A high performance liquid chromatograph for food detection

Abstract

The application provides a high performance liquid chromatograph for food detection. The high performance liquid chromatograph for food detection comprises a chromatograph mechanism and a liquid pumping mechanism arranged above the chromatograph mechanism. The chromatograph mechanism comprises a power system, a sample injection system and a separation system arranged below the sample injection system. The high performance liquid chromatograph for food detection provided by the application only needs to pull a connecting pipe when being installed, and the connection with a solvent bottle can be completed by automatically moving down sealing shells, communication blocks and other components by spring elastic force, so that the operation is simple, time is saved, the connection efficiency is improved. Moreover, by extending the liquid pumping head into the interior of the solvent bottle, the device can better adapt to different liquid levels, reduce the interruption of sample injection caused by insufficient liquid, reduce the workload of the operator, avoid repeated sample injection caused by insufficient liquid, and waste samples and reagents.

Description

Technical Field

[0001] This invention relates to the field of food testing, and more particularly to a high-performance liquid chromatograph for food testing. Background Technology

[0002] With increasingly stringent food safety regulations, high-performance liquid chromatography (HPLC), with its advantages of high separation efficiency, high sensitivity, and high selectivity, has become an indispensable core device in food testing, widely used for the quantitative analysis of trace components such as pesticide residues, additives, and toxins. However, design flaws in the bottle connectors of traditional HPLC systems have long constrained the improvement of detection efficiency and data reliability, becoming a key bottleneck restricting technological development.

[0003] Traditional bottle connectors leave the bottle opening directly exposed to the laboratory environment when not in use. Since HPLC mobile phases often use mixtures of organic solvents and water, these solvents are volatile, and prolonged exposure can lead to changes in solvent concentration, causing baseline drift. For example, acetonitrile evaporation can reduce the proportion of organic phase in the mobile phase, causing a shift in column retention time and affecting the accuracy of quantitative results. Simultaneously, airborne microorganisms can contaminate the mobile phase, multiplying in the chromatographic system and forming biofilms that can clog the column or detector flow cell, causing abnormal peak shapes. Furthermore, traditional bottle connectors rely on manual tightening, requiring operators to repeatedly adjust the bottle position to ensure alignment. This process is time-consuming and prone to leakage due to misalignment. Additionally, the fixed tubing length of traditional connectors means that when the liquid level in the bottle is low, the tubing may not reach the liquid, leading to sample injection interruption. To complete the test, operators need to frequently replenish the mobile phase or change the vial, which not only increases the workload but may also lead to repeated injections due to insufficient liquid, wasting samples and reagents. This results in significant defects in the existing chromatograph vial head connectors in terms of contamination prevention, connection efficiency, and liquid extraction, making it difficult to meet the high precision and high efficiency requirements of food testing.

[0004] Therefore, it is necessary to provide a high-performance liquid chromatograph for food testing to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a high-performance liquid chromatograph for food testing, which solves the problems of traditional HPLC systems where the bottle opening is exposed when the bottle head connector is placed, leading to baseline drift caused by concentration changes due to organic solvent evaporation, abnormal peak shape caused by microbial contamination clogging the system, and the time-consuming and leaky process of manually tightening the connection. Furthermore, the inability to extract liquid when the fixed tubing is at a low liquid level results in sample injection interruption and repeated injections, making it difficult to meet the high precision and high efficiency requirements of food testing.

[0006] To solve the above-mentioned technical problems, the present invention provides a high-performance liquid chromatograph for food testing, comprising: a chromatograph mechanism and a liquid extraction mechanism, wherein the liquid extraction mechanism is disposed above the chromatograph mechanism; The chromatograph includes a power system, an injection system, a separation system located below the injection system, a detection system, a data processing system, and a placement assembly located above the power system. The power system includes at least a degasser and a quaternary proportional valve. The injection system has the function of automatically injecting samples and introducing liquids. The separation system includes at least a chromatographic column. The detection system can select different detectors, including: an ultraviolet detector, a fluorescence detector, and a color difference detector. The liquid extraction mechanism includes four elastic components, which are respectively connected to four connecting tubes. The four connecting components are connected to four connecting tubes and are respectively connected to four sealing components through a filter assembly. The filter assembly is located inside the sealing assembly.

