An injection and reaction apparatus for detecting pesticide residues in organic solvent extracts using a liquid-phase enzymatic inhibition method.

Abstract

This invention discloses a sample introduction and reaction device for detecting pesticide residues in organic solvent extracts using a liquid-phase enzyme inhibition method. The device includes a reaction tube and a cap, which are detachably assembled. The cap seals the reaction tube and contains a hollow column. A sample introduction card is sealed inside the hollow column, and the reaction tube contains enzyme reagents. This invention can be used for the liquid-phase enzyme inhibition method to detect pesticide residues extracted from organic solvents, eliminating interference from organic solvents in the enzyme inhibition detection. The device integrates the sample introduction card and enzyme reagents beforehand, sealing the sample introduction card within the hollow column for easy portability. The hollow column also serves as a support for solvent evaporation from the sample introduction card, facilitating rapid solvent evaporation. The cap and tube serve a dual purpose. This invention features a simple structure, ease of use, simple operation, short detection time, and low cost. It is suitable for on-site testing of large quantities of samples during food distribution and is easy to promote and use.

Description

Technical Field

[0001] This utility model belongs to the field of laboratory analytical instruments, specifically relating to an injection and reaction device for detecting pesticide residues in organic solvent extracts using a liquid-phase enzyme inhibition method. Background Technology

[0002] The rapid detection of organophosphorus and carbamate pesticide residues based on cholinesterase inhibition is currently the earliest developed rapid pesticide residue detection method on the market and the most widely used rapid detection method in my country's agricultural product circulation sector. However, due to limitations in the reaction conditions of the enzyme reagents themselves, traditional enzyme inhibition methods mostly use aqueous solutions for sample extraction. Since most pesticides are lipid-soluble, water extraction leads to low extraction rates of the target pesticides and poor reliability of the detection results. According to existing literature, under the extraction conditions of traditional enzyme inhibition methods, the extraction rate of most organophosphorus and carbamate pesticides is less than 50%, seriously affecting the sensitivity and reliability of the detection. Using organic solvents for sample extraction is a direct and effective means to solve this problem.

[0003] However, enzyme reagents are water-soluble. If organic solvents are used to extract samples, the organic solvents can damage the enzyme reagents, making it difficult to directly detect the sample solutions obtained from organic solvent extraction using enzyme inhibition methods. In previous studies, the applicant utilized the rapid self-evaporation of organic solvents on paper surfaces to achieve enzyme inhibition detection of organic solvent samples on microfluidic paper chips and enzyme inhibition rapid test cards. However, both microfluidic paper chips and enzyme inhibition rapid test cards involve solid-phase enzyme inhibition reactions, requiring visual identification and comparison of color changes, allowing only semi-quantitative analysis and making them prone to errors.

[0004] Solution-based methods offer significant advantages over the aforementioned rapid test cards and paper chips (solid-phase enzyme inhibition method) in terms of detection sensitivity and resistance to stray light / color interference, resulting in more reliable detection results, as data can be acquired using spectrophotometers, fluorometers, and other detection equipment. However, in existing technologies, conventional liquid-phase enzyme inhibition methods are difficult to directly detect organic solvent extracts. They generally require complex solvent removal methods and steps (such as rotary evaporation and nitrogen blowing) followed by fixed-volume reconstitution of the sample with aqueous solvents such as buffer solutions before the subsequent enzyme inhibition reaction can proceed. This involves numerous operational steps and high equipment dependence. Furthermore, for small-volume samples, there is very little residue in the tube after solvent removal, and residues can splash and adhere to the tube wall during solvent evaporation. Reconstitution requires ensuring complete dissolution of the substances in the tube, making the actual operation complex and prone to human error. For milliliter-sized samples, solvent evaporation or large-scale sample processing also causes significant environmental pollution. Conversely, not using organic solvents for sample extraction leads to poor pesticide extraction rates, resulting in high false negative rates and unreliable results.

[0005] Therefore, it is necessary to develop new reaction devices and methods to solve the compatibility problem between liquid-phase enzyme inhibition and organic solvent extraction. Utility Model Content

[0006] The purpose of this invention is to provide an injection and reaction device for detecting pesticide residues in organic solvent extracts using a liquid-phase enzyme inhibition method, thereby solving the compatibility problem between liquid-phase enzyme inhibition reactions and organic phase extraction sample pretreatment. This device integrates multiple functions, including chip injection, solvent separation, and enzyme reaction. When used in conjunction with conventional pesticide residue enzyme inhibition solution detection systems, it allows pesticide components in organic solvents to participate in the liquid-phase enzyme inhibition reaction simply, rapidly, and at low cost, enabling rapid screening and detection of target pesticides using this method.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] An injection and reaction apparatus for detecting pesticide residues in organic solvent extracts using a liquid-phase enzyme inhibition method, the apparatus comprising a reaction tube and a cap, the cap and the reaction tube being detachably assembled, the cap sealing the reaction tube, the cap having a hollow column, the hollow column containing a sealed injection card, and the reaction tube containing enzyme reagents.

