One-way negative pressure adsorption sampling and filtering device and method

Abstract

The present invention provides a one-way negative pressure adsorption sampling and filtering device and method, the device includes a liquid collection tube, the liquid inlet end of which is provided with an oblique puncture port, and the liquid outlet end of which is connected to a one-way valve; a filter, the liquid inlet end of which is connected to the one-way valve, and the liquid outlet end of which is connected to a stop valve; a negative pressure metering bottle, the liquid inlet end of which is connected to the stop valve through a connecting tube; the liquid outlet end of which is connected to a negative pressure vacuum pump through an air guide tube; a filter cavity is provided in the filter, and the filter cavity is filled with a filter medium. The device simplifies the operating procedures and improves the operational safety. The filter medium used in the method of the present invention is a microporous filter membrane, and the specific operating process includes: instrument assembly - disinfection - sterile puncture and drainage - negative pressure flow control - quantitative adsorption and filtration - sample preparation and storage - transportation - clean area filter membrane transfer - transfer to biochemical culture. By directly collecting water samples and preparing microporous filter membrane samples by adsorption at the water quality sampling site, the purpose of real-time, convenient, fast and pollution-free sample preparation is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of biological and chemical filtration sample preparation, and in particular relates to a one-way negative pressure adsorption sampling filtration device and method. Background Art

[0002] In routine biochemical analysis, filtration is often used to prepare reagents, standard solutions, and liquid samples for purposes such as impurity removal, homogenization, purification, and sterilization. Impurity removal refers to the removal of larger particles, crystals, gels, and flocculent matter from solutions through filtration. Homogenization involves the use of filtration to separate dispersed particles in suspensions and emulsions, reducing their size and improving their uniformity. Purification involves the removal of tiny particles, plankton, minerals, and heavy metal ions through membrane filtration. Sterilization utilizes the bacterial filtration properties of nanoporous membranes to prevent microorganisms from penetrating the filtrate interface.

[0003] Currently, solvent filters commonly used in chemical laboratories and analytical laboratories are divided into organic and inorganic types according to the filter membrane material. The material is made of all-glassware, which is large in volume and mass. It is often fragile during the experimental operation process. It is also a forward open filtration. Experimental operators need to pour and transfer solutions, which poses a greater safety operation risk and is not conducive to closed and sterile operations.

[0004] In addition, drinking water is contaminated by microorganisms such as Pseudomonas aeruginosa, which affects the safety of drinking water quality. Therefore, it is necessary to conduct safety testing on drinking water quality.

[0005] Traditional testing and sample preparation methods typically involve collecting aqueous solution samples on-site using containers, bringing them back to the laboratory, and performing sterile filtration on a Class 100 clean bench. However, currently used filtration equipment is bulky and lacks matching disinfection equipment. Furthermore, because water sample collection and preparation are performed in stages, testing cycles are naturally prolonged, increasing the risk of cross-contamination. Furthermore, the disinfection, sampling, transfer, and filtration processes are complex and meticulous, placing high demands on testers and intensive workload, slowing down efficiency.

[0006] Traditional sample preparation methods involve lengthy sampling, transfer, and filter preparation processes, requiring a spacious cleanroom environment and space, and thorough disinfection of collection containers. Otherwise, target microorganisms are susceptible to the effects of the water storage container, sampling environment, and transportation conditions, leading to the uncertainty of secondary contamination, such as contact with storage materials, outdoor air, and multiple transfers. Therefore, without significant impact, it is necessary to develop new sampling equipment to simplify the water quality sample preparation process and improve work efficiency. Summary of the Invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide a one-way negative pressure adsorption sampling and filtration device, which reduces the complicated operation process of liquid transfer filtration through the synchronous operation of adsorption filtration, avoids the risks of solution filtration operations such as those that are volatile, corrosive, and susceptible to contamination, and improves the safety protection performance of experimental filtration operations.

[0008] Another object of the present invention is to provide a minimally invasive aseptic operation method for preparing microbial filter membrane samples. The filter medium used in this method is a microporous filter membrane. By adopting a one-way negative pressure adsorption sampling and filtration device, it can complete the characteristics of minimally invasive puncture, one-way cutoff, reverse liquid extraction, negative pressure filtration, strain adsorption, filtrate metering, negative pressure adsorption and high-temperature disinfection. It can also directly adsorb and prepare microporous filter membrane samples of target microorganisms at the water quality sampling site, complete water sample collection and filter membrane filtration operations at one time, and achieve the purpose of real-time, convenient, fast and pollution-free sample preparation.

[0009] To achieve the above objectives, the technical solutions of the present invention are as follows.

