Rapid screening device for pesticide residues in grains
By integrating a smart sample cup with temperature control and vibration coordination and a dual mass spectrometry module, the problem of inaccurate and inefficient detection of novel succinate dehydrogenase inhibitor pesticides in imported grains has been solved, achieving high-throughput and high-precision pesticide residue detection and improving the ability to supervise food safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-03-13
AI Technical Summary
Existing technologies lack rapid and accurate detection methods for novel succinate dehydrogenase inhibitor pesticides in imported grains, resulting in inaccurate and inefficient detection. In particular, the detection of pesticide residues in complex grain matrices faces the problem of thermosensitive pesticide degradation.
The system employs an intelligent sample cup with integrated temperature control and vibration coordination, and a dual mass spectrometry module that integrates screening and confirmation. This module includes a conveyor belt, sample cup, time-of-flight mass spectrometer, and liquid chromatography-tandem mass spectrometer to achieve adaptive sample fixation, low-temperature maintenance, and continuous mixing. The entire detection process is automated through a central control system.
It enables high-throughput, high-precision, and rapid detection of multiple pesticide residues in complex grain matrices, improving the accuracy and reproducibility of detection, reducing human error, and enhancing the regulatory efficiency of grain import ports.
Smart Images
Figure CN121656445A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of food safety testing technology, specifically to a rapid screening device for pesticide residues in grains. Background Technology
[0002] Food security is a crucial foundation of national security. However, the residues of various pesticides widely used in the planting, storage, and transportation of grains, especially the complex and diverse new succinate dehydrogenase inhibitors, pose a potential threat to public health and the agricultural ecosystem. Currently, there are no unified rapid detection methods and standards for these pesticides in imported grain varieties such as soybeans, wheat, and corn in my country, leading to a practical dilemma in port supervision: "unable to detect, slow to detect, and inaccurate to detect."
[0003] Based on research conducted by the General Administration of Customs (Project No.: 2024HK110), 14 target pesticides were identified as core detection targets to address the need for rapid screening of novel SDHI fungicides in imported grains. These pesticides include: benzalkonium chloride, pyraclostrobin, pyraclostrobin, fluopyram, fluopyram, fluopyram, fluopyram, bifenthionamide, isopyram, fluopyram, fluopyram, isoflucypram, inpyrfluxam, and triflupyridine. The reasons for selecting these 14 pesticides are as follows: First, some of these pesticides (such as benzimidazole and pyrimethanil) have temporary limits set in GB2763-2021 "National Food Safety Standard Maximum Residue Limits for Pesticides in Food," but lack corresponding detection methods; second, the five newly marketed pesticides (such as isoflucypram and inpyrfluxam) have not yet established limit standards, and there are no reports of their simultaneous detection in grains; third, current research mainly focuses on fruit and vegetable substrates, and there is a gap in detection methods for complex grain substrates such as soybeans and wheat. Therefore, developing a technology and device that can achieve simultaneous, rapid, and accurate screening of multiple pesticides is of great significance for ensuring the quality and safety of imported grains and improving customs clearance efficiency.
