Pesticide residue detection equipment and detection method thereof

Abstract

The invention relates to detection equipment, and discloses pesticide residue detection equipment and a detection method thereof.The detection equipment comprises a base and a cover plate, a detection position is arranged on the upper end face of the base and close to the side of the cover plate, and a sample containing frame is detachably installed on the base; the sample placing rack comprises a light shielding cover which can cover the detection position and sample detection cylinders which are fixed on the light shielding cover and are in one-to-one correspondence with the rapid detection card fixing parts, and the bottom of each sample detection cylinder is provided with a sample liquid dropper of which the lower end part can extend to the upper part of the corresponding rapid detection card fixing part when the light shielding cover covers the detection position; a liquid taking rod capable of conveying sample liquid in the sample detection cylinder into the sample liquid dropper is arranged in the sample detection cylinder. According to the invention, by arranging the detachable sample placing rack, the light shielding and heat preservation effects during sample detection can be achieved, so that the influence of external temperature and light on a detection result is effectively reduced, and the accuracy of a field pesticide residue detection result is improved.

Description

Technical Field

[0001] The present invention relates to a detection device, and more particularly to a pesticide residue detection device. Background Art

[0002] Currently, common pesticide residue detection devices mainly consist of a device body, rapid test cards, several containers, droppers, etc. There is a heating sheet on the device body, and a card slot is provided at the heating sheet to fix the rapid test card. The rapid test card has two round tablets in red and white. Ensure that the red tablet (containing indophenol acetate (color developer) and acetic acid) faces upward, and the white tablet (containing cholinesterase extracted from bovine serum) is aligned with the heating plate. The white round tablet will catalyze the hydrolysis reaction of indophenol acetate (color developer) in the red round tablet to generate the blue product indophenol. If the sample contains organophosphorus or carbamate pesticides, the pesticides will inhibit the activity of cholinesterase, resulting in the hydrolysis reaction being blocked, the blue product being reduced, and the color becoming lighter; The determination is based on the color of the white tablet: Sky blue: Negative, indicating no pesticide residue or the concentration is lower than the safety standard.

[0003] White or light blue: Positive, indicating that the pesticide residue exceeds the standard and further treatment is required.

[0004] This type of detection device can quickly detect different samples. It can not only be operated in the laboratory, but also be directly operated in the field due to its portability.

[0005] However, in the actual operation process, it is found that there are differences in the detection results of this type of detection device in the laboratory and in the field. The main reason is that the laboratory is in a constant temperature environment. In the field environment, if the temperature is low, the enzymatic reaction will be slowed down, and there is also ultraviolet light irradiation in the field environment. External light will not only accelerate the decomposition and oxidation process of pesticides, but also interfere with the color reaction. Therefore, it is often difficult to obtain relatively accurate detection results in field operations. Summary of the Invention

[0006] The present invention aims at the problems existing in the process of detecting pesticide residues in the field by existing pesticide residue detection devices, and provides a pesticide residue detection device and its detection method.

[0007] In order to solve the above technical problems, the present invention is solved by the following technical solutions: Pesticide residue detection equipment, including a base and a cover plate. There is a detection position on the upper end surface of the base and close to the cover plate side. At the detection position, there are multiple rapid test card fixing parts arranged at equal intervals along the length direction of the base. At the rapid test card fixing parts, there are heating sheets capable of heating the rapid test cards. A sample placement rack is detachably installed on the base. The sample placement rack includes a light-shielding cover that can cover the detection position and sample detection cylinders fixed on the light-shielding cover and corresponding to the rapid test card fixing parts one by one. At the bottom of the sample detection cylinder, there is a sample liquid dropper pipe whose lower end can extend above the rapid test card fixing part when the light-shielding cover covers the detection position. Inside the sample detection cylinder, there is a liquid extraction rod capable of transporting the sample liquid in the sample detection cylinder into the sample liquid dropper pipe.

[0008] Preferably, at both ends of the base along the length direction, there are plug-in seats. At the plug-in seats, there are plug-in slots with upward openings. The light-shielding cover is in the shape of a rectangular shell with a lower end opening, and on the upper end surface, there is a U-shaped plug-in part with a downward opening. When the two ends of the U-shaped plug-in part are inserted into the plug-in slots, the light-shielding cover covers the detection position. The connection method between the plug-in seat and the light-shielding cover makes its installation and disassembly very convenient.

