Solid phase microextraction head for detecting pyrethroid pesticide residues and preparation and use method thereof
A solid-phase microextraction head, prepared by electrochemical polymerization on the surface of stainless steel wire, solves the problem of cumbersome sample pretreatment in the detection of pyrethroid pesticide residues, and achieves efficient detection of pyrethroid pesticide residues in fruits and vegetables with high recovery rate and good linearity.
Patent Information
- Application Number
- CN202611552136.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-10-09
- Publication Date
- 2026-11-06
AI Technical Summary
Existing methods for detecting pyrethroid pesticide residues involve cumbersome and time-consuming sample pretreatment, and lack simple and efficient detection methods.
Stainless steel wire was used as the working electrode, platinum wire as the counter electrode, and Ag/AgCl as the reference electrode. An electrolyte was prepared by dissolving 3-amino-9-ethylcarbazole, dopamine hydrochloride, hexafluorophosphate, and 4-butylperchlorate in N,N-dimethylformamide. A solid-phase microextraction head was prepared by electrochemical polymerization on the surface of stainless steel wire using cyclic voltammetry. Hexafluorophosphate affected the electrochemical polymerization process of the comonomer, making the surface of the extraction head rougher and the pores denser.
The method significantly improves the adsorption performance of the coating. When the extraction head is coupled with GC-MS, the residues of pyrethroid pesticides in fruits and vegetables are detected. Under optimized conditions, the spiked recovery rate is between 84% and 109%, with good linearity, and the method is practical.
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Figure CN123046301A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of analytical chemistry technology, specifically relating to a solid-phase microextraction head for detecting pyrethroid pesticide residues and its preparation and usage method. Background Technology
[0002] Pyrethroid pesticides are currently one of the most important pesticide products, used to control various pests and diseases. However, excessive ingestion of their residues by humans can have fatal toxic effects. Therefore, strict regulations are necessary for pyrethroid residues in food. Thus, establishing green and efficient methods for detecting pyrethroid pesticide residues is a research endeavor of great practical significance. Currently, the detection methods for pyrethroid pesticide residues in European and American standards, as well as national and industry standards in various countries, mainly include chromatographic methods such as gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and liquid chromatography-mass spectrometry (HPLC-MS). However, all of these methods inevitably involve cumbersome and time-consuming sample pretreatment. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a solid phase microextraction head with good linear response and simple method for detecting pyrethroid pesticide residues in fruits and vegetables, as well as a method for its preparation and use. This invention also provides a solid-phase microextraction head, its usage method, and its application.
[0004] The technical solution adopted by this invention to solve its technical problem is: A method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues includes the following steps: S1: An electrolyte is prepared by mixing 3-amino-9-ethylcarbazole, dopamine hydrochloride, hexafluorophosphate, 4-butylammonium perchlorate, and N,N-dimethylformamide as solvents. S2: A three-electrode system is formed by using stainless steel wire as the working electrode, platinum wire as the counter electrode, and Ag / AgCl as the reference electrode, and immersing the electrodes in the electrolyte. S3: A solid-phase microextraction head was prepared by cyclic voltammetry with current applied to the electrode.
[0005] Preferably, in the preparation method of the solid-phase microextraction head for detecting pyrethroid pesticide residues of the present invention, the hexafluorophosphate is one or more selected from O-(benzotriazol-1-yl)-N,N,N',N'-di(cyclopentane)onium hexafluorophosphate, 1-hexadecyl-2,3-dimethylimidazolium hexafluorophosphate, benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate, 7-azabenzotriazol-1-yloxy)triphosphine hexafluorophosphate, and 1-(chloro-1-pyrrolylmethylene)pyrrolidineonium hexafluorophosphate.
[0006] Preferably, in the preparation method of the solid-phase microextraction head for detecting pyrethroid pesticide residues of the present invention, the concentration of 3-amino-9-ethylcarbazole in the electrolyte is 0.1-0.2 mol / L; The concentration of dopamine hydrochloride is 0.05-0.08 mol / L; The concentration of the hexafluorophosphate is 6-10 μg / mL; The concentration of the 4-butylperchlorate ammonium is 0.4-0.6 mol / L.