[0004] Currently, although some automated pesticide residue detection equipment exists, as per the "Methods for Rapid Detection and Harmless Treatment of Pesticide Residues in Agricultural Products," while achieving both transportation and visual inspection of agricultural products, their focus is on the connection between transportation and detection. They also lack measures to maintain the physicochemical stability of the sample extract during transportation. Specifically, the environmental temperature fluctuations experienced by the extract on the conveyor belt may cause degradation of heat-sensitive pesticides (such as some novel succinate dehydrogenase inhibitors, i.e., SDHIs fungicides), affecting the accuracy of subsequent quantitative analysis. Therefore, developing an intelligent sample cup and transportation mechanism capable of adaptive sample tube fixation, low-temperature maintenance, and continuous mixing is of crucial practical significance for ensuring the accuracy and reproducibility of pesticide residue detection results in complex grain matrices and improving the regulatory efficiency of imported grain ports. Summary of the Invention
[0005] To address the aforementioned issues, this invention provides a rapid screening device for pesticide residues in grains. By integrating an intelligent sample cup with temperature control and vibration coordination functions and a dual mass spectrometry module that integrates screening and confirmation, it achieves fully automated, high-throughput, and highly accurate rapid detection of multiple pesticide residues in complex grain matrices.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a rapid screening device for pesticide residues in grain, comprising an extraction component, a purification component, a collaborative detection component, and a central control system connected in series; a transmission component is provided at the connection between the extraction component and the purification component;
[0007] The transmission assembly includes a conveyor belt with several discs detachably connected to it. Each disc has several sample cups detachably connected to it. All sample cups have the same diameter and include an inner cup and an outer cup. The inner sidewall of the inner cup is surrounded by an elastic pad. The cup wall of the inner cup is made of a thermochromic material. The inner bottom wall of the outer cup is equipped with a piezoelectric vibration unit. Each piezoelectric vibration unit is electrically connected to a power source. Each piezoelectric vibration unit includes a composite stacked semiconductor cooling chip and a piezoelectric vibration element. The input end of the semiconductor cooling chip is electrically connected to the positive terminal of the power source, and the output end of the piezoelectric vibration element is electrically connected to the negative terminal of the power source.
[0008] The collaborative detection component includes a time-of-flight mass spectrometer and a liquid chromatography-tandem mass spectrometer set in series. The time-of-flight mass spectrometer and the liquid chromatography-tandem mass spectrometer communicate with the central control system through a data interaction interface. The time-of-flight mass spectrometer first completes the qualitative screening of 14 novel succinate dehydrogenase inhibitor pesticides. The screening results are automatically triggered by the central control system to perform quantitative confirmation of the target substances by the liquid chromatography-tandem mass spectrometer.
[0009] The central control system has a pre-stored standard spectrum library of 14 target pesticides and parameters for eliminating interference from grain matrix, and coordinates and integrates the entire process of extraction, purification and detection components.
[0010] The technical principles of the above solution are as follows:
[0011] After solvent extraction by the extraction assembly, the sample is transferred to a sampling tube and placed into a sample cup. An elastic pad can accommodate sampling tubes of different sizes. When the conveyor belt starts, the sample cup enters the conveying process, and the central control system supplies power to the piezoelectric vibration unit. The current flows sequentially through the semiconductor cooling chip and the piezoelectric vibration element along a preset path, forming a series circuit. In this process, the semiconductor cooling chip operates first, its cold end actively cooling the temperature-sensitive material inside the cup, causing the cup wall to shrink controllably, thus tightly adhering to the outer wall of the sampling tube and achieving self-adaptive fixation. Subsequently, the current drives the piezoelectric vibration element to generate high-frequency mechanical vibration. This vibration is transmitted to the sample liquid through the cup, continuously mixing and preventing sedimentation. The sample cup then enters the purification assembly under the conveyor belt.
[0012] After entering the detection phase, the sample extract is introduced into the co-detection component. Time-of-flight mass spectrometry (TOF-MS) first performs a full scan of the sample, leveraging its high resolution and precise mass number determination capabilities to rapidly identify 14 target pesticides. This identification result is transmitted in real-time to the central control system via a data interface. The system automatically compares the results with preset standard spectral libraries and matrix interference parameters. Once a suspected positive signal is detected, liquid chromatography-tandem mass spectrometry (LC-MS) is immediately triggered to initiate precise quantitative analysis of the target compound. The tandem use of the two mass spectrometry systems achieves a seamless transition from rapid non-targeted screening to precise targeted quantification, significantly improving the efficiency and accuracy of detecting multiple pesticide residues in complex grain matrices.
