Method for detecting pesticide residues on leaf surfaces of crops in situ

Abstract

The invention provides a method for in-situ detection of pesticide residues on crop leaf surfaces, which comprises the following steps: randomly taking fresh crop leaf surfaces, spraying pesticides with different gradient concentrations on the crop leaf surfaces, and drying to obtain a series of pesticide residue leaf surfaces detected by an XPS spectrometer with gradient concentrations; establishing and obtaining a standard curve of the relationship between the leaf surface pesticide residue concentration and the XPS characteristic element peak intensity; the method comprises the following steps: performing element qualitative analysis on the surface of a pesticide sample through an XPS technology, and judging the type and residue condition of the pesticide by detecting whether specific elements exist in the sample or not; or the surface of the pesticide sample is detected through the XPS technology, and quantitative analysis is carried out through the standard curve. After the pesticide residue leaf surface is prepared, the qualitative and in-situ detection characteristics of the XPS are utilized, so that the residual condition of the pesticide in the environment can be conveniently, quickly and accurately represented.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide residue detection, and in particular to a method for in-situ detection of pesticide residues on crop leaves. Background Art

[0002] In modern agriculture, pesticides play an important role in preventing and controlling pests, weeds and increasing crop yields. However, in the actual application of pesticides, more than 90% of pesticides are ineffective against target crops and will be lost through volatilization, spray drift, photolysis, leaf sliding, rain leaching, etc. At the same time, excessive and irrational use of these pesticides will seriously affect food safety and the development of drug resistance in target organisms. All these problems will gradually lead to ecosystem destruction and environmental pollution, and ultimately threaten human health. Therefore, how to achieve rapid, sensitive, and in-situ detection of pesticide residues in the environment is an important and urgent scientific issue.

[0003] XPS is a surface analysis method that measures the energy carried by the inner electrons of the atoms on the surface of the material when they escape under X-ray irradiation, obtains information such as the composition, chemical state and electronic structure of the elements on the surface of the material, and realizes in-situ and non-destructive characterization analysis of the chemical composition of the sample surface. The existing technology directly uses XPS spectrometers to detect pesticide residues on leaves, but has the disadvantages of low sample signals and poor linear correlation between qualitative and quantitative analysis, which limits the application of XPS spectroscopy technology in the detection of environmental pesticide residues.

[0004] Therefore, it is necessary to provide a method for preparing foliar pesticide residues with a simple and efficient qualitative and quantitative analysis with high linear correlation. Summary of the invention

[0005] The purpose of the present invention is to provide a method for in-situ detection of pesticide residues on crop leaves, to use XPS technology to perform in-situ characterization of pesticide residues on crop leaves, to study the residual amount and distribution of pesticides on the crop surface, and to provide a basis for the rationality and safety assessment of pesticide use, which is of great significance for ensuring food safety and environmental quality.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] The present invention provides a method for in-situ detection of pesticide residues on crop leaves, the method comprising:

[0008] Randomly select fresh crop leaves, spray pesticides with different gradient concentrations on the crop leaves, and after drying, obtain a series of gradient concentrations of pesticide residue leaves detected by XPS spectrometer;

[0009] Establish and obtain the standard curve between the concentration of pesticide residues on leaves and the peak intensity of XPS characteristic elements;

[0010] The XPS technique is used to perform qualitative element analysis on the surface of pesticide samples, and the type and residue of pesticides are determined by detecting the presence or absence of specific elements in the samples; or the XPS technique is used to detect the surface of pesticide samples, and quantitative analysis is performed using the standard curve.

[0011] Furthermore, the crop foliage includes wheat or soybean foliage.

[0012] Furthermore, the pesticide is selected from one of tebuconazole (TEB) and fluorophenyletheramide (FB).

[0013] Furthermore, the different gradient concentrations include 10 -5 M, 5×10 -5 M, 10 -4 M, 5×10 -4 M, 10 -3 M, 2×10 - 3 M.

[0014] Furthermore, the drying specifically includes:

[0015] Dry in a vacuum oven at 34°C-36°C for 7-9 hours, and then dry in a freeze dryer for 7-9 hours.