[0009] Furthermore, the reaction tube is a hollow cavity with one end open, and can be made of materials such as glass, plastic, or quartz. From a cost perspective, a disposable plastic tube is preferred.

[0010] The shape of the tube is similar to that of a conventional centrifuge tube, and can be cylindrical, conical-cylindrical combination, or cuboid, etc. Various tube shapes do not affect the function of this utility model and can all be used in this utility model.

[0011] The reaction tube body and the tube cap are detachable and can be fitted with snap-fit, threaded fit, etc.

[0012] Furthermore, a hollow column extending upward or downward with the end face of the tube cap as its bottom surface is provided on the top or bottom surface of the tube cap. The open end of the hollow column is provided with a sealing film or sealing cap to seal the hollow column.

[0013] Furthermore, the cavity inside the hollow cylinder is equipped with a sample injection card.

[0014] The open end of the hollow column can be sealed with a waterproof sealing membrane or a sealing cap. The sealing cap and the hollow column can be assembled through a snap-fit ​​structure, a threaded structure, etc.

[0015] Furthermore, the sample injection card is a test paper or other porous sheet or plate material that can withstand organic solvents, preferably a test paper material.

[0016] The shape and area of ​​the injection card are not specifically required and can be modified according to experimental needs, but the diameter of the unfolded injection card must be greater than the outer diameter of the hollow column. Before use, the injection card should be folded and sealed inside the hollow column.

[0017] Furthermore, when the reaction tube body and the tube cap are snap-fitted together, the hollow column is positioned below the end face of the tube cap, and the column body can be inserted into the neck opening of the reaction tube body.

[0018] When the reaction tube body and the tube cap are threaded together, the open end of the reaction tube body is provided with an external thread or an internal thread, the tube cap is provided with a corresponding internal thread or an external thread, and the hollow cylinder is set on the top of the end face of the tube cap. After the tube cap and the reaction tube body are assembled, the hollow cylinder is located above the tube cap.

[0019] Furthermore, the hollow cylinder of the tube cap has an upward opening, so when the tube cap is placed on a table, the open end face of the hollow cylinder is parallel to the table, which can be used for a flat-laid sample card.

[0020] The enzyme reagent is a conventional esterase reagent commonly used in the enzyme inhibition method for rapid pesticide detection. The esterase reagent can be acetylcholinesterase, butyrylcholinesterase, phytoesterase, etc., with acetylcholinesterase being preferred. The enzyme reagent is generally a liquid enzyme reagent, prepared in advance with PBS or other types of buffer solutions to a suitable concentration, and then sealed and stored in the reaction tube. Alternatively, the reaction tube may also contain a solid enzyme reagent, used in conjunction with an additional buffer solution. Before use, an appropriate volume of buffer solution is added directly to the reaction tube, and the solid enzyme reagent is thoroughly mixed to obtain a liquid enzyme reagent for later use.

[0021] The sample introduction and reaction apparatus for detecting pesticide residues in organic solvent extracts using liquid-phase enzyme inhibition method can be used for detecting pesticide residues in organic solvent extracts using liquid-phase enzyme inhibition method. The method used is as follows:

[0022] (1) The sample to be tested was extracted with an organic solvent to obtain an extract;

[0023] (2) Remove the tube cap, open the sealing film or sealing cap of the hollow column of the tube cap, take out the injection card, and inject the sample according to one of the following methods:

[0024] (a) Immerse the injection card in the extraction solution, then remove the injection card and place it on the table with the opening of the hollow column of the tube cap facing upwards. Unfold the injection card and lay it flat on the open end face of the hollow column to allow it to evaporate naturally.

[0025] (b) With the hollow cylinder of the tube cap facing upwards, place the tube cap on the table, unfold the injection card and lay it flat on the open end face of the hollow cylinder, add the extract drop onto the injection card, and let it evaporate naturally.

[0026] The natural evaporation generally involves placing the injection card for 3-5 minutes until the organic solvent evaporates completely.