[0013] The above approach has the following beneficial effects:
[0014] 1. This solution utilizes a central control system to coordinate and control the entire process of extraction, purification, transfer, and detection, achieving a high degree of automation in sample pretreatment and analysis. Sample cups automatically rotate under the drive of a conveyor belt. Combined with the intelligent triggering mechanism of time-of-flight mass spectrometry and liquid chromatography-tandem mass spectrometry, this significantly increases detection throughput and reduces human error, making it suitable for the rapid screening needs of large batches of samples at imported grain ports.
[0015] 2. This solution achieves a synergistic effect of "first cooling and shrinking for fixation, then vibration for mixing and preventing sedimentation" under current-driven configuration by connecting a semiconductor cooling chip and a piezoelectric vibration element in series in a stacked manner. This design not only allows a single cup to adapt to sampling tubes of different sizes, improving equipment compatibility, but more importantly, it provides a stable low-temperature and dynamic environment for sample transport, effectively preventing problems such as degradation of heat-sensitive pesticides, fat oxidation, protein adhesion, and tube wall adsorption, significantly improving the accuracy and repeatability of target analyte detection in complex grain matrices.
[0016] 3. This scheme employs a combined detection strategy of time-of-flight mass spectrometry (TOF-MS) and liquid chromatography-tandem mass spectrometry (LC-MS / MS), constructing an integrated workflow from rapid non-targeted screening to precise targeted confirmation. TOF-MS provides preliminary qualitative analysis with high resolution, and its results are evaluated in real-time by the central control system, automatically triggering LC-MS / MS for quantitative verification, with seamless integration between the two. This design leverages the broad-spectrum screening advantages of TOF-MS while also considering the precise quantitative characteristics of LC-MS / MS in complex matrices, fundamentally solving the technical bottlenecks of traditional methods that suffer from both slow and inaccurate detection, and comprehensively improving the monitoring capability for novel succinate dehydrogenase inhibitor pesticide residues.
[0017] Furthermore, pressure sensors are installed on the bottom and sidewalls of the elastic pad, and the pressure sensors are connected to the central control system.
[0018] Beneficial effects: By setting up a pressure sensor, the system can sense in real time whether the sampling tube is in place and its placement status, ensuring that the sample cup only starts the subsequent temperature control and vibration process when it is carrying the sample, thus avoiding energy waste.
[0019] Furthermore, the inner diameter of the elastic pad is the same as the average value of the sampling tube.
[0020] Beneficial effects: Designing the inner diameter of the elastic pad to match the average diameter of commonly used sampling tubes can provide basic support and cushioning during initial placement, reducing the risk of container breakage, and working in conjunction with the subsequent temperature-controlled shrinkage mechanism to achieve self-adaptation for all diameters of the sampling tube.
[0021] Furthermore, an RFID tag is embedded in the side wall of the outer cup.
[0022] Beneficial effects: Radio frequency identification (RFID) tags enable the automatic identification and tracking of sample numbers and batches, laying the foundation for accurate traceability and data association throughout the entire process.
[0023] Furthermore, both the outlet of the extraction component and the inlet of the purification component are equipped with identification sensors that are connected to the central control system. The identification sensors are used to read the type of grain based on the radio frequency identification tag.
[0024] Beneficial effects: The identification sensor can automatically read the grain type information (such as soybeans, wheat) from the sample cup label. Based on this, the system automatically calls the preset extraction solvent ratio and purification parameters that match the matrix characteristics, realizing personalized adaptation of the processing method and significantly improving the accuracy and efficiency of pretreatment.
[0025] Furthermore, the extraction component includes a solvent mixing mechanism, which has built-in storage chambers for three solvents: acetonitrile, ethyl acetate, and n-hexane. Each of the solvent storage chambers is connected to a metering pump via an electromagnetic valve, allowing for automatic mixing of the extraction solvents according to a preset ratio.
[0026] Beneficial effects: The integrated automatic solvent mixing mechanism can accurately and automatically prepare mixed extraction solvents of different polarities according to instructions, replacing the tedious and error-prone manual preparation steps. This not only improves efficiency but also ensures the consistency of extraction conditions between different batches.
