Sample pretreatment device for food safety detection

Abstract

The invention relates to the field of food detection, and discloses a sample pretreatment device for food safety detection.The sample pretreatment device comprises a shell, a crushing mechanism, a centrifugal mechanism, a material distributing mechanism, a solid-phase extraction mechanism and a nitrogen blowing mechanism are arranged in the shell, and after a food sample is crushed by the crushing mechanism, juice enters the centrifugal mechanism to be subjected to centrifugal treatment; the material separation mechanism is used for temporarily storing and separating centrifuged supernate, the solid-phase extraction mechanism is used for carrying out solid-phase extraction on a plurality of separated samples, and the nitrogen blowing mechanism and the solid-phase extraction mechanism are matched to complete nitrogen blowing work. Through structural innovation and function integration, five functional modules including crushing, centrifuging, material separation, extraction and nitrogen blowing concentration are integrated into the same equipment; the occupied area of the equipment is reduced, the operation process is optimized, the manual intervention frequency is reduced, and the pretreatment efficiency and reliability of the food safety detection sample are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of food detection, and specifically refers to a sample pretreatment device for food safety detection. Background Art

[0002] In the field of food safety detection, sample pretreatment is a key link to ensure the accuracy and reliability of detection results. The traditional sample pretreatment process faces many technical bottlenecks: Firstly, the sample crushing efficiency is low and the uniformity is insufficient. Existing crushing equipment mostly uses fixed-spacing grinding or single-speed crushing, which is difficult to meet the differentiated crushing requirements of different texture samples (such as fruits, vegetables, meats, grains), often resulting in a reduced efficiency in the latter half of the crushing process. Secondly, the degree of automation of centrifugal separation is insufficient. Traditional centrifugal equipment requires manual feeding, discharging, and transferring the supernatant, and cannot be seamlessly connected with links such as crushing and extraction, resulting in a high risk of sample exposure, easy contamination, and a cumbersome operation process, making it difficult to meet the requirements of batch detection. Thirdly, the solid-phase extraction and nitrogen blowing concentration links rely on manual operation. Traditional solid-phase extraction requires manual control of the eluent flow rate and vacuum degree, and the test tube position and nitrogen flow rate need to be frequently adjusted during the nitrogen blowing process, which is not only time-consuming and laborious, but also may cause loss of target analytes due to operation errors, affecting the detection sensitivity.

[0003] In addition, the independent operation of multi-link equipment results in a low degree of integration. Steps such as crushing, centrifugation, extraction, and concentration require the cooperation of multiple pieces of equipment, occupying a large space and having poor process connection, making it difficult to achieve full-process automation of sample pretreatment. Especially when facing frequent operations for a certain detection, such as frequently performing multiple pesticide residue detections, the existing technology requires the use of multiple pieces of equipment, restricting the improvement of detection efficiency.

[0004] Therefore, developing an automated pretreatment device integrating crushing, centrifugation, material distribution, solid-phase extraction, and nitrogen blowing has become an urgent need to solve the pain points of the existing technology and improve the efficiency and accuracy of food safety detection. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above difficulties and provide a sample pretreatment device for food safety detection.

[0006] To solve the above technical problem, the technical solution provided by the present invention is: A sample pretreatment device for food safety detection, including a housing, in which a crushing mechanism, a centrifugal mechanism, a material distribution mechanism, a solid-phase extraction mechanism, and a nitrogen blowing mechanism are provided; The crushing mechanism includes a first motor, an adjustment mechanism, a grinding table, and a grinding bowl. The first motor drives the grinding table to rotate, the adjustment mechanism adjusts the distance between the grinding table and the grinding bowl, and a feeding head is provided at the bottom of the grinding bowl; The centrifugal mechanism includes a turntable, a liquid tank and a top plate. A plurality of liquid tanks are evenly installed on the turntable. A second motor is provided on the top of the top plate. The second motor drives the top plate to rotate. The top plate blocks the top opening of the liquid tank and drives the turntable to rotate. The material separation mechanism temporarily stores and diverts the supernatant after centrifugation, the solid phase extraction mechanism performs solid phase extraction on multiple samples after diversion, and the nitrogen blowing mechanism cooperates with the solid phase extraction mechanism to complete the nitrogen blowing work.

