Integrated sampling and purification device

Abstract

The utility model discloses an integrated sampling purification device relates to sample pretreatment technical field. The utility model discloses: sampler and purification subassembly, sampler includes sampling cylinder, sampling needle and piston subassembly, sampling needle is connected in one end of sampling cylinder, and its inside is provided with the sampling hole of the intercommunication sampling cylinder inner chamber, and one end of piston subassembly seals and slides in the sampling cylinder inner chamber, and the other end extends to the other end outside of sampling cylinder, and purification subassembly includes the first hydrophilic filter disc, adsorption pad and second hydrophilic filter disc that are sealedly connected in the sampling cylinder inner chamber between sampling needle and piston subassembly in the direction of being away from sampling needle in proper order. Through the push -and -pull cycle of piston subassembly, can realize sample sampling and sample secondary purification simultaneously, help the quick efficient detection of pesticide residue, reduce the content of the interfering substance contained in solution, avoid the influence of interfering substance to the detection result, improve the accuracy and detection efficiency of detection process.

Description

Technical Field

[0001] This utility model relates to the field of sample pretreatment technology, and more specifically to an integrated sampling and purification device. Background Technology

[0002] Rapid detection technology for pesticide residues in agricultural products has received considerable attention in recent years. Accurate determination of the types and amounts of pesticide contaminants is crucial for ensuring the quality and safety of agricultural products. Colloidal gold is currently the most commonly used rapid detection product; however, due to limitations in aqueous solvent extraction technology for agricultural products, existing extraction methods often result in extracts containing the target pesticide containing large amounts of water-soluble sugars, phenols, and other compounds. These significantly interfere with the precision and accuracy of rapid colorimetric test strips, making scientific and precise judgment difficult and leading to false negatives and false positives. Therefore, purification of the extract to reduce interference is necessary before testing.

[0003] Traditional dispersion solid-phase extraction methods require repeated sample transfers and steps such as vortexing, centrifugation, and filtration, each of which must be performed independently, making the entire purification process cumbersome and time-consuming. Therefore, developing a simple and efficient pretreatment solution purification device has significant application value. Utility Model Content

[0004] In view of this, the present invention aims to provide an integrated sampling and purification device to at least partially solve the problem that the existing dispersed solid phase extraction method requires repeated sample transfer and steps such as vortexing, centrifugation and filtration, each of which must be completed independently, making the entire purification process cumbersome and time-consuming.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An integrated sampling and purification device includes:

[0007] A sampler, comprising a sampling tube, a sampling needle, and a piston assembly; the sampling needle is connected to one end of the sampling tube and has a sampling hole inside that communicates with the inner cavity of the sampling tube; one end of the piston assembly is sealed and slides within the inner cavity of the sampling tube, and the other end extends to the outside of the other end of the sampling tube.

[0008] A purification assembly comprising a first hydrophilic filter, an adsorption pad, and a second hydrophilic filter, which are sequentially installed in the inner cavity of the sampling cylinder between the sampling needle and the piston assembly in a direction away from the sampling needle.

[0009] The beneficial effects achievable by this invention are as follows: This device can absorb sample solutions, and during the absorption process, the sample solution undergoes a first purification by sequentially passing through a first hydrophilic filter, an adsorption pad, and a second hydrophilic filter. Then, during the dispensing of the absorbed solution for detection, the solution undergoes a second purification by sequentially passing through the second hydrophilic filter, the adsorption pad, and the first hydrophilic filter. This push-pull cycle simultaneously achieves sample collection and secondary purification, facilitating rapid and efficient detection of pesticide residues. It also reduces the content of interfering substances in the solution, preventing these substances from affecting the detection results and improving the accuracy and efficiency of the detection process.

[0010] Preferably, the piston assembly includes a piston, a push rod, and a pull handle. The piston slides in a sealed manner within the inner cavity of the sampling cylinder. One end of the push rod is connected to the piston, and the other end extends to the outer side of the sampling cylinder away from the sampling needle. The pull handle is fixed to the other end of the push rod.

[0011] Preferably, the sampling tube has a cylindrical structure with an inner diameter of 5-10 mm.

[0012] Preferably, the length of the sampling tube is 70-120mm; the length of the push rod is greater than or equal to the length of the sampling tube.

[0013] Preferably, the inner diameter of the sampling needle hole is 0.1-1 mm.

[0014] Preferably, the adsorption pad has multiple layers, and a third hydrophilic filter is disposed between adjacent adsorption pads.

[0015] Preferably, the thickness of the first hydrophilic filter, the second hydrophilic filter, and the third hydrophilic filter is not less than 1 mm.

[0016] Preferably, the pore size of the filter holes on the first hydrophilic filter, the second hydrophilic filter, and the third hydrophilic filter is 5-80 μm.

[0017] Preferably, the thickness of each layer of the adsorption pad is not less than 1 mm.