[0016] Furthermore, when the crop leaf surface is wheat and the pesticide deposited on the leaf surface is fluphenazine, the standard curve of the relationship between the leaf pesticide residue concentration and the XPS characteristic element peak intensity is y1=0.923x1+0.131, wherein x1 is the concentration of fluphenazine pesticide on the wheat leaf surface in mM, and y1 is the XPS characteristic element peak intensity.

[0017] Furthermore, when the crop leaf surface is soybean and the pesticide deposited on the leaf surface is fluorophenyletheramide, the standard curve of the relationship between the leaf pesticide residue concentration and the XPS characteristic element peak intensity is y2=0.831x2+0.154, wherein x2 is the concentration of fluorophenyletheramide pesticide on the soybean leaf surface in mM, and y2 is the XPS characteristic element peak intensity.

[0018] Furthermore, when the crop leaf surface is wheat and the pesticide deposited on the leaf surface is tebuconazole, the standard curve of the relationship between the leaf pesticide residue concentration and the XPS characteristic element peak intensity is y1=0.335x1+0.306, wherein x1 is the concentration of tebuconazole pesticide on the wheat leaf surface in mM, and y1 is the XPS characteristic element peak intensity.

[0019] Furthermore, when the crop leaf surface is soybean and the pesticide deposited on the leaf surface is tebuconazole, the standard curve of the relationship between the leaf surface pesticide residue concentration and the XPS characteristic element peak intensity is y2=0.306x2+0.263, wherein x2 is the concentration of tebuconazole pesticide on the soybean leaf surface in mM, and y2 is the XPS characteristic element peak intensity.

[0020] Furthermore, the method also includes: using XPS spectroscopy to perform in-situ qualitative and quantitative analysis of pesticide residues in different parts of the leaf surface, and evaluating the residual amount, distribution, and penetration of pesticide residues on the leaf surface.

[0021] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0022] 1. The present invention provides a method for in-situ detection of pesticide residues on crop leaves. After preparing the pesticide residue leaves, the qualitative and in-situ detection characteristics of XPS are used to conveniently, quickly and accurately characterize the residual situation of such pesticides in the environment. The existing technology overcomes the shortcomings of low sample signal and poor linear correlation between qualitative and quantitative analysis in directly using XPS spectrometer to detect pesticide residue leaves.

[0023] 2. The present invention provides a method for in-situ detection of pesticide residues on crop leaves, which is simple, efficient, and has the characteristics of high sensitivity and high resolution. It can realize trace detection of pesticide residues, understand the residual amount and distribution of pesticides on the surface of crops, and provide a basis for the rationality of pesticide use and safety evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of using XPS spectroscopy technology to detect pesticide residues on leaves in situ.

[0026] Figure 2 XPS spectroscopy is used to quantitatively detect the different concentrations of fluorophenyletheramide pesticide residues on wheat leaves. 2(a) is the molecular structure of fluorophenyletheramide. Figure 2 (b) is a schematic diagram of wheat leaf surface. Figure 2 (c) is the XPS data of fluorophenyletheramide, wheat leaf surface, and fluorophenyletheramide (1 mM) on wheat leaf surface. Figure 2 (d) XPS fine spectrum of the characteristic fluorine element of fluorophenyl ether amide deposited on wheat.

[0027] Figure 3XPS spectroscopy is used to quantitatively detect the different concentrations of fluorophenyletheramide pesticide residues on soybean leaves. 3(a) is the molecular structure of fluorophenyletheramide. Figure 3 (b) is a schematic diagram of soybean leaf surface. Figure 1 (c) is the XPS data of fluorophenyletheramide, wheat leaf surface, and fluorophenyletheramide (1 mM) on soybean leaf surface. Figure 3 (d) Figure 3 (d) XPS fine spectrum of the characteristic fluorine element of fluorophenyl ether amide deposited on soybean.

[0028] Figure 4 This is the XPS standard curve after different concentrations of fluorophenyletheramide pesticides are deposited on the crop leaves. Figure 4 (a) XPS standard curve of different concentrations of fluorophenyletheramide pesticides deposited on wheat leaves. Figure 4 (b) XPS standard curves of different concentrations of fluorophenyletheramide pesticides after deposition on soybean leaves.