[0027] In method (a), the injection card is immersed in the extraction solution for more than 10 seconds, preferably 10 to 20 seconds.

[0028] (3) After the organic solvent on the injection card evaporates, put the injection card into the reaction tube and immerse it completely in the enzyme reagent. Cover the reaction tube with the tube cap and seal it. Shake the tube to ensure that the injection card is fully immersed. After incubation, perform detection by liquid phase enzyme inhibition method.

[0029] Furthermore, in step (3), the incubation is generally carried out for 5 to 15 minutes.

[0030] The steps of the liquid-phase enzyme inhibition method are generally as follows: open the tube cap, add the enzyme activity probe, incubate for 3-5 minutes, and then use visual method for qualitative or semi-quantitative determination, or use photometric method for quantitative detection of enzyme residual activity data in the reaction solution, and calculate the pesticide content level in the sample to be tested.

[0031] In step (3), if necessary, the reaction tube is inverted and shaken thoroughly so that the injection card is fully immersed in the enzyme reagent.

[0032] The photometric method can be performed using a spectrophotometer or a fluorescence spectrophotometer.

[0033] In step (1), the sample to be tested is extracted with an organic solvent. The main extracts are organophosphorus and carbamate pesticide residues. Since organophosphorus and carbamate pesticides are poorly water-soluble and easily soluble in organic solvents, the extraction rate of the sample is too low when using aqueous solution. Extraction with organic solvent can improve the extraction efficiency and the recovery rate can reach more than 90%, thereby improving the accuracy and reliability of the detection.

[0034] This utility model has the following beneficial effects:

[0035] The sample introduction and reaction device provided by this invention is the first to realize the application of organic solvent sample introduction card in liquid phase enzyme inhibition method, eliminating the interference of organic solvent on enzyme inhibition detection.

[0036] (1) The present invention integrates the injection card and enzyme reagent together in advance. The injection card is sealed in the hollow column with a sealing film or sealing cap, which separates it from the enzyme reagent. This saves reagent storage space and avoids the experimental preparation process being too complicated during rapid detection. The device is easy to carry and suitable for rapid on-site detection.

[0037] (2) The hollow column and internal cavity of the tube cap serve as both a storage space for the injection card and a support for the solvent evaporation of the injection card during application. The hollow column also helps the solvent evaporate quickly. The tube cap has two functions in one, reducing the complexity of the device and making it easy to use.

[0038] (3) Unlike the solvent evaporation-sample reconstitution operation in the traditional liquid-phase enzyme inhibition method, the injection card of this utility model does not require the reconstitution operation after solvent evaporation. After rapid separation in situ, the entire injection card is directly immersed in the enzyme reagent solution. The pesticide components on the injection card do not need to undergo additional elution operations and directly participate in the enzyme inhibition reaction. The solution after the reaction is detected by conventional spectrophotometer, fluorescence spectrophotometer and other methods. At this time, the injection card can remain in the reaction tube without additional separation and removal of the injection card, which is simple to operate.

[0039] This invention creatively combines an organic solvent injection card with a liquid-phase enzyme inhibition method, integrating the injection and reaction functions into one device. It can assist in the direct detection of organophosphorus and carbamate pesticide residues in organic solvents, meeting the dual requirements of combining sample organic phase pretreatment with enzyme inhibition and zero contact between organic solvents and the liquid-phase detection system. Moreover, it greatly simplifies the steps of sample enzyme reagent preparation and quantitative liquid extraction in traditional methods, improving the detection efficiency of actual samples.

[0040] This utility model is reasonably designed, with a flexible and simple structure, low manufacturing difficulty and low cost, making it suitable for large-scale mass production. It is easy to use and operate, with short detection time and low cost, and can be applied to the on-site detection of large batches of samples in the food circulation process. The application of this utility model to detect pesticide residues has high sensitivity, high efficiency and high accuracy, and has great value for promotion and application. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the overall structure of the sample introduction and reaction device in Example 1.

[0042] Figure 2 This is an exploded view of the sample introduction and reaction device structure in Example 1.

[0043] Figure 3 This is a flowchart of the sample introduction and reaction device of this utility model for rapid detection of pesticide residues extracted by organic solvents.

[0044] Figure 4 This is a working curve diagram of the detection of different pesticides in organic solvents using this device.

[0045] Figure 1 , 2 In the middle, 1-reaction tube body; 2-tube cap; 21-end face; 22-hollow cylinder; 23-sealing membrane; 3-sample injection card. Detailed Implementation

[0046] The multifunctional chip of this utility model will be further described below with reference to specific embodiments and accompanying drawings, but the scope of protection of this utility model is not limited thereto.