[0007] As an improvement: a driving rod is provided on the top of the grinding table, a spline groove is provided on the driving rod, a spline shaft matching the spline groove is provided at the output end of motor one, the adjustment mechanism includes a fixed plate and a lifting plate, motor one is fixed on the fixed plate, the driving rod is rotatably arranged on the lifting plate, and the lifting plate drives the driving rod to move up and down at the bottom of the fixed plate.

[0008] As an improvement: a swinging platform is symmetrically slidably provided on the outside of the driving rod, a spring is provided between the rear end of the swinging platform and the driving rod, a wiping platform cooperating with the swinging platform is rotatably provided on the outside of the lifting plate, a threaded rod is provided on the top of the wiping platform, and a threaded hole cooperating with the threaded rod is provided on the fixed plate.

[0009] As an improvement: the liquid tank is installed obliquely on the installation hole on the turntable, a sealing plate abutting against the top of the liquid tank is provided at the bottom of the top plate, and a plurality of feeding ports staggered with the sealing plate are provided on the top plate.

[0010] As an improvement: a liquid pushing platform is slidingly provided on the inner side of the liquid tank, a back plate is provided at the bottom of the liquid pushing platform through a through hole at the bottom of the liquid tank, a second spring is provided between the back plate and the liquid tank, a liquid outlet pipe column is provided at the bottom of the turntable, a lifting platform is slidingly provided on the outer side of the liquid outlet pipe column, a compression spring is provided between the bottom of the turntable and the lifting platform, a pushing platform is provided on the side of the lifting platform which abuts and slides with the bottom of the back plate, a pushing plate is rotatably provided at the bottom of the lifting platform, and a cylinder is provided at the bottom of the push plate.

[0011] As an improvement: a transmission platform 1 is evenly arranged on the top side of the turntable, and a transmission platform 2 cooperating with the transmission platform 1 is evenly arranged on the bottom side of the top plate. When the transmission platform 1 is inserted into the gap between the adjacent transmission platform 2, the sealing plate abuts against the top of the liquid tank, and the top plate drives the turntable and the lifting platform to rotate. When the top of the transmission platform 1 abuts against the bottom of the transmission platform 2, a gap is left between the sealing plate and the top of the liquid tank, and the lifting platform pushes the liquid pushing platform to perform liquid discharge.

[0012] As an improvement: the material distribution mechanism includes a liquid storage tank and a liquid separation tank, the liquid storage tank and the liquid separation tank are connected by a pipeline, and a plurality of liquid separation tubes are evenly arranged at the bottom of the liquid separation tank; the solid phase extraction mechanism includes a straight feeding tube; the nitrogen blowing mechanism includes a fixed frame and a test tube rack, the test tube rack is rotatably arranged on the fixed frame, a partition plate is arranged on the top of the fixed frame, and a vacuum chamber is arranged under the partition plate; an air supply branch pipe is arranged on the straight feeding tube, and a nitrogen delivery device connected to the air supply branch pipe is arranged in the shell.

[0013] As an improvement: a liquid separation chamber is provided at the bottom of the liquid separation pipe, a cross piston plate is provided inside the liquid separation chamber, a piston platform is provided at the top of the feeding straight pipe, a cross sliding groove matching the cross piston plate is provided on the piston platform, a cylinder two is provided on the partition plate, a displacement plate is provided at the output end of the cylinder two, and the piston platform is fixed to the through hole on the displacement plate.