[0007] Preferably, the lower part of the power system is connected to the sample injection system, the lower part of the sample injection system is connected to the separation system, the lower part of the separation system is connected to the detection system, the lower part of the detection system is connected to the upper part of the data processing system, and the front of the power system, sample injection system, separation system, detection system and data processing system are all provided with door panels. The placement component is fixedly connected to the upper part of the power system and is connected to the power system.

[0008] Preferably, the top end of the elastic component is fixedly connected to the outside of the connecting tube, the other end of the connecting tube is connected to the connecting component, the bottom of the connecting tube is fixedly connected to the filter component, the bottom of the filter component is slidably connected to the sealing component, and the bottom of the connecting component is fixedly connected to the top of the sealing component. The connecting pipe is connected to the placement component, and the elastic component is fixedly connected above the placement component.

[0009] Preferably, the placement assembly includes a placement platform, four mounting slots are provided on the top of the placement platform, four limiters are fixedly connected to the lower part of the inner wall of the placement platform, and a flexible tube is snapped into the lower part of the placement platform, wherein solvent bottles are snapped into two of the limiters. The hose is connected to the power system, the elastic component is fixedly connected in the mounting groove, the bottom ends of the two sealing components are snapped onto the top of the two solvent bottles, and the other end of the connecting tube is connected to the hose.

[0010] Preferably, the limiter includes a cylindrical shell, an inner ring is fixedly connected to the lower part of the inner wall of the cylindrical shell, and inclined grooves are formed on both the inner wall of the cylindrical shell and the inner wall of the inner ring. A plurality of friction pads are fixedly connected to the inner wall of the cylindrical shell. The outer wall of the solvent bottle is engaged with the inner wall of the outer shell or the inner wall of one of the inner rings, and the lower part of the outer shell is fixedly connected to the placement platform.

[0011] Preferably, the elastic component includes a sliding sleeve, a sliding rod slidably connected inside the sliding sleeve, a washer fixedly connected to the bottom end of the sliding rod, the washer being located inside the sliding sleeve, a first spring being provided inside the sliding sleeve, the two ends of the first spring being fixedly connected to the lower part of the inner wall of the sliding sleeve and the lower part of the washer respectively, a mounting block being fixedly connected to the lower part of the sliding sleeve, and a connecting bracket being fixedly connected to the top end of the sliding rod; The mounting block is fixedly connected inside the mounting groove, and the connecting bracket is fixedly connected outside the connecting pipe.

[0012] Preferably, the sealing assembly includes a sealing shell, the bottom of which is conical, the outer surface of which is covered with an elastic sealing material, a limiting groove and a sliding groove on the upper surface of which are provided. The filter assembly is slidably connected in the limiting groove, and the connecting assembly is slidably connected in the sliding groove.

[0013] Preferably, a connecting ring is fixedly connected to the bottom of the sealing shell, the connecting ring is sleeved on the outside of the slide groove, a sealing ring is fixedly connected to the inner wall of the slide groove, four rubber pads are fixedly connected to the inner wall of the connecting ring, and the four rubber pads are all fan-shaped. A plurality of air inlets are opened at the bottom of the sealing shell, and a plurality of one-way valves are fixedly connected to the top of the sealing shell, and the plurality of one-way valves are respectively connected to the top of the plurality of air inlets. The connecting assembly is fixedly connected to the top of the sealing shell.

[0014] Preferably, the filter assembly includes a sealing cylinder, the bottom of which is fixedly connected to a limiting ring, and a plurality of filter screens are disposed outside the sealing cylinder; The limiting ring is slidably connected in the limiting groove, and the top end of the sealing cylinder is fixedly connected to the bottom of the connecting assembly.

[0015] Preferably, the connecting component includes a connecting block, a second spring is fixedly connected to the lower part of the connecting block, the lower part of the connecting block is connected to the liquid extraction tube, a liquid extraction head is fixedly connected to the bottom end of the liquid extraction tube, the liquid extraction head has several through holes, and the liquid extraction head is connected to the liquid extraction tube. The diameter of the liquid extraction head is adapted to the diameter of the chute, the diameter of the liquid extraction tube is smaller than the diameter of the liquid extraction head, the bottom end of the second spring is fixedly connected to the top of the sealing shell, the bottom of the connecting block is fixedly connected to the sealing cylinder, the connecting block is connected to the connecting pipe, and the elastic force of the first spring is greater than the elastic force of the second spring.

