Batch rapid suction filtration device and method for small-size samples

Abstract

The invention discloses a batch rapid suction filtration device and method for small-size samples, and belongs to the field of laboratory vacuum suction filtration and sample pretreatment devices. The device comprises a suction filtration funnel, a small-volume collecting pipe, a collecting pipe limiting device, a vacuum suction filtration bottle and a vacuum pump. And a detachable small-volume collecting pipe is arranged in the vacuum filtration bottle and is used for directly collecting filtrate. The collecting pipe limiting device is used for enabling the small-size collecting pipe to be coaxial or nearly coaxial with the falling center line of filtrate and preventing displacement, and it is guaranteed that the filtrate stably enters the small-size collecting pipe. After suction filtration is completed, the next sample treatment can be continued only by taking out the collecting pipe limiting device, pouring out the filtrate and flushing / replacing the filtrate, and the suction filtration bottle does not need to be repeatedly cleaned, so that the cleaning and turnover cost of batch operation is remarkably reduced, and the small-volume filtrate emptying efficiency and the continuous treatment capacity are improved.

Description

Technical Field

[0001] This invention relates to the field of laboratory vacuum filtration and sample pretreatment devices, and more particularly to a batch rapid filtration device for small-volume samples. Background Technology

[0002] Conventional vacuum filtration typically uses conical flasks, with common sizes of 250 mL and above. When the volume of filtrate for a single filtration is only about 10 mL or even smaller, filtrate tends to remain at the bottom and on the walls of the flask and is not completely poured out. For batch sample processing, frequent cleaning of the vacuum flask is necessary, which is time-consuming and prone to cross-contamination. While placing small test tubes directly inside the vacuum flask to collect the filtrate could significantly reduce the cleaning burden, the test tubes are prone to shifting, tipping, or misalignment within the flask, leading to collection failures. Therefore, there is an urgent need for a structural solution and batch vacuum filtration method that can automatically center and stably limit the position of test tubes within the flask and allows for quick assembly and disassembly.

[0003] Chinese invention patent application publication (CN 106474799A) discloses a "filtration device and filtration method." This device allows for quick replacement of the collection bottle when changing the liquid to be filtered, reducing the risk of cross-contamination and improving experimental efficiency, thus solving the problem of rapid batch filtration. However, because the storage hopper is designed as a cylinder and its size is similar to that of the collection bottle, when filtration of small-volume samples, some of the originally small amount of sample may adhere to the side wall of the filtration bottle, resulting in excessive experimental error. Meanwhile, utility model patents (CN221230317U and CN218421414U) also disclose a "filtration device," which has a conical flask design, resulting in a large volume and significant adhesion error, making it unsuitable for small-volume samples. Furthermore, the entire device needs to be cleaned before filtration of the next sample, making the operation inconvenient and slow.

[0004] The aforementioned defects are particularly prominent in filtration tests of nano-zero-valent iron and its heavy metal-loaded composite materials, because the air contact time of nano-zero-valent iron during transfer and exposure is extremely short. The ability to directly collect and rapidly recycle nano-zero-valent iron to improve the continuous processing efficiency of filtration plays a crucial role in reducing the air contact time of nano-zero-valent iron during transfer and exposure, thereby reducing its oxidation risk. Currently, no existing technology has been found that can solve this problem. Summary of the Invention

[0005] The technical problem to be solved by the present invention is the deficiency pointed out in the background art. The present invention provides a batch rapid filtration device for small-volume samples, which allows the filtrate to directly enter a detachable small-volume collection tube. After filtration, it is only necessary to remove the collection tube, empty the liquid, and rinse / replace it to continue the next sample processing, thereby significantly reducing the cleaning burden and improving the continuous processing efficiency of small-volume samples.

[0006] The technical solution of the present invention is as follows.