[0027] Furthermore, the flow rate adjustment accuracy of the metering pump is ≤0.01mL / min, and the mixing chamber of the solvent mixing mechanism is equipped with an ultrasonic stirring component to ensure uniform mixing of the extraction solvent.
[0028] Beneficial effects: The high-precision metering pump ensures extremely accurate solvent ratios, while ultrasonic stirring enables instantaneous, all-around forced mixing. The combination of these two technologies fundamentally eliminates extraction efficiency fluctuations caused by solvent ratio deviations or uneven mixing, ensuring the reproducibility and reliability of the method.
[0029] Furthermore, the purification component uses replaceable solid-phase extraction columns or QuECHERS packed columns, and achieves automatic liquid flow through the column and separation of waste liquid through air pressure drive.
[0030] Beneficial effects: The modular and replaceable purification column design allows the device to flexibly meet different purification needs. Compared with traditional gravity or manual methods, the air pressure driven column flow method provides stable and controllable flow rate, avoiding differences in purification effect caused by uneven flow rate. At the same time, it realizes automatic collection of waste liquid, further improving the automation and standardization of the entire process.
[0031] Furthermore, time-of-flight mass spectrometry and liquid chromatography-tandem mass spectrometry are connected via a switching valve, allowing for automatic switching of detection modes according to screening needs.
[0032] Beneficial effects: By using a switching valve to achieve intelligent physical connection between the two mass spectrometry flow paths, the system can seamlessly and automatically transfer samples requiring confirmation into the liquid chromatography-tandem mass spectrometry channel based on the initial screening results of time-of-flight mass spectrometry. This integrated "screening-confirmation" design eliminates cumbersome manual transfer steps and greatly shortens the detection cycle.
[0033] Furthermore, the standard spectral library of the central control system contains primary accurate mass numbers, secondary fragment ion information, and retention time data for 14 target pesticides, including benzylfluopyram, pyraclostrobin, pyraclostrobin, flupyrfluopyram, flupyraclostrobin, flupyrfluoxam, bifenpyraclostrobin, isoprophiamil, flupyroxyfen, flupyroxyfen, isoflucypram, inpyrfluxam, and triflupyridine. It can automatically complete the comparison and matching of detection data.
[0034] Beneficial effects: The central control system can perform rapid and accurate qualitative and quantitative analysis based on multi-dimensional data, such as precision mass, fragment ions and retention time, and automatically eliminate matrix interference, minimizing the workload of manual data analysis and the risk of subjective misjudgment, and ensuring the authority and efficiency of the test results. Attached Figure Description
[0035] Figure 1 This is a connection diagram of an embodiment of the rapid screening device for pesticide residues in grains according to the present invention;
[0036] Figure 2 This is a schematic diagram of the disc body of an embodiment of the rapid screening device for pesticide residues in grains of the present invention;
[0037] Figure 3 This is a schematic isometric cross-sectional view of the sample cup in an embodiment of the rapid screening device for pesticide residues in grains according to the present invention.
[0038] The reference numerals in the accompanying drawings include: 1. Disc; 2. Sample cup; 3. Outer cup; 4. Inner cup; 5. Elastic pad; 6. Semiconductor cooling chip; 7. Piezoelectric vibration element. Detailed Implementation
[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0042] The following detailed description illustrates the specific implementation method:
[0043] Example:
[0044] Rapid screening of novel succinate dehydrogenase inhibitors (SDHIs) pesticide residues in imported grains faces several technical challenges: First, the complex matrix of grains (e.g., soybeans are rich in fat, and wheat contains protein and is prone to adhesion) makes traditional extraction and purification processes susceptible to interference; second, there are numerous types of SDHIs pesticides, requiring rapid screening of 14 target pesticides, including benzalkonium chloride, pyraclostrobin, pyraclostrobin, fluopyram, fluopyram, fluopyram, fluopyram, bifenthiophanate-methyl, isopyram, fluopyram, fluopyram, isoflucypram, inpyrfluxam, and triflupyridine; third, existing detection procedures are mostly step-by-step operations with low automation and efficiency, and heat-sensitive pesticides are easily degraded during sample processing, affecting quantitative accuracy.
