A sample pretreatment device for food safety detection

Abstract

The application relates to the field of food detection, and discloses a sample pretreatment device for food safety detection, which comprises a shell, a crushing mechanism, a centrifugal mechanism, a material distribution mechanism, a solid-phase extraction mechanism and a nitrogen blowing mechanism are arranged in the shell; juice is obtained after the food sample is crushed, and the juice is subjected to centrifugal treatment in the centrifugal mechanism; the supernatant after centrifugation is temporarily stored and distributed in the material distribution mechanism; the multiple samples after distribution are subjected to solid-phase extraction in the solid-phase extraction mechanism; and the nitrogen blowing mechanism cooperates with the solid-phase extraction mechanism to complete nitrogen blowing work. Through structural innovation and function integration, the crushing, centrifugal, material distribution, extraction and nitrogen blowing concentration five function modules are integrated in the same equipment, the equipment floor area is reduced, the operation process is optimized, the manual intervention frequency is reduced, and the efficiency and reliability of the food safety detection sample pretreatment are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of food testing, and in particular to a sample pretreatment device for food safety testing. Background Art

[0002] In the field of food safety testing, sample pretreatment is a key link to ensure the accuracy and reliability of test results. The traditional sample pretreatment process faces many technical bottlenecks: First, the sample crushing efficiency is low and the uniformity is insufficient. Existing crushing equipment mostly adopts fixed-pitch grinding or single-speed crushing, which is difficult to adapt to the differentiated crushing requirements of samples of different textures (such as fruits and vegetables, meat, and grains), often resulting in reduced efficiency in the second half of crushing; second, the degree of automation of centrifugal separation is insufficient. Traditional centrifugal equipment requires manual loading, unloading and transfer of supernatant, and cannot be seamlessly connected with crushing, extraction and other links, resulting in high risk of sample exposure and susceptibility to contamination. The operation process is cumbersome and difficult to meet batch testing needs; third, solid-phase extraction and nitrogen blow concentration links rely on manual operation. Traditional solid-phase extraction requires manual control of the eluent flow rate and vacuum degree. The test tube position and nitrogen flow rate need to be frequently adjusted during the nitrogen blow, which is not only time-consuming and labor-intensive, but may also lead to loss of target analytes due to operational errors, affecting detection sensitivity.

[0003] Furthermore, the independent operation of multiple equipment links results in a low level of integration. Steps such as crushing, centrifugation, extraction, and concentration require the coordination of multiple devices, which takes up a lot of space and creates poor process integration, making it difficult to fully automate sample pretreatment. This is especially true when a single test is frequently performed, such as frequent pesticide residue testing. Existing technologies require the use of multiple devices, limiting efficiency.

[0004] Therefore, the development of an automated pretreatment device that integrates crushing, centrifugation, material separation, solid phase extraction, and nitrogen blowing has become an urgent need to solve the pain points of existing technologies and improve the efficiency and accuracy of food safety testing. 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 testing.

[0006] To solve the above technical problems, the present invention provides a technical solution as follows: a sample pretreatment device for food safety testing, comprising a housing, in which a crushing mechanism, a centrifugal mechanism, a material separation mechanism, a solid phase extraction mechanism, and a nitrogen blowing mechanism are provided;

[0007] The crushing mechanism includes a motor, an adjustment mechanism, a grinding table and a grinding bowl. The motor drives the grinding table to rotate, and the adjustment mechanism adjusts the distance between the grinding table and the grinding bowl. A feeding head is provided at the bottom of the grinding bowl.

[0008] The centrifugal mechanism comprises a rotating disc, liquid tanks and a top plate, the plurality of liquid tanks are uniformly installed on the rotating disc, the top plate is provided with a motor two at the top, the motor two drives the top plate to rotate, the top plate seals the top opening of the liquid tank, and drives the rotating disc to rotate;

[0009] The distribution mechanism temporarily stores and distributes the supernatant after centrifugation, the solid-phase extraction mechanism performs solid-phase extraction on the plurality of samples after distribution, and the nitrogen blowing mechanism cooperates with the solid-phase extraction mechanism to complete the nitrogen blowing work.