[0016] Compared with related technologies, the high-performance liquid chromatograph for food testing provided by this invention has the following advantages: This invention provides a high-performance liquid chromatograph (HPLC) for food testing. During installation, pulling the connecting tube causes the slide bar to slide within the groove, simultaneously moving the sealing shell, connecting block, and sealing cylinder horizontally upwards. At this point, the solvent bottle to be tested is placed inside the outer shell of the instrument. Then, the connecting tube is released. Under the pull of the first spring, the connecting tube quickly moves the sealing shell, sealing cylinder, and connecting block downwards. When the sealing shell engages with the top nozzle of the solvent bottle, the first spring continues to pull the connecting block downwards, causing the second spring to contract. At this point, the connecting block causes the suction tube and suction head to gradually slide out of the groove and into the solvent bottle, allowing the suction head to contact the liquid inside the solvent bottle. The subsequent sample injection system and power operation then commence. During operation, liquid is drawn from the solvent bottle via a flexible tube and a suction head. As the liquid is drawn, outside air gradually enters the air inlet through the one-way valve and then into the solvent bottle, ensuring that the pressure inside the solvent bottle remains relatively stable. Installation is simple: just pull the connecting tube, and the spring force automatically lowers the sealing shell, connecting block, and other components to complete the connection with the solvent bottle. This method is easy to use, saves time, and improves connection efficiency. Furthermore, by inserting the suction head into the solvent bottle, the device can better adapt to different liquid levels, reducing the risk of sample interruption due to insufficient liquid, lowering the operator's workload, and avoiding repeated sample injections due to insufficient liquid, thus preventing waste of samples and reagents. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a preferred embodiment of the high-performance liquid chromatograph for food testing provided by the present invention. Figure 2 A schematic diagram of the structure for placing the components; Figure 3 This is a schematic diagram of the limit switch. Figure 4 This is a schematic diagram of the liquid extraction mechanism in use. Figure 5 This is a schematic diagram of the liquid extraction mechanism in its unused state. Figure 6 for Figure 5 Enlarged structural diagram at point A; Figure 7 This is a structural schematic diagram of the cross-section of the sealing assembly; Figure 8 This is a structural diagram of an exploded connecting component.