[0029] Figure 5 The XPS spectrum is used to qualitatively determine the concentrations of fluorophenyl ether amide pesticide residues in different parts of soybeans. Figure 5 (a) XPS spectrometer detects the concentration of fluorophenyletheramide in different parts of soybean leaves. Figure 5 (b) XPS spectrometer detection of the concentration of fluorophenyl ether amide in different parts of soybean roots.

[0030] Figure 6 The XPS spectrum is used to qualitatively determine the concentrations of fluorophenyl ether amide pesticide residues in different parts of wheat. Figure 6 (a) XPS spectrometer detects the concentration of fluorophenyletheramide in different parts of wheat leaves. Figure 6 (b) XPS spectrometer detection of the concentration of fluorophenyletheramide in different parts of wheat roots.

[0031] Figure 7 The XPS spectrum is used to quantitatively detect the different concentrations of tebuconazole pesticide residues on wheat leaves. 7(a) is the molecular structure of fluorophenyletheramide and a schematic diagram of wheat leaves. Figure 7 (b) is the XPS data of fluorophenyletheramide, wheat leaf surface, and fluorophenyletheramide (1 mM) on wheat leaf surface. Figure 7 (c) XPS fine spectrum of characteristic fluorine element of fluorophenyl ether amide deposited on wheat. Figure 7 (d) is the XPS standard curve of different concentrations of tebuconazole pesticide deposited on wheat leaves.

[0032] Figure 8 The XPS spectrum is used to quantitatively detect the different concentrations of tebuconazole pesticide residues on wheat leaves. 8(a) is the molecular structure of fluorophenyletheramide and a schematic diagram of soybean leaves. Figure 8(b) is the XPS data of fluorophenyletheramide, soybean leaf surface, and fluorophenyletheramide (1 mM) on wheat leaf surface. Figure 8 (c) XPS fine spectrum of the characteristic fluorine element of fluorophenyl ether amide deposited on soybean. Figure 8 (d) is the XPS standard curve of different concentrations of tebuconazole pesticide deposited on soybean leaves. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below in conjunction with specific implementations and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific implementations and examples are used to illustrate the present invention, rather than to limit the present invention.

[0034] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In the event of a conflict, the present specification takes precedence.

[0035] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or obtained by existing methods.

[0036] The general idea of ​​the present invention is as follows:

[0037] According to a typical embodiment of the present invention, a method for preparing a leaf surface of pesticide residues detected by an XPS spectrometer is provided, the method comprising:

[0038] Step S1, randomly taking fresh crop leaves, spraying pesticides of different gradient concentrations on the crop leaves, and after drying, obtaining a series of pesticide residue leaves detected by XPS spectrometer with gradient concentrations;

[0039] Step S2, establishing and obtaining a standard curve of the relationship between the concentration of pesticide residues on the leaf surface and the peak intensity of the XPS characteristic elements;

[0040] Step S3, performing elemental qualitative analysis on the surface of the pesticide sample by XPS technology, and judging the type and residue of the pesticide by detecting the presence or absence of specific elements in the sample; or performing quantitative analysis by detecting the surface of the pesticide sample by XPS technology and using the standard curve.

[0041] In step S1, the size of the fresh pesticide residue leaf surface is preferably 2 cm×1 cm.

[0042] The crop foliage includes wheat or soybean foliage.

[0043] The pesticide is selected from one of tebuconazole and fluorophenyl ether amide.

[0044] The different gradient concentrations include 10 -5 M, 5×10 -5 M, 10 -4 M, 5×10 -4 M, 10 -3 M, 2×10 -3 M.

[0045] The drying specifically includes: drying in a vacuum drying oven at 34° C.-36° C. for 7-9 hours, and then drying in a freeze dryer for 7-9 hours.

[0046] Place the pesticide residue leaf surface in a vacuum drying oven at 34°C-36°C (preferably 35°C) and dry it for 7-9 hours (preferably 8 hours), then place the pesticide residue leaf surface in a freeze dryer and dry it for 7-9 hours (preferably 8 hours) to prepare the pesticide residue leaf surface for in-situ detection by XPS spectrometer.

[0047] The reason for drying the leaf surface in a vacuum drying oven at 34℃-36℃ for 7-9h is that this drying temperature and drying time are conducive to the dehydration and drying of the crop leaf surface. If the temperature is higher, the pesticide on the leaf surface will decompose and the leaf surface will become brittle, which is not conducive to sample preparation and analysis. If the temperature is lower, the leaf surface cannot be effectively dehydrated and sample preparation and analysis cannot be performed.