[0010] As an improvement: the grinding table top is provided with a driving rod, the driving rod is provided with a spline groove, the output end of the motor one is provided with a spline shaft matched with the spline groove, the adjusting mechanism comprises a fixed plate and a lifting plate, the 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 on the bottom of the fixed plate.

[0011] As an improvement: the driving rod is symmetrically provided with a shaking table outside and slides, a spring one is arranged between the rear end of the shaking table and the driving rod, a wiping table matched with the shaking table is rotatably arranged outside the lifting plate, a threaded rod is arranged at the top of the wiping table, and a threaded hole matched with the threaded rod is arranged on the fixed plate.

[0012] As an improvement: the liquid tank is obliquely installed on the mounting hole on the rotating disc, the bottom of the top plate is provided with a sealing plate abutting against the top of the liquid tank, and a plurality of feeding openings are arranged on the top plate in a staggered manner with the sealing plate.

[0013] As an improvement: a liquid pushing table is slidably arranged inside the liquid tank, a resisting plate is arranged on the bottom of the liquid pushing table and passes through the through hole in the bottom of the liquid tank, a spring two is arranged between the resisting plate and the liquid tank, a liquid outlet pipe column is arranged on the bottom of the rotating disc, a lifting table is slidably arranged outside the liquid outlet pipe column, a compression spring is arranged between the bottom of the rotating disc and the lifting table, a pushing table abutting against and slidably matched with the bottom of the resisting plate is arranged on the side of the lifting table, a pushing plate is rotatably arranged on the bottom of the lifting table, and a cylinder one is arranged on the bottom of the pushing plate.

[0014] As an improvement: a transmission table one is uniformly arranged on the top of the rotating disc, a transmission table two matched with the transmission table one is uniformly arranged on the side of the bottom of the top plate, when the transmission table one is inserted into the gap between adjacent transmission table two, the sealing plate abuts against the top of the liquid tank, the top plate drives the rotating disc and the lifting table to rotate, when the top of the transmission table one abuts against the bottom of the transmission table two, the sealing plate leaves a gap with the top of the liquid tank, and the lifting table drives the liquid pushing table to perform the liquid outlet action.

[0015] As an improvement: the distribution mechanism comprises a liquid storage tank and a liquid distribution tank, the liquid storage tank and the liquid distribution tank are communicated through a pipeline, a plurality of liquid distribution pipes are uniformly arranged on the bottom of the liquid distribution tank, the solid-phase extraction mechanism comprises a feeding straight pipe, the nitrogen blowing mechanism comprises a fixing frame and a test tube frame, the test tube frame is rotatably arranged on the fixing frame, a partition plate is arranged on the top of the fixing frame, a vacuum chamber is arranged below the partition plate, a gas feeding branch pipe is arranged on the feeding straight pipe, and a nitrogen gas conveying device connected with the gas feeding branch pipe is arranged in the shell.

[0016] As an improvement: the bottom of the liquid distributor is provided with a liquid distribution chamber, the inner side of the liquid distribution chamber is provided with a cross piston plate, the top of the feeding straight pipe is provided with a piston table, the piston table is provided with a cross sliding groove matched with the cross piston plate, the partition plate is provided with a gas cylinder II, the output end of the gas cylinder II is provided with a displacement plate, and the piston table is fixed in the through hole of the displacement plate.

[0017] The beneficial effects of the present application compared with the prior art are that: the present application integrates the functions of crushing, centrifuging, distributing, extracting and nitrogen blowing concentration into the same device through structural innovation and function integration, reduces the equipment floor space, optimizes the operation process, reduces the frequency of manual intervention, and significantly improves the efficiency and reliability of food safety detection sample pretreatment.