[0009] Preferably, the upper end part of the sample liquid dropper pipe connected to the bottom of the sample detection cylinder forms a sealed end. In the middle of the sealed end, there is a perforation for the liquid extraction rod to pass through. The lower end of the liquid extraction rod extends into the sample liquid dropper pipe through the perforation. On the inner wall of the perforation, there is an annular groove, and in the annular groove, there is a sealing member capable of sealing the gap between the outer wall of the liquid extraction rod and the inner wall of the perforation. The setting of the sealing member can achieve the sealing of the bottom of the sample detection cylinder and ensure the smooth progress of the liquid extraction process of the liquid extraction rod.

[0010] Preferably, along the axial direction on the outer wall of the liquid extraction rod, there are multiple quantitative liquid extraction grooves arranged in sequence. The quantitative liquid extraction grooves are located at the lower end position of the liquid extraction rod, and the liquid extraction rod can move axially back and forth in the perforation. By extracting liquid through the quantitative sampling grooves, the liquid extraction amount can be effectively controlled, ensuring the accuracy of the detection results.

[0011] Preferably, inside the sample detection cylinder, there is also a filter cylinder arranged coaxially with the sample detection cylinder. In the middle of the wall of the filter cylinder, there are filter holes, and the liquid extraction rod is located inside the filter cylinder. The setting of the filter cylinder can further filter the suspended matter in the supernatant, further improving the accuracy of the detection results.

[0012] Preferably, the sample detection cylinder includes a cylinder body and a cylinder cover. The upper end part of the liquid extraction rod extends out of the cylinder cover and is provided with a control handle for pushing or pulling out the liquid extraction rod. On the sample detection cylinder, there is also a limit plate installed above the control handle for limiting the upward movement stroke of the control handle. The setting of the limit plate enables the operator to not need to overly consider the pulling degree when pulling up the liquid extraction rod, but to control the pulling stroke by itself according to the limit plate, which is accurate and efficient.

[0013] Preferably, a limit plate mounting seat is fixed on the side wall of the sample detection cylinder. An adjustable connecting rod is mounted on the limit plate mounting seat, and the limit plate is mounted on the upper end of the connecting rod. The adjustable setting of the connecting rod can realize the up and down adjustment of the limit plate to meet the limits for different liquid taking amounts.

[0014] Preferably, an arc-shaped indicating plate with an inner surface fitting the outer surface of the cylinder cover is fixed on the limit plate. Scale lines are provided on the inner surface of the arc-shaped indicating plate in the height direction of the sample detection cylinder, and the position of the scale lines relative to the upper surface of the cylinder cover is matched with the number of quantitative liquid taking grooves that can enter the sample detection cylinder. The setting of the arc-shaped indicating plate enables the operator to more intuitively judge the liquid taking amount.

[0015] Preferably, the connecting rod is a screw rod threadedly connected to the limit plate mounting seat, and a knob for driving the connecting rod to rotate in the limit plate mounting seat is provided at the upper end of the connecting rod. The height of the connecting rod is adjusted by rotating the knob, which is convenient and fast to operate.

[0016] The detection method of the pesticide residue detection device is to perform detection with the aforementioned pesticide residue detection device, which specifically includes the following steps: Step S1: Prepare the extraction solution, and a conventional extraction solution on the market can be used; Step S2: Cut the required detection samples into pieces respectively, and take 5 g of each and put them into different sample detection cylinders; Step S3: Add 10 ml of extraction solution to each sample detection cylinder; Step S4: After covering the sample detection cylinder, shake the whole sample placement rack; Step S5: Open the cover plate, first insert the rapid test card at the rapid test card fixing part, and then install the sample placement rack on the base and let it stand for 2 min; Step S6: Use the liquid taking rod to transport the sample liquid in the sample detection cylinder to the sample liquid dropper, and the liquid in the sample dropper is dropped on the white tablet; Step S7: Press the "Start" key of the device to start the reaction stage and wait for 10 - 13 min; Step S8: After the reaction ends, the device emits a prompt sound. Remove the sample placement rack and close the cover plate so that the red tablet fits on the white tablet; Step S9: Enter the color development stage. In this stage, the heating sheet maintains a constant temperature of 38 °C for 3 - 4 min; Step S10: Read the detection result.