[0018] Labels in the diagram: 1. Chromatography apparatus; 2. Liquid extraction apparatus; 11. Power system; 12. Sample introduction system; 13. Separation system; 14. Detection system; 15. Data processing system; 16. Placement components; 21. Flexible component; 22. Connecting pipe; 23. Sealing component; 24. Filtering component; 25. Connecting component; 161. Placement platform; 162. Mounting slot; 163. Hoses; 164. Limiter; 165. Solvent bottle; 211. Sliding sleeve; 212. Sliding rod; 213. Washer; 214. First spring; 215. Mounting block; 216. Connecting bracket; 231. Sealing shell; 232. Limiting groove; 233. Sliding groove; 234. Sealing ring; 235. Connecting ring; 236. Rubber pad; 237. Air inlet; 238. One-way valve; 241. Sealing cylinder; 242. Limiting ring; 243. Filter screen; 251. Connecting block; 252. Second spring; 253. Suction tube; 254. Suction head; 255. Through hole; 1641. Outer shell of cylinder; 1642. Inner ring; 1643. Inclined groove; 1644. Friction pad. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Please refer to the following: Figures 1 to 8 A high-performance liquid chromatograph for food testing includes: a chromatograph unit 1 and a liquid extraction unit 2, wherein the liquid extraction unit 2 is positioned above the chromatograph unit 1; The chromatograph unit 1 includes a power system 11, an injection system 12, a separation system 13 located below the injection system 12, a detection system 14, a data processing system 15, and a placement assembly 16 located above the power system 11. The power system 11 includes at least a degasser and a quaternary proportional valve. The injection system 12 has the function of automatically injecting samples and introducing liquid. The separation system 13 includes at least a chromatographic column. The detection system 14 can select different detectors, including: an ultraviolet detector, a fluorescence detector, and a color difference detector. The liquid extraction mechanism 2 includes four elastic components 21, each connected to one of four connecting pipes 22, and four connecting components 25 connected to the four connecting pipes 22. Each of the four connecting components 25 is connected to one of four sealing components 23 via a filter assembly 24. The filter assembly 24 is located within the sealing component 23. During installation, pulling the connecting pipes 22 causes the slide rod 212 to slide within the slide groove 233, simultaneously causing the sealing shell 231, the connecting block 251, and the sealing cylinder 241 to move horizontally upwards. At this point, the solvent bottle 165 to be tested is placed inside the outer shell 1641 of the cylinder, and then the connecting tube 22 is released. Under the tension of the first spring 214, the connecting tube 22 quickly moves the sealing shell 231, the sealing cylinder 241, and the connecting block 251 downwards. When the sealing shell 231 is engaged at the top of the solvent bottle 165, the tension of the first spring 214 continues to pull the connecting block 251 downwards, causing the second spring 252 to contract. At this time, the connecting block 251 drives the suction tube 253. The suction head 254 gradually slides out of the slide groove 233 and extends into the solvent bottle 165, allowing the suction head 254 to contact the liquid inside the solvent bottle 165. During subsequent operation of the sample injection system 12 and power system, liquid is drawn from the solvent bottle 165 through the hose 163 and the suction head 254. During the liquid extraction process, outside air gradually enters the air inlet 237 along the one-way valve 238 and then into the solvent bottle 165, ensuring that the air pressure inside the solvent bottle 165 does not easily change. Since installation only requires pulling the connecting tube 22, the spring force automatically lowers components such as the sealing shell 231 and the connecting block 251, completing the connection with the solvent bottle 165. This simple operation saves time and improves connection efficiency. Furthermore, by extending the suction head 254 into the solvent bottle 165, the device can better adapt to different liquid levels, reducing sample injection interruptions due to insufficient liquid, reducing the workload of operators, and avoiding repeated sample injections due to insufficient liquid, thus preventing waste of samples and reagents.

[0021] The lower part of the power system 11 is connected to the sample injection system 12, the lower part of the sample injection system 12 is connected to the separation system 13, the lower part of the separation system 13 is connected to the detection system 14, and the lower part of the detection system 14 is connected to the upper part of the data processing system 15. Door panels are provided on the front of the power system 11, sample injection system 12, separation system 13, detection system 14, and data processing system 15. The placement component 16 is fixedly connected to the upper part of the power system 11 and is connected to the power system 11. The top end of the elastic component 21 is fixedly connected to the outside of the connecting tube 22, and the other end of the connecting tube 22 is connected to the connecting component 25. The lower part of the connecting tube 22 is fixedly connected to the filter component 24, and the bottom of the filter component 24 is slidably connected to the sealing component 25. Inside 3, the lower part of the connecting component 25 is fixedly connected to the upper part of the sealing component 23. The connecting pipe 22 is connected to the placement component 16. The elastic component 21 is fixedly connected to the upper part of the placement component 16. After disassembly, since the sealing shell 231 is not resisted, the second spring 252 will push the sealing shell 231 and the connecting block 251 away from each other under its own elastic force. At this time, the sealing cylinder 241 slides in the sealing shell 231, and the limiting ring 242 is in a snap-fit ​​state with the inner wall of the limiting groove 232. The liquid extraction head 254 and the liquid extraction tube 253 are completely located in the sliding groove 233. Through the isolation effect of the sealing cylinder 241 and the sealing shell 231, external bacteria can be prevented from contaminating the surface of the liquid extraction head 254 and the liquid extraction tube 253, thereby ensuring the accuracy of subsequent test data. During disassembly, simply grasp the solvent bottle 165 with one hand to ensure its position is fixed, then pull the connecting tube 22 upwards to allow the sealing cylinder 241 to slide within the limiting groove 232. When it slides to the limit position, continue to pull the connecting block 251 to separate the sealing shell 231 from the solvent bottle 165, thus completing the disassembly step. Compared with the prior art, the vertical upward pulling method is more convenient than the spiral loosening method, thereby improving the disassembly efficiency of the device.

