Pretreatment Device for Detecting Residual Pesticides in Vegetables

Abstract

The present invention discloses a pretreatment device for detecting residual pesticides in vegetables, which comprises a horizontal bottom plate, a rectangular frame, a first electric cylinder for pushing the rectangular frame to move back and forth along a straight guide rail, a test tube bin, a second electric cylinder for pushing the test tube bin to move up and down, a sample tube, a filter tube, a vacuum pump, a crushing mechanism, an extraction liquid adding mechanism and a tool cleaning mechanism. The pretreatment device for detecting residual pesticides in vegetables of the present invention can automatically crush vegetable samples, automatically add extraction liquid into vegetable samples, separate the extraction liquid from the filter tube into the sample tube by means of negative pressure filtration, and can automatically clean the crushing knife. The pretreatment device for detecting residual pesticides in vegetables can improve the pretreatment efficiency of vegetable pesticide residue detection. The pretreatment device for detecting residual pesticides in vegetables of the present invention is also applicable to the pretreatment of pesticide residue detection of other agricultural products such as fruits.

Description

Technical Field

[0001] The present invention relates to the technical field of residual pesticide detection, and particularly to a pretreatment device for detecting residual pesticides in vegetables. Background Art

[0002] During the cultivation of vegetables, in order to resist pests and diseases, most vegetables need to be sprayed with pesticides multiple times to ensure their maturity and marketability in a short period. Generally, leafy and stem vegetables, fruits, and legumes have more pesticide residues, while root vegetables have less. To prevent people from purchasing vegetables with excessive pesticide residues, it is necessary to detect the pesticide residues in vegetables. Among them, the pretreatment of vegetable samples is a crucial step in the whole pesticide residue detection. The pretreatment of vegetable samples includes steps such as crushing the weighed samples, adding an extractant for extraction, and obtaining the extract by filtration. However, in the prior art, the pretreatment of vegetable samples is usually manually completed, resulting in low efficiency. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a pretreatment device for detecting residual pesticides in vegetables, so as to solve the technical problems of pretreating vegetable samples during the detection of residual pesticides and improving the working efficiency of pretreatment.

[0004] The pretreatment device for detecting residual pesticides in vegetables of the present invention includes a horizontal bottom plate, a straight guide rail provided on the horizontal bottom plate, a rectangular frame provided on the straight guide rail and slidably matched with the straight guide rail, a first electric cylinder provided on the horizontal bottom plate for pushing the rectangular frame to move back and forth along the straight guide rail, a cuboid-shaped test tube bin located above the rectangular frame, and a second electric cylinder vertically provided in the rectangular frame for pushing the test tube bin to move up and down. A plurality of cylindrical cavities are provided in the length direction of the test tube bin, and a sample tube is inserted into each cylindrical cavity. A filter tube is inserted into each sample tube. The filter tube includes a filter tube body with drain holes provided at the bottom and a filter membrane fixed outside the filter tube body and covering the drain holes. A liquid storage cavity is formed between the bottom of the filter tube body and the bottom of the sample tube. A ventilation hole communicating with the cylindrical cavity is provided in the upper part of the sample tube. A circular tube edge is provided at the mouth of the sample tube. Rubber sealing gaskets are provided on the top and bottom surfaces of the circular tube edge. The edge of the mouth of the filter tube is pressed on the rubber sealing gaskets.

[0005] The pretreatment device for detecting residual pesticides in vegetables further includes exhaust branch pipes corresponding to and communicating with each cylindrical cavity one by one, an exhaust main pipe connected to each exhaust branch pipe, a vacuum pump connected to the exhaust main pipe, and an electric air valve provided on each exhaust branch pipe.

[0006] The pre-treatment device for detecting residual pesticides in vegetables further includes a crushing mechanism. The crushing mechanism includes crushing knives corresponding to the filter tubes one by one. Each crushing knife includes a hollow knife rod arranged vertically and a knife body fixed at the lower end of the hollow knife rod. The crushing mechanism further includes a gearbox. The gearbox includes a box body, and transmission gears are arranged in the box body on each hollow knife rod. The transmission gears mesh with each other. A motor is further arranged on the top of the gearbox. A driving gear is arranged on the rotor shaft of the motor. A driven gear meshing with the driving gear is arranged on one of the hollow knife rods. A bracket for supporting the box body is arranged on the horizontal bottom plate;