[0018] Preferably, each layer of the adsorption pad is a disc-shaped structure made by pressing one or more of the following materials: carboxylated multi-walled carbon nanotubes and silicon dioxide.

[0019] As can be seen from the above technical solution, compared with the prior art, the present invention discloses an integrated sampling and purification device, which has the following beneficial effects:

[0020] 1. This device is easy to operate. It can achieve sample collection and purification simply by moving the piston assembly up and down in the sampling cylinder. The purification process does not require tedious and time-consuming steps such as repeated sample transfer, vortexing and centrifugation. It has the advantages of simple operation, portability, small size, low cost, time saving and high efficiency.

[0021] 2. The device can perform two purification processes during sample extraction and ejection, effectively removing interfering substances from the sample to be tested, thus improving the accuracy and reliability of the test results.

[0022] 3. By cleaning the push rod, sampling cylinder, first hydrophilic filter and second hydrophilic filter, and replacing the adsorbent and sampling needle, this device can be reused, reducing detection costs. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 A schematic diagram of the integrated sampling and purification device provided by this utility model.

[0025] Figure 2 A schematic diagram of the process structure for testing using the integrated sampling and purification device provided by this utility model.

[0026] Figure 3 This is a diagram of the detection results in Example 2.

[0027] Figure 4 The images show the chromatograms of the strawberry extract obtained in Example 3 before and after purification.

[0028] Figure 5 The image shows the color development of the colloidal gold test strip before and after purification of the strawberry extract obtained in Example 4.

[0029] In the figure: 1. Sampling cylinder, 2. Sampling needle, 3. Piston assembly, 31. Piston, 32. Push rod, 33. Pull handle, 4. First hydrophilic filter, 5. Adsorption pad, 6. Second hydrophilic filter. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] Example 1:

[0034] Please see Figures 1-2 This utility model discloses an integrated sampling and purification device, including a sampler and a purification component.

[0035] The sampler includes a sampling cylinder 1, a sampling needle 2, and a piston assembly 3; the sampling needle 2 is connected to one end of the sampling cylinder 1, and a sampling hole communicating with the inner cavity of the sampling cylinder 1 is opened inside it; one end of the piston assembly 3 is sealed and slides in the inner cavity of the sampling cylinder 1, and the other end extends to the outside of the other end of the sampling cylinder 1.

[0036] The purification assembly includes a first hydrophilic filter 4, an adsorption pad 5, and a second hydrophilic filter 6, which are sequentially installed in the inner cavity of the sampling cylinder 1 between the sampling needle 2 and the piston assembly 3 in a direction away from the sampling needle 2, and the first hydrophilic filter 4, the adsorption pad 5, and the second hydrophilic filter 6 are all arranged close to the sampling needle 2.

[0037] like Figure 2As shown, in use, the head of the sampling needle 2 is placed into the solution to be purified. Pulling the piston assembly 3 upwards causes the solution to pass through the sampling needle 2 and sequentially through the first hydrophilic filter 4, the adsorption pad 5, and the second hydrophilic filter 6, before being drawn into the inner cavity of the sampling cylinder 1, completing the first purification. Then, pushing the piston assembly 3 downwards causes the solution in the sampling cylinder 1 to pass sequentially through the second hydrophilic filter 6, the adsorption pad 5, and the first hydrophilic filter 4, before being discharged through the sampling needle 2, completing the second purification. This push-pull cycle is then completed, simultaneously achieving sample sampling and purification. The sample extract after the second purification can be directly used for detection. This device has the advantages of simple operation, portability, small size, low cost, time saving, and high efficiency.

[0038] Specifically, the piston assembly 3 includes a piston 31, a push rod 32, and a pull handle 33. The piston 31 is sealed and slides within the inner cavity of the sampling cylinder 1. One end of the push rod 32 is connected to the piston 31, and the other end extends to the outer side of the sampling cylinder 1 away from the sampling needle 2. The pull handle 33 is fixed to the other end of the push rod 32. The push rod 32 and the pull handle 33 can be made of plastic, and the piston 31 is a rubber stopper.

[0039] Specifically, the sampling cylinder 1 is made of plastic, which is inexpensive and highly safe. In some other embodiments, a corrosion-resistant metal material may also be used. The sampling cylinder 1 has a cylindrical structure with a length of 70-120 mm, and the length of the push rod 32 is greater than or equal to the length of the sampling cylinder 1. The inner diameter of the sampling cylinder is 5-10 mm, and the inner diameter of the piston 31 is usually slightly larger than the inner diameter of the sampling cylinder 1, with a difference not exceeding 0.2 mm.

[0040] Specifically, the sampling needle 2 is preferably made of stainless steel, with a pointed head and an inner diameter of 0.1-1mm for its sampling hole.