[0007] A batch rapid filtration device for small-volume samples, wherein the volume of the small-volume sample is less than or equal to 10 mL, the filtration device includes a filtration funnel, a small-volume collection tube, a collection tube limiting device, a vacuum filtration flask and a vacuum pump. The small-volume collection tube is a glass test tube, and the vacuum filtration bottle has a vacuum interface on its side wall. The vacuum interface is connected to the vacuum pump through a vacuum pipe, and an anti-backflow device is installed on the vacuum pipe. The collection tube limiting device includes a guide sleeve, a limiting base, and a cartridge frame. The guide sleeve has a guide chamfer at its tail end, and its inner diameter is adapted to the outer diameter of the small-volume collection tube. The guide sleeve and the small-volume collection tube are coaxial. The limiting base is made of elastic material, and its central part is concave. The shape of the concave part is adapted to the bottom shape of the small-volume collection tube, and it is used to support and axially limit the small-volume collection tube. The guide sleeve is fixed downward at the upper end of the cartridge frame, and the recessed part of the limiting base is fixed upward at the lower end of the cartridge frame, forming a collection tube limiting device. The outer dimensions of the collection tube limiting device are adapted to the inner diameter of the waist of the vacuum filtration bottle, and the top position is higher than the waist position of the vacuum filtration bottle. After the small volume collection tube is inserted into the collection tube limiting device and the collection tube limiting device is inserted into the vacuum filtration bottle, the small volume collection tube, the collection tube limiting device, and the vacuum filtration bottle remain coaxial. Insert the tail of the filtration funnel into the small-volume collection tube from the top of the vacuum filtration flask to complete the assembly of the filtration device.

[0008] Preferably, the collecting tube limiting device further includes a positioning ring, which is fixed in the middle of the cartridge frame. Its inner diameter is adapted to the outer diameter of the small-volume collecting tube, and it is used to radially limit the small-volume collecting tube to suppress shaking.

[0009] Preferably, it also includes an N-way parallel vacuum manifold, the N branches of which are respectively connected to the vacuum interfaces of N vacuum filtration flasks, and the main port of the N-way parallel vacuum manifold is connected to a vacuum pump.

[0010] Preferably, the filtration funnel is provided with filter paper / membrane, which is a series of products with multiple filtration rates to adapt to the filtration requirements of various filtration samples.

[0011] Preferably, a rubber ring is installed at the contact point between the filtration funnel and the vacuum filtration flask for sealing connection.

[0012] Preferably, the anti-backflow structure is a check valve or a one-way valve.

[0013] Preferably, the small-volume sample is a suspension or slurry of nano-zero ferric iron or a suspension or slurry of nano-zero ferric iron loaded with heavy metals. The filter paper / membrane in the filtration funnel of the filtration device achieves solid-liquid separation of the sample. After filtration, the filtrate is collected by the small-volume collection tube of the filtration device, and the nano-zero ferric iron solid phase or the nano-zero ferric iron loaded with heavy metals solid phase is obtained by the filter paper / membrane.

[0014] This invention also provides a method for filtration of small-volume samples, which utilizes a batch rapid filtration device for small-volume samples. The working process is as follows: the small-volume sample is added to the filtration funnel, the vacuum pump is started to form a negative pressure, and the filtrate is filtered through the filter paper / membrane in the filtration funnel and then directly enters the small-volume collection tube; after filtration is completed, the vacuum pump is turned off, the small-volume collection tube is removed, the filtrate is poured out and rinsed or replaced, and then it can be inserted again to continue the filtration of the next small-volume sample, without the need for frequent cleaning of the filtration flask.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The filtrate of small volume samples is collected directly in a small volume collection tube, reducing the residue in the vacuum filtration bottle and improving the convenience of emptying and quantification. (2) Multi-station parallel filtration can be achieved through N parallel vacuum manifolds, improving the capacity for large-volume processing; (3) After filtration, only the small volume collection tube needs to be removed, the liquid poured out and rinsed / replaced before the next sample can be processed, reducing the frequency of repeated cleaning of the filtration flask, improving the continuous processing efficiency of small volume samples, and improving the batch processing efficiency. (4) Filter paper / membrane can be selected with different filtration rates to suit different sample systems; (5) The rubber ring provides cushioning and protection, reducing the risk of breakage caused by frequent handling of glassware; (6) Setting up an anti-backflow structure can reduce the risk of backflow contamination caused by pump stoppage or pressure fluctuations; (7) The device directly places a small volume collecting tube in the vacuum filtration flask to collect the filtrate, and ensures the stability and centering of the small volume collecting tube by the collecting tube limiting device.