[0010] A one-way negative pressure adsorption sampling and filtering device, comprising:

[0011] A liquid collection tube, the liquid inlet end of which is provided with an oblique puncture port, and the liquid outlet end of which is connected to a one-way valve;

[0012] A filter, the liquid inlet end of which is connected to the one-way valve, and the liquid outlet end of which is connected to a stop valve;

[0013] A negative pressure metering bottle, the liquid inlet of which is connected to the stop valve via a connecting pipe; and the liquid outlet of which is connected to the negative pressure vacuum pump via an air guide tube;

[0014] A filter cavity is provided in the filter, and the filter cavity is filled with filter medium.

[0015] Furthermore, the side edges of the filter cavity close to the liquid inlet and the liquid outlet are provided with protective films; the filter medium is any one or more of sand core, filter paper, activated carbon, diatomaceous earth, and anhydrous sodium sulfate.

[0016] Furthermore, a protective membrane is provided on one side of the filter cavity close to the liquid outlet, and the filter medium is a microporous filter membrane for adsorbing microbial samples; the microporous filter membrane is a 0.45 μm filter membrane.

[0017] Furthermore, the liquid collection tube is a minimally invasive puncture tube; the tube head of the liquid collection tube is provided with a sterile protective cover; the length of the liquid collection tube is 5 to 20 cm.

[0018] Furthermore, the one-way valve comprises:

[0019] A connecting pipe having a one-way cut-off cavity provided therein;

[0020] The movable cut-off component is arranged in the one-way cut-off cavity; and as the liquid flows, the movable cut-off component and the one-way cut-off cavity are combined to form a channel for the liquid to pass through.

[0021] Furthermore, the movable cut-off component includes:

[0022] A cut-off block is provided at the liquid inlet end of the one-way cut-off chamber; one side of the cut-off block is provided with an arc-shaped sealing portion, and the other side is connected to a limiting sliding rod;

[0023] A blocking groove body is provided at the liquid outlet end of the one-way cut-off cavity; a return spring is provided in the blocking groove body, and one end of the limiting slide rod passes through the return spring and out of the blocking groove body;

[0024] The blocking tank body is fixedly connected to the liquid outlet end of the one-way cut-off cavity through a plurality of fixing blocks.

[0025] Furthermore, the outer diameter of the arc-shaped sealing portion is larger than the inner diameter of the connecting pipe; and one side of the arc-shaped sealing portion abuts against the inner wall of the one-way cut-off cavity.

[0026] Furthermore, the filter comprises a first filter and a second filter, wherein the first filter is sealed and detachably connected to the second filter;

[0027] The first filter and the second filter are combined to form a filter cavity for accommodating the filter medium; a sealing ring is provided on the outer edge of the filter cavity.

[0028] Furthermore, a sealing head is provided on the negative pressure metering bottle, and a liquid level metering tube is provided in the negative pressure metering bottle; one end of the sealing head abuts against one end of the liquid level metering tube, and the negative pressure metering bottle is connected to the liquid level metering tube;

[0029] The sealing head is provided with a liquid inlet joint and an exhaust joint, one end of the liquid inlet joint located in the sealing head extends into the liquid level metering tube, and the other end is sealed and detachably connected to the connecting pipe;

[0030] One end of the exhaust joint located in the sealing head is arranged on the upper side of the liquid level metering tube, and the other end is sealed and detachably connected to the air guide tube.

[0031] The present invention also provides a method for aseptically preparing microbial filter membrane samples using the one-way negative pressure adsorption sampling and filtration device, comprising the following steps:

[0032] S1. Assemble the liquid collection tube, one-way valve, filter, stop valve and negative pressure metering bottle and disinfect them;

[0033] S2. Connect the negative pressure measuring bottle to the negative pressure vacuum pump, and pierce the beveled end of the liquid collection tube into the water sample, open the stop valve, start the negative pressure vacuum pump, and the water sample enters the negative pressure measuring bottle through the filter. The microorganisms in the water sample are adsorbed on the filter medium and used to prepare the microporous filter membrane sample, wherein the filter medium is a microporous filter membrane;

[0034] After adsorption sampling and filtration, when the filtrate reaches a certain volume, close the stop valve;

[0035] S3. Place the one-way valve, filter, and stop valve in a sterile storage box for sample preparation and storage, and then transfer the microporous filter membrane sample in the clean area;

[0036] S4. Transfer the microorganisms on the microporous filter membrane sample into a culture dish for biochemical culture for water quality microbial testing.

[0037] Beneficial effects of the present invention:

[0038] 1. The device of the present invention reduces the complicated operation process of liquid transfer filtration through the synchronous operation of adsorption filtration, avoids the risks of filtration operation of volatile, corrosive and contaminated solutions, and improves the safety protection performance of experimental filtration operation.