[0017] Since the present invention adopts the above technical solutions, it has remarkable technical effects: By providing a detachable sample placement rack, the present invention can achieve the effects of light shielding and heat preservation during sample detection, thereby effectively reducing the impact of external temperature and light on the detection results and improving the accuracy of field pesticide residue detection results. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention.

[0019] Figure 2 is Figure 1 a schematic structural diagram after removing the sample placement rack in

[0020] Figure 3 is a schematic structural diagram of the sample placement rack in Embodiment 1 of the present invention.

[0021] Figure 4 is Figure 1 a sectional view of

[0022] Figure 5 is Figure 4 a partial enlarged view of part A in

[0023] Figure 6 is a schematic structural diagram of the sample detection cylinder in Embodiment 1 of the present invention. Detailed Embodiments

[0024] The present invention will be further described in detail below in conjunction with the drawings and embodiments.

[0025] Embodiment 1 A pesticide residue detection device, as Figures 1-6 shown, includes a base 1 and a cover plate 2. On the upper end surface of the base 1 and near the cover plate 2 side, there is a detection position 101. The detection position 101 is provided with a plurality of rapid test card fixing parts 102 arranged at equal intervals along the length direction of the base 1. At the rapid test card fixing part 102, there is a heating sheet 105 capable of heating the rapid test card.

[0026] The rapid test card fixing part 102 includes a rapid test card insertion slot 322 and a rapid test card support plate 323. The rapid test card is inserted at the rapid test card insertion slot 322 and the white tablet is kept on the heating sheet 105, and the red tablet is supported on the support plate 323. On the inner side wall of the cover plate 2, there is a pressing block 201. When the cover plate 2 is closed on the base 1, the pressing block 201 can press the red tablet tightly on the white tablet.

[0027] A sample placement rack 3 is detachably installed on the base 1, and it is specifically installed and disassembled by plugging. During the operation, it only needs to be inserted from top to bottom or picked up from bottom to top, which is very convenient.

[0028] The specific structure is as follows: The sample placement rack 3 includes a light-shielding cover 301 that can cover the detection position 101 and sample detection cylinders 302 fixed on the light-shielding cover 301 and corresponding one-to-one with the rapid test card fixing parts 102; the sample detection cylinders 302 are installed on the base 1 through this placement rack in one step to form an integral body. This structural form, on the one hand, does not require each sample to be equipped with a separate sample container and a pipette like existing detection equipment, reducing the number of small parts during the carrying process; on the other hand, when shaking and mixing the samples, multiple samples can be processed synchronously, without shaking them one by one, which can save a lot of time and improve efficiency when there are many samples.

[0029] Plug-in seats 103 are provided at both ends of the base 1 along the length direction. Plug-in grooves 104 with upward openings are provided at the plug-in seats 103. The light-shielding cover 301 is in the shape of a rectangular shell with a lower end opening, and a U-shaped plug-in part 305 with a downward opening is provided on the upper end surface. When the two ends of the U-shaped plug-in part 305 are inserted into the plug-in grooves 104, the light-shielding cover 301 covers the detection position 101, and it can block light and keep warm for the speed test cards at each rapid test card fixing part 102 during the test process.

[0030] A sample liquid dropper 303 is provided at the bottom of the sample detection cylinder 302, and when the light-shielding cover 301 covers the detection position 101, the lower end of the sample liquid dropper 303 extends above the rapid test card fixing part 102. A liquid taking rod 304 is provided in the sample detection cylinder 302, which can transport the sample liquid in the sample detection cylinder 302 into the sample liquid dropper 303.

[0031] When installing the sample placement rack 3, just insert the two ends of the U-shaped plug-in part 305 on it into the plug-in grooves 104 to complete the installation. At this time, the liquid outlet of the sample liquid dropper 303 is above the white tablet, and a certain distance is reserved between them. The distance should not be too large to prevent the sample liquid from splashing out of the range where the white tablet is located.