[0022] The placement assembly 16 includes a placement platform 161. Four mounting slots 162 are provided above the placement platform 161. Four limiters 164 are fixedly connected to the lower part of the inner wall of the placement platform 161. A flexible hose 163 is snapped into the lower part of the placement platform 161. Solvent bottles 165 are snapped into two of the limiters 164. The flexible hose 163 is connected to the power system 11. An elastic component 21 is fixedly connected to the mounting slot 162. The bottom ends of two sealing components 23 are snapped into the upper parts of two solvent bottles 165. The other end of the connecting pipe 22 is connected to the flexible hose 163. The limiter 164 includes a cylindrical shell 1641. An inner ring 1642 is fixedly connected to the lower part of the inner wall of the cylindrical shell 1641. Both the inner wall of the cylindrical shell 1641 and the inner wall of the inner ring 1642 have inclined... The inner wall of the outer shell 1641 is fixedly connected to the groove 1643 and several friction pads 1644. The outer wall of the solvent bottle 165 is engaged with the inner wall of the outer shell 1641 or the inner wall of one of the inner rings 1642. The lower part of the outer shell 1641 is fixedly connected to the placement platform 161. Because the inclined groove 1643 is opened in the outer shell 1641 and the inner ring 1642, when solvent bottles 165 of different sizes are placed, the outer wall of the solvent bottle 165 will contact the inclined groove 1643 inside the inner ring 1642 or the outer shell 1641. Under the action of the friction pads 1644, it is not easy for it to slide horizontally. This ensures that the bottle mouth of the solvent bottle 165 is always in the same vertical square with the bottom of the sealing shell 231, thereby reducing the difficulty of using the device.

[0023] The elastic component 21 includes a sliding sleeve 211, a sliding rod 212 slidably connected inside the sliding sleeve 211, a washer 213 fixedly connected to the bottom end of the sliding rod 212, the washer 213 being located inside the sliding sleeve 211, a first spring 214 disposed inside the sliding sleeve 211, the two ends of the first spring 214 being fixedly connected to the lower part of the inner wall of the sliding sleeve 211 and the lower part of the washer 213 respectively, a mounting block 215 fixedly connected to the lower part of the sliding sleeve 211, and a connecting bracket 216 fixedly connected to the top end of the sliding rod 212. 15 is fixedly connected in the mounting groove 162, the connecting bracket 216 is fixedly connected to the outside of the connecting pipe 22, the sealing assembly 23 includes a sealing shell 231, the bottom of the sealing shell 231 is conical, the outer surface of the sealing shell 231 is wrapped with elastic sealing material, a limiting groove 232 is opened on the top of the sealing shell 231, a sliding groove 233 is opened on the top of the sealing shell 231, the filter assembly 24 is slidably connected in the limiting groove 232, the connecting assembly 25 is slidably connected in the sliding groove 233, and the bottom of the sealing shell 231 is fixed. A connecting ring 235 is fixedly connected to the slide groove 233. A sealing ring 234 is fixedly connected to the inner wall of the slide groove 233. Four rubber pads 236, each fan-shaped, are fixedly connected to the inner wall of the connecting ring 235. Several air inlets 237 are opened at the bottom of the sealing shell 231, and several one-way valves 238 are fixedly connected to the top of the sealing shell 231. Each one-way valve 238 communicates with the top of one of the air inlets 237. (Connecting assembly 2) 5 is fixedly connected above the sealing shell 231. Because it is equipped with a connecting ring 235 and rubber pads 236, when the liquid suction head 254 slides out of the slide groove 233, the multiple rubber pads 236 will be squeezed and deformed and flipped along the connecting ring 235. At this time, the liquid suction head 254 can slide out of the slide groove 233. After the liquid suction head 254 slides into the slide groove 233, the multiple rubber pads 236 will reset and be in a stacked state, completing the sealing of the bottom of the slide groove 233, thereby improving the sealing performance of the device. Because a sealing ring 234 and a sliding groove 233 are provided, and the diameter of the sliding groove 233 is matched with the diameter of the suction head 254, on the one hand, when the suction head 254 is completely located in the sliding groove 233, its outer wall contacts the sealing ring 234, thereby sealing the through hole 255 and preventing impurities from entering. On the other hand, the inner wall of the sliding groove 233 is larger than the suction tube 253, thereby reducing the resistance when the suction tube 253 slides inside the sliding groove 233 and reducing the difficulty of operating the device. The filter assembly 24 includes a sealing cylinder 241, with a limiting ring 242 fixedly connected to the bottom of the sealing cylinder 241. Several filter screens 243 are disposed outside the sealing cylinder 241. The limiting ring 242 is slidably connected within a limiting groove 232. The top of the sealing cylinder 241 is fixedly connected to the bottom of a connecting assembly 25. The connecting assembly 25 includes a connecting block 251, with a second spring 252 fixedly connected to the bottom of the connecting block 251. The bottom of the connecting block 251 is connected to a suction pipe 253. A suction head 254 is fixedly connected to the bottom of the suction pipe 253. The suction head 254 has several through holes 255 and is connected to the suction pipe 253. The diameter of the suction head 254 is adapted to the diameter of the sliding groove 233. The diameter of the suction tube 253 is smaller than the diameter of the suction head 254. The bottom end of the second spring 252 is fixedly connected to the top of the sealing shell 231, and the bottom of the connecting block 251 is fixedly connected to the sealing cylinder 241. The connecting block 251 is connected to the connecting tube 22. The elastic force of the first spring 214 is greater than that of the second spring 252. Since the elastic force of the second spring 252 is less than that of the first spring 214, the sealing shell 231 is difficult to move after the sealing block contacts the nozzle of the solvent bottle 165. The elastic force of the second spring 252 is less than that of the first spring 214, so that the second spring 252 gradually contracts during the process of the connecting block 251 being pulled down by the first spring 214, ensuring that the suction head 254 can be directly inserted into the solvent bottle 165.