[0047] Example 1

[0048] A schematic diagram of the overall structure of an injection and reaction apparatus for detecting pesticide residues in organic solvent extracts using a liquid-phase enzyme inhibition method is shown below. Figure 1 As shown in the diagram, the exploded structure is as follows: Figure 2 As shown.

[0049] The device includes a reaction tube body 1 and a cap 2. The cap 2 and the reaction tube body 1 are detachably assembled. The cap 2 seals the reaction tube body 1. The cap 2 has a hollow column 22. The hollow column 22 has a cavity inside and is sealed with a sample injection card 3. The reaction tube body 1 contains enzyme reagents (not shown in the figure).

[0050] The reaction tube 1 is a hollow cavity with one end open. It can be made of materials such as glass, plastic, or quartz. From a cost perspective, a disposable plastic tube is preferred.

[0051] In a preferred embodiment, the volume of reaction tube 1 is 1-2 mL, and the shape of the tube is similar to that of a conventional centrifuge tube, and can be cylindrical, conical-cylindrical combination, or cuboid, etc. Figure 1 As shown, it is a combination of a cone and a cylinder.

[0052] The reaction tube body 1 and the tube cap 2 are detachable and can be fitted with snap-fit, threaded fit, etc.

[0053] Furthermore, a hollow column 22 is provided on the top or bottom of the end face 21 of the tube cap 2, extending upward or downward with the end face 21 of the tube cap 2 as the bottom surface. The open end of the hollow column 22 is provided with a sealing film 23 or a sealing cap to seal the hollow column 22.

[0054] In a preferred embodiment, such as Figure 1 As shown, the reaction tube 1 and the cap 2 are snap-fitted together. There are multiple ways to achieve the snap-fitting. In a preferred embodiment, the reaction tube 1 has a radially outward protruding step on its outer circumferential surface near the opening end, and the cap 2 has a downwardly extending skirt on the outer edge of the lower surface of the end face. The step and the skirt are interference-fitted to achieve the snap-fitting seal.

[0055] And, as Figure 1 , 2As shown, when the reaction tube 1 and the cap 2 are snap-fitted together, the hollow column 22 is located below the end face 21 of the cap 2, and the column body can be inserted into the neck opening of the reaction tube 1. The end face of the cap 2 and the opening end of the reaction tube 1 are snap-fitted together.

[0056] In another preferred embodiment, the reaction tube 1 and the cap 2 can also be threaded together. The open end of the reaction tube 1 is provided with external or internal threads, and the cap 2 is provided with corresponding internal or external threads to achieve a threaded seal. When the reaction tube 1 and the cap 2 are threaded together, the hollow cylinder 22 is positioned above the end face 21 of the cap 2. After the cap 2 and the reaction tube 1 are assembled, the hollow cylinder 22 is located above the cap 2.

[0057] Furthermore, the cavity inside the hollow cylinder 22 is equipped with a sample injection card 3.

[0058] The open end of the hollow column 22 can be sealed with a waterproof sealing membrane 23 or a sealing cap. The sealing cap and the open end of the hollow column 22 can be assembled by a snap-fit ​​structure, a threaded structure, etc.

[0059] Furthermore, the injection card 3 is a test paper or other porous sheet or plate material that can withstand organic solvents, preferably a test paper material.

[0060] The shape and area of ​​the injection card 3 are not specifically required and can be modified according to experimental needs, but the diameter of the injection card 3 after unfolding must be greater than the outer diameter of the hollow column 22. Before use, the injection card 3 is folded and sealed inside the hollow column 22.

[0061] In a preferred embodiment, the injection card is preferably a circular test paper injection card with a diameter of 1 cm, and the outer diameter of the hollow column 22 is less than 1 cm.

[0062] The hollow cylinder 22 of the tube cap 2 has an opening facing upwards. When the tube cap 2 is placed on the table, the opening end face of the hollow cylinder 22 should be parallel to the table so that it can be used to lay out the injection card and facilitate drying.

[0063] A schematic diagram of the process for detecting pesticide residues in organic solvent extracts of vegetable and fruit samples using the sample introduction and reaction apparatus of this invention via liquid-phase enzyme inhibition is shown below. Figure 3 As shown.

[0064] Figure 3 In Figure A, the actual sample to be tested is shown, with vegetables as a typical example. The actual sample to be tested can be any solid or liquid sample.