[0007] Preferably, the method for preparing the solid-phase microextraction head for detecting pyrethroid pesticide residues of the present invention involves pretreating the stainless steel wire in step S2. The pretreating method includes the following steps: S21: Take stainless steel wire and polish it. S22: Ultrasonic cleaning of stainless steel wire using nitric acid solution; S23: Ultrasonic cleaning of stainless steel wire is performed using deionized water and ethanol respectively; S24: Dry the stainless steel wire by baking or air drying.
[0008] Preferably, in the preparation method of the solid-phase microextraction head for detecting pyrethroid pesticide residues of the present invention, the potential of the cyclic voltammetry in step S3 is 0~2V, the scanning speed is 100mV / S, and the number of cycles is more than 100.
[0009] Preferably, the method for preparing the solid-phase microextraction head for detecting pyrethroid pesticide residues of the present invention further includes step S4; Step S4: Bake the obtained solid-phase microextraction head at 220-250℃ under an inert gas or nitrogen atmosphere for 60-90 minutes.
[0010] A solid-phase microextraction head for detecting pyrethroid pesticide residues according to the present invention is prepared by the above-described preparation method.
[0011] Preferably, the solid-phase microextraction head of the present invention is used in the detection of pyrethroid pesticide residues in fruits and vegetables.
[0012] The present invention also provides a method for using a solid-phase microextraction head. Using the solid-phase microextraction head described above, the solid-phase microextraction head is placed in a container containing the analyte for headspace extraction. The extraction temperature is 50°C to 70°C; the extraction time is 10 min to 50 min; the stirring rate is 500 r / min to 600 r / min; and the desorption time is more than 6 minutes.
[0013] Preferably, in the method of use of the present invention, the substance to be detected is permethrin, cypermethrin, deltamethrin, or deltamethrin.
[0014] The beneficial effects of this invention are: This invention discloses a method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues. A stainless steel wire is used as the working electrode, a platinum wire as the counter electrode, and Ag / AgCl as the reference electrode. 3-Amino-9-ethylcarbazole, dopamine hydrochloride, hexafluorophosphate, and 4-butylperchlorate are dissolved in N,N-dimethylformamide to prepare an electrolyte. The solid-phase microextraction head is prepared by electrochemical polymerization on the surface of the stainless steel wire using cyclic voltammetry. The introduction of hexafluorophosphate affects the electrochemical polymerization process of the comonomer, making the surface of the extraction head rougher and the pores denser, significantly improving the adsorption performance of the coating. When this extraction head is coupled with GC-MS, headspace extraction detection of permethrin, cypermethrin, deltamethrin, and deltamethrin in fruits and vegetables is performed. Under optimized conditions, the recoveries are between 84% and 109%, with good linearity, indicating the method's practicality. Attached Figure Description
[0015] The technical solution of this application will be further described below with reference to the accompanying drawings and embodiments.
[0016] Figure 1 The CV curve of the solid-phase microextraction head is shown in Comparative Example 1. Figure 2 Comparative Example 3: Solid-phase microextraction head CV curves; Figure 3 The CV curve of the solid-phase microextraction head in Example 1; Figure 4 The CV curve for the solid-phase microextraction head in Example 2; Figure 5 The CV curve for the solid-phase microextraction head in Example 3; Figure 6 The CV curve for the solid-phase microextraction head in Example 5; Figure 7 The CV curve for the solid-phase microextraction head in Example 4; Figure 8 SEM images of solid phase microextraction heads for Comparative Examples 1 and 2 (where A / B are Comparative Example 1 and C / D are Comparative Example 2). Figure 9 SEM images of solid-phase microextraction head for Comparative Example 3 (where A is magnified 2000 times and B is magnified 200 times). Figure 10 SEM images of the solid-phase microextraction head in Example 2 (where A is magnified 2000 times and B is magnified 200 times). Figure 11 The images shown are SEM images of the solid-phase microextraction head in Example 1 (where A is magnified by 2000x and B is magnified by 200x). Figure 12SEM images of the solid-phase microextraction head in Example 4 (where A is magnified 2000 times and B is magnified 200 times). Figure 13 SEM images of the solid-phase microextraction head in Example 5 (where A is magnified 2000 times and B is magnified 200 times). Figure 14 SEM images of the solid-phase microextraction head in Example 3 (where A is magnified 2000 times and B is magnified 200 times). Figure 15 The curve showing the effect of extraction temperature on peak area; Figure 16 The curve showing the effect of extraction time on peak area; Figure 17 The curve showing the effect of stirring rate on peak area; Figure 18 The curve showing the effect of desorption time on peak area; Figure 19 This is a linear relationship curve between pyrethroid concentration and peak area; Figure 20 The chromatogram of the cabbage sample; Figure 21 Chromatogram of a spiked cabbage sample; Figure 22 Linear correlation diagram for the recovery of tagged cabbage; Figure 23 Chromatogram of a peach sample; Figure 24 Chromatogram of a spiked peach sample; Figure 25 Linear correlation plot for the recovery of tagged peaches. Detailed Implementation
[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.