[0007] The pre-treatment device for detecting residual pesticides in vegetables further includes an extraction liquid adding mechanism. The extraction liquid adding mechanism includes a rotary pipe joint arranged at the upper end of the hollow knife rod, a liquid adding branch pipe connected to the rotary pipe joint, a liquid adding main pipe connected to the liquid adding branch pipe, a metering pump with an outlet connected to the liquid adding main pipe, an extraction liquid storage tank, and an infusion pipe connecting the inlet of the metering pump and the extraction liquid storage tank. An electric valve is arranged on each liquid adding branch pipe;

[0008] The pre-treatment device for detecting residual pesticides in vegetables further includes a knife cleaning mechanism. The knife cleaning mechanism includes a water adding branch pipe connected to the liquid adding branch pipe and located on the outlet side of the electric water valve, a water adding main pipe connected to the water adding branch pipe, a water pump with an outlet connected to the water adding main pipe, a water tank, and a water pipe connecting the inlet of the water pump and the water tank. A first electric valve is arranged on the water adding main pipe; Drainage holes communicating with the lower ends of the cylindrical cavities are further arranged on the test tube bin. A drain pipe is arranged at the bottom of one of the cylindrical cavities. A second electric valve is arranged on the drain pipe. A window for avoiding the drain pipe and the second electric valve is arranged on the top of the rectangular frame. A sewage tank for collecting the wastewater discharged from the drain pipe is arranged in the rectangular frame.

[0009] Advantages of the present invention:

[0010] The pre-treatment device for detecting residual pesticides in vegetables of the present invention can automatically crush vegetable samples, automatically add extraction liquid into the vegetable samples, can separate the extraction liquid from the filter tube into the sample tube by means of negative pressure filtration, can automatically clean the crushing knives, and can improve the pre-treatment efficiency of vegetable pesticide residue detection. The pre-treatment device for detecting residual pesticides in vegetables of the present invention is also applicable to the pre-treatment of pesticide residue detection of other agricultural products such as fruits. Description of the Drawings

[0011] Figure 1 It is a three-dimensional structural schematic diagram of the pre-treatment device for detecting residual pesticides in vegetables;

[0012] Figure 2 It is a three-dimensional structural schematic diagram of the pre-treatment device for detecting residual pesticides in vegetables from another perspective;

[0013] Figure 3 It is a schematic perspective view of a partial sectional structure of a pretreatment device for detecting residual pesticides in vegetables;

[0014] Figure 4 It is a schematic perspective view of the second electric cylinder pushing up the test tube bin;

[0015] Figure 5 It is a schematic perspective sectional structure view of a sample tube and a filter tube. Specific embodiments

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0017] As shown in the figure, the pretreatment device for detecting residual pesticides in vegetables in this embodiment includes a horizontal bottom plate 1, a straight guide rail 2 provided on the horizontal bottom plate, a rectangular frame 3 provided on the straight guide rail and slidably matched with the straight guide rail, a first electric cylinder 4 provided on the horizontal bottom plate for pushing the rectangular frame to move back and forth along the straight guide rail, a cuboid-shaped test tube bin 5 located above the rectangular frame, and a second electric cylinder 6 vertically arranged in the rectangular frame for pushing the test tube bin to move up and down. A plurality of cylindrical cavities 7 are arranged in the length direction of the test tube bin, and a sample tube 8 is inserted into each cylindrical cavity. A filter tube 9 is inserted into each sample tube; the filter tube includes a filter tube body 91 with a drain hole at the bottom and a filter membrane 92 fixed outside the filter tube body and covering the drain hole; a liquid storage cavity 10 is formed between the bottom of the filter tube body and the bottom of the sample tube. A ventilation hole 11 communicating with the cylindrical cavity is provided at the upper part of the sample tube. A circular tube edge is provided at the mouth of the sample tube, and rubber sealing gaskets 12 are provided on the top surface and the bottom surface of the circular tube edge. The edge of the mouth of the filter tube is pressed on the rubber sealing gasket.

[0018] The pretreatment device for detecting residual pesticides in vegetables further includes exhaust branch pipes 13 corresponding to and communicating with each cylindrical cavity one by one, an exhaust main pipe 14 connected to each exhaust branch pipe, a vacuum pump 15 connected to the exhaust main pipe, and an electric air valve 16 provided on each exhaust branch pipe. The exhaust branch pipes and the exhaust main pipe are made of soft rubber hoses in specific implementation.