[0024] The working principle of the high-performance liquid chromatograph for food testing provided by this invention is as follows: During installation, pull the connecting pipe 22 to make the slide rod 212 slide within the slide groove 233, causing the sealing shell 231, the connecting block 251, and the sealing cylinder 241 to move horizontally upwards synchronously. After placing the solvent bottle 165 to be tested inside the outer shell 1641, release the connecting pipe 22. Under the tension of the first spring 214, the connecting pipe 22 will quickly move the sealing shell 231, the sealing cylinder 241, and the connecting block 251 downwards. When the sealing shell 231 is engaged at the top nozzle of the solvent bottle 165, the tension of the first spring 214 continues to pull the connecting block 251 downwards, causing the first... When the second spring 252 contracts, the connecting block 251 drives the liquid extraction tube 253 and the liquid extraction head 254 to gradually slide out of the slide groove 233 and extend into the solvent bottle 165, so that the liquid extraction head 254 comes into contact with the liquid inside the solvent bottle 165. When the subsequent sample injection system 12 and power are running, the liquid inside the solvent bottle 165 will be extracted through the hose 163 and the liquid extraction head 254. During the liquid extraction process, outside air will gradually enter the air inlet 237 along the one-way valve 238 and enter the solvent bottle 165 along the air inlet 237, ensuring that the air pressure inside the solvent bottle 165 does not change easily. During disassembly, simply grasp the solvent bottle 165 with one hand to ensure its position is fixed, then pull the connecting tube 22 upward to allow the sealing cylinder 241 to slide within the limiting groove 232. After sliding to the limit position, continue to pull the connecting block 251 to separate the sealing shell 231 from the solvent bottle 165, thereby completing the disassembly step. After the disassembly is completed, since the sealing shell 231 is not subject to resistance, the second spring 252 will push the sealing shell 231 and the connecting block 251 away from each other under its own elastic force. The sealing cylinder 241 slides inside the sealing shell 231, and the limiting ring 242 is in a snap-fit ​​state with the inner wall of the limiting groove 232. At this time, the liquid suction head 254 and the liquid suction tube 253 are completely located in the sliding groove 233.