[0018] 1. The distance between the grinding table and the grinding bowl is dynamically changed through the adjusting mechanism, and the height is self-adaptively adjusted by the centrifugal force of the swinging table, so that the crushing pressure and the rotating speed can be automatically optimized according to the sample crushing stage, the whole process efficient treatment from coarse crushing of large particles to grinding of fine particles is realized, the filter hole is prevented from being blocked, and the subsequent centrifugal separation effect is improved;

[0019] 2. The transmission cooperation design of the top plate and the rotating disc realizes the full automation of slurry automatic injection, centrifugal separation and supernatant pushing, without manual intervention, reduces the sample pollution risk, and the inclined liquid tank and the liquid pushing table structure ensure complete solid-liquid separation and high recovery rate of supernatant;

[0020] 3. The liquid storage tank and the liquid distribution tank are temporarily stored and divided, combined with the linkage of the cross piston plate and the piston table, so that solid phase extraction can be performed on multiple samples at the same time, the vacuum chamber negative pressure and the nitrogen positive pressure double action are matched to speed up the eluent flow rate, shorten the enrichment time, and improve the target analyte recovery rate. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present application.

[0022] Figure 2 It is a structural schematic diagram of the present application.

[0023] Figure 3 It is a structural schematic diagram of the crushing mechanism of the present application.

[0024] Figure 4 It is an exploded view of the crushing mechanism of the present application.

[0025] Figure 5 It is a sectional view of the crushing mechanism of the present application.

[0026] Figure 6 It is a structural schematic diagram of the centrifugal mechanism of the present application.

[0027] Figure 7 It is an exploded view of the centrifugal mechanism of the present application.

[0028] Figure 8 is a sectional view of the centrifugal mechanism of the present application.

[0029] Figure 9 is a structural schematic diagram of the distributing mechanism, the solid-phase extraction mechanism and the nitrogen blowing mechanism of the present application.

[0030] Figure 10 is a structural schematic diagram of the liquid distribution chamber of the present application.

[0031] Figure 11 is a structural schematic diagram of the piston table of the present application.

[0032] As shown in the figure: 1, the shell; 2, the crushing mechanism; 3, the centrifugal mechanism; 4, the distributing mechanism; 5, the solid-phase extraction mechanism; 6, the nitrogen blowing mechanism; 11, the top cover; 12, the sealing cover; 21, the motor one; 211, the spline shaft; 22, the adjusting mechanism; 221, the fixed plate; 222, the lifting plate; 223, the wiping table; 224, the threaded rod; 23, the grinding table; 231, the driving rod; 232, the spline groove; 233, the flinging table; 234, the spring one; 24, the grinding bowl; 241, the sieve hole; 242, the feeding head; 243, the valve one; 31, the rotating disc; 311, the mounting hole; 312, the transmission table one; 313, the liquid collection inclined table; 314, the liquid outlet column; 315, the compression spring; 316, the ball table; 32, the liquid tank; 321, the liquid pushing table; 322, the resisting plate; 323, the spring two; 33, the top plate; 331, the motor two; 332, the transmission table two; 333, the sealing plate; 334, the inlet; 34, the lifting table; 341, the pushing table; 35, the air cylinder one; 36, the pushing plate; 41, the liquid storage tank; 411, the ball groove pipe; 412, the valve two; 42, the liquid distribution tank; 43, the liquid distribution pipe; 431, the valve three; 44, the liquid distribution chamber; 441, the cross piston plate; 51, the feeding straight pipe; 511, the air feeding branch pipe; 512, the piston table; 513, the cross sliding groove; 52, the air cylinder two; 53, the displacement plate; 61, the fixed frame; 62, the connecting column; 63, the partition plate; 64, the test tube rack; 65, the test tube. DETAILED DESCRIPTION

[0033] The present application will be further described in detail below with reference to the accompanying drawings.