[0016] (8) This invention is particularly applicable to small-volume samples that are highly active, easily oxidized and deactivated, and highly sensitive to processing time, such as nano-zero-valent iron suspensions, slurries, and suspensions of nano-zero-valent iron-loaded heavy metal composite materials. Through the structure of "small-volume collection tube directly receiving the filtrate" and the operation method of "the collection tube can be quickly removed and replaced after filtration," the solid-liquid separation and collection process forms a direct, short-path flow, significantly reducing the air exposure time and residence time of the sample during container transfer, opening and pouring, and repeated washing. This effectively inhibits the oxidation passivation and activity decay of nano-zero-valent iron, maintaining Fe... 0 Effective content and its reduction / adsorption reaction capacity.

[0017] (9) The small volume collection tube can be taken out separately and sealed in time, reducing the risk of residual dead volume, sample loss and cross-contamination caused by traditional large container filtration, and improving the consistency and repeatability of batch sample processing. For slurry systems that are easy to settle and agglomerate, the present invention shortens the operation time and reduces disturbance, which can reduce the error caused by stratification and agglomeration solidification, enabling such samples to achieve higher turnover frequency, more stable sample state and more reliable analysis results. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the filtration device of the present invention; Figure 2 This is a schematic diagram of the structure of the collection tube limiting device in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of the collection tube limiting device in Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of a four-way parallel vacuum manifold.

[0019] In the diagram, 1-vacuum filtration funnel, 2-rubber ring, 3-filter paper / membrane, 4-small volume collection tube, 5-collection tube limiting device, 6-anti-backflow structure, 7-vacuum filtration bottle, 8-cassette frame, 9-vacuum pump, 10-four-way parallel vacuum manifold, 11-guide sleeve, 12-limiting base, 13-positioning ring. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] Example 1

[0022] Figure 1 This is a schematic diagram of the overall structure of the filtration device of the present invention. Figure 2 This is a schematic diagram of the collecting tube limiting device in Embodiment 1 of the present invention. Figures 1-2 Therefore, the present invention provides a batch rapid filtration device for small-volume samples, wherein the volume of the small-volume sample is less than or equal to 10 mL. The filtration device includes a filtration funnel 1, a small-volume collection tube 4, a collection tube limiting device 5, a vacuum filtration flask 7, and a vacuum pump 9.

[0023] The small-volume collection tube 4 is a glass test tube, and the vacuum filtration bottle 7 has a vacuum interface on its side wall. This vacuum interface is connected to the vacuum pump 9 through a vacuum pipe, and an anti-backflow device 6 is installed on the vacuum pipe.

[0024] The collection tube limiting device 5 includes a guide sleeve 11, a limiting base 12, and a cartridge frame 8. The guide sleeve 11 has a guide chamfer at its tail end. The inner diameter of the guide sleeve 11 is adapted to the outer diameter of the small volume collection tube 4, and the guide sleeve 11 and the small volume collection tube 4 are coaxial. The limiting base 12 is made of elastic material, and the central part is concave. The shape of the concave part is adapted to the bottom shape of the small volume collection tube 4, and it is used to support and axially limit the small volume collection tube 4.