[0014] The beneficial effects of the present invention compared with the prior art are as follows: through structural innovation and function integration, the present invention integrates five functional modules of crushing, centrifugation, material distribution, extraction, and nitrogen blowing concentration into the same device, reducing the floor area of the device, optimizing the operation process, reducing the frequency of manual intervention, and significantly improving the efficiency and reliability of the pretreatment of food safety detection samples. Specifically: 1. By adjusting the mechanism to dynamically change the distance between the grinding table and the grinding bowl, and using the centrifugal force of the swing table to drive the height to adaptively adjust, the crushing pressure and speed can be automatically optimized according to the sample crushing stage, realizing efficient processing of the whole process from coarse crushing of large particles to fine grinding of fine particles, avoiding clogging of the filter holes, and improving the subsequent centrifugal separation effect; 2. The transmission cooperation design of the top plate and the turntable realizes the full automation of automatic injection of slurry, centrifugal separation, and pushing of the supernatant, without manual intervention, reducing the risk of sample contamination. At the same time, the inclined liquid tank and the liquid pushing platform structure ensure complete solid-liquid separation and high recovery rate of the supernatant; 3. The material distribution mechanism, through the temporary storage and shunt design of the liquid storage tank and the liquid separation tank, combined with the linkage of the cross piston plate and the piston platform, can simultaneously perform solid-phase extraction on multiple samples. With the dual effects of the negative pressure in the vacuum chamber and the positive pressure of nitrogen, the flow rate of the eluent is accelerated, the enrichment time is shortened, and the recovery rate of the target analyte is improved. Description of the Drawings

[0015] Figure 1 is the structural schematic diagram of the present invention.

[0016] Figure 2 is the internal structural schematic diagram of the present invention.

[0017] Figure 3 is the structural schematic diagram of the crushing mechanism of the present invention.

[0018] Figure 4 is the exploded view of the crushing mechanism of the present invention.

[0019] Figure 5 is the sectional view of the crushing mechanism of the present invention.

[0020] Figure 6 is the structural schematic diagram of the centrifugal mechanism of the present invention.

[0021] Figure 7 is the exploded view of the centrifugal mechanism of the present invention.

[0022] Figure 8 is the sectional view of the centrifugal mechanism of the present invention.

[0023] Figure 9 It is a schematic structural diagram of the material distribution mechanism, solid phase extraction mechanism and nitrogen blowing mechanism of the present invention.

[0024] Figure 10 It is a schematic structural diagram of the liquid separation chamber of the present invention.

[0025] Figure 11 It is a schematic structural diagram of the piston platform of the present invention.

[0026] As shown in the figure: 1. Housing; 2. Crushing mechanism; 3. Centrifugal mechanism; 4. Material distribution mechanism; 5. Solid phase extraction mechanism; 6. Nitrogen blowing mechanism; 11. Top cover; 12. Sealing cover; 21. Motor 1; 211. Spline shaft; 22. Adjusting mechanism; 221. Fixed plate; 222. Lifting plate; 223. Cleaning table; 224. Threaded rod; 23. Grinding table; 231. Driving rod; 232. Spline groove; 233. Centrifugal table; 234. Spring 1; 24. Mortar; 241. Sieve holes; 242. Feeding head; 243. Valve 1; 31. Turntable; 311. Mounting holes; 312. Transmission platform 1; 313. Liquid collecting inclined platform; 314. Liquid outlet pipe column; 315. Compression spring; 316. Ball platform; 32. Liquid tank; 321. Liquid pushing platform; 322. Bracing plate; 323. Spring 2; 33. Top plate; 331. Motor 2; 332. Transmission platform 2; 333. Sealing plate; 334. Feeding port; 34. Lifting platform; 341. Pushing platform; 35. Cylinder 1; 36. Pushing plate; 41. Liquid storage tank; 411. Ball groove pipe; 412. Valve 2; 42. Liquid separation tank; 43. Liquid separation pipe; 431. Valve 3; 44. Liquid separation chamber; 441. Cross piston plate; 51. Feeding straight pipe; 511. Air supply branch pipe; 512. Piston platform; 513. Cross sliding groove; 52. Cylinder 2; 53. Displacement plate; 61. Fixed frame; 62. Connecting column; 63. Partition plate; 64. Test tube rack; 65. Test tube. Detailed implementation manners

[0027] The following further describes the present invention in detail with reference to the accompanying drawings.

[0028] Combined with the attached Figure 1 and the attached Figure 2 As shown, a sample pretreatment device for food safety detection includes a housing 1. Inside the housing 1, there are a crushing mechanism 2, a centrifugal mechanism 3, a material distribution mechanism 4, a solid phase extraction mechanism 5 and a nitrogen blowing mechanism 6. After the food sample is crushed by the crushing mechanism 2, the juice enters the centrifugal mechanism 3 for centrifugal treatment. The material distribution mechanism 4 temporarily stores and diverts the supernatant after centrifugation. The solid phase extraction mechanism 5 performs solid phase extraction on multiple samples after diversion. The nitrogen blowing mechanism 6 cooperates with the solid phase extraction mechanism 5 to complete the nitrogen blowing work.