[0018] Treatment of substrate materials: Use a 1.8 cm long, 0.25 mm diameter stainless steel wire as the base material. First, accurately measure and cut the required length of stainless steel wire using a ruler. Then, repeatedly polish the stainless steel wire on a smooth table until its surface is smooth and straight. Place the polished stainless steel wire in a 25 ml glass beaker and add a 1:1 volume ratio of nitric acid and deionized water for immersion treatment to initially remove the oxide layer and oil stains on the surface of the stainless steel wire. Then, place the beaker in an ultrasonic cleaner and ultrasonically treat it for 5 minutes at room temperature to further remove tiny impurities on the surface of the stainless steel wire. After ultrasonic treatment, rinse twice with deionized water to remove residual acid, and then rinse twice with anhydrous ethanol to remove moisture and organic impurities. Finally, place the stainless steel wire in an electric heating drying oven and dry it at 80 degrees Celsius for 30 minutes. Remove it for later use, or allow it to air dry naturally.
[0019] Examples 1-7 This embodiment provides a method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues, comprising the following steps: S1: An electrolyte was prepared by mixing 3-amino-9-ethylcarbazole, dopamine hydrochloride, hexafluorophosphate, 4-butylammonium perchlorate, and N,N-dimethylformamide as solvents; (see Table 1 for specific hexafluorophosphate substances and concentrations). S2: A three-electrode system is formed by using stainless steel wire as the working electrode, platinum wire as the counter electrode, and Ag / AgCl as the reference electrode, and immersing the electrodes in the electrolyte. S3: A solid-phase microextraction head was prepared by cyclic voltammetry with current applied to the electrode.
[0020] Comparative Example 1 and Comparative Example 2 This embodiment provides a method for preparing a solid-phase microextraction head, including the following steps: S1: Prepare an electrolyte solution by mixing 3-amino-9-ethylcarbazole and 4-butylammonium perchlorate as electrolytes; (see Table 1 for specific substance concentrations, and N,N-dimethylformamide as solvent). S2: A three-electrode system is formed by using stainless steel wire as the working electrode, platinum wire as the counter electrode, and Ag / AgCl as the reference electrode, and immersing the electrodes in the electrolyte. S3: A solid-phase microextraction head was prepared by cyclic voltammetry with current applied to the electrode.
[0021] Comparative Example 3 This embodiment provides a method for preparing a solid-phase microextraction head, including the following steps: S1: An electrolyte solution was prepared using 3-amino-9-ethylcarbazole, dopamine hydrochloride, and 4-butylperchlorate as electrolytes; the specific concentrations of the substances are shown in Table 1, and the solvent was N,N-dimethylformamide. S2: A three-electrode system is formed by using stainless steel wire as the working electrode, platinum wire as the counter electrode, and Ag / AgCl as the reference electrode, and immersing the electrodes in the electrolyte. S3: A solid-phase microextraction head was prepared by cyclic voltammetry with current applied to the electrode.