[0045] To address the above problems, the present invention proposes the following... Figure 1 The device shown is a rapid screening device for pesticide residues in grain, comprising an extraction component, a purification component, a collaborative detection component, and a central control system connected in series; a transmission component is provided at the connection between the extraction component and the purification component.
[0046] The transmission assembly includes a conveyor belt, on which several discs 1 are detachably connected. Several sample cups 2 are detachably connected to each disc 1. The sample cups 2 have the same diameter. Each sample cup 2 includes an inner cup 4 and an outer cup 3. An elastic pad 5 is provided around the inner side wall of the inner cup 4. Pressure sensors are provided on the bottom and side wall of the elastic pad 5. The pressure sensors are connected to the central control system. The inner diameter of the elastic pad 5 is the same as the average value of the sampling tube.
[0047] The inner cup body 4 is made of thermochromic material. The inner bottom wall of the outer cup body 3 is provided with piezoelectric vibration units. Each piezoelectric vibration unit is electrically connected to a power source. Each piezoelectric vibration unit includes a composite stacked semiconductor cooling chip 6 and a piezoelectric vibration element 7. The input end of the semiconductor cooling chip 6 is electrically connected to the positive terminal of the power source, and the output end of the piezoelectric vibration element 7 is electrically connected to the negative terminal of the power source.
[0048] Radio frequency identification tags are embedded on the three side walls of the outer cup body. Identification sensors connected to the central control system are installed at the outlet of the extraction component and the inlet of the purification component. The identification sensors are used to read the type of grain based on the radio frequency identification tags.
[0049] The extraction component includes a solvent mixing mechanism, which has built-in storage chambers for three solvents: acetonitrile, ethyl acetate, and n-hexane. Each storage chamber is connected to a metering pump via an electromagnetic valve, allowing for automatic mixing of the extraction solvents according to a preset ratio. The metering pump has a flow rate adjustment accuracy of ≤0.01mL / min, and the mixing chamber of the solvent mixing mechanism is equipped with an ultrasonic stirring component to ensure uniform mixing of the extraction solvents.
[0050] The purification unit uses replaceable solid-phase extraction columns or QuECHERS packed columns, and achieves automatic liquid flow through the column and separation of waste liquid through air pressure.
[0051] The collaborative detection component includes a time-of-flight mass spectrometer (TOF-MS) and a liquid chromatography-tandem mass spectrometer (LC-MS / MS) configured in series. The TOF-MS and LC-MS / MS communicate with the central control system via a data interface. The TOF-MS first performs qualitative screening of 14 novel succinate dehydrogenase inhibitor pesticides. The screening results are automatically triggered by the central control system to perform quantitative confirmation of the target analytes using the LC-MS / MS. The TOF-MS and LC-MS / MS are connected by a switching valve, which can automatically switch the detection mode according to the screening requirements.
[0052] The central control system has a pre-stored standard spectral library of 14 target pesticides and parameters for eliminating interference from grain matrix. It coordinates and integrates the entire process of extraction, purification and detection components. The standard spectral library of the central control system contains the primary accurate mass number, secondary fragment ion information and retention time data of 14 target pesticides, including benzylfluopyram, pyrimethanil, pyraclostrobin, flupyrfluthamide, flupyraclostrobin, flupyrfluthamide, bifenthiophanate-methyl, isoprophiazone, flupyroxyfen, flupyroxyfenozide, isoflucypram, inpyrfluxam and triflupyridine. It can automatically complete the comparison and matching of detection data.