[0039] 2. The device of the present invention is composed of three units: sampling, filtration and negative pressure connected in sequence. The sampling unit mainly includes a liquid collection tube and a one-way valve. The liquid is sucked through the liquid collection tube, and the one-way cut-off and reverse liquid extraction functions are realized. The filtration unit includes a filter and a cut-off valve. A filter medium and a protective membrane are added to the filter cavity of the filter. When the filter medium adopts a microporous filter membrane, it can be used to realize negative pressure filtration and bacterial strain adsorption functions. The negative pressure unit includes a negative pressure metering bottle. The negative pressure is maintained in the negative pressure metering bottle by a negative pressure vacuum pump, and then the filtrate is quantitatively adsorbed in the negative pressure metering bottle to realize the filtrate metering and negative pressure adsorption functions. The overall device is lightweight, easy to carry, and pressure-resistant. The connection has good air tightness, the negative pressure is adjustable, and the negative pressure is not less than 0.04MPa.

[0040] 3. The device of the present invention combines negative pressure adsorption liquid extraction at static liquid level with one-way multi-media adsorption filtration, which can improve the laboratory's inspection timeliness and work efficiency, prevent biochemical operation safety risks, avoid open environmental pollution, reduce the workload of personnel in routine operations during the inspection process, and solve the complex manual operation problems in pouring liquids, adsorption transfer, and quantitative filtration during laboratory testing.

[0041] 4. The filter medium used in the method of the present invention is a microporous filter membrane, and the sampling tube is a minimally invasive puncture tube. The specific operation process includes: instrument assembly-disinfection-aseptic puncture and drainage-negative pressure flow control-quantitative adsorption and filtration-sample preparation and storage and transportation-clean area filter membrane transfer-transfer to biochemical culture. This method simplifies the sample preparation operation process, can complete the characteristics and functions such as minimally invasive puncture, one-way cutoff, reverse extraction, negative pressure filtration, strain adsorption, filtrate metering, negative pressure adsorption and high temperature disinfection, and directly adsorbs and prepares microporous filter membrane samples of target microorganisms at the water quality sampling site, completes water sample collection and membrane filtration operations at one time, and achieves the purpose of real-time, convenient, fast and pollution-free sample preparation; avoids cross-contamination between water sample collection and on-site preparation, simplifies the operation process, and improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic structural diagram of a one-way negative pressure adsorption sampling and filtering device according to one embodiment of the present invention.

[0043] Figure 2 for Figure 1 Schematic diagram of the structure of part A.

[0044] Figure 3 for Figure 1 Schematic diagram of the structure of the liquid extraction pipe.

[0045] Figure 4 for Figure 1 Schematic diagram of the structure of the one-way valve.

[0046] Figure 5 for Figure 4 Schematic cross-section of the one-way valve.

[0047] Figure 6 for Figure 4 Schematic diagram of the one-way valve in use.

[0048] Figure 7 for Figure 1 Schematic cross-section of the filter.

[0049] Figure 8 for Figure 1 Schematic diagram of the structure of a medium negative pressure metering bottle.

[0050] Figure 9 This is a structural schematic diagram of a one-way negative pressure adsorption sampling and filtering device according to another embodiment of the present invention.

[0051] In the figure, 1, liquid collection tube; 11, oblique puncture port; 12, oblique connector; 13, sterile protective cover of the tube head;

[0052] 2. One-way valve; 21. Connecting pipe; 211. One-way cutoff chamber; 22. Movable cutoff component; 221. Cutoff block; 222. Arc-shaped sealing portion; 223. Limiting slide bar; 224. Blocking groove; 225. Return spring; 226. Fixed block;

[0053] 3. Filter; 31. Filter chamber; 32. Filter medium; 33. Protective membrane; 34. First filter; 35. Second filter; 36. Sealing ring; 4. Stop valve;

[0054] 5. Negative pressure metering bottle; 51. Sealing head; 52. Liquid inlet connector; 53. Exhaust connector; 54. Liquid level metering tube; 541. Tube mouth limiter; 55. Bottle mouth clamping part; 6. Connecting tube; 7. Air guide tube; 8. Negative pressure vacuum pump. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0056] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0057] Example 1

[0058] See also Figure 1 , a schematic diagram of the structure of a one-way negative pressure adsorption sampling and filtration device provided by an embodiment of the present invention. This device is primarily used for laboratory biochemical filtration and liquid collection operations. The device includes a liquid collection tube 1, a filter 3, and a negative pressure metering bottle 5.

[0059] See also Figures 1 to 3 The liquid inlet end of the liquid taking tube 1 is provided with an oblique puncture port 11, and the liquid outlet end thereof is connected with a one-way valve 2. The liquid is sucked through the liquid taking tube, and the one-way cut-off and reverse liquid extraction functions are realized.