[0034] The present application will be further described in detail below with reference to the accompanying drawings. Figure 1 The present application will be further described in detail below with reference to the accompanying drawings. Figure 2 As shown in the figure, a sample pretreatment device for food safety detection includes a shell 1, which is provided with a crushing mechanism 2, a centrifugal mechanism 3, a distributing 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 distributing mechanism 4 temporarily stores and distributes the supernatant after centrifugation. The solid-phase extraction mechanism 5 performs solid-phase extraction on the multiple samples after distribution. The nitrogen blowing mechanism 6 cooperates with the solid-phase extraction mechanism 5 to complete the nitrogen blowing work.

[0035] Combined with attachment Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4 As shown, the crushing mechanism 2 includes a motor 21, an adjusting mechanism 22, a grinding table 23 and a grinding mortar 24. The motor 21 drives the grinding table 23 to rotate, and the adjusting mechanism 22 adjusts the distance between the grinding table 23 and the grinding mortar 24. A sieve hole 241 is provided at the bottom of the grinding mortar 24, and a feeding head 242 is provided below the sieve hole 241. A valve 243 is provided on the feeding head 242. A driving rod 231 is provided at the top of the grinding table 23, and a spline groove 232 is provided on the driving rod 231. The output end of the motor 21 is provided with a spline shaft 211 that cooperates with the spline groove 232. The adjusting mechanism 22 includes a fixed plate 221 and a lifting plate 222. The motor 21 is fixed on the fixed plate 221. A top cover 11 is hingedly provided at the top feed port of the shell 1. The fixed plate 221 is fixed in the top cover 11. The driving rod 231 is rotatably provided on the lifting plate 222, and the lifting plate 222 drives the driving rod 231 to move up and down at the bottom of the fixed plate 221.

[0036] Combined with attachment Figure 3 , Attachment Figure 4 and attached Figure 5 As shown, a throwing platform 233 is symmetrically slidably provided on the outside of the driving rod 231, a spring 234 is provided between the rear end of the throwing platform 233 and the driving rod 231, a wiping platform 223 is rotatably provided on the outside of the lifting plate 222 and cooperates with the throwing platform 233, a threaded rod 224 is provided on the top of the wiping platform 223, and a threaded hole is provided on the fixing plate 221 to cooperate with the threaded rod 224.

[0037] Traditional sample crushing methods have problems such as insufficient crushing, difficulty in adapting to the crushing requirements of different stages, and inconvenient separation of residue and slurry. As a result, the subsequent filtration work is affected, the filter holes are easily clogged by large particles, and the processing efficiency is low, which cannot meet the rapid pretreatment needs of diverse samples.

[0038] In order to solve the above problems, the crushing mechanism 2 is improved. In the initial preparation, the food sample is placed in the grinding bowl 24. The height of the lifting plate 222 is adjusted by rotating the threaded rod 224 on the top of the rubbing table 223, and then the top cover 11 is covered. In the crushing stage, the motor 21 is started, and its spline shaft 211 drives the driving rod 231 to rotate at 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 stage of crushing, the food sample is in a large particle state. After the grinding table 23 presses the sample, it is subjected to a large resistance from the sample, and the rotation speed of the grinding table 23 is relatively small. After the sample is gradually crushed from the large particle state, the resistance encountered by the grinding table 23 is reduced and the rotation speed is increased. At this time, the crushing efficiency of the grinding table 23 on the sample is reduced, and it is necessary to lower the height of the grinding table 23 to increase the pressure on the sample.

[0039] As the speed of the grinding table 23 increases, the centrifugal force of the throwing table 233 becomes greater, thereby overcoming the spring resistance and moving outward, and the outer rotation radius of the throwing table 233 gradually becomes larger. After the throwing table 233 contacts the rubbing table 223 during rotation, friction is generated with the rubbing table 223, thereby driving the rubbing table 223 to rotate, and the rubbing table 223 drives the threaded rod 224 to rotate, thereby causing the lifting plate 222 to descend, meeting the demand for the grinding table 23 to descend. This method can also achieve the height adjustment of the grinding table 23 by controlling the speed and rotation direction of the motor 21. After the sample jams the grinding table 23 or the grinding table 23 contacts the grinding mortar 24, the resistance encountered by the grinding table 23 suddenly increases, thereby causing the speed of the grinding table 23 to drop rapidly. At this time, the rotation radius of the throwing table 23 becomes smaller, thereby preventing the grinding table 23 from moving further downward, and having an emergency protection function.