[0019] The pretreatment device for detecting residual pesticides in vegetables further includes a crushing mechanism. The crushing mechanism includes a crushing knife 17 corresponding to each filter tube. The crushing knife includes a hollow knife rod 171 arranged vertically and a knife body 172 fixed at the lower end of the hollow knife rod. The crushing mechanism further includes a gear box. The gear box includes a box body 18. Transmission gears 19 are arranged in the box body and on each hollow knife rod. The transmission gears mesh with each other. A motor 20 is further provided on the top of the gear box. A driving gear 21 is provided on the rotor shaft of the motor. A driven gear 22 meshing with the driving gear is provided on one of the hollow knife rods. A bracket 23 for supporting the box body is provided on the horizontal bottom plate.

[0020] The pre - treatment device for detecting residual pesticides in vegetables further includes an extraction liquid adding mechanism. The extraction liquid adding mechanism includes a rotary pipe joint 24 arranged at the upper end of the hollow tool bar, a liquid adding branch pipe 25 connected to the rotary pipe joint, a liquid adding main pipe 26 connected to the liquid adding branch pipe, a metering pump 27 with its liquid outlet connected to the liquid adding main pipe, an extraction liquid storage tank 28, and an infusion pipe 29 connecting the liquid inlet of the metering pump and the extraction liquid storage tank. An electric valve 30 is arranged on each liquid adding branch pipe.

[0021] The pre - treatment device for detecting residual pesticides in vegetables further includes a tool cleaning mechanism. The tool cleaning mechanism includes a water adding branch pipe 31 connected to the liquid adding branch pipe and located on the outlet side of the electric water valve, a water adding main pipe 32 connected to the water adding branch pipe, a water pump 33 with its water outlet connected to the water adding main pipe, a water tank 34, and a water pipe 35 connecting the water inlet of the water pump and the water tank. A first electric water valve 36 is arranged on the water adding main pipe; a drain hole 37 communicating with the lower end of each cylindrical cavity is also arranged on the test tube bin. A drain pipe 38 is arranged at the bottom of one of the cylindrical cavities, and a second electric water valve 39 is arranged on the drain pipe. A window 40 for avoiding the drain pipe and the second electric water valve is arranged on the top of the rectangular frame, and a sewage tank 41 for collecting the wastewater discharged from the drain pipe is arranged inside the rectangular frame.

[0022] In this embodiment, the pre - treatment device for detecting residual pesticides in vegetables works under the control of a PLC controller, and its working process is as follows:

[0023] In the first step, the weighed vegetable sample is put into the filter tube 9.

[0024] In the second step, the PLC controls the second electric cylinder 6 to push the test tube bin 5 upward until the mouth of the filter tube 9 contacts the bottom surface of the box body 18.

[0025] In the third step, the PLC controls the metering pump 27 to work, and the PLC sequentially controls each electric valve 30 to open, so as to pump a set amount of extraction liquid into each filter tube 9.

[0026] In the fourth step, the PLC controls the motor 20 to work. The motor drives the crushing knife 17 to rotate at a high speed through gears, so as to crush the vegetable sample, and make the residual pesticides on the surface and inside of the vegetables dissolve in the extraction liquid.

[0027] In the fifth step, the PLC controls the second electric cylinder 6 to push the test tube bin 5 downward, so that the crushing knife 17 is withdrawn from the filter tube 9.

[0028] In the sixth step, the PLC controls the vacuum pump 15 to work. The vacuum pump discharges the air in the liquid storage cavity 10, so as to form a negative pressure in the liquid storage cavity 10. The liquid in the filter tube 9 enters the liquid storage cavity 10 through the filter membrane 92 under the negative pressure.

[0029] Step 7: The PLC controls the first electric cylinder 4 to push the rectangular frame 3 forward, then the operator takes out the filter tube 9, and then takes out the sample tube 8 manually. After the liquid in the sample tube stands still, the extract and water are separated, and the extract can be taken out for subsequent detection operations.

[0030] Step 8: The PLC controls the first electric cylinder 4 to pull the rectangular frame 3 back to its original position, and then controls the second electric cylinder 6 to push the test tube bin 5 up until it contacts the bottom surface of the box body 18.