[0060] The head of the liquid collection tube 1 can be made of various corrosion-resistant materials and diameters. For example, the material of the head is compatible with the liquid. The length of the liquid collection tube 1 is determined by the medium in which it is immersed, and is approximately 5 to 20 cm. The outer and inner diameters of the liquid collection tube 1 are approximately 2 to 8 mm. Specifically, the inner diameter of the liquid collection tube 1 decreases from top to bottom, and the inner diameter of the beveled end of the liquid collection tube 1 is 2 to 5 mm.

[0061] An oblique joint 12 is provided on the liquid outlet end of the liquid collection pipe 1, and the oblique joint 12 is sealed and detachably connected to the liquid inlet end of the one-way valve 2. Of course, the upper end size of the oblique joint 12 is larger than the lower end size. For example, the upper inner diameter size of the oblique joint 12 is approximately 12.6 mm, and the lower inner diameter size is approximately 12.2 mm. Of course, a sealing ring can also be sleeved on the lower end of the one-way valve 2, and the upper outer diameter size of the sealing ring is approximately 12.6 mm, and the lower outer diameter size is approximately 12.2 mm. The lower end of the one-way valve 2 is pressed tightly into the oblique joint 12, and the sealing ring is tightly fitted on the inner wall of the oblique joint 12, thereby improving the sealing tightness of the oblique joint 12 and the one-way valve 2. Of course, a clamping component can also be added at the connection end of the oblique joint 12 and the one-way valve 2 to further improve the connection tightness.

[0062] See also Figure 1 and Figure 7 The liquid inlet end of the filter 3 is connected to the one-way valve 2, and the liquid outlet end of the filter 3 is connected to the stop valve 4; the liquid inlet end of the negative pressure metering bottle 5 is connected to the stop valve 4 through the connecting pipe 6, and the liquid outlet end of the negative pressure metering bottle 5 is connected to the negative pressure vacuum pump 8 through the air guide tube 7.

[0063] For example, the upper inner diameter of the liquid outlet of the one-way valve 2 is approximately 11.6 mm, and the lower inner diameter is approximately 10.6 mm; the upper outer diameter of the liquid inlet of the filter 3 is approximately 11.6 mm, the lower outer diameter is approximately 10.6 mm, and the inner pore diameter is approximately 5 mm; thus, the liquid inlet of the filter 3 can be tightly plugged into the liquid outlet of the one-way valve 2. The upper outer diameter of the liquid outlet of the filter 3 is approximately 10.6 mm, the lower outer diameter is approximately 11.6 mm, and the inner pore diameter is approximately 4 mm; the upper inner diameter of the liquid inlet of the stop valve 4 is approximately 10.6 mm, the lower inner diameter is approximately 11.6 mm, and the inner pore diameter is approximately 4 mm; thus, the liquid outlet of the filter 3 can be tightly plugged into the liquid inlet of the stop valve 4.

[0064] Filter 3 includes a filter cavity 31 filled with a filter medium 32. When used for filtration in chemical or analytical laboratories, protective membranes 33 are installed on the side edges of filter cavity 31 near the liquid inlet and outlet. Filter medium 32 can be any one or more of a sand core, filter paper, activated carbon, diatomaceous earth, and anhydrous sodium sulfate. Different filter media can be selected based on the type of liquid being filtered and the purpose of the filtration.

[0065] To facilitate replacement of the multi-media filter material, the filter 3 is detachable. Specifically, the filter 3 includes a first filter 34 and a second filter 35, which are sealed and detachably connected. The first and second filters 34, 35 combine to form a filter cavity 31 for accommodating the filter medium 32. A sealing ring 36 is provided on the outer edge of the filter cavity 31.

[0066] For example, the first filter and the second filter are connected by screw threads, forming a connected cavity between the first and second filters, namely, the filter cavity 31. After the filter medium and the protective membrane are placed, the volume of the cavity can be reduced by tightening the first and second filters, thereby pressing the protective membrane against the filter medium 32.

[0067] In this embodiment, the oblique puncture port 11 facilitates puncture and liquid collection. Due to the relatively long length of the liquid collection tube 1, the liquid collection tube 1 can be directly inserted into the liquid medium to be collected, eliminating the need for the operator to carry, transfer, and pour the liquid. This allows for real-time, convenient, fast, and pollution-free negative pressure suction filtration and liquid collection. Of course, the provision of the one-way valve 2 enables one-way shutoff and reverse liquid extraction functions, and prevents liquid from flowing back into the sampled liquid during negative pressure sampling, causing secondary contamination of the sampled liquid.

[0068] By combining negative pressure adsorption of static liquid level with one-way multi-media adsorption filtration, the device can improve the laboratory's testing timeliness and work efficiency, prevent biochemical operation safety risks, avoid open environmental pollution, reduce the workload of personnel in routine operations during testing, and solve the complex manual operation problems in pouring liquids, adsorption transfer, and multi-media filtration during laboratory testing.

[0069] See also Figures 4 to 6 The one-way valve 2 includes a connecting pipe 21 and a movable cut-off component 22 .