[0025] Compared with related technologies, the high-performance liquid chromatograph for food testing provided by this invention has the following advantages: Because of the connection ring 235 and rubber pads 236, when the pump head 254 slides out of the slide groove 233, the multiple rubber pads 236 will be squeezed and deformed and flipped along the connection ring 235. At this time, the pump head 254 can slide out of the slide groove 233. After the pump head 254 slides into the slide groove 233, the multiple rubber pads 236 will reset and be in a stacked state, completing the sealing of the bottom of the slide groove 233, thereby improving the sealing performance of the device. Because a sealing ring 234 and a sliding groove 233 are provided, and the diameter of the sliding groove 233 is matched with the diameter of the suction head 254, on the one hand, when the suction head 254 is completely located in the sliding groove 233, its outer wall contacts the sealing ring 234, thereby sealing the through hole 255 and preventing impurities from entering. On the other hand, the inner wall of the sliding groove 233 is larger than the suction tube 253, thereby reducing the resistance when the suction tube 253 slides inside the sliding groove 233 and reducing the difficulty of operating the device. Since the elastic force of the second spring 252 is less than that of the first spring 214, the sealing shell 231 is difficult to move after the sealing block contacts the nozzle of the solvent bottle 165. The elastic force of the second spring 252 is less than that of the first spring 214, so that the second spring 252 gradually contracts during the process of the connecting block 251 being pulled down by the first spring 214, ensuring that the liquid suction head 254 can be inserted into the solvent bottle 165. Because the inclined grooves 1643 are opened in the outer shell 1641 and the inner ring 1642, when solvent bottles 165 of different sizes are placed, the outer wall of the solvent bottle 165 will contact the inclined grooves 1643 inside the inner ring 1642 or the outer shell 1641, and under the action of the friction pad 1644, it is not easy to slide horizontally, ensuring that the bottle mouth of the solvent bottle 165 is always in the same vertical square with the bottom of the sealing shell 231, thereby reducing the difficulty of using the device.

[0026] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A high-performance liquid chromatograph for food detection, characterized in that, include: The chromatograph mechanism (1) and the liquid extraction mechanism (2) are arranged above the chromatograph mechanism (1); The chromatograph unit (1) includes a power system (11), an injection system (12), a separation system (13) located below the injection system (12), a detection system (14), a data processing system (15), and a placement assembly (16) located above the power system (11). The power system (11) includes at least a degasser and a quaternary proportional valve. The injection system (12) has the function of automatically injecting samples and introducing liquid. The separation system (13) includes at least a chromatographic column. The detection system (14) can select different detectors, including: an ultraviolet detector, a fluorescence detector, and a color difference detector. The liquid extraction mechanism (2) includes four elastic components (21), and the four elastic components (21) are respectively connected to four connecting pipes (22), four connecting components (25) are connected to the four connecting pipes (22), and the four connecting components (25) are respectively connected to four sealing components (23) through a filter component (24), wherein the filter component (24) is located inside the sealing component (23); The top end of the elastic component (21) is fixedly connected to the outside of the connecting tube (22), and the other end of the connecting tube (22) is connected to the connecting component (25); The elastic component (21) includes a sliding sleeve (211), a sliding rod (212) is slidably connected inside the sliding sleeve (211), a pad (213) is fixedly connected to the bottom end of the sliding rod (212), the pad (213) is located inside the sliding sleeve (211), a first spring (214) is provided inside the sliding sleeve (211), the two ends of the first spring (214) are fixedly connected to the lower part of the inner wall of the sliding sleeve (211) and the lower part of the pad (213) respectively, an mounting block (215) is fixedly connected to the lower part of the sliding sleeve (211), and a connecting bracket (216) is fixedly connected to the top end of the sliding rod (212). The connecting component (25) includes a connecting block (251), a second spring (252) is fixedly connected to the lower part of the connecting block (251), the lower part of the connecting block (251) is connected to the liquid extraction tube (253), the bottom end of the liquid extraction tube (253) is fixedly connected to a liquid extraction head (254), the liquid extraction head (254) has several through holes (255) on its outside, and the liquid extraction head (254) is connected to the liquid extraction tube (253); The diameter of the suction tube (253) is smaller than the diameter of the suction head (254), the connecting block (251) is connected to the connecting tube (22), and the elastic force of the first spring (214) is greater than the elastic force of the second spring (252). The mounting block (215) is fixedly connected in the mounting groove (162) included in the placement component (16), and the connecting bracket (216) is fixedly connected to the outside of the connecting tube (22).