[0025] The guide sleeve 11 is fixed downward at the upper end of the cartridge frame 8, and the recessed part of the limiting base 12 is fixed upward at the lower end of the cartridge frame 8, forming a collection tube limiting device 5. The outer dimensions of the collection tube limiting device 5 are adapted to the inner diameter of the waist of the vacuum filtration bottle 7, and the top position is higher than the waist position of the vacuum filtration bottle 7. After the small volume collection tube 4 is inserted into the collection tube limiting device 5 and the collection tube limiting device 5 is inserted into the vacuum filtration bottle 7, the small volume collection tube 4, the collection tube limiting device 5, and the vacuum filtration bottle 7 remain coaxial.

[0026] Insert the tail of the filtration funnel 1 into the small-volume collection tube 4 from the top of the vacuum filtration flask 7 to complete the assembly of the filtration device.

[0027] Example 2

[0028] Figure 3 This is a schematic diagram of the collecting tube limiting device in Embodiment 2 of the present invention. Figure 3 As can be seen, in this embodiment, the collecting tube limiting device 5 also includes a positioning ring 13, which is fixed in the middle of the cartridge frame 8. Its inner diameter is adapted to the outer diameter of the small volume collecting tube 4, and it is used to radially limit the small volume collecting tube 4 to suppress shaking.

[0029] The other structures are the same as in Example 1.

[0030] Example 3

[0031] Figure 4 This is a schematic diagram of a four-way parallel vacuum manifold. Figure 4 As can be seen, the vacuum filtration device of the present invention also includes a four-way parallel vacuum manifold 10, the four branches of which are respectively connected to the vacuum interfaces of the four vacuum filtration bottles 7, and the main port of the four-way parallel vacuum manifold 10 is connected to the vacuum pump 9.

[0032] In the above three embodiments, a rubber ring 2 is installed at the contact point between the filtration funnel 1 and the vacuum filtration flask 7 for sealing connection. The filtration funnel 1 is provided with filter paper / membrane 3, which is a series of products with various filtration rates to adapt to the filtration requirements of various filtration samples. The anti-backflow structure 6 is a check valve or a one-way valve.

[0033] In the above three embodiments, the small volume sample is a suspension or slurry of nano-zero ferric iron or a suspension or slurry of nano-zero ferric iron loaded with heavy metal composite material. The filter paper / membrane 3 in the filtration funnel 1 of the filtration device realizes solid-liquid separation of the sample. After filtration, the filtrate is collected by the small volume collection tube 4 of the filtration device, and the nano-zero ferric iron solid phase or nano-zero ferric iron loaded with heavy metal solid phase is obtained by the filter paper / membrane 3.

[0034] Specifically, the small-volume sample is preferably a suspension or slurry of nano-zero-valent iron, or a suspension or slurry of nano-zero-valent iron-loaded heavy metal composite material. Because these samples are highly reactive, easily oxidized and passivated, and have small volumes and high turnover requirements, the operational timeliness of the solid-liquid separation and collection stages is crucial. The filtration device, by setting a small-volume collection tube 4 and cooperating it with a vacuum filtration flask 7, enables the filtrate to be directly received and collected independently by the small-volume collection tube 4, avoiding the time loss caused by repeated opening, pouring, transferring, and cleaning during traditional filtration. After filtration, the small-volume collection tube 4 can be quickly removed and replaced, forming a short-path process of "direct collection and immediate use" for continuous filtration of similar samples. This significantly shortens the filtrate collection and sample switching time, reduces sample exposure and waiting time in the air, and lowers the concentration of nano-zero-valent iron Fe. 0 To mitigate the risk of passivation and deactivation due to oxidation, and to maintain its reduction / adsorption reactivity.

[0035] Meanwhile, the filter paper / membrane 3 in the filtration funnel 1 achieves solid-liquid separation of the sample and obtains a nano-zero-valent iron solid phase or a nano-zero-valent iron-loaded heavy metal solid phase on the filter paper / membrane 3. Combined with the immediate sealing of the small-volume collection tube 4, it can reduce residual dead volume and sample retention, reduce cross-contamination and dilution errors, and thus improve the consistency of sample state and the reproducibility of results under batch processing conditions.