[0070] A one-way shutoff cavity 211 is provided within the connecting tube 21. For example, the connecting tube 21 includes a first connecting member 201 and a second connecting member 202. The upper end of the first connecting member 201 abuts against the inner wall of the second connecting member 202, and the first connecting member 201 and the second connecting member 202 are threadedly connected. Of course, a sealing ring can also be provided on the end of the first connecting member 201 to improve the sealing and tightness of the connection between the first connecting member 201 and the second connecting member 202. This forms a channel for liquid to pass between the first connecting member 201 and the second connecting member 202.

[0071] The movable cut-off component 22 is disposed in the one-way cut-off cavity 211 ; and as the liquid flows, the movable cut-off component 22 and the one-way cut-off cavity 211 combine to form a channel for the liquid to pass through.

[0072] Specifically, the movable cut-off component 22 includes a cut-off block 221 and a blocking groove 224 .

[0073] A stop block 221 is mounted at the liquid inlet end of the one-way stop chamber 211. A curved sealing portion 222 is provided on one side of the stop block 221, and a limiting slide 223 is connected to the other side. The one-way stop chamber 211 has a curved inner wall near the liquid inlet, and the stop block's curved sealing portion abuts against this wall, sealing the liquid inlet of the one-way stop chamber.

[0074] The blocking groove 224 is located at the liquid outlet of the one-way shutoff chamber 211. A return spring 225 is installed within the blocking groove 224. One end of the limiting slide 223 passes through the return spring 225 and out of the blocking groove 224. Here, a receiving groove is provided between the blocking groove 224 and the shutoff block 221, forming a receiving cavity. The return spring 225 is located within the receiving cavity. The blocking groove 224 is provided with a through groove. One end of the limiting slide 223 is fixed in the receiving groove of the shutoff block 221, while the other end passes through the through groove and can move along the through groove.

[0075] During use, when the chamber is in a normal pressure environment, the arc-shaped sealing portion of the cut-off block abuts against the arc-shaped inner wall of the one-way cut-off chamber. At this time, the spring is in a compressed state, so that the cut-off block remains abutted against the liquid inlet of the one-way cut-off chamber.

[0076] When the chamber is in a negative pressure environment, the cutoff block is opened by the negative pressure on the one hand, and on the other hand, the water sample is drawn upward to drive the cutoff block to abut against the blocking groove body, thereby opening the one-way cutoff cavity and forming a channel for liquid to pass through.

[0077] When the liquid passes through, as the negative pressure decreases, the negative pressure on the cut-off block decreases. When it is less than the restoring force of the spring, the cut-off block moves downward and abuts against the arc-shaped inner wall of the one-way cut-off cavity. At this time, the spring is in a compressed state and the liquid inlet is closed.

[0078] The blocking tank body 224 is fixedly connected to the liquid outlet end of the one-way cutoff cavity 211 by a plurality of fixing blocks 226. Here, due to the fixing blocks, a plurality of liquid outlet holes are formed between the blocking tank body and the inner wall of the one-way cutoff cavity near the liquid outlet, which facilitates the passage of liquid while fixing the blocking tank body.

[0079] The outer diameter of the arc-shaped sealing portion 222 is larger than the inner diameter of the connecting tube 21 ; one side of the arc-shaped sealing portion 222 abuts against the inner wall of the one-way cutoff cavity 211 to seal the liquid inlet of the one-way cutoff cavity.

[0080] Please refer again Figures 1 to 2 and Figure 8 A sealing head 51 is provided on the negative pressure metering bottle 5, and the sealing head 51 is sealed and detachably connected to the negative pressure metering bottle 5; for example, the sealing head 51 and the negative pressure metering bottle 5 are sealed and connected by threads.

[0081] A liquid level measuring tube 54 is provided in the negative pressure metering bottle 5; one end of the sealing head 51 abuts against one end of the liquid level measuring tube 54, and the negative pressure metering bottle 5 is connected to the liquid level measuring tube 54; a liquid inlet joint 52 and an exhaust joint 53 are provided on the sealing head 51, one end of the liquid inlet joint 52 located in the sealing head extends into the liquid level measuring tube 54, and the other end is sealed and detachably connected to the connecting tube 6; one end of the exhaust joint 53 located in the sealing head is provided on the upper side of the liquid level measuring tube 54, and the other end is sealed and detachably connected to the air guide tube 7.

