Comparative Example 5 is significantly reduced. Comparative Example 6 The difference between this comparative example and Example 2 is that GCB is replaced by CNTs in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with a purifier 50 mg PSA, 50 mg C18 and 20 mg CNTs, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 7 The difference between this comparative example and Example 2 is that GCB is replaced by Envi-crab in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 20 mg Envi-crab, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Table 7 Recovery rates of Example 2, Comparative Example 6 and Comparative Example 7 Figure 5 Example 2 is recorded as 50 mg PSA + 50 mg C18 + 20 mg GCB, Comparative Example 6 is recorded as 50 mg PSA + 50 mg C18 + 20 mg CNTs, and Comparative Example 5 is recorded as 50 mg PSA + 50 mg C18 + 20 mg Envi-crab. Figure 5 It can be seen that compared with Comparative Examples 6 and 7, Example 2 has a higher recovery rate for 32 kinds of pesticides detected in fresh pepper, all of which are higher than 70%, between 71.05-99.19%, while Comparative Example 6 uses multi-walled carbon nanotubes (CNTs) instead of GCB. Except for the increased recovery rates of dinotefuran, methyl thiophanate and oxadiazine, the recovery rates of other pesticides are significantly reduced, indicating that there are differences in the adsorption selectivity between CNTs and different pesticide molecules. Comparative Example 7 uses Envi-crab to replace GCB, and the recovery rates of dinotefuran, dimethoate, azoxystrobin and indoxacarb are significantly reduced, indicating that when Example 2 uses PSA+C18+GCB as a purifier combination, the recovery rates of 32 kinds of pesticides are all above 70%, and the purification effect of dimethoate, imidacloprid and triadimenol is significantly better than that of Comparative Examples 6 and 7. Comparative Example 8 The difference between this comparative example and Example 2 is that the content of PSA is reduced to 0.5 times that of Example 2 in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 25 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 9 The difference between this comparative example and Example 2 is that the content of PSA is increased to twice that of Example 2 in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 100 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 10 The difference between this comparative example and Example 2 is that the content of PSA is increased to 4 times that of Example 2 in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 200 mg PSA, 50 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 11 The difference between this comparative example and Example 2 is that in step S2, the content of C18 is reduced to 0.8 times that of Example 2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 40 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 12 The difference between this comparative example and Example 2 is that in step S2, the content of C18 is increased to 1.2 times that of Example 2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 60 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 13 The difference between this comparative example and Example 2 is that in step S2, the content of C18 is increased to 1.4 times that of Example 2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 70 mg C18 and 20 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 14 The difference between this comparative example and Example 2 is that the content of GCB is increased to 0.5 times that of Example 2 in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 10 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Comparative Example 15 The difference between this comparative example and Example 2 is that the content of GCB is increased to 1.5 times that of Example 2 in step S2. A method for detecting pesticides in fresh pepper based on an improved rapid filtration purification technology comprises the following steps: S1. Weigh 2g of fresh pepper and grind it evenly into a 50mL centrifuge tube, directly add 15mL of extraction solvent (acetonitrile:formic acid = 99:1) and vortex the sample for 1min, take the supernatant for later use, and obtain the pretreated fresh pepper extract; S2. A rapid filtration purification column was filled with purifiers 50 mg PSA, 50 mg C18 and 30 mg GCB, and a desiccant 266 mg anhydrous sodium sulfate and 133 mg sodium chloride to obtain an improved rapid filtration purification column; S3. 2 mL of pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified blank matrix solution was obtained through the filter membrane; S4. Prepare 32 pesticide standard solutions into mixed standard working solutions at seven concentration levels (0.2-3200 μg / kg) using blank matrix solution; S5. The purified sample was detected by ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, wherein the chromatographic conditions were as follows: chromatographic column: C18 column (Poroshell 120, 1.9 μm, Agilent, 2.1×100 mm), column temperature 40° C., flow rate 0.3 mL / min, injection volume 5 μL; The mass spectrometry conditions are as follows: ionization mode: electrospray ionization (ESI) positive ion mode, capillary voltage 4500V, nebulizing gas pressure 2Bar, drying gas 8L / min, drying temperature 220°C; The mobile phase conditions are: phase A is 10% methanol water (containing 0.1% formic acid), phase B is methanol, and the gradient elution is shown in Table 1. Table 8 Recovery rates of Example 2, Comparative Example 8, Comparative Example 9 and Comparative Example 10 Table 9 Recovery rates of Example 2, Comparative Example 11, Comparative Example 12 and Comparative Example 13 Table 10 Recovery rates of Example 2, Comparative Example 14 and Comparative Example 15 Figure 6 In A, Example 2 is recorded as 50 mg PSA + 50 mg C18 + 20 mg GCB, Comparative Example 8 is recorded as 25 mg PSA + 50 mg C18 + 20 mg GCB, Comparative Example 9 is recorded as 100 mg PSA + 50 mg C18 + 20 mg GCB, and Comparative Example 10 is recorded as 200 mg PSA + 50 mg C18 + 20 mg GCB. Figure 6A It can be seen that with the increase of PSA dosage, the number of pesticides with a recovery rate (≥70%) of 32 pesticides detected in fresh pepper shows a trend of first increasing, then decreasing, and then tending to a stable state. In Example 2, the PSA dosage is 50 mg, and the detection recovery rates of 32 pesticides in fresh pepper are all ≥70%, indicating that excessive PSA will have a certain adsorption effect on some pesticides, thereby affecting their recovery rate. Figure 6 In B, Example 2 is recorded as 50 mg PSA + 50 mg C18 + 20 mg GCB, Comparative Example 11 is recorded as 50 mg PSA + 40 mg C18 + 20 mg GCB, Comparative Example 12 is recorded as 50 mg PSA + 60 mg C18 + 20 mg GCB, and Comparative Example 13 is recorded as 50 mg PSA + 60 mg C18 + 20 mg GCB. From Table 9 and Figure 6 It can be seen that with the increase of C18 dosage, the number of pesticides with a recovery rate (≥70%) of 32 pesticides detected in fresh pepper showed a trend of first increasing, then decreasing, and then increasing, indicating that too high a dosage will increase costs and cause waste. Figure 6 Example 2 in C is recorded as 50 mg PSA + 50 mg C18 + 20 mg GCB, Comparative Example 14 is recorded as 50 mg PSA + 50 mg C18 + 10 mg GCB, and Comparative Example 15 is recorded as 50 mg PSA + 50 mg C18 + 30 mg GCB. Figure 6 It can be seen that with the increase of GCB dosage, the number of pesticides with a recovery rate (≥70%) of 32 pesticides in fresh pepper showed a trend of first increasing and then decreasing. In Example 2, the GCB dosage was 20 mg, and the detection recovery rate of 32 pesticides in fresh pepper (≥80%) was 24, which was higher than the other dosage combinations. The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology, characterized in that: The following steps are involved: S1. Fresh pepper is evenly crushed, and the extraction solvent is directly added and vortexed to extract to obtain a pretreated fresh pepper extract; S2. The pretreated fresh pepper extract was added to the improved rapid filtration purification column, and the push rod was pushed at a constant speed of 1 drop / second to purify the matrix, and the purified sample was obtained through the filter membrane; S3. The purified samples were tested using ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry to obtain the absorption peak areas of 32 pesticides, and then the contents of the 32 pesticides in fresh pepper were obtained based on the standard curve.