[0032] To ensure the smooth extraction of the sample liquid, a sealing end 306 is formed at the upper end of the sample liquid dropper 303 connected to the bottom of the sample detection cylinder 302. A through hole 308 for the liquid taking rod 304 to pass through is formed in the middle of the sealing end 306. The lower end of the liquid taking rod 304 extends into the sample liquid dropper 303 through the through hole 308. An annular groove 307 is provided on the inner wall of the through hole 308, and a sealing member 309 that can seal the gap between the outer wall of the liquid taking rod 304 and the inner wall of the through hole 308 is provided in the annular groove 307. The sealing member 309 can be an O-ring embedded in the annular groove 307. The bottom of the sample detection cylinder 302 is sealed through the O-ring to ensure the smooth progress of the liquid taking process of the liquid taking rod 304.

[0033] In this embodiment, a plurality of quantitative liquid extraction grooves 310 are sequentially arranged on the outer wall of the liquid extraction rod 304 along the axial direction. The quantitative liquid extraction grooves 310 are located at the lower end position of the liquid extraction rod 304. The liquid extraction rod 304 can move axially back and forth within the perforation 308. The sample detection cylinder 302 includes a cylinder body 313 and a cylinder cover 314. The cylinder cover 314 is covered on the cylinder body 313 by means of threads to prevent liquid from splashing out during shaking.

[0034] The upper end of the liquid extraction rod 304 extends out of the cylinder cover 314 and is provided with a control handle 315 for pushing or pulling out the liquid extraction rod 304. During the liquid extraction process, the operator pulls up the control handle 315 to move the liquid extraction rod 304 upward, so that the quantitative liquid extraction grooves 310 on its outer wall move to the sample detection cylinder 302, and then pushes down the control handle 315 to move the liquid extraction rod 304 downward into the sample liquid dropper 303. During the downward movement, the quantitative liquid extraction grooves 310 will bring the sample liquid in the sample detection cylinder 302 into the sample liquid dropper 303. After entering the sample liquid dropper 303, it will drip down along the flow channel formed between the inner wall of the sample liquid dropper 303 and the outer wall of the liquid extraction tube onto the rapid test card.

[0035] During the detection process, generally about 2 - 4 drops of sample liquid, about 80 microliters, need to be dropped on the white tablet. In the design, the liquid extraction volume of each quantitative liquid extraction groove 310 can be designed to be about one drop, so that the liquid extraction volume can be controlled by controlling the number of quantitative liquid extraction grooves 310 entering the sample detection cylinder 302.

[0036] In order to further ensure that the number of quantitative liquid extraction grooves 310 entering the sample detection cylinder 302 can be accurately controlled and avoid operation errors, a limit plate 316 for limiting the upward movement stroke of the control handle 315 is also installed on the sample detection cylinder 302 above the control handle 315. When the operator pulls up the control handle 315 to move the liquid extraction rod 304 upward, it will be blocked by the limit plate 316 when pulled to the limit plate 316 and cannot be pulled further, ensuring that the operator will not pull up the liquid extraction rod 304 excessively.

[0037] In order to extract different amounts of sample liquid, the height of the limit plate 316 is also made adjustable. Specifically, a limit plate mounting seat 317 is fixed on the side wall of the sample detection cylinder 302. An adjustable connecting rod 318 is installed on the limit plate mounting seat 317. The limit plate 316 is installed at the upper end of the connecting rod 318. Among them, the connecting rod 318 is a screw rod threadedly connected to the limit plate mounting seat 317, and a knob 321 for driving the connecting rod 318 to rotate within the limit plate mounting seat 317 is provided at the upper end of the connecting rod 318.

[0038] When faced with different samples that require different amounts of liquid to be taken, the staff can adjust the position of the connecting rod 318 by rotating the knob 321, and then adjust the height of the limiting plate 316. In addition, an arc-shaped indicator plate 319 with an inner surface that fits the outer surface of the cylinder cover 314 is fixed on the limiting plate 316. Scale lines 320 are provided on the arc-shaped indicator plate 319 in the height direction of the sample detection cylinder 302. The position of the scale lines 320 relative to the upper surface of the cylinder cover 314 is matched with the number of quantitative liquid extraction grooves 310 that can enter the sample detection cylinder 302, enabling the staff to more intuitively observe the amount of liquid taken.