[0040] Combined with attachment Figure 1 , Attachment Figure 2 , Attachment 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 tilted. 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 shell 1. The top plate 33 blocks the top opening of the liquid tank 32 and drives the turntable 31 to rotate. A sealing plate 333 is provided at the bottom of the top plate 33 to abut the top of the liquid tank 32. A plurality of feed ports 334 are provided on the top plate 33, and the feed ports 334 and the sealing plate 333 are arranged at intervals.

[0041] Combined with attachment Figure 6 , Attachment Figure 7 and attached Figure 8 As shown, a liquid pushing platform 321 is slidingly provided on the inner side of the liquid tank 32, and a push plate 322 is provided at the bottom of the liquid pushing platform 321 through the through hole at the bottom of the liquid tank 32, and a spring 2 323 is provided between the push plate 322 and the liquid tank 32, and a liquid collecting inclined platform 313 is provided on the top of the turntable 31 on the inner side of the liquid tank 32, and a liquid outlet column 314 is provided at the bottom of the turntable 31 which is connected to the axial through hole of the liquid collecting inclined platform 313, and a lifting platform 34 is slidingly provided on the outer side of the liquid outlet column 314, and a compression spring 315 is provided between the bottom of the turntable 31 and the lifting platform 34, and a pushing platform 341 is provided on the side of the lifting platform 34 which abuts and slides with the bottom of the push plate 322, and a pushing plate 36 is rotatably provided at the bottom of the lifting platform 34, and a cylinder 1 35 is provided at the bottom of the pushing plate 36.

[0042] Combined with attachment Figure 6 , Attachment Figure 7 and attached Figure 8As shown, 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 that cooperates 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 perform the liquid discharge action.

[0043] In order to meet the integration requirements with the crushing mechanism 2 and the dividing 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 integrated sample pretreatment concept of this device. Therefore, the centrifugal mechanism 3 is required to meet the function of automatic loading and unloading.

[0044] In order to solve the above problems, a top plate 33 and a lifting platform 34 are added. In the feeding stage, the motor 2 331 is started, driving the top plate 33 to rotate so that the feeding port 334 is aligned with the liquid tank 32. Then the cylinder 1 35 pushes the push plate 36 to move up, and 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 transmission platform 1 312 and the bottom of the transmission platform 2 332 are aligned and abutted. The top boss of the transmission platform 1 312 is inserted into the bottom groove of the transmission platform 2 332. At this time, the rotation of the top plate 33 will drive the turntable 31 to rotate, open the valve 1 243, and the crushing mechanism 2 will process The final sample slurry is injected into the liquid tank 32 from the feed port 334 through the feeding head 242. By intermittently rotating the turntable 31, the slurry injection work of multiple liquid tanks 32 is completed. Then 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 transmission platform 1 312 and the transmission platform 2 332 are staggered. The lifting platform 34 rises. At this time, 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, thereby realizing centrifugal treatment of the slurry inside the liquid tank 32, thereby realizing solid-liquid separation.

[0045] During the discharging stage, the lifting platform 34 descends and the top plate 33 is rotated to align the feed port 334 with the liquid tank 32. Then the lifting platform 34 rises, so that the top of the transmission platform 1 312 abuts against the bottom of the transmission platform 2 332. Then the push plate 36 pushes the lifting platform 34 to continue to rise, compressing the compression spring 315. After the abutment plate 322 contacts the push platform 341, the push platform 341 pushes the abutment plate 322 to move, causing the liquid pushing platform 321 to move in the liquid tank 32, pushing the supernatant after centrifugation to flow down from the opening at the top of the liquid tank 32 and flow into the liquid outlet column 314 along the liquid collecting inclined platform 313, completing the liquid discharge action.