[0048] The reason for freeze drying for 7-9 hours: if the drying time is too short, it is not conducive to the dehydration of the leaf surface and affects the detection signal strength; if the drying time is too long, the leaf surface becomes brittle and cannot be prepared for testing.

[0049] The purpose of the present invention is to provide a new in-situ, rapid, trace detection method for residual pesticides on plant surfaces based on XPS spectrometer. The sensitive, rapid, and non-destructive detection characteristics of XPS technology are used to perform in-situ qualitative and quantitative analysis of residual pesticides (flufenamide and tebuconazole) on the leaves of wheat and soybeans, and establish a new method for detecting residual pesticides on the leaves at different concentrations (10 - 5 M—2×10 -3 M) The mathematical model relationship between the peak intensity of characteristic elements detected by the pesticide and XPS spectrometer can achieve a fast, stable and simple assessment of the concentration of pesticide residues on the leaves. On this basis, the XPS spectrometer technology can be used to perform in-situ qualitative and quantitative detection of pesticide residues in different parts of the crop leaf surface (leaf tip, leaf seed, leaf tail) and different parts of the crop (root, stem, leaf), and evaluate the residual amount and distribution of pesticide residues on the plant leaf surface, providing a basis for the rationality and safety assessment of pesticide use, which is of great significance for ensuring food safety and environmental quality.

[0050] The present application will be described in detail below with reference to embodiments and experimental data.

[0051] Example 1: Preparation of fluorophenyletheramide pesticide residue leaf surface

[0052] 1 mL of different concentrations (10 -5 M—2×10 -3 M) of fluorophenylether amide and tebuconazole pesticide droplets were sprayed on the leaves of wheat and soybean crops respectively. After drying in the shade for 1 day, 2cm×1cm of crop leaves were cut and dried at 35°C for 8h. Then, the crop leaves were attached to a glass slide and freeze-dried for 8h to prepare the leaves to be tested for pesticide residues. Then, the conductive glue was glued to the sample holder, and the electron neutralization gun eliminated the surface charging effect. The surface was etched with chloride ions, and the etching time was 90s each time. XPS scanned the spectrum, peak position fitting, calculated the relative content of the main F1s and Cl2p elements, and analyzed the peak position attribution, such as Figure 1 shown.

[0053] Example 2: In-situ qualitative and quantitative characterization of fluorophenyl ether amide pesticide residues on leaves using XPS technology

[0054] The concentrations were 10 -5 M, 5×10 -5 M, 1×10 -4 M, 5×10 -4 M, 1×10 -3 and 2×10 -3 M fluorophenyl ether amide pesticide, spray 1mL of different concentrations of the above pesticide on the leaves of wheat and soybeans, dry in the shade, take samples and place them between glass slides and put them in a constant temperature oven at 35℃ to form flat samples to be tested, take samples from the epidermis, make slices with a thickness of 0.5mm and a diameter of >5mm, place them between glass slides, put them in a constant temperature oven at 35℃ to dry, stick them to the sample holder with conductive glue, and use an electron neutralization gun to eliminate the surface charging effect. Then use an XPS spectrometer to scan the C, N, O, and F elements of fluorophenyl ether amide on the leaves of wheat and soybeans, and analyze the relative element ratio of F1s. Figure 2 As shown in the figure, the characteristic peak of the characteristic F1s element of fluorophenyletheramide pesticide at 687eV can be accurately detected on the wheat leaf surface by XPS spectroscopy technology, proving the existence of fluorophenyletheramide pesticide. The F element detection content of 1mM fluorophenyletheramide pesticide on the wheat leaf surface is as high as 1.1wt%. Similarly, we also use XPS technology to perform in-situ detection of fluorophenyletheramide pesticide on soybean leaves, and can also accurately and quickly quantitatively and qualitatively detect the characteristic F1s element peak and element content of fluorophenyletheramide ( Figure 3 ).