[0041] Specifically, the sampling cylinder 1 has a connecting cylinder formed at one end near the sampling needle 2, which communicates with its inner cavity. The tail end of the sampling needle 2 is provided with an outer sleeve that communicates with the sampling hole and is fitted with the connecting cylinder. The connection and communication between the sampling needle 2 and the sampling cylinder 1 are achieved through the connecting cylinder and the outer sleeve.

[0042] Specifically, the sampling needle 2 is also covered with a protective cap, which is a cylindrical structure closed at one end. The head of the sampling needle can be inserted into the inner cavity of the protective cap from the open end until the inner wall of the protective cap is tightly fitted with the outer sleeve. After removing the protective cap, the sampling needle 2 can be used for sampling. When storing, the protective cap is put on to protect the sampling needle 2.

[0043] Specifically, both the first hydrophilic filter 4 and the second hydrophilic filter 6 are made of hydrophilic plastic, which can be washed and reused. Their thickness is 2-50mm, their diameter is 5-10mm, and their pore size is 5-80μm.

[0044] More specifically, the adsorption pad 5 is a disc-shaped structure formed by pressing a mixture of 150 mg of carboxylated multi-walled carbon nanotubes with an outer diameter of 10-20 nm and silica particles with a diameter of 10-20 μm. Its diameter is 5-10 mm and its thickness is not less than 1 mm. Furthermore, by adjusting the type and ratio of raw materials in the adsorption pad, the purification of pretreatment solutions for various types of agricultural products can be achieved.

[0045] In this embodiment, when placing the purification assembly, the piston assembly is removed, and the first hydrophilic filter 4, the adsorption pad 5, and the second hydrophilic filter 6 are inserted layer by layer through the upper opening of the sampling cylinder. Then, the second hydrophilic filter 6 is pressed downwards using a metal rod, causing the purification assembly to slide to the lower part of the sampling cylinder 1. Since the diameter of each layer is approximately the same as the inner diameter of the sampling cylinder, the purification assembly can be locked in place at the lower part of the sampling cylinder 1 after installation without moving up or down. When the purification assembly needs to be removed for cleaning or replacement, it can be pushed back out from the bottom opening of the sampling cylinder 1 using a metal rod. The purification assembly is simple to install and easy to clean or replace.

[0046] In some other embodiments, the adsorption pad 5 can be multi-layered, and a third hydrophilic filter is disposed between each two adjacent layers of the adsorption pad 5. The third hydrophilic filter is made of hydrophilic plastic, can be washed and reused, and has a thickness of 2-50 mm, a diameter of 5-10 mm, and a pore size of 5-80 μm. Depending on the type of sample solution to be purified, the materials of the multi-layer adsorption pads 5 can be the same or different to fully purify various interfering substances in the sample solution.

[0047] Example 2:

[0048] The integrated sampling and purification device described in Example 1 was used for the purification and analysis of aqueous extracts of six pesticides—tebuconazole, acetamiprid, pyrimethanil, carbendazim, cyazofamid, and thiamethoxam—in strawberries.

[0049] Strawberry pretreatment for control group:

[0050] Step 1: Wipe the soil off the strawberry sample and chop it into 1cm cubes. Weigh 2g of strawberry cubes into a 15ml centrifuge tube, add 6ml of extraction solution, cap, vortex or shake vigorously for 1 minute, and let stand for 5 minutes.

[0051] Step 2: Use the integrated sampling and purification device to take 1 ml of sample extract, place the head of the sampling needle 2 below the surface of the extract, pull the push rod 32 upward, and after all the extract has passed through the second hydrophilic filter 6, push the push rod 32 downward.

[0052] Step 3: Inject the appropriate amount of purified extract from Step 2 into the sample cell of the colloidal gold immunochromatographic card.

[0053] Experimental group strawberry pretreatment:

[0054] Step 1: Add a mixed standard solution of 6 pesticides to the strawberry sample extract at a concentration of 500 μg / L, and let stand for 30 minutes. Add 6 mL of extract, vortex or shake vigorously for 1 minute, and let stand for 5 minutes.

[0055] Step 2: Take 1 ml of extract, place the head of sampling needle 2 below the surface of the extract, pull the push rod 32 of the integrated sampling and purification device upward, and after all the extract has passed through the second hydrophilic filter 6, push the push rod 32 downward.

[0056] Step 3: Collect the purified extract and drop an appropriate amount of the extract into the sample cell of the colloidal gold immunochromatographic card.

[0057] Figure 3 The results show the analysis of strawberry extract processed using an integrated purification and sampling device, coupled with colloidal gold immunochromatographic assay cards. Card A detected carbendazim, boscalid, and thiamethoxam, while card B detected cyproconazole, acetamiprid, and pyrimethanil. The results show that the triplet T lines in the strawberry blank solutions (A1, B1) are stronger than the C line, indicating that the strawberry blank solutions tested negative for all six pesticides. The T lines in the strawberry additive solutions (A2, B2) are weaker than the C line, indicating that the strawberry additive solutions tested positive for all six pesticides. These results demonstrate that strawberry extract purified using the integrated purification and sampling device of Example 1 is suitable for the qualitative analysis of six pesticides.