[0039] When setting, multiple scale lines 320 corresponding one by one to the number of quantitative liquid extraction grooves 310 can be provided on the arc-shaped indicator plate 319 in the height direction. When different scale lines 320 are flush with the upper surface of the cylinder cover 314, it means that different numbers of quantitative liquid extraction grooves 310 can enter the sample detection cylinder 302, that is, the staff can intuitively judge the amount of liquid taken.

[0040] Through the above mechanism, on the one hand, quantitative liquid extraction can be achieved, and on the other hand, the operator does not need to consider the displacement amount of pulling up the liquid extraction rod 304 during operation, reducing the operation time and improving the operation efficiency.

[0041] To further ensure the detection accuracy, a filter cylinder 311 coaxial with the sample detection cylinder 302 is also provided in the sample detection cylinder 302. Filter holes 312 are provided in the middle of the cylinder wall of the filter cylinder 311. The position of the filter holes 312 should not be too low or too high. Setting it in the middle can make the liquid in the sample detection cylinder 302 basically the upper-layer liquid, and ensure that the liquid can smoothly enter the filter cylinder 311 and the liquid level in the filter cylinder 311 has a corresponding height.

[0042] The liquid extraction rod 304 is located inside the filter cylinder 311. During the static process after the samples in the sample detection cylinder 302 are shaken evenly, the upper part is the supernatant and the lower part is the precipitate. The upper supernatant will enter the filter cylinder 311 through the filter holes 312, reducing the sample debris floating in the supernatant in the detection liquid.

[0043] Embodiment 2 In this embodiment, a detection method for a pesticide residue detection device is provided. It uses the pesticide residue detection device in Embodiment 1 for detection, and specifically includes the following steps: Step S1, configure the extraction solution; Step S2, cut the required detection samples into pieces and take 5 g each and put them into different sample detection cylinders 302; the volume of the sample detection cylinder 302 is about 20 - 25 ml; Step S3, add 15 ml of extraction solution to each sample detection cylinder 302; Step S4: After covering the sample detection cylinder 302, shake the entire sample placement rack 3; Step S5: Open the cover plate 2. First, insert the rapid test card at the rapid test card fixing part 102, and then install the sample placement rack 3 on the base 1 and let it stand for 2 minutes; Step S6: Use the liquid extraction rod 304 to transport the sample liquid in the sample detection cylinder 302 into the sample liquid dropper 303, and the liquid in the sample dropper is dropped onto the white tablet; Step S7: Press the "Start" key of the device to start the reaction stage and wait for 10 - 13 minutes; Step S8: After the reaction ends, the device emits a prompt sound. Remove the sample placement rack 3 and close the cover plate 2; Step S9: Enter the color development stage. In this stage, the heating plate 105 maintains a constant temperature of 38 °C for 3 - 4 minutes; Step S10: Read the test result.

[0044] It is easy to understand that those skilled in the art can combine, split, recombine, etc. the embodiments of the present application based on one or several embodiments provided by the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0045] In summary, the above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the patent of the present invention.

Claims

1. Pesticide residue detection equipment, including a base (1) and a cover plate (2). On the upper end surface of the base (1) and near the side of the cover plate (2), there is a detection position (101). The detection position (101) is provided with a plurality of rapid test card fixing parts (102) evenly spaced along the length direction of the base (1). At the rapid test card fixing part (102), there is a heating sheet (105) capable of heating the rapid test card. It is characterized in that: A sample placement rack (3) is detachably mounted on the base (1). The sample placement rack (3) includes a light-shielding cover (301) that can cover the detection position (101), and sample detection cylinders (302) fixed on the light-shielding cover (301) and corresponding one-to-one with the rapid test card fixing parts (102). A sample liquid dropper (303) is provided at the bottom of the sample detection cylinder (302), and when the light-shielding cover (301) covers the detection position (101), the lower end of the sample liquid dropper (303) extends above the rapid test card fixing part (102). A liquid taking rod (304) is provided in the sample detection cylinder (302) and can convey the sample liquid in the sample detection cylinder (302) into the sample liquid dropper (303).