[0055] Example 3: Quantitative detection of different concentrations of fluorophenyl ether amide residues on leaves by XPS technology

[0056] The concentrations were 10 -5 M, 5×10 -5 M, 1×10-4 M, 5×10 -4 M, 1×10 -3 and 2×10 -3 M fluorophenyl ether amide pesticide, spray 1mL of the above pesticides at different concentrations on the leaves of wheat and soybeans, dry in the shade, take samples and place them between glass slides and put them in a constant temperature oven at 35℃ to form flat samples to be tested, take samples from the epidermis, make slices with a thickness of 0.5mm and a diameter of >5mm, place them between glass slides, put them in a constant temperature oven at 35℃ to dry, and stick them on the sample holder with conductive glue. XPS spectrometer detects the leaves containing different concentrations of fluorophenyl ether amide online, and analyzes the relative content of F1s elements on the leaves containing different concentrations of fluorophenyl ether amide. Finally, draw the correlation curve between the concentration and the content of F1s detected by XPS spectrum, perform linear fitting, and establish the mathematical model relationship between the peak intensity of F1s elements detected by XPS spectrometer and different concentrations of fluorophenyl ether amide on wheat leaves. The fitting equation has a good correlation ( Figure 4 ). Similarly, the same method can be used to quantitatively detect different concentrations of fluorophenyletheramide on soybean leaves using XPS spectroscopy technology, and a fitting curve between concentration and XPS detection element F1s can be drawn to evaluate the pesticide residue on the leaves. The above results show that XPS spectroscopy technology has high sensitivity and high detection accuracy for quantitative detection of fluorophenyletheramide pesticides on leaves.

[0057] Example 4: Detection of pesticide residues in different parts of crops using XPS technology

[0058] Fluorophenyletheramide pesticide was prepared with a concentration of 1mM and sprayed on the leaves of wheat and soybeans. After one week, samples were taken from various parts of the wheat and soybeans to prepare XPS spectrum test samples. XPS spectrometer technology was used to conduct in situ qualitative and quantitative detection of pesticide residues in different parts of the crop leaf surfaces (leaf tip, leaf middle, leaf tail) and different parts of the crops (roots, stems, leaves), and evaluate the residue and distribution of fluophenyletheramide pesticide on the plant leaves.

[0059] Table 1-XPS spectrum detection of pesticide residues of fluorophenyletheramide in different roots of wheat

[0060]

[0061] like Figure 5 As shown, the XPS technique was used to conduct in-situ detection of different parts of soybean leaves (leaf tip, leaf middle, and leaf tail) after spraying fluorophenyletheramide, and the characteristic F1s element of fluorophenyletheramide was effectively detected. The F1s content in the leaf tip, leaf middle, and leaf tail was 0.17wt%, 0.18wt%, and 0.24wt%, respectively, indicating that fluorophenyletheramide pesticides were mainly deposited and adsorbed on the tail of soybean leaves. At the same time, the XPS technique was used to characterize the absorption and transport concentration of fluorophenyletheramide in soybeans (roots) ( Figure 7), the results showed that fluorophenyletheramide can be absorbed by soybeans, and the F1s content of fluorophenyletheramide detected in soybean roots reached 0.33wt%, indicating that fluorophenyletheramide pesticides are mainly accumulated in soybean roots. Through XPS technology, we can characterize the residues and distribution of fluorophenyletheramide pesticides in different parts of crops online and in situ, providing a basis for the rationality and safety evaluation of pesticide use.

[0062] Example 5: Application of XPS technology to the detection of other pesticide residues on leaves