[0082] In this embodiment, a liquid level scale is provided on the outer wall of the liquid level metering tube, which facilitates negative pressure flow control and quantitative adsorption filtration. In order to improve the negative pressure filtration effect, please refer to Figure 2 The mouth of the negative pressure measuring bottle 5 is provided with a mouth clamping portion 55, and the mouth of the liquid level measuring tube 54 is provided with a mouth limiting portion 541. The liquid level measuring tube 54 is accommodated in the negative pressure measuring bottle 5. At this time, the mouth limiting portion 541 is clamped on the mouth clamping portion 55, so that a spacer cavity is formed between the liquid level measuring tube 54 and the negative pressure measuring bottle 5. Because there is a connecting hole between the liquid level measuring tube 54 and the mouth clamping portion, the spacer cavity is connected to the inner cavity of the liquid level measuring tube 54. Of course, multiple vents can also be provided on the mouth of the liquid level measuring tube 54, further connecting the spacer cavity with the liquid level measuring tube 54 through the multiple vents. This facilitates the formation of a negative pressure environment in the spacer cavity.

[0083] The negative pressure metering bottle 5 provided in this embodiment is a positive negative pressure bottle, and the liquid inlet connector 52 and the exhaust connector 53 are both located at the top of the negative pressure metering bottle 5, with the bottle mouth facing upward, so as to facilitate the formation of a negative pressure environment.

[0084] Among them, the end of the liquid inlet connector 52 located in the negative pressure measuring bottle extends into the nozzle of the liquid level measuring tube 54, while the end of the exhaust connector 53 located in the negative pressure measuring bottle is located on the upper side of the nozzle of the liquid level measuring tube 54. Therefore, when aspirating liquid through the liquid inlet connector and negative pressure suction through the exhaust connector do not affect each other, it can prevent the liquid entering the liquid level measuring tube through the liquid inlet connector during negative pressure suction from being sucked into the negative pressure vacuum pump along with the negative pressure suction. Of course, both the liquid inlet connector 52 and the exhaust connector 53 are provided with control valves. The negative pressure vacuum pump 8 can form a negative pressure environment in the inner cavity of the negative pressure measuring bottle 5 and maintain the negative pressure environment of the entire device to facilitate quick and convenient adsorption and filtration of the sample liquid. The exhaust connector 53 is connected to the negative pressure vacuum pump 8 via the air guide tube 7 to form a negative pressure environment. The liquid inlet connector 52 is connected to the stop valve 4 via the connecting pipe 6 for sampling and filtering, and allows the sampled liquid to flow into the liquid level measuring tube 54 and achieve quantitative sampling. By arranging a liquid level measuring tube 54 in the negative pressure measuring bottle 5, quantitative measurement can be performed during sampling to achieve quantitative measurement sampling of the filtrate. A pressure gauge is connected to the suction end of the negative pressure vacuum pump 8, and the negative pressure is adjusted by the pressure gauge to form a reasonable negative pressure sampling environment.

[0085] Example 2

[0086] See also Figure 9 , is a structural diagram of a one-way negative pressure adsorption sampling and filtering device provided by another embodiment of the present invention, the device includes a liquid collection tube 1, a filter 3 and a negative pressure measuring bottle 5. The structure of the device is basically the same as that of Example 1, except that,

[0087] The negative pressure metering bottle 5 includes a liquid inlet opening and a negative pressure exhaust port. The liquid inlet opening is arranged at the bottom of the negative pressure metering bottle 5, and the negative pressure exhaust port is arranged on the side wall of the top of the negative pressure metering bottle 5. The liquid inlet opening is connected to the stop valve 4 through a connecting pipe 6, and the negative pressure exhaust port is connected to the negative pressure vacuum pump 8 through an air guide pipe 7, thereby forming a negative pressure environment for the device to facilitate quick and convenient filtration of the sample liquid.

[0088] In this embodiment, the negative pressure metering bottle 5 is a reverse negative pressure bottle with its mouth facing downward. A liquid inlet connector 52 is provided on the liquid inlet opening, and an exhaust connector is provided on the negative pressure exhaust port. Both the liquid inlet connector 52 and the exhaust connector 53 are connected to the inner cavity of the negative pressure metering bottle 5. Control valves are also provided on both the liquid inlet connector 52 and the exhaust connector 53. A liquid level scale is provided on the outer wall of the negative pressure metering bottle 5 to facilitate negative pressure flow control and quantitative adsorption filtration.

[0089] Example 3

[0090] See also Figure 1 Another embodiment of the present invention provides a one-way negative pressure adsorption sampling and filtering device, the structure of which is basically the same as that of Example 1, except that:

[0091] This device is primarily used for the aseptic preparation of microbial samples. The liquid collection tube 1 is a minimally invasive puncture tube. A sterile protective cap 13 is provided over the tip of the tube to provide sterile protection. The tube 1 is 15 to 20 cm long.

[0092] A protective membrane 33 is provided on one side of the filter chamber 31 near the liquid outlet, and the filter medium 32 is a microporous filter membrane for adsorbing microbial samples. The microporous filter membrane 32 is a 0.45 μm filter membrane.