[0046] Combined with attachment Figure 1 , Attachment 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 is provided at the bottom of the liquid outlet column 314 for rotatably cooperating with the ball groove material pipe 411, and the inner through hole of the ball table 316 is connected to the ball groove material pipe 411. The liquid storage tank 41 and the liquid separation tank 42 are connected through a pipeline, and a valve 2 412 is provided on the pipeline. A plurality of liquid separation pipes 43 are evenly provided at the bottom of the liquid separation tank 42, and a valve 3 431 is provided on the liquid separation pipe. 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.

[0047] Combined with attachment Figure 9 , Attachment Figure 10 and attached Figure 11 As shown, the solid phase extraction mechanism 5 includes a feed straight pipe 51, an air supply branch pipe 511 is provided on the feed straight pipe 51, and the air supply branch pipe 511 is connected to the nitrogen delivery pipe. A nitrogen delivery device is provided inside the shell 1, and a liquid separation chamber 44 is provided at the bottom of the liquid separation pipe 43. 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 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.

[0048] Combined with attachment 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 mounted on the fixed frame 61. A waste liquid collection tank is provided at the bottom of the fixed frame 61. A connecting column 62 is provided on the fixed frame 61. A partition plate 63 is provided on the top of the connecting column 62. A vacuum chamber is provided below the partition plate 63. A vacuum machine connected to the vacuum chamber is provided inside the shell 1. A sealing cover 12 is hingedly provided on the shell 1 at the vacuum chamber. A heating plate is provided on the shell 1 at the vacuum chamber. A water supply machine for injecting water into the vacuum chamber is provided inside the shell 1.

[0049] The supernatant obtained after centrifugation of the sample needs to be subjected to solid-phase extraction to enrich the target analytes and obtain a higher-purity solution to be tested. Common solid-phase extraction equipment usually relies on experimental personnel to complete the process, with cumbersome steps and the use of many instruments and equipment, which is not conducive to the realization of automated processing.

[0050] This device improves the material distribution mechanism 4, solid phase extraction mechanism 5 and 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, valve 2 412 is opened, and the supernatant enters the liquid separation tank 42 and is then diverted to multiple liquid separation pipes 43.

[0051] During the enrichment stage of solid-phase extraction, the test tube 65 is kept offset from the feed straight tube 51, valve three 431 is opened, and the supernatant enters the liquid separation chamber 44, and enters the feed straight tube 51 through the cross slide 513 on the piston platform 512. The target analyte is enriched on the solid phase filler inside the piston platform 512, and the feed straight tube 51 discharges the waste liquid into the waste liquid collection tank at the bottom of the fixed frame 61.

[0052] During the elution stage of solid-phase extraction, the test tube rack 64 is rotated and the test tube 65 is placed in it, 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 it flows into the liquid separation chamber 44 and stays above the solid phase filler. Then the vacuum machine is turned on to evacuate the vacuum chamber below the partition plate 63. The negative pressure below the solid phase filler will suck the eluent down to the test tube 65. At the same time, the cylinder 2 52 pushes the displacement plate 53 to move upward. On the one hand, it drives the feeding straight tube 51 to move upward, so that the cross piston plate 441 is inserted into the cross slide 513, sealing the top of the eluent in the liquid separation chamber 44, and giving positive pressure to the washing liquid to accelerate the flow of the washing liquid. On the other hand, the bottom of the feeding straight tube 51 moves upward to prepare for nitrogen blowing.

[0053] After the solid phase extraction is completed, the top of the separation chamber 44 is kept closed, the vacuum machine is turned off, the water supply machine and the heating plate are turned on, the water in the vacuum chamber is heated, and the heat is transferred to the solution to be tested inside the test tube 65. The nitrogen is blown toward the liquid surface of the solution to be tested through the feed straight pipe 51 by the nitrogen delivery device to concentrate the solution to be tested after solid phase extraction.

[0054] The above description of the present invention and its embodiments is non-limiting. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by the above and, without departing from the purpose of the present invention, designs structures and embodiments similar to the technical solution without creatively designing, they shall fall within the scope of protection of the present invention.