[0029] Combined with the attached Figure 1 、attachedFigure 2 , append Figure 3 and append Figure 4 As shown in Figure 4 , the crushing mechanism 2 includes a first motor 21, an adjusting mechanism 22, a grinding table 23 and a grinding bowl 24. The first motor 21 drives the grinding table 23 to rotate. The adjusting mechanism 22 adjusts the distance between the grinding table 23 and the grinding bowl 24. A sieve hole 241 is provided at the bottom of the grinding bowl 24. A feeding head 242 is provided below the sieve hole 241. A first valve 243 is provided on the feeding head 242. A driving rod 231 is provided at the top of the grinding table 23. A spline groove 232 is provided on the driving rod 231. A spline shaft 211 that mates with the spline groove 232 is provided at the output end of the first motor 21. The adjusting mechanism 22 includes a fixing plate 221 and a lifting plate 222. The first motor 21 is fixed on the fixing plate 221. A top cover 11 is hinged at the feeding port at the top of the housing 1. The fixing plate 221 is fixed inside the top cover 11. The driving rod 231 is rotatably arranged on the lifting plate 222. The lifting plate 222 drives the driving rod 231 to move up and down at the bottom of the fixing plate 221.

[0030] Combined with append Figure 3 , append Figure 4 and append Figure 5 As shown in Figure 5 , swing tables 233 are symmetrically and slidably arranged on the outer side of the driving rod 231. A first spring 234 is provided between the rear end of the swing table 233 and the driving rod 231. A wiping table 223 that mates with the swing table 233 is rotatably arranged on the outer side of the lifting plate 222. A threaded rod 224 is provided at the top of the wiping table 223. A threaded hole that mates with the threaded rod 224 is provided on the fixing plate 221.

[0031] Traditional sample crushing methods have problems such as insufficient crushing, difficulty in adapting to the crushing requirements of different stages, inconvenient separation of residues and slurry, etc., resulting in an impact on the subsequent filtration work. The filter holes are easily blocked by large particle materials, and the processing efficiency is low, unable to meet the rapid pretreatment requirements of diverse samples.

[0032] To solve the above problems, the crushing mechanism 2 is improved. Initial preparation: Put the food sample into the grinding bowl 24. By rotating the threaded rod 224 at the top of the wiping table 223, adjust the height of the lifting plate 222. Then cover the top cover 11. Crushing stage: Start the first motor 21. Its spline shaft 211 drives the driving rod 231 to rotate at a high speed. The driving rod 231 drives the grinding table 23 to rotate and crush the food in the grinding bowl 24. In the initial crushing stage, the food sample is in a large particle state. After the grinding table 23 presses on the sample, it is subject to a large resistance from the sample, and the rotation speed of the grinding table 23 is relatively low. After the sample is gradually crushed from the large particle state, the resistance received by the grinding table 23 decreases, and the rotation speed increases. At this time, the crushing efficiency of the grinding table 23 for the sample decreases, and it is necessary to lower the height of the grinding table 23 to increase the pressure on the sample.

[0033] Due to the increase in the rotation speed of the grinding table 23, the centrifugal force of the swing table 233 becomes larger, so it moves outward to overcome the spring resistance. The outer rotation radius of the swing table 233 gradually becomes larger. When the swing table 233 contacts the wiping table 223 during rotation, friction is generated with the wiping table 223, thereby driving the wiping table 223 to rotate. The wiping table 223 drives the threaded rod 224 to rotate, so that the lifting plate 222 descends to meet the requirement of the grinding table 23 to descend. This method can also adjust the height of the grinding table 23 by controlling the rotation speed and rotation direction of the first motor 21. After the sample jams the grinding table 23 or the grinding table 23 contacts the grinding bowl 24, the resistance received by the grinding table 23 suddenly becomes larger, so that the rotation speed of the grinding table 23 drops rapidly. At this time, the rotation radius of the swing table 233 becomes smaller, thus preventing the further downward movement of the grinding table 23, and having an emergency protection function.