[0063] The concentrations were 10 -5 M, 5×10 -5 M, 1×10 -4 M, 5×10 -4 M, 1×10 -3 and 2×10 -3 M tebuconazole pesticide, spray 1mL of different concentrations of the above pesticides on the leaves of wheat and soybeans, dry in the shade, take samples and place them between glass slides and put them in a constant temperature oven at 35℃ to form flat samples to be tested, take samples from the epidermis, make slices with a thickness of 0.5mm and a diameter of >5mm, place them between glass slides, put them in a constant temperature oven at 35℃ to dry, stick them to the sample holder with conductive glue, and use an electron neutralization gun to eliminate the surface charging effect. Then use an XPS spectrometer to scan the C, N, O, and Cl elements of tebuconazole on the leaves of wheat and soybeans, and analyze the relative element ratio of Cl2p. Figure 8 As shown in the figure, the characteristic Cl 2p element peak of tebuconazole pesticide at 200eV can be accurately detected on the wheat leaf surface by XPS spectroscopy technology, proving the presence of tebuconazole pesticide, where the Cl element detection content of 1mM tebuconazole pesticide on the wheat leaf surface is 0.66wt%. Similarly, we also use XPS technology to perform in-situ detection of fluorophenyletheramide pesticide on soybean leaves, and can also accurately and quickly quantitatively and qualitatively detect the characteristic Cl2p element peak and element content of tebuconazole ( Figure 8 ). Finally, we draw the correlation curve between the relative content of Cl 2p detected by XPS spectrum and the leaf surface containing different concentrations of tebuconazole, and establish a mathematical model between different concentrations of fluorophenyletheramide on the wheat leaf surface and the peak intensity of Cl 2p detected by XPS spectrometer. The fitting results have a good linear relationship, indicating that XPS technology has a certain universality for the detection of pesticide residues on the leaf surface. The above experiments show that XPS spectroscopy technology has high sensitivity, high detection accuracy and stable reliability for in-situ quantitative detection of pesticide residues on the leaf surface, and has important application prospects in the field of environmental pesticide residue detection.

[0064] Finally, it should be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements that are inherent to such process, method, article, or apparatus.

[0065] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for in-situ detection of pesticide residues on crop leaves, characterized in that: The method comprises: Randomly select fresh crop leaves, spray pesticides with different gradient concentrations on the crop leaves, and after drying, obtain a series of gradient concentrations of pesticide residue leaves detected by XPS spectrometer; Establish and obtain the standard curve between the concentration of pesticide residues on leaves and the peak intensity of XPS characteristic elements; The XPS technique is used to perform qualitative element analysis on the surface of pesticide samples, and the type and residue of pesticides are determined by detecting the presence or absence of specific elements in the samples; or the XPS technique is used to detect the surface of pesticide samples, and quantitative analysis is performed using the standard curve.

2. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: The crop foliage includes wheat or soybean foliage.

3. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: The pesticide is selected from one of tebuconazole and fluorophenyl ether amide.

4. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: The different gradient concentrations include 10 -5 M, 5×10 -5 M, 10 -4 M, 5×10 -4 M, 10 -3 M, 2×10 -3 M.

5. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: The drying specifically comprises: Dry in a vacuum oven at 34°C-36°C for 7-9 hours, and then dry in a freeze dryer for 7-9 hours.

6. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: When the crop leaf surface is wheat and the pesticide deposited on the leaf surface is fluorophenyletheramide, the standard curve of the relationship between the leaf pesticide residue concentration and the XPS characteristic element peak intensity is y1=0.923x1+0.131, wherein x1 is the concentration of fluorophenyletheramide pesticide on the wheat leaf surface in mM, and y1 is the XPS characteristic element peak intensity.

7. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: When the crop leaf surface is soybean and the pesticide deposited on the leaf surface is fluorophenyletheramide, the standard curve of the relationship between the leaf pesticide residue concentration and the XPS characteristic element peak intensity is y2=0.831x2+0.154, wherein x2 is the concentration of fluorophenyletheramide pesticide on the soybean leaf surface in mM, and y2 is the XPS characteristic element peak intensity.

8. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: When the crop leaf surface is wheat and the pesticide deposited on the leaf surface is tebuconazole, the standard curve of the relationship between the leaf surface pesticide residue concentration and the XPS characteristic element peak intensity is y1=0.335x1+0.306, wherein x1 is the concentration of tebuconazole pesticide on the wheat leaf surface in mM, and y1 is the XPS characteristic element peak intensity.

9. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: When the crop leaf surface is soybean and the pesticide deposited on the leaf surface is tebuconazole, the standard curve of the relationship between the leaf surface pesticide residue concentration and the XPS characteristic element peak intensity is y2=0.306x2+0.263, wherein x2 is the concentration of tebuconazole pesticide on the soybean leaf surface in mM, and y2 is the XPS characteristic element peak intensity.

10. The method for in-situ detection of pesticide residues on crop leaves according to claim 1, characterized in that: The method also includes: using XPS spectroscopy to perform in-situ qualitative and quantitative analysis of pesticide residues on different parts of the leaf surface, and evaluating the residual amount, distribution and penetration of the pesticide residues on the leaf surface.

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