2. The high-performance liquid chromatograph for food detection according to claim 1, characterized in that, The power system (11) is connected to the sample injection system (12) at the bottom, the sample injection system (12) is connected to the separation system (13) at the bottom, the separation system (13) is connected to the detection system (14) at the bottom, the detection system (14) is connected to the data processing system (15) at the top, and the power system (11), sample injection system (12), separation system (13), detection system (14) and data processing system (15) are all provided with door panels on the front. The placement component (16) is fixedly connected to the top of the power system (11) and is connected to the power system (11).

3. The high-performance liquid chromatograph for food detection according to claim 2, characterized in that, The bottom of the filter assembly (24) is slidably connected within the sealing assembly (23); The connecting tube (22) is connected to the placement component (16), and the elastic component (21) is fixedly connected above the placement component (16).

4. The high-performance liquid chromatograph for food detection according to claim 3, characterized in that, The placement assembly (16) includes a placement platform (161), four mounting slots (162) are provided on the upper part of the placement platform (161), four limiters (164) are fixedly connected to the lower part of the inner wall of the placement platform (161), and a flexible tube (163) is snapped into the lower part of the placement platform (161), wherein a solvent bottle (165) is snapped into two of the limiters (164). The hose (163) is connected to the power system (11), the elastic component (21) is fixedly connected in the mounting groove (162), the bottom ends of the two sealing components (23) are snapped onto the top of the two solvent bottles (165), and the other end of the connecting pipe (22) is connected to the hose (163).

5. The high-performance liquid chromatograph for food testing according to claim 4, characterized in that, The limiter (164) includes a cylindrical shell (1641), an inner ring (1642) is fixedly connected to the lower part of the inner wall of the cylindrical shell (1641), and inclined grooves (1643) are provided on the inner wall of the cylindrical shell (1641) and the inner wall of the inner ring (1642). A plurality of friction pads (1644) are fixedly connected to the inner wall of the cylindrical shell (1641). The outer wall of the solvent bottle (165) is engaged with the inner wall of the outer shell (1641) or the inner wall of one of the inner rings (1642), and the lower part of the outer shell (1641) is fixedly connected to the placement platform (161).

6. The high-performance liquid chromatograph for food testing according to claim 5, characterized in that, The sealing assembly (23) includes a sealing shell (231), the bottom of which is conical, and the sealing shell (231) is wrapped with an elastic sealing material. A limiting groove (232) is provided on the top of the sealing shell (231), and a sliding groove (233) is provided on the top of the sealing shell (231).

7. The high-performance liquid chromatograph for food testing according to claim 6, characterized in that, A connecting ring (235) is fixedly connected to the bottom of the sealing shell (231). The connecting ring (235) is sleeved on the outside of the slide groove (233). A sealing ring (234) is fixedly connected to the inner wall of the slide groove (233). Four rubber pads (236) are fixedly connected to the inner wall of the connecting ring (235), and the four rubber pads (236) are all fan-shaped. Several air inlets (237) are opened at the bottom of the sealing shell (231). Several one-way valves (238) are fixedly connected to the top of the sealing shell (231). Several one-way valves (238) are respectively connected to the top of several air inlets (237).

8. The high-performance liquid chromatograph for food testing according to claim 7, characterized in that, The filter assembly (24) includes a sealing cylinder (241), a limiting ring (242) is fixedly connected to the bottom of the sealing cylinder (241), and a plurality of filter screens (243) are provided outside the sealing cylinder (241). The limiting ring (242) is slidably connected in the limiting groove (232).

9. The high-performance liquid chromatograph for food detection according to claim 8, characterized in that, The diameter of the suction head (254) is adapted to the diameter of the chute (233), the bottom end of the second spring (252) is fixedly connected to the top of the sealing shell (231), and the bottom of the connecting block (251) is fixedly connected to the sealing cylinder (241).

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