[0053] In practical applications, taking a batch of imported soybeans as an example, the specific implementation process is as follows: First, the extraction unit performs preliminary processing on the grain sample. The solvent mixing mechanism automatically prepares the extraction solvent according to a preset ratio, such as a mixture of acetonitrile and n-hexane, based on the characteristics of soybeans as a high-fat matrix, and ensures uniformity through ultrasonic stirring. After extraction, the operator places the sampling tube containing the extract into... Figure 2 The sample cup 2 is located inside the disc 1 shown.
[0054] Subsequently, the system enters the automated transfer and sample fitting stage. For example... Figure 3 As shown, the inner cup 4 of sample cup 2 is made of thermochromic material. When a sampling tube with a diameter smaller than the inner diameter of the cup is placed inside, the pressure sensors on the side wall and bottom of the inner cup 4 will detect insufficient contact pressure. This signal immediately triggers the activation of the semiconductor cooling chip 6 to actively cool the inner cup 4. The thermochromic material undergoes controllable shrinkage deformation as the temperature decreases, thus tightly wrapping the smaller sampling tube and ensuring its stability during subsequent high-speed transport and vibration. At the same time, the RFID tag on the outer wall of the cup is read by the identification sensor at the inlet, and the central control system receives the information that the sample currently being carried is a "soybean" sample, so as to call up the corresponding processing parameters.
[0055] Driven by the conveyor belt, sample cup 2 is smoothly transported from the extraction station to the purification station. During this process, considering the high fat content and easy oxidation of soybean samples, the semiconductor cooling chip 6 and the piezoelectric vibration element 7 are tightly integrated in a composite stack, forming a series circuit. When current flows through this circuit, it follows the principle of "cooling first, then vibration": the current first flows through the semiconductor cooling chip 6, cooling one side and actively cooling the inner cup 4 made of thermochromic material, causing it to shrink and tightly wrap the sampling tube; subsequently, the current continues to the piezoelectric vibration element 7 connected in series, driving it to generate high-frequency micro-vibration; when the semiconductor cooling chip 6 is working, its hot end generates heat, and the subsequent operation of the piezoelectric vibration element 7 effectively dissipates this accumulated heat through mechanical vibration, improving the heat dissipation efficiency of the cooling chip and preventing a decrease in cooling efficiency due to overheating. The vibration of the piezoelectric vibration unit itself directly acts on the cup body, achieving continuous mixing of the sample solution. For soybean samples, the aforementioned low-temperature environment effectively prevented fat melting and oxidation, while continuous synergistic vibration prevented fat or protein particles from depositing on the tube walls and bottom, and ensured the uniformity of solvent evaporation if concentration is required in the future.
[0056] When sample cup 2 accurately reaches the purification component, the system automatically selects a QuECHERS packed column to purify the soybean extract according to a preset program. A pneumatically driven system propels the liquid through the column, automatically separating it from waste liquid; the entire process is efficient and closed.
[0057] Finally, the purified sample enters the collaborative detection component. Time-of-flight mass spectrometry (TOF-MS) first performs a rapid full scan, using a pre-stored standard spectral library of 14 target pesticides for qualitative screening. Preliminary qualitative screening is completed by automatically comparing the detection data with the spectral library information and incorporating soybean matrix interference exclusion parameters. If a suspected positive signal is detected (such as the detection of benzimidazole or isoflucypram), the central control system immediately redirects the sample flow path to liquid chromatography-tandem mass spectrometry (LC-MS) via a switching valve. LC-MS, according to system instructions, performs precise quantitative analysis of the target compound, achieving a seamless transition from non-targeted screening to targeted confirmation. The central control system integrates the qualitative results from TOF-MS with the quantitative data from LC-MS, automatically generating a detection report and enabling full-process traceability of the sample via RFID tags.