[0031] Step 9: The PLC controls the first electric water valve 36 to open, then controls the water pump 33 to pump a certain amount of cleaning water into the cylindrical cavity 7, and then controls the motor 20 to drive the crushing knife 17 to rotate. The crushing knife 17 rotates in the clean water to clean the tool. Finally, control the second electric water valve 39 to open to drain the waste water into the sewage tank 41. Repeat this step several times to thoroughly clean the crushing tool.

[0032] In this embodiment of the pretreatment device for detecting residual pesticides in vegetables, it can automatically crush vegetable samples, automatically add extract to vegetable samples, separate the extract from the filter tube into the sample tube by negative pressure filtration, and can automatically clean the crushing knife. This pretreatment device for detecting residual pesticides in vegetables can improve the pretreatment efficiency of detecting pesticide residues in vegetables. This pretreatment device for detecting residual pesticides in vegetables in this embodiment is also applicable to the pretreatment of detecting pesticide residues in other agricultural products such as fruits.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. Vegetable residual pesticide detection pretreatment device, characterized in that: It includes a horizontal bottom plate, a straight guide rail arranged on the horizontal bottom plate, a rectangular frame arranged on the straight guide rail and slidingly matched with the straight guide rail, a first electric cylinder arranged on the horizontal bottom plate for pushing the rectangular frame to move back and forth along the straight guide rail, a cuboid-shaped test tube bin located above the rectangular frame, and a second electric cylinder vertically arranged in the rectangular frame for pushing the test tube bin to move up and down. A number of cylindrical cavities are arranged in the length direction of the test tube bin, and a sample tube is inserted into each cylindrical cavity, and a filter tube is inserted into each sample tube; the filter tube includes a filter tube body with drain holes arranged at the bottom and a filter membrane fixed outside the filter tube body and covering the drain holes; a liquid storage cavity is formed between the bottom of the filter tube body and the bottom of the sample tube, a ventilation hole communicating with the cylindrical cavity is arranged at the upper part of the sample tube, a circular tube edge is arranged at the mouth of the sample tube, rubber sealing gaskets are arranged on the top surface and the bottom surface of the circular tube edge, and the edge of the mouth of the filter tube is pressed on the rubber sealing gaskets; The vegetable residual pesticide detection pretreatment device further includes exhaust branch pipes corresponding to and communicating with each cylindrical cavity one by one, an exhaust main pipe connected to each exhaust branch pipe, a vacuum pump connected to the exhaust main pipe, and electric air valves arranged on each exhaust branch pipe; The vegetable residual pesticide detection pretreatment device further includes a crushing mechanism. The crushing mechanism includes crushing knives corresponding to the filter tubes one by one. The crushing knives include vertically arranged hollow knife rods and knife bodies fixed at the lower ends of the hollow knife rods. The crushing mechanism further includes a gear box. The gear box includes a box body and transmission gears arranged on each hollow knife rod and located in the box body. The transmission gears mesh with each other. A motor is further arranged on the top of the gear box. A driving gear is arranged on the rotor shaft of the motor. A driven gear meshing with the driving gear is arranged on one of the hollow knife rods. A bracket for supporting the box body is arranged on the horizontal bottom plate; The vegetable residual pesticide detection pretreatment device further includes an extraction liquid adding mechanism. The extraction liquid adding mechanism includes a rotary pipe joint arranged at the upper end of the hollow knife rod, a liquid adding branch pipe connected to the rotary pipe joint, a liquid adding main pipe connected to the liquid adding branch pipe, a metering pump with an outlet connected to the liquid adding main pipe, an extraction liquid storage tank, and an infusion pipe connecting the inlet of the metering pump and the extraction liquid storage tank. An electric valve is arranged on each liquid adding branch pipe; The vegetable residual pesticide detection pretreatment device further includes a tool cleaning mechanism. The tool cleaning mechanism includes a water adding branch pipe connected to the liquid adding branch pipe and located on the outlet side of the electric valve, a water adding main pipe connected to the water adding branch pipe, a water pump with an outlet connected to the water adding main pipe, a water tank, and a water pipe connecting the inlet of the water pump and the water tank. A first electric water valve is arranged on the water adding main pipe; a drain hole communicating with the lower end of each cylindrical cavity is further arranged on the test tube bin. A drain pipe is arranged at the bottom of one of the cylindrical cavities. A second electric water valve is arranged on the drain pipe. A window for avoiding the drain pipe and the second electric water valve is arranged on the top of the rectangular frame. A sewage tank for collecting the waste water discharged from the drain pipe is arranged in the rectangular frame.

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