[0022] Table 1: Substances and Concentrations in Examples and Comparative Examples
[0023] Example 1 Cyclic voltammetry (CV) curves were analyzed using Examples 1-5 and Comparative Examples 1 and 3, and the results were obtained respectively. Figures 1-7 ,in Figure 1 This is the cyclic voltammetry (CV) curve of the solid-phase microextraction head in Comparative Example 1. Figure 2 The figure shows the cyclic voltammetry (CV) curves of the solid-phase microextraction head in Comparative Example 3. Figure 3 The image shows the cyclic voltammetry (CV) curve of the solid-phase microextraction head in Example 1. Figure 4 This is the cyclic voltammetry (CV) curve of the solid-phase microextraction head in Example 2. Figure 5 The image shows the cyclic voltammetry (CV) curve of the solid-phase microextraction head in Example 3. Figure 6 The image shows the cyclic voltammetry (CV) curve of the solid-phase microextraction head in Example 5. Figure 7 The image shows the cyclic voltammetry (CV) curves of the solid-phase microextraction head from Example 4. The solid-phase microextraction heads prepared in Examples 1-5 and Comparative Examples 1 and 3 were observed under a scanning electron microscope (SEM) to examine their microstructure.
[0024] from Figure 1 It can be seen that two distinct oxidation peaks appear at 0.80 V and 1.75 V. Both the peak current and oxidation potential decrease with increasing scan number, which is related to the gradual decrease in the conductivity of the coating. At the same time, a thin coating can be observed on the surface of the steel wire. Figure 2 CV curve and Figure 1 The curves are similar. Figure 3-6 and Figure 1 In comparison, they are largely similar, but the oxidation peak potential at 0.8V is earlier, indicating that the hexafluorophosphate ionic liquid affects the electrochemical polymerization. Figure 7 The results show that oxidation begins at 0.3 V and a significant oxidation peak appears at 1.0 V, indicating that 7-azabenzotriazol-1-yloxo)tris(trimethylazol)phosphine hexafluorophosphate has a greater impact on the electrochemical polymerization of the comonomer than other hexafluorophosphates.
[0025] Figure 8These are scanning electron microscope (SEM) images of the solid-phase microextraction heads obtained in Comparative Examples 1 and 2, where A and B are images of Comparative Example 1, and C and D are images of Comparative Example 2. The images show that the surface of the solid-phase microextraction head is rough, with an undulating, wrinkled structure and numerous uniformly distributed micropores. In the low-magnification SEM images, polymerization is observed to grow horizontally towards the steel wire, exhibiting a grooved pattern. Images C and D indicate that increasing the concentration of 3-amino-9-ethylcarbazole to 0.2 mol / L... -1 At that time, the undulating and wrinkled structure became more obvious, the number of surface pores increased, and the surface small particle structure was clearly visible when observed at low magnification.
[0026] Figure 9 The image shows a scanning electron microscope (SEM) image of the solid-phase microextraction head obtained in Comparative Example 3. The image shows reduced wrinkles, but the pore size on its surface is larger, which can be clearly observed even in low-magnification images. The surface of the solid-phase microextraction head has many pores, but the pores are unevenly distributed and relatively dense. The entire coating is novel, and the coating can be well adsorbed on the surface of the stainless steel wire. The coating is dense and has a rough surface.
[0027] Figure 10 The image shows a scanning electron microscope image of the solid-phase microextraction head obtained in Example 2. It can be seen that there is a porous structure on the surface, but the number of pores is significantly reduced and the surface is more compact.
[0028] Figure 11 The image is a scanning electron microscope image of the solid-phase microextraction head obtained in Example 1. It can be seen that the surface has cracks and still has a porous structure.
[0029] Figure 12 The image shows a scanning electron microscope image of the solid-phase microextraction head obtained in Example 4. It can be seen that there are some small pores on the surface, the surface is dense, and a rougher structure can be observed at low magnification.
[0030] Figure 13 The image shows a scanning electron microscope image of the solid-phase microextraction head obtained in Example 5, which shows cracks and small pores on the surface.
[0031] Figure 14 The image is a scanning electron microscope image of the solid-phase microextraction head obtained in Example 3. A film-like substance can be seen on the surface, and there are still many small pores. The coating surface is rough.
[0032] Figures 10 to 14 This indicates that the addition of hexafluorophosphate makes the surface of the solid-phase microextraction head rougher and the pores denser.
[0033] Example 2 The solid-phase microextraction heads prepared in Examples 1-5 were aged and subjected to headspace extraction.