Claims

1. A sample pretreatment device for food safety testing, comprising a housing (1), wherein 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) are provided in the housing (1), characterized in that: The crushing mechanism (2) includes a motor (21), an adjusting mechanism (22), a grinding table (23) and a grinding bowl (24). The 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 mounted on the turntable (31). 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. The top plate (33) blocks the top opening of the liquid tank (32) and drives the turntable (31) to rotate. The material separation mechanism (4) temporarily stores and separates the supernatant after centrifugation, the solid phase extraction mechanism (5) performs solid phase extraction on the multiple samples after separation, and the nitrogen blowing mechanism (6) cooperates with the solid phase extraction mechanism (5) to complete the nitrogen blowing work; A driving rod (231) is provided on the top of the grinding table (23), a spline groove (232) is provided on the driving rod (231), a spline shaft (211) that matches the spline groove (232) is provided on the output end of the motor 1 (21), the adjustment mechanism (22) includes a fixed plate (221) and a lifting plate (222), the motor 1 (21) is fixed on the fixed plate (221), the driving rod (231) is rotatably provided on the lifting plate (222), and the lifting plate (222) drives the driving rod (231) to move up and down at the bottom of the fixed plate (221); A swinging platform (233) is symmetrically slidably provided on the outside of the driving rod (231), a spring (234) is provided between the rear end of the swinging platform (233) and the driving rod (231), a rubbing platform (223) is rotatably provided on the outside of the lifting plate (222) and cooperates with the swinging platform (233), a threaded rod (224) is provided on the top of the rubbing platform (223), and a threaded hole cooperating with the threaded rod (224) is provided on the fixing plate (221).

2. A sample pretreatment device for food safety testing according to claim 1, characterized in that: The liquid tank (32) is obliquely mounted on the mounting hole (311) on the turntable (31); a sealing plate (333) is provided at the bottom of the top plate (33) and abuts against the top of the liquid tank (32); and a plurality of feed ports (334) are provided on the top plate (33) and are staggered with the sealing plate (333).

3. A sample pretreatment device for food safety testing according to claim 2, characterized in that: A liquid pushing platform (321) is provided on the inner side of the liquid tank (32) for sliding, a back plate (322) is provided on the bottom of the liquid pushing platform (321) through a through hole at the bottom of the liquid tank (32), a second spring (323) is provided between the back plate (322) and the liquid tank (32), a liquid outlet column (314) is provided on the bottom of the turntable (31), a lifting platform (34) is provided on the outer side of the liquid outlet column (314) for sliding, a compression spring (315) is provided between the bottom of the turntable (31) and the lifting platform (34), a pushing platform (341) is provided on the side of the lifting platform (34) for abutting and slidingly cooperating with the bottom of the back plate (322), a pushing plate (36) is provided on the bottom of the lifting platform (34) for rotation, and a cylinder (35) is provided on the bottom of the pushing plate (36).

4. A sample pretreatment device for food safety testing according to claim 3, 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) that matches 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 perform the liquid discharge action.

5. The sample pretreatment device for food safety testing according to claim 1, characterized in that: The material distribution mechanism (4) includes a liquid storage tank (41) and a liquid separation tank (42), the liquid storage tank (41) and the liquid separation tank (42) are connected through a pipeline, and 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) includes a feeding straight pipe (51), and the nitrogen blowing mechanism (6) includes a fixed frame (61) and a test tube rack (64). The test tube rack (64) is rotatably arranged on the fixed frame (61), and a partition plate (63) is provided on the top of the fixed frame (61). A vacuum chamber is provided below the partition plate (63). The feeding straight pipe (51) is provided with an air supply branch pipe (511), and a nitrogen delivery device connected to the air supply branch pipe (511) is provided in the shell (1).

6. A sample pretreatment device for food safety testing according to claim 5, 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 on the inner side of the liquid separation chamber (44), a piston platform (512) is provided on the top of the feeding straight tube (51), a cross slide (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 the through hole on the displacement plate (53).

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