[0034] Combined with the attached Figure 1 、attached Figure 2 、attached Figure 6 and attached Figure 7 As shown, the centrifugal mechanism 3 includes a turntable 31, a liquid tank 32 and a top plate 33. A plurality of liquid tanks 32 are evenly installed in the mounting holes 311 on the turntable 31. The liquid tanks 32 are inclined. A second motor 331 is provided on the top of the top plate 33. The second motor 331 drives the top plate 33 to rotate in the housing 1. The top plate 33 seals the top opening of the liquid tank 32 and drives the turntable 31 to rotate. A sealing plate 333 that abuts against the top of the liquid tank 32 is provided at the bottom of the top plate 33. A plurality of feeding ports 334 are provided on the top plate 33, and the feeding ports 334 and the sealing plate 333 are arranged at intervals.

[0035] Combined with the attached Figure 6 、attached Figure 7 and attached Figure 8 As shown, a liquid pushing table 321 is slidably arranged inside the liquid tank 32. A bottom plate 322 is provided at the bottom of the liquid pushing table 321 through a through hole at the bottom of the liquid tank 32. A second spring 323 is provided between the bottom plate 322 and the liquid tank 32. A liquid collecting inclined table 313 is provided inside the liquid tank 32 on the top of the turntable 31. A liquid outlet pipe column 314 communicating with the axial through hole of the liquid collecting inclined table 313 is provided at the bottom of the turntable 31. A lifting table 34 is slidably arranged outside the liquid outlet pipe column 314. A compression spring 315 is provided between the bottom of the turntable 31 and the lifting table 34. A pushing table 341 that abuts against the bottom of the bottom plate 322 and is slidably matched is provided on the side of the lifting table 34. A pushing plate 36 is rotatably provided at the bottom of the lifting table 34. A first cylinder 35 is provided at the bottom of the pushing plate 36.

[0036] Combined with the attached Figure 6 、attached Figure 7 and attached Figure 8As shown, on the top side of the turntable 31, drive platforms one 312 are evenly provided. On the bottom side of the top plate 33, drive platforms two 332 that cooperate with the drive platforms one 312 are evenly provided. When the drive platform one 312 is inserted into the gap between adjacent drive platforms two 332, the sealing plate 333 abuts against the top of the liquid tank 32. The top plate 33 drives the turntable 31 and the lifting platform 34 to rotate. When the top of the drive platform one 312 abuts against the bottom of the drive platform two 332, there is a gap between the sealing plate 333 and the top of the liquid tank 32, and the lifting platform 34 pushes the liquid pushing platform 321 to perform the liquid discharging action.

[0037] In order to meet the integration requirements with the crushing mechanism 2 and the material distribution mechanism 4, the centrifugal mechanism 3 needs to be improved. The existing centrifugal equipment requires manual loading and unloading, which does not conform to the concept of integrated sample pretreatment of this device. Therefore, the centrifugal mechanism 3 needs to meet the function of automatic loading and unloading.

[0038] To solve the above problems, a top plate 33 and a lifting platform 34 are added. In the feeding stage, the second motor 331 is started to drive the top plate 33 to rotate, aligning the feeding port 334 with the liquid tank 32. Subsequently, the first cylinder 35 pushes the push plate 36 upward. The push plate 36 drives the lifting platform 34 to rise. The lifting platform 34 drives the turntable 31 to rise through the compression spring 315, so that the top of the drive platform one 312 abuts against the bottom of the drive platform two 332 in an aligned state. The convex platform at the top of the drive platform one 312 is inserted into the groove at the bottom of the drive platform two 332. At this time, the rotation of the top plate 33 will drive the turntable 31 to rotate, opening the first valve 243. The sample slurry processed by the crushing mechanism 2 is injected into the liquid tank 32 from the feeding port 334 through the feeding head 242. By intermittently rotating the turntable 31, the slurry injection work for multiple liquid tanks 32 is completed. Subsequently, the lifting platform 34 descends, and the top plate 33 rotates to align the sealing plate 333 with the top of the liquid tank 32, and the drive platform one 312 is misaligned with the drive platform two 332. The lifting platform 34 rises. At this time, the drive platform one 312 is inserted into the gap between adjacent drive platforms two 332, and the sealing plate 333 abuts against the top of the liquid tank 32. The top plate 33 drives the turntable 31 and the lifting platform 34 to rotate, realizing the centrifugal treatment of the slurry inside the liquid tank 32, thereby realizing solid-liquid separation.