[0034] The aging processes for Examples 1, 4, and 5 are as follows: The aging process is as follows, divided into three stages: The process begins at room temperature, then increases to 90°C and holds for 30 minutes, then increases to 180°C and holds for 30 minutes, and finally increases to 230°C and holds for 60 minutes. The entire process is carried out in an inert gas (such as argon) or nitrogen atmosphere.
[0035] The aging process in Example 2 is as follows: The aging process is as follows, divided into three stages: The process begins by heating from room temperature to 90°C and holding for 20 minutes, then increasing the temperature to 180°C and holding for 20 minutes, and finally increasing the temperature to 250°C and holding for 40 minutes. The entire process is carried out in an inert gas (such as argon) or nitrogen atmosphere.
[0036] The aging process in Example 3 is as follows: The aging process is as follows, divided into three stages: The process begins at room temperature, then increases to 90°C and holds for 30 minutes, then increases to 180°C and holds for 30 minutes, and finally increases to 220°C and holds for 80 minutes. The entire process is carried out in an inert gas (such as argon) or nitrogen atmosphere.
[0037] The preparation method of the detection solution is as follows: Four types of pyrethroids (permethrin, cypermethrin, fenvalerate, and deltamethrin) were prepared into solutions of 100 ng / mL, 500 ng / mL, 750 ng / mL, 1000 ng / mL, and 3000 ng / mL, respectively, using acetone.
[0038] The solid-phase microextraction head prepared in Example 5 was used to perform headspace extraction on 100 ng / mL of permethrin.
[0039] Add 10 mL of saturated sodium chloride solution to a 15 mL headspace extraction flask. Add the detection solution and solid-phase microextraction head to the headspace extraction flask. Seal the headspace extraction flask and heat it in a water bath to the extraction temperature while stirring to carry out the extraction. After the extraction time is reached, use GC-MS for sample injection, desorption, and separation analysis.
[0040] The headspace extraction method was as follows: extraction temperature was 30℃, 40℃, 50℃, 60℃, and 70℃; extraction time was 10 min, 20 min, 30 min, 40 min, and 50 min; stirring rate was 200 r / min, 300 r / min, 400 r / min, 500 r / min, and 600 r / min; and desorption time was 2 min, 3 min, 4 min, 5 min, and 6 min.
[0041] Figure 15The curve shows the peak area variation when the extraction temperature ranges from 30 ℃ to 70 ℃. The peak area reaches its maximum at 50 ℃, therefore, this temperature is the optimal temperature.
[0042] Figure 16 The curves show the peak area changes when the extraction time is between 10 min and 50 min. It can be seen that the peak areas of the four substances are larger at an extraction time of 30 min than at other extraction times, indicating that the extraction effect is the best at this time.
[0043] Figure 17 The curves show the peak area variation when the stirring rate is between 200 r / min and 600 r / min. It can be seen that the peak area reaches its maximum value at a stirring rate of 600 r / min, indicating that the extraction effect is best at this speed.
[0044] Figure 18 The curves show the peak area changes when the desorption time is between 2 min and 6 min. This indicates that a desorption time of 6 min or longer is more suitable.
[0045] Figure 19 The analysis was performed on pyrethroids with concentrations ranging from 100 to 3000 ng / mL. It can be seen that the peak area increases with increasing concentration and has a good linear correlation, indicating that this method has reference value.
[0046] Example 3 The solid-phase microextraction head prepared in Example 5 was coupled with GC-MS to detect permethrin, cypermethrin, deltamethrin, and deltamethrin in fresh Chinese cabbage and peaches. The results showed that all four pyrethroids were successfully detected. The spiked concentrations of Chinese cabbage were 500 ng / mL, 1000 ng / mL, and 3000 ng / mL, and all four target analytes were detected in the spiked Chinese cabbage samples. The chromatograms of the Chinese cabbage are shown below. Figure 20 The chromatogram of spiked cabbage is as follows: Figure 21 As the spiked concentration increased, the peak areas of the four target analytes also increased, indicating that this method can be used for the detection of permethrin, cypermethrin, deltamethrin, and deltamethrin in fruits and vegetables. Figure 22 The spiked recoveries of the samples showed good linear correlation. Table 2 shows that the recoveries of the spiked samples from Chinese cabbage ranged from 89% to 104%, indicating the practicality of this method. The chromatogram of peaches is shown below. Figure 23 The chromatogram of spiked peaches is as follows: Figure 24 As the spiked concentration increased, the peak areas of the extraction head for the four target analytes continuously increased, indicating that this method can be used for the detection of permethrin, cypermethrin, deltamethrin, and deltamethrin in fruits and vegetables. Figure 25As shown in Table 3, the spiked recovery of the samples exhibited a good linear correlation. The spiked recovery rate of peaches ranged from 84% to 109%, indicating that this method is practical.