2. The pesticide residue detection device according to claim 1, characterized in that: Plug-in seats (103) are provided at both ends of the base (1) along the length direction. An upward-opening plug-in slot (104) is provided at the plug-in seat (103). The light-shielding cover (301) is in the shape of a rectangular shell with an open lower end, and a U-shaped plug-in part (305) with a downward opening is provided on the upper end surface. When the two ends of the U-shaped plug-in part (305) are inserted into the plug-in slot (104), the light-shielding cover (301) covers the detection position (101).

3. The pesticide residue detection device according to claim 1, characterized in that: The upper end of the sample liquid dropper (303) connected to the bottom of the sample detection cylinder (302) forms a sealed end (306). A perforation (308) for the liquid taking rod (304) to pass through is formed in the middle of the sealed end (306). The lower end of the liquid taking rod (304) extends into the sample liquid dropper (303) through the perforation (308). An annular groove (307) is provided on the inner wall of the perforation (308), and a seal (309) capable of sealing the gap between the outer wall of the liquid taking rod (304) and the inner wall of the perforation (308) is provided in the annular groove (307).

4. The pesticide residue detection device according to claim 3, characterized in that: A plurality of quantitative liquid taking grooves (310) are sequentially provided on the outer wall of the liquid taking rod (304) along the axial direction. The quantitative liquid taking grooves (310) are located at the lower end position of the liquid taking rod (304), and the liquid taking rod (304) can move axially back and forth in the perforation (308).

5. The pesticide residue detection device according to claim 1, wherein: A filter cylinder (311) coaxial with the sample detection cylinder (302) is further provided in the sample detection cylinder (302). Filter holes (312) are provided in the middle of the wall of the filter cylinder (311), and the liquid taking rod (304) is located in the filter cylinder (311).

6. The pesticide residue detection device according to claim 4, characterized in that: The sample detection cylinder (302) includes a cylinder body (313) and a cylinder cover (314). The upper end of the liquid taking rod (304) extends out of the cylinder cover (314) and is provided with a control handle (315) for pushing or pulling out the liquid taking rod (304). A limit plate (316) for limiting the upward movement stroke of the control handle (315) is further installed above the control handle (315) on the sample detection cylinder (302).

7. The pesticide residue detection device according to claim 6, wherein: A limit plate mounting seat (317) is fixed on the side wall of the sample detection cylinder (302). A connecting rod (318) capable of being adjusted up and down is installed on the limit plate mounting seat (317), and the limit plate (316) is installed at the upper end of the connecting rod (318).

8. The pesticide residue detection device according to claim 7, wherein: An arc-shaped indicating plate (319) with an inner surface fitting the outer surface of the cylinder cover (314) is fixed on the limit plate (316). Scale lines (320) are provided in the height direction of the sample detection cylinder (302) on the inner surface of the arc-shaped indicating plate (319). The position of the scale lines (320) relative to the upper surface of the cylinder cover (314) is coordinated with the number of quantitative liquid extraction grooves (310) that can enter the sample detection cylinder (302).

9. The pesticide residue detection device according to claim 7, characterized in that: The connecting rod (318) is a screw rod threadedly connected to the limit plate mounting seat (317). A knob (321) for driving the connecting rod (318) to rotate within the limit plate mounting seat (317) is provided at the upper end of the connecting rod (318).

10. Detection method of pesticide residue detection equipment, characterized in that: It is detected using the pesticide residue detection device described in any one of claims 1-9, specifically including the following steps: Step S1, prepare the extraction solution; Step S2, cut the required test samples into pieces and take 5 g of each and put them into different sample detection cylinders (302); Step S3, add 10 ml of extraction solution to each sample detection cylinder (302); Step S4, cover the sample detection cylinder (302) and shake the entire sample placement rack (3); Step S5, open the cover plate (2), first insert the rapid test card at the rapid test card fixing part (102), then install the sample placement rack (3) on the base (1), and let it stand for 2 min; Step S6, use the liquid extraction rod (304) to transfer the sample liquid in the sample detection cylinder (302) into the sample liquid dropper (303), and the liquid in the sample dropper drips onto the white tablet; Step S7, press the "start" button of the device to start the reaction stage and wait for 10 - 13 min; Step S8, after the reaction ends, the device emits a prompt sound, remove the sample placement rack (3) and close the cover plate (2); Step S9, enter the color development stage. In this stage, the heating sheet (105) maintains a constant temperature of 38 °C for 3 - 4 min; Step S10, read the test result.

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