[0039] In the discharging stage, the lifting platform 34 descends, and the top plate 33 is rotated to align the feeding port 334 with the liquid tank 32. Subsequently, the lifting platform 34 rises to make the top of the drive platform one 312 abut against the bottom of the drive platform two 332. Then the push plate 36 pushes the lifting platform 34 to continue rising, compressing the compression spring 315. After the abutting plate 322 contacts the pushing platform 341, the pushing platform 341 pushes the abutting plate 322 to move, causing the liquid pushing platform 321 to move inside the liquid tank 32, pushing the centrifuged supernatant liquid to flow down from the opening at the top of the liquid tank 32 and flowing into the liquid discharging pipe column 314 along the liquid collecting inclined platform 313, completing the liquid discharging action.

[0040] Combined with attached Figure 1 、attached Figure 2 and attachedFigure 9 As shown, the material distribution mechanism 4 includes a liquid storage tank 41 and a liquid separation tank 42. A ball groove material pipe 411 is provided on the top of the liquid storage tank 41, and a ball table 316 rotatably matched with the ball groove material pipe 411 is provided at the bottom of the liquid outlet column 314, and the inner through hole of the ball table 316 is connected with the ball groove material pipe 411. The liquid storage tank 41 is connected with the liquid separation tank 42 through a pipeline, and a valve 2 412 is provided on the pipeline. A plurality of liquid separation pipes 43 are evenly arranged at the bottom of the liquid separation tank 42, and valve 3 431 is provided on the liquid separation pipe 43. One side of the liquid separation tank 42 is connected to the eluent delivery pipe, and a liquid delivery device connected to the eluent delivery pipe is provided inside the shell 1.

[0041] Combined with Figure 9 , Attachment Figure 10 and attached Figure 11 As shown, the solid phase extraction mechanism 5 includes a feed straight pipe 51, a gas supply branch pipe 511 is provided on the feed straight pipe 51, and the gas supply branch pipe 511 is connected to the nitrogen delivery pipe. A nitrogen delivery device is provided inside the shell 1. A liquid separation chamber 44 is provided at the bottom of the liquid separation pipe 43, and a cross piston plate 441 is provided on the inner side of the liquid separation chamber 44. A piston platform 512 is provided on the top of the feed straight pipe 51, and a cross slide groove 513 matching the cross piston plate 441 is provided on the piston platform 512. A solid phase filler is provided in the cavity at the bottom of the piston platform 512, and a cylinder 2 52 is provided on the partition plate 63. A displacement plate 53 is provided at the output end of the cylinder 2 52, and the piston platform 512 is fixed to the through hole on the displacement plate 53. Combined with Figure 1 , Attachment Figure 2 and attached Figure 9 As shown, the nitrogen blowing mechanism 6 includes a fixed frame 61 and a test tube rack 64, a plurality of test tubes 65 are placed on the test tube rack 64, the test tube rack 64 is rotatably arranged on the fixed frame 61, a waste liquid collecting tank is arranged at the bottom of the fixed frame 61, a connecting column 62 is arranged on the fixed frame 61, a partition plate 63 is arranged on the top of the connecting column 62, a vacuum chamber is arranged below the partition plate 63, a vacuum machine connected to the vacuum chamber is arranged inside the shell 1, a sealing cover 12 is hingedly arranged at the vacuum chamber of the shell 1, a heating plate is arranged at the vacuum chamber of the shell 1, and a water supply machine for injecting water into the vacuum chamber is arranged inside the shell 1.

[0042] The supernatant obtained after centrifugation of the sample needs to be subjected to solid phase extraction treatment to enrich the target analyte and obtain a solution to be tested with higher purity. Common solid phase extraction equipment usually relies on experimenters to complete the process, with cumbersome steps and a large number of instruments and equipment used, which is not conducive to the realization of automated processing.