[0065] Figure B shows the extraction of the sample after it has been pulverized and added to a centrifuge tube containing an organic solvent. Commonly used solvents include ethyl acetate and acetonitrile.

[0066] Figure C shows the process of opening the tube cap of this device, opening the sealing membrane at the open end of the hollow column, and removing the injection card. The reaction tube contains acetylcholinesterase solution as the enzyme reagent.

[0067] Figure D shows the hollow cylinder with the tube cap facing upwards placed on the table. The injection card is unfolded and laid flat on the open end face of the hollow cylinder. The extract or pesticide standard solution obtained in step B is added dropwise onto the injection card, and then left to stand for 3-5 minutes.

[0068] Alternatively, the entire sample card can be immersed in the test solution obtained in step B for 10 seconds and then removed.

[0069] Figure E shows the injection card being unfolded and laid flat on the open end face of the hollow column, left to air dry for 3-5 minutes;

[0070] Figure F shows the process of placing the injection card into the reaction tube, sealing the reaction tube with the cap, gently shaking the reaction tube to immerse the injection card completely in the acetylcholinesterase solution, incubating at a suitable temperature, adding the enzyme activity probe, and continuing incubation to allow the probe to react with the enzyme reagent.

[0071] Figure G shows the results of colorimetric analysis using visual methods for qualitative / semi-quantitative judgment, or the data of enzyme activity measured quantitatively using a spectrophotometer or fluorometer to calculate pesticide residue levels.

[0072] Example 2

[0073] To verify the reliability of this invention, standard curves for four typical organophosphorus and carbamate pesticides in water and different organic solvents were determined according to the steps in Example 1. The recoveries of the typical pesticides dichlorvos and chlorpyrifos at different spiking levels in different actual samples were also determined. Specific experiments are as follows:

[0074] (1) Prepare single-component standard solutions of different concentrations of methamidophos, parathion, dichlorvos and chlorpyrifos using ethyl acetate as solvent; prepare acetylcholinesterase activity probe solution with a concentration of 0.1 mM using water. In this embodiment, the acetylcholinesterase activity probe is indoleacetic acid.

[0075] (2) Open the tube cap of this device, open the sealing film at the opening end of the hollow column, and take out the folded injection card. The reaction tube contains an acetylcholinesterase solution prepared with PBS buffer at pH 7.4 as the enzyme reagent, with an enzyme concentration of 0.02 U / ml; the injection card is a circular filter paper with a diameter of 1 cm; the solvent in the reaction tube is 2 mL, and the outer diameter of the hollow column in the tube cap is 0.8 cm.

[0076] (3) Place the hollow cylinder of the tube cap with the opening facing upward on the table, unfold the injection card and place it on the open end face of the hollow cylinder of the tube cap, use a pipette to transfer 50 μL of methamidophos pesticide solution, drop it onto the surface of the injection card, and let the injection card air dry naturally for 3 minutes.

[0077] (4) Place the injection card into the reaction tube, tighten the cap, and shake the reaction tube by hand to immerse the injection card completely in the enzyme reagent.

[0078] (5) After incubating at 37℃ for 10 min, add 10 μL of 0.1 mM acetylcholinesterase activity probe solution and continue the reaction at 37℃ for 5 min; take the solution after the reaction and use a fluorometer to measure the fluorescence intensity of the solution.

[0079] (6) Following the steps of (2) to (5), repeat the determination of data for different concentrations of methamidophos solution. Plot the data using Origin software with methamidophos concentration as the abscissa and fluorescence intensity as the ordinate. Fit the data using the Hill equation and plot the standard curve of the pesticide response.

[0080] (7) Following steps (2) to (6), determine and plot the standard curves for parathion, dichlorvos, and chlorpyrifos pesticides, respectively. See the summary of specific results below. Figure 4 .

[0081] (8) Using hexane, acetonitrile, and water instead of ethyl acetate, standard solutions were prepared and tested according to steps (2) to (7). Working curves were plotted, and it was found that the working curves obtained by different solvents were basically the same. That is to say, even if the extraction solvent and the standard solution solvent are different, the working curve can still be used for the quantification of pesticides in the sample.

[0082] Example 3

[0083] The recovery rates of dichlorvos and chlorpyrifos in orange, lettuce, and chili pepper samples were determined using the method described in Example 2. The specific experiments are as follows:

[0084] (1) Remove the stems from the oranges and homogenize them. Place 2g of the homogenized sample into each centrifuge tube and add 100μL of dichlorvos standard solution of different concentrations into each centrifuge tube, so that the dichlorvos concentrations in the centrifuge tubes are 0, 1.0, 2.0 and 10.0 ppb, respectively. Vortex mix and let stand for 30min to allow the pesticide to fully contact the sample.