[0047] Spiked recovery experiments were conducted on cabbage and peaches, and the following results were obtained: Table 2 Results of the spiked recovery experiment of Chinese cabbage
[0048] Table 3 Results of Peaches Spiced Recovery
[0049] The main instruments and models used in this application, and the main sources of reagents, are as follows: Table 4. Main Instruments and Models
[0050] Table 5 Main Reagent Sources
[0051] Table 6. GC conditions for pyrethroids
[0052] MS conditions: Ion source (EI) temperature 230 ℃; interface temperature 260 ℃.
[0053] Based on the above-described preferred embodiments according to this application, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues, characterized in that, Includes the following steps: S1: An electrolyte is prepared by mixing 3-amino-9-ethylcarbazole, dopamine hydrochloride, hexafluorophosphate, 4-butylammonium perchlorate, and N,N-dimethylformamide as solvents. S2: A three-electrode system is formed by using stainless steel wire as the working electrode, platinum wire as the counter electrode, and Ag / AgCl as the reference electrode, and immersing the electrodes in the electrolyte. S3: A solid-phase microextraction head was prepared by cyclic voltammetry with current applied to the electrode.
2. The method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues according to claim 1, characterized in that, The hexafluorophosphate is one or more of the following: O-(benzotriazol-1-yl)-N,N,N',N'-di(cyclopentane)onium hexafluorophosphate, 1-hexadecyl-2,3-dimethylimidazolium hexafluorophosphate, benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate, 7-azabenzotriazol-1-yloxy)tris(trimethylazol)phosphine hexafluorophosphate, and 1-(chloro-1-pyrrolylmethylene)pyrrolidineonium hexafluorophosphate.
3. The method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues according to claim 1, characterized in that, The concentration of 3-amino-9-ethylcarbazole in the electrolyte is 0.1-0.2 mol / L; The concentration of dopamine hydrochloride is 0.05-0.08 mol / L; The concentration of the hexafluorophosphate is 6-10 μg / mL; The concentration of the 4-butylperchlorate ammonium is 0.4-0.6 mol / L.
4. The method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues according to any one of claims 1-3, characterized in that, The stainless steel wire described in step S2 is pretreated by means of the following steps: S21: Take stainless steel wire and polish it. S22: Ultrasonic cleaning of stainless steel wire using nitric acid solution; S23: Ultrasonic cleaning of stainless steel wire is performed using deionized water and ethanol respectively; S24: Dry the stainless steel wire by baking or air drying.
5. The method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues according to any one of claims 1-3, characterized in that, In step S3, the cyclic voltammetry method has a potential of 0 to 2 V, a scan rate of 100 mV / s, and a cycle count of more than 100.
6. The method for preparing a solid-phase microextraction head for detecting pyrethroid pesticide residues according to any one of claims 1-3, characterized in that, It also includes step S4; Step S4: Bake the obtained solid-phase microextraction head at 220-250℃ under an inert gas or nitrogen atmosphere for 60-90 minutes.
7. A solid-phase microextraction head for detecting pyrethroid pesticide residues, characterized in that, It is prepared by the preparation method of any one of claims 1-6.
8. The application of the solid-phase microextraction head according to claim 7 in the detection of pyrethroid pesticide residues in fruits and vegetables.
9. A method of using a solid-phase microextraction head, characterized in that, Using the solid-phase microextraction head as described in claim 7, the solid-phase microextraction head is placed in a container containing the analyte for headspace extraction. The extraction temperature is 50°C to 70°C; the extraction time is 10 min to 50 min; the stirring rate is 500 r / min to 600 r / min; and the desorption time is more than 6 minutes.
10. The method of use according to claim 9, characterized in that, The substance to be detected is permethrin, cypermethrin, fenvalerate, or deltamethrin.