[0043] The device improves the material distribution mechanism 4, the solid phase extraction mechanism 5 and the nitrogen blowing mechanism 6. In the feeding stage, the supernatant treated by the centrifugal mechanism 3 enters the ball trough material pipe 411 through the ball table 316, and flows into the liquid storage tank 41 for temporary storage. In the material distribution stage, the valve 2 412 is opened, and the supernatant enters the liquid separation tank 42, and then is divided into multiple liquid separation tubes 43.

[0044]

[0044] During the enrichment stage of solid-phase extraction, keep the test tube 65 misaligned with the feeding straight tube 51, open the valve three 431, the supernatant enters the liquid separation chamber 44, and enters the feeding straight tube 51 through the cross chute 513 on the piston platform 512. The target analyte is enriched on the solid-phase packing inside the piston platform 512, and the feeding straight tube 51 discharges the waste liquid into the waste liquid collection tank at the bottom of the fixing rack 61.

[0045] During the elution stage of solid-phase extraction, rotate the test tube rack 64 and place the test tube 65 so that the feeding straight tube 51 is inserted into the test tube 65. The liquid feeding device sends the eluent to the liquid separation tank 42 and flows into the liquid separation chamber 44, staying above the solid-phase packing. Then, turn on the vacuum machine to evacuate the vacuum chamber below the partition plate 63. The pressure below the solid-phase packing is negative, which will suck the eluent and flow down into the test tube 65. At the same time, the cylinder two 52 pushes the displacement plate 53 upward. On the one hand, it drives the feeding straight tube 51 upward, so that the cross piston plate 441 is inserted into the cross chute 513, sealing the upper part of the eluent in the liquid separation chamber 44 and applying positive pressure to the washing liquid to accelerate the flow of the washing liquid. On the other hand, it makes the bottom of the feeding straight tube 51 move upward to prepare for nitrogen blowing.

[0046]

[0045] After the solid-phase extraction is completed, keep the top of the liquid separation chamber 44 closed, turn off the vacuum machine, turn on the water feeder and the heating plate, heat the water in the vacuum chamber, transfer the heat to the solution to be detected inside the test tube 65, and blow nitrogen through the feeding straight tube 51 to the liquid surface of the solution to be detected by the nitrogen delivery device to concentrate the solution to be detected after solid-phase extraction.

[0047] The above describes the present invention and its embodiments. This description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. All in all, if those of ordinary skill in the art are inspired by it and design similar structural modes and embodiments without creative work without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A sample pretreatment device for food safety detection, comprising a housing (1). Inside the housing (1), there are a crushing mechanism (2), a centrifugal mechanism (3), a material distribution mechanism (4), a solid-phase extraction mechanism (5) and a nitrogen blowing mechanism (6). It is characterized in that: The crushing mechanism (2) includes a first motor (21), an adjusting mechanism (22), a grinding table (23) and a grinding bowl (24). The first motor (21) drives the grinding table (23) to rotate. The adjusting mechanism (22) adjusts the distance between the grinding table (23) and the grinding bowl (24). A feeding head (242) is provided at the bottom of the grinding bowl (24); The centrifugal mechanism (3) includes a turntable (31), a liquid tank (32) and a top plate (33). A plurality of liquid tanks (32) are evenly installed on the turntable (31). A second motor (331) is provided at the top of the top plate (33). The second motor (331) drives the top plate (33) to rotate. The top plate (33) seals the top opening of the liquid tank (32) and drives the turntable (31) to rotate; The material distribution mechanism (4) temporarily stores and diverts the supernatant after centrifugation. The solid-phase extraction mechanism (5) performs solid-phase extraction on a plurality of samples after diversion. The nitrogen blowing mechanism (6) cooperates with the solid-phase extraction mechanism (5) to complete the nitrogen blowing work.

2. The sample pretreatment device for food safety detection according to claim 1, wherein: A driving rod (231) is provided at the top of the grinding table (23). A spline groove (232) is provided on the driving rod (231). A spline shaft (211) that cooperates with the spline groove (232) is provided at the output end of the first motor (21). The adjusting mechanism (22) includes a fixing plate (221) and a lifting plate (222). The first motor (21) is fixed on the fixing plate (221). The driving rod (231) is rotatably arranged on the lifting plate (222). The lifting plate (222) drives the driving rod (231) to move up and down at the bottom of the fixing plate (221).