[0058] Example 3:

[0059] Following the experimental group method in Example 2, the collected and purified extract was filtered through a 0.22 μm aqueous filter membrane to physically intercept macromolecules in the extract, and then analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry.

[0060] The results of ultra-high performance liquid chromatography-tandem mass spectrometry analysis are shown in Table 1. The results show that the recoveries of the six pesticides ranged from 85% to 113%, and the relative standard deviations ranged from 1% to 10%, meeting the requirements for pesticide residue analysis. These results indicate that the integrated sampling and purification device has little impact on pesticide content and meets the standards for pesticide detection in agricultural products.

[0061] Table 1. Results of Additive Recovery of Six Pesticides

[0062]

[0063] Chromatograms of strawberry extract before and after purification are shown below. Figure 4 . Figure 4The unpurified strawberry extract showed a significant peak after 1.2 minutes, indicating the presence of interfering matrices. The purified extract, however, exhibited lower and more stable intensity, with no obvious interfering matrices observed. These results demonstrate that the purification device has a good purification effect and can significantly remove interfering matrices (such as water-soluble sugars and phenolic compounds) from the strawberry extract.

[0064] Example 4:

[0065] Following the experimental group method in Example 2, the purified extract was collected, and an appropriate amount of the extract was dropped into the sample cell of the colloidal gold immunochromatographic card to observe the effect of strawberry extract purification on the dispersibility of the colloidal gold test strip.

[0066] The results are as follows Figure 5 As shown, the colloidal gold in the strawberry extract after purification (A) showed more uniform color development than that before purification (B), with no obvious color spots and clear color band boundaries. This indicates that the dispersibility of the colloidal gold in the strawberry extract after purification (A) was better than that before purification (B). This result demonstrates that the purification device can improve the dispersibility of colloidal gold and effectively reduce false negative and false positive results.

[0067] In summary, based on the experimental data from Examples 2-4, it is shown that the integrated sampling and purification device provided in Example 1 of this utility model has a good purification effect, can significantly eliminate interfering substances in the sample solution to be tested, and improve the accuracy and reliability of the detection results.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0069] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An integrated sampling and purification device, characterized in that, include: The sampler includes a sampling cylinder (1), a sampling needle (2), and a piston assembly (3); the sampling needle (2) is connected to one end of the sampling cylinder (1), and a sampling hole communicating with the inner cavity of the sampling cylinder (1) is opened inside it; one end of the piston assembly (3) is sealed and slides in the inner cavity of the sampling cylinder (1), and the other end extends to the outside of the other end of the sampling cylinder (1); The purification assembly includes a first hydrophilic filter (4), an adsorption pad (5), and a second hydrophilic filter (6) which are sequentially installed in the inner cavity of the sampling cylinder (1) between the sampling needle (2) and the piston assembly (3) in a direction away from the sampling needle (2).

2. The integrated sampling and purification device according to claim 1, characterized in that, The piston assembly (3) includes a piston (31), a push rod (32) and a pull handle (33). The piston (31) is sealed and slides within the inner cavity of the sampling cylinder (1). One end of the push rod (32) is connected to the piston (31), and the other end extends to the outer side of the sampling cylinder (1) away from the sampling needle (2). The pull handle (33) is fixed to the other end of the push rod (32).

3. The integrated sampling and purification device according to claim 2, characterized in that, The sampling tube (1) is a cylindrical structure with an inner diameter of 5-10 mm.

4. The integrated sampling and purification device according to claim 3, characterized in that, The length of the sampling tube (1) is 70-120mm; the length of the push rod (32) is greater than or equal to the length of the sampling tube (1).

5. The integrated sampling and purification device according to claim 1, characterized in that, The inner diameter of the sampling needle (2) hole is 0.1-1mm.

6. The integrated sampling and purification device according to any one of claims 1-5, characterized in that, The adsorption pad (5) is provided with multiple layers, and a third hydrophilic filter is provided between adjacent adsorption pads (5).

7. The integrated sampling and purification device according to claim 6, characterized in that, The thickness of the first hydrophilic filter (4), the second hydrophilic filter (6), and the third hydrophilic filter is not less than 1 mm.

8. The integrated sampling and purification device according to claim 6, characterized in that, The pore size of the filter holes on the first hydrophilic filter (4), the second hydrophilic filter (6) and the third hydrophilic filter is 5-80 μm.

9. The integrated sampling and purification device according to claim 6, characterized in that, The thickness of each layer of the adsorption pad (5) is not less than 1 mm.

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