2. The method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 1, characterized in that: The extraction solvent in step S1 is a combination of acetonitrile and formic acid.

3. A method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 4, characterized in that: The ratio of acetonitrile to formic acid in step S1 is 99:(0.9-1).

4. The method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 1, characterized in that: The vortex oscillation time in step S1 is 1-2 minutes.

5. The method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 1, characterized in that: The improved rapid filtration purification column in step S2 is filled with a purifying agent and a desiccant.

6. The method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 5, characterized in that: The purifier is a combination of ethylenediamine-N-propyl silane silica gel + octadecylsilane bonded silica gel + graphitized carbon black, and the ratio of the purifier to the purified sample to be tested is 25:25:10:

1.

7. The method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 5, characterized in that: The desiccant is a combination of anhydrous sodium sulfate and sodium chloride, and the ratio of the desiccant to the purified sample to be tested is 1:2:

1.

8. The method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 1, characterized in that: The chromatographic conditions of the ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometer in step S3 are: chromatographic column Agilent Poroshell 120C18 column, chromatographic column specifications 1.9 μm, 2.1×100 mm, column temperature 40°C, flow rate 0.3 mL / min, injection volume 5 μL; the mass spectrometry conditions of the ultra-high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometer are: ionization mode is electrospray ionization positive ion mode, capillary voltage is 4500 V, nebulization gas pressure is 2 Bar, drying gas flow rate is 8 L / min, and drying temperature is 220°C.

9. The method for detecting 32 pesticides in fresh pepper based on improved rapid filtration purification technology according to claim 1, characterized in that: The 32 kinds of pesticides in step S4 include propamocarb, dinotefuran, thiamethoxam, imidacloprid, clothianidin, dimethoate, dichlorvos, methyl thiophanate, fenthion sulfoxide, fenthion sulfone, metalaxyl, promethazine, flumorph, azoxystrobin, boscalid, malathion, dimethomorph, cyproconazole, triadimefon, myclobutanil, chlorfenapyr, triazophos, triadimenol, flusilazole, idemeton-methyl, kresoxim-methyl, tebuconazole, phoxim, cadusafosfo, indoxacarb, chlorpyrifos, and pyraclostrobin.

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