[0058] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A rapid screening device for pesticide residues in grain, characterized in that, It includes an extraction component, a purification component, a collaborative detection component, and a central control system connected in series; a transmission component is provided at the connection between the extraction component and the purification component; The transmission assembly includes a conveyor belt, on which several discs (1) are detachably connected. Several sample cups (2) are detachably connected inside each disc (1). The sample cups (2) have the same diameter. Each sample cup (2) includes an inner cup (4) and an outer cup (3). The inner sidewall of the inner cup (4) is surrounded by an elastic pad (5). The cup wall of the inner cup (4) is made of thermochromic material. The inner bottom wall of the outer cup (3) is provided with a piezoelectric vibration unit. Each piezoelectric vibration unit is electrically connected to a power source. Each piezoelectric vibration unit includes a composite stacked semiconductor cooling chip (6) and a piezoelectric vibration element (7). The input end of the semiconductor cooling chip (6) is electrically connected to the positive terminal of the power source. The output end of the piezoelectric vibration element (7) is electrically connected to the negative terminal of the power source. The collaborative detection component includes a time-of-flight mass spectrometer and a liquid chromatography-tandem mass spectrometer set in series. The time-of-flight mass spectrometer and the liquid chromatography-tandem mass spectrometer communicate with the central control system through a data interaction interface. The time-of-flight mass spectrometer first completes the qualitative screening of 14 novel succinate dehydrogenase inhibitor pesticides. The screening results are automatically triggered by the central control system to perform quantitative confirmation of the target substances by the liquid chromatography-tandem mass spectrometer. The central control system has a pre-stored standard spectrum library of 14 target pesticides and parameters for eliminating interference from grain matrix, and coordinates and integrates the entire process of extraction, purification and detection components.
2. The rapid screening device for pesticide residues in grains according to claim 1, characterized in that, Pressure sensors are provided on the bottom and side walls of the elastic pad (5), and the pressure sensors are connected to the central control system signal.
3. The rapid screening device for pesticide residues in grains according to claim 2, characterized in that, The inner diameter of the elastic pad (5) is the same as the average value of the sampling tube.
4. The rapid screening device for pesticide residues in grains according to claim 3, characterized in that, The outer cup body (3) has an embedded radio frequency identification tag on its side wall.
5. The rapid screening device for pesticide residues in grain according to claim 4, characterized in that, Both the outlet of the extraction component and the inlet of the purification component are equipped with identification sensors that are connected to the central control system. The identification sensors are used to read the type of grain based on the radio frequency identification tag.
6. The rapid screening device for pesticide residues in grain according to claim 5, characterized in that, The extraction component includes a solvent mixing mechanism, which has built-in storage chambers for three solvents: acetonitrile, ethyl acetate, and n-hexane. All the solvent storage chambers are connected to a metering pump via electromagnetic valves, which can automatically mix the extraction solvents according to a preset ratio.
7. The rapid screening device for pesticide residues in grain according to claim 6, characterized in that, The metering pump has a flow rate adjustment accuracy of ≤0.01mL / min, and the mixing chamber of the solvent mixing mechanism is equipped with an ultrasonic stirring component to ensure uniform mixing of the extraction solvent.
8. The rapid screening device for pesticide residues in grain according to claim 7, characterized in that, The purification unit uses replaceable solid-phase extraction columns or QuECHERS packed columns, and achieves automatic liquid flow through the column and separation of waste liquid through air pressure.
9. The rapid screening device for pesticide residues in grain according to claim 8, characterized in that, Time-of-flight mass spectrometry and liquid chromatography-tandem mass spectrometry are connected via a switching valve, which can automatically switch the detection mode according to screening needs.
10. The rapid screening device for pesticide residues in grain according to claim 9, characterized in that, The standard spectral library of the central control system contains primary accurate mass numbers, secondary fragment ion information, and retention time data for 14 target pesticides, including benzylflufenoxam, pyrimethanil, pyraclostrobin, flupyroxyfen, fluopyram, fluopyram, fluopyram, bifenpyraclostrobin, isoprophiafen, fluopyram aniline, fluopyram hydroxylamine, isoflucypram, inpyrfluxam, and triflupyridine. It can automatically perform comparison and matching of detection data.