[0093] In this embodiment, a microporous filter membrane and a protective membrane 33 are sequentially arranged within the filter chamber along the direction of liquid flow. The microporous filter membrane is primarily used to adsorb microbial samples and filter water samples. The protective membrane is positioned on the side of the filter chamber near the liquid outlet to prevent damage to the microporous filter membrane caused by negative pressure. For example, the protective membrane is a plastic film.

[0094] In this embodiment, the device mainly includes a sampling unit, a filtration unit and a negative pressure unit. The sampling unit is used to realize minimally invasive puncture, one-way cutoff, and reverse liquid extraction functions; the filtration unit is used to realize negative pressure filtration and bacterial adsorption functions; and the negative pressure unit is used to realize filtrate metering and negative pressure adsorption functions.

[0095] The device is primarily constructed of lightweight, transparent, pressure-resistant, corrosion-resistant, heat-resistant, easily sterilizable, and age-resistant materials, with PP (polypropylene) plastic being the preferred choice for custom injection molding. All sampling and filtration components must be hermetically sealed, heat-resistant, and resistant to ageing and deformation. Negative pressure components must be pressure-resistant, have airtight connections, and have an adjustable negative pressure of at least 0.07 MPa.

[0096] The device is small in size and light in weight, easy to carry indoors and outdoors, with simple connection and combination and convenient operation. It can perform minimally invasive puncture, negative pressure drainage and adsorption lifting on the mouth of bottles (barrels) containing liquids, greatly improving the safety and convenience of operation and having good application value.

[0097] The device can be used to establish a sterile operation method for preparing microbial filter membrane samples using the filter membrane method, and can be expanded to other microbial testing application fields.

[0098] The aseptic operation method for minimally invasively preparing microbial filter membrane samples using the one-way negative pressure adsorption sampling and filtration device comprises the following steps:

[0099] S1, assemble the liquid collection tube 1, the one-way valve 2, the filter 3, the stop valve 4 and the negative pressure measuring bottle 5 and disinfect them;

[0100] S2. Connect the negative pressure measuring bottle 5 to the negative pressure vacuum pump 8, and pierce the beveled end of the liquid collection tube 1 into the water sample. Open the stop valve 4 and start the negative pressure vacuum pump 8. The water sample enters the negative pressure measuring bottle 5 through the filter 3. The microorganisms in the water sample are adsorbed on the filter medium 32 and are used to prepare the microporous filter membrane sample, wherein the filter medium 32 is a microporous filter membrane;

[0101] After adsorption sampling and filtration, when the filtrate reaches a certain volume, close the stop valve 4;

[0102] S3. Place the one-way valve 2, filter 3 and stop valve 4 in a sterile storage box for sample preparation and storage, and then transfer the microporous filter membrane sample in the clean area;

[0103] S4. Transfer the microorganisms on the microporous filter membrane sample into a culture dish for biochemical culture for water quality microbial testing.

[0104] The method mainly includes the following steps: instrument assembly - disinfection - sterile puncture and drainage - negative pressure flow control - quantitative adsorption filtration - sample preparation, storage and transportation - clean area filter membrane transfer - transfer to biochemical culture.

[0105] Before testing, the device needs to be assembled and disinfected. Disinfection uses high-temperature disinfection. The surface of the bottled water is minimally invasively disinfected. The sterile protective cover 13 of the tube head connected to the liquid collection tube is opened, and the liquid collection tube is inserted into the bottled water for adsorption sampling and filtration. At this time, the filtrate enters the negative pressure metering bottle, and the microorganisms are adsorbed on the 0.45μm microporous filter membrane to prepare the target bacteria attached filter membrane sample. It is transferred to the clean bench through a sterile storage box, and then the microporous filter membrane is transferred and placed on CN agar medium for subsequent microbiological testing procedures.

[0106] Compared with traditional methods, this method combines water sampling with membrane filtration, implements minimally invasive aseptic procedures, avoids cross-contamination between water sampling and on-site preparation, shortens the testing process, and enables the one-time preparation of the target microbial filter membrane, which can then be brought back to the laboratory for the next biochemical culture procedure, improving testing timeliness and work efficiency. This method avoids the phenomenon that traditional methods, due to the delay in microbial testing samples, can cause microorganisms to exhibit different survival and growth curves over a certain period of time. Under the objective conditions of water quality and nutrient sources, the survival status of the target microorganisms will be out of sync with the current water quality status, which will have an unrealistic impact on the evaluation of real-time data results.

[0107] In this embodiment, however, the water sample in the filter chamber only meets the growth requirements of the microorganisms and does not form logarithmic growth. Therefore, by combining static liquid level negative pressure adsorption sampling with unidirectional microporous membrane adsorption filtration sample preparation, this method can improve the timeliness and efficiency of testing under environmental conditions outside the laboratory. During on-site sample collection, water quality microbiological test samples can be quickly and conveniently prepared, preventing biochemical operation safety risks and ensuring the validity of test results.