3. The sample pretreatment device for food safety detection according to claim 2, wherein: Swing tables (233) are symmetrically and slidably arranged on the outer side of the driving rod (231). A first spring (234) is provided between the rear end of the swing table (233) and the driving rod (231). A wiping table (223) that cooperates with the swing table (233) is rotatably arranged on the outer side of the lifting plate (222). A threaded rod (224) is provided at the top of the wiping table (223). A threaded hole that cooperates with the threaded rod (224) is provided on the fixing plate (221).

4. A sample pretreatment device for food safety detection according to claim 1, characterized in that: The liquid tank (32) is inclined and installed on the installation hole (311) on the turntable (31). A sealing plate (333) that abuts against the top of the liquid tank (32) is provided at the bottom of the top plate (33). A plurality of feeding ports (334) that are arranged in a staggered manner with the sealing plate (333) are provided on the top plate (33).

5. A sample pretreatment device for food safety detection according to claim 4, characterized in that: A liquid pushing platform (321) is slidably provided on the inner side of the liquid tank (32), a stopper (322) is provided at the bottom of the liquid pushing platform (321) and passes through a through hole at the bottom of the liquid tank (32), a second spring (323) is provided between the stopper (322) and the liquid tank (32), a liquid outlet column (314) is provided at the bottom of the turntable (31), a lifting platform (34) is slidably provided on the outer side of the liquid outlet column (314), a compression spring (315) is provided between the bottom of the turntable (31) and the lifting platform (34), a pusher (341) is provided on the side of the lifting platform (34) and is in contact with and slidably matched with the bottom of the stopper (322), a pusher plate (36) is rotatably provided at the bottom of the lifting platform (34), and a cylinder (35) is provided at the bottom of the pusher plate (36).

6. The sample pretreatment device for food safety detection according to claim 5, characterized in that: The top side of the turntable (31) is evenly provided with a transmission platform 1 (312), and the bottom side of the top plate (33) is evenly provided with a transmission platform 2 (332) matched with the transmission platform 1 (312). When the transmission platform 1 (312) is inserted into the gap between the adjacent transmission platform 2 (332), the sealing plate (333) abuts against the top of the liquid tank (32), and the top plate (33) drives the turntable (31) and the lifting platform (34) to rotate. When the top of the transmission platform 1 (312) abuts against the bottom of the transmission platform 2 (332), a gap is left between the sealing plate (333) and the top of the liquid tank (32), and the lifting platform (34) pushes the liquid pushing platform (321) to discharge liquid.

7. A sample pretreatment device for food safety detection according to claim 1, characterized in that: The material distribution mechanism (4) comprises a liquid storage tank (41) and a liquid separation tank (42), the liquid storage tank (41) and the liquid separation tank (42) are connected via a pipeline, a plurality of liquid separation tubes (43) are evenly arranged at the bottom of the liquid separation tank (42), the solid phase extraction mechanism (5) comprises a feeding straight tube (51), the nitrogen blowing mechanism (6) comprises a fixed frame (61) and a test tube rack (64), the test tube rack (64) is rotatably arranged on the fixed frame (61), a partition plate (63) is arranged on the top of the fixed frame (61), a vacuum chamber is provided below the partition plate (63), a gas supply branch pipe (511) is arranged on the feeding straight tube (51), and a nitrogen gas delivery device connected to the gas supply branch pipe (511) is arranged in the housing (1).

8. A sample pretreatment device for food safety detection according to claim 7, characterized in that: A liquid separation chamber (44) is provided at the bottom of the liquid separation tube (43), a cross piston plate (441) is provided inside the liquid separation chamber (44), a piston platform (512) is provided at the top of the feeding straight tube (51), a cross slide groove (513) matching the cross piston plate (441) is provided on the piston platform (512), a cylinder 2 (52) is provided on the partition plate (63), a displacement plate (53) is provided at the output end of the cylinder 2 (52), and the piston platform (512) is fixed to a through hole on the displacement plate (53).

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