[0085] (2) Add 2 mL of ethyl acetate to each centrifuge tube described in (1) as the sample extraction solution, vortex to mix, let stand for 5 min or centrifuge for 2 min until the solvent separates into layers, and take the supernatant as the test solution for later use.

[0086] (3) Measure the detection signal of the test liquid according to the method of steps (2) to (5) in Example 2; substitute the measured fluorescence intensity value into the working curve equation of dichlorvos drawn in Example 2, calculate the concentration of dichlorvos pesticide in the four samples, and calculate the spiked recovery rate of each sample.

[0087] (4) Replace the dichlorvos pesticide in steps (1) to (3) with different concentrations of chlorpyrifos pesticide and determine the spiked recovery rate of chlorpyrifos pesticide in orange samples.

[0088] (4) Using lettuce and chili pepper samples to replace the orange samples in (1) to (3), respectively, the spiked recoveries of dichlorvos and chlorpyrifos in the lettuce and chili pepper samples were determined. The spiked recovery results are shown in Tables 1 and 2:

[0089] Table 1. Spiked recoveries of dichlorvos pesticide in different samples

[0090]

[0091] Table 2. Spiked recoveries of chlorpyrifos in different samples

[0092]

[0093] The results show that the sample introduction and reaction device of this invention, when used in the liquid-phase enzyme inhibition method, can simultaneously perform multiple functions such as solvent separation, pesticide sample introduction, and enzyme reaction, demonstrating good performance in the detection of different samples and pesticides. This device solves the long-standing problem of incompatibility between the liquid-phase enzyme inhibition method and organic solvents, significantly improving the sensitivity, accuracy, and reliability of the liquid-phase enzyme inhibition method in pesticide residue detection. Furthermore, compared with traditional liquid-phase enzyme inhibition methods, this device is simpler to operate and more convenient to use, which is of great significance for ensuring the quality and safety of agricultural products such as vegetables and fruits in my country.

Claims

1. A sample injection and reaction device for detecting pesticide residue components in an organic solvent extract by liquid phase enzyme inhibition method, characterized in that The device includes a reaction tube body and a cap, which are detachably assembled with the reaction tube body. The cap seals the reaction tube body, and the cap has a hollow column. A sample injection card is sealed inside the hollow column, and the reaction tube body contains enzyme reagents.

2. The sample introduction and reaction apparatus of claim 1, wherein The reaction tube is a hollow cavity with one end open.

3. The sample injection and reaction device of claim 1, wherein The reaction tube body and the tube cap are detachable with a snap-fit ​​or a threaded fit.

4. The sample introduction and reaction apparatus of claim 1, wherein Above or below the end face of the tube cap, there is a hollow column extending upward or downward with the end face of the tube cap as the bottom surface. The open end of the hollow column is provided with a sealing membrane or sealing cap to seal the hollow column. The cavity inside the hollow column is equipped with a sample injection card.

5. The sample introduction and reaction apparatus of claim 4, wherein The open end of the hollow column is sealed with a waterproof sealing membrane or a sealing cap, and the sealing cap is assembled with the hollow column through a snap-fit ​​structure or a threaded structure.

6. The sample introduction and reaction apparatus of claim 4, wherein The injection card is a test paper or a porous sheet or plate material that can withstand organic solvents.

7. The sample introduction and reaction apparatus of claim 5, wherein The diameter of the injection card after unfolding is larger than the outer diameter of the hollow column. After folding, the injection card is sealed and stored inside the hollow column.

8. The sample introduction and reaction apparatus of claim 7, wherein The tube cap is placed on the table with the hollow cylindrical opening facing upwards and the open end face of the hollow cylindrical opening parallel to the table, for use in laying out the injection card.

9. The sample introduction and reaction apparatus of claim 4, wherein The reaction tube and the cap are snap-fitted together. The hollow column is located below the end face of the cap, and the column body is inserted into the neck opening of the reaction tube during assembly.

10. The sample introduction and reaction apparatus of claim 4, wherein When the reaction tube body and the tube cap are threaded together, the open end of the reaction tube body is provided with an external thread or an internal thread, and the tube cap is provided with a matching internal thread or an external thread. The hollow cylinder is located on the top of the end face of the tube cap. After the tube cap and the reaction tube body are assembled, the hollow cylinder is located above the tube cap.

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