[0108] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A one-way negative pressure adsorption sampling and filtering device, characterized in that: include: A liquid collection tube (1), the liquid inlet end of which is provided with an oblique puncture port (11), and the liquid outlet end of which is connected to a one-way valve (2); A filter (3), the liquid inlet end of which is connected to the one-way valve (2), and the liquid outlet end of which is connected to a stop valve (4); A negative pressure metering bottle (5), the liquid inlet end of which is connected to the stop valve (4) via a connecting pipe (6); and the liquid outlet end of which is connected to a negative pressure vacuum pump (8) via an air guide pipe (7); The filter (3) comprises a first filter (34) and a second filter (35), wherein the first filter (34) and the second filter (35) are sealed and detachably connected; The first filter (34) and the second filter (35) are combined to form a filter cavity (31) for accommodating a filter medium (32); a sealing ring (36) is provided on the outer edge of the filter cavity (31); The filter cavity (31) is provided with a protective film (33) on its side edges near the liquid inlet and the liquid outlet; the filter medium (32) is any one or more of a sand core, filter paper, activated carbon, diatomaceous earth, and anhydrous sodium sulfate; or, the filter cavity (31) is provided with a protective film (33) on one side near the liquid outlet, and the filter medium (32) is a microporous filter membrane for adsorbing microbial samples; The negative pressure metering bottle (5) is provided with a sealing head (51), and a liquid level metering tube (54) is provided in the negative pressure metering bottle (5); one end of the sealing head (51) abuts against one end of the liquid level metering tube (54), and the negative pressure metering bottle (5) is communicated with the liquid level metering tube (54); The sealing head (51) is provided with a liquid inlet joint (52) and an exhaust joint (53); one end of the liquid inlet joint (52) located in the sealing head extends into the liquid level metering tube (54), and the other end is sealed and detachably connected to the connecting tube (6); One end of the exhaust joint (53) located in the sealing head is arranged on the upper side of the liquid level metering tube (54), and the other end is sealed and detachably connected to the air guide tube (7).

2. The one-way negative pressure adsorption sampling and filtering device according to claim 1, characterized in that: The liquid collection tube (1) is a minimally invasive puncture tube; a tube head sterile protective cover (13) is provided on the tube head of the liquid collection tube (1); and the length of the liquid collection tube (1) is 5 to 20 cm.

3. The one-way negative pressure adsorption sampling and filtering device according to claim 1, characterized in that: The one-way valve (2) comprises: a connecting pipe (21) in which a one-way cut-off chamber (211) is provided; A movable cut-off component (22) is disposed in the one-way cut-off cavity (211); As the liquid flows, the movable cut-off component (22) and the one-way cut-off cavity (211) are combined to form a channel for the liquid to pass through.

4. The one-way negative pressure adsorption sampling and filtering device according to claim 3, characterized in that: The movable cut-off component (22) comprises: A cut-off block (221) is provided at the liquid inlet end of the one-way cut-off chamber (211); one side of the cut-off block (221) is provided with an arc-shaped sealing portion (222), and the other side is connected to a limiting sliding rod (223); A blocking groove (224) is provided at the liquid outlet end of the one-way cut-off cavity (211); a return spring (225) is provided in the blocking groove (224); one end of the limiting slide rod (223) passes through the return spring (225) and passes out of the blocking groove (224); The blocking tank body (224) is fixedly connected to the liquid outlet end of the one-way cut-off cavity (211) via a plurality of fixing blocks (226).

5. The one-way negative pressure adsorption sampling and filtering device according to claim 4, characterized in that: The outer diameter of the arc-shaped sealing portion (222) is larger than the inner diameter of the connecting pipe (21); one side of the arc-shaped sealing portion (222) abuts against the inner wall of the one-way cut-off cavity (211).

6. A method for aseptically preparing microbial filter membrane samples using the device of claim 1, characterized in that: The following steps are involved: S1. Assemble the liquid collection tube, one-way valve, filter, stop valve and negative pressure metering bottle and disinfect them; S2. Connect the negative pressure metering bottle to the negative pressure vacuum pump, and pierce the beveled end of the liquid collection tube into the water sample, open the stop valve, start the negative pressure vacuum pump, and the water sample enters the negative pressure metering bottle through the filter. The microorganisms in the water sample are adsorbed on the filter medium and used to prepare the microporous filter membrane sample, wherein the filter medium is a microporous filter membrane; after the adsorption sampling and filtration, when the filtrate reaches a certain volume, close the stop valve; S3. Place the one-way valve, filter, and stop valve in a sterile storage box for sample preparation and storage, and then transfer the microporous filter membrane sample in the clean area; S4. Transfer the microorganisms on the microporous filter membrane sample into a culture dish for biochemical culture for water quality microbial testing.

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