[0036] This invention also provides a method for filtration of small-volume samples. The method utilizes a batch rapid filtration device for small-volume samples. The working process is as follows: the small-volume sample is added to the filtration funnel 1, the vacuum pump 9 is started to form a negative pressure, and the filtrate is filtered through the filter paper / membrane 3 in the filtration funnel 1 and then directly enters the small-volume collection tube 4. After filtration is completed, the vacuum pump 9 is turned off, the small-volume collection tube 4 is removed, the filtrate is poured out and rinsed or replaced, and then it can be inserted again to continue the filtration of the next small-volume sample. There is no need to frequently clean the filtration flask 7.

Claims

1. A batch rapid filtration device for small-volume samples, wherein the volume of the small-volume sample is less than or equal to 10 mL, characterized in that, The filtration device includes a filtration funnel (1), a small-volume collection tube (4), a collection tube limiting device (5), a vacuum filtration flask (7), and a vacuum pump (9). The small volume collection tube (4) is a glass test tube. The vacuum filtration bottle (7) has a vacuum interface on its side wall. The vacuum interface is connected to the vacuum pump (9) through a vacuum pipe. An anti-backflow device (6) is installed on the vacuum pipe. The collection tube limiting device (5) includes a guide sleeve (11), a limiting base (12), and a cartridge frame (8). The tail of the guide sleeve (11) is provided with a guide chamfer. The inner diameter of the guide sleeve (11) is adapted to the outer diameter of the small volume collection tube (4). The guide sleeve (11) and the small volume collection tube (4) are coaxial. The limiting base (12) is made of elastic material. The central part is concave. The shape of the concave part is adapted to the bottom shape of the small volume collection tube (4). It is used to support and axially limit the small volume collection tube (4). The guide sleeve (11) is fixed downward at the upper end of the cartridge frame (8), and the recessed part of the limiting base (12) is fixed upward at the lower end of the cartridge frame (8), forming a collection tube limiting device (5). The outer dimensions of the collection tube limiting device (5) are adapted to the inner diameter of the waist of the vacuum filtration bottle (7), and the top position is higher than the waist position of the vacuum filtration bottle (7). After the small volume collection tube (4) is inserted into the collection tube limiting device (5) and the collection tube limiting device (5) is inserted into the vacuum filtration bottle (7), the small volume collection tube (4), the collection tube limiting device (5), and the vacuum filtration bottle (7) remain coaxial. Insert the tail of the filtration funnel (1) into the small volume collection tube (4) from the top of the vacuum filtration bottle (7) to complete the assembly of the filtration device.

2. The batch rapid filtration device for small-volume samples according to claim 1, characterized in that, The collecting tube limiting device (5) also includes a positioning ring (13), which is fixed in the middle of the cartridge frame (8). Its inner diameter is adapted to the outer diameter of the small volume collecting tube (4) and is used to radially limit the small volume collecting tube (4) to suppress shaking.

3. The batch rapid filtration device for small-volume samples according to claim 1, characterized in that, It also includes an N-way parallel vacuum manifold, whose N branches are connected to the vacuum interfaces of N vacuum filtration bottles (7) respectively, and whose main port is connected to the vacuum pump (9).

4. A batch rapid filtration device for small-volume samples according to claim 1, 2, or 3, characterized in that, The filtration funnel (1) is provided with filter paper / filter membrane (3), which is a series of products with multiple filtration rates to meet the filtration needs of various filtration samples.

5. A batch rapid filtration device for small-volume samples according to claim 1, 2, or 3, characterized in that, A rubber ring (2) is installed at the contact point between the filtration funnel (1) and the vacuum filtration flask (7) for sealing connection.

6. A batch rapid filtration device for small-volume samples according to claim 1, 2, or 3, characterized in that, The anti-backflow structure (6) is a check valve or a one-way valve.

7. A batch rapid filtration device for small-volume samples according to claim 1, 2, or 3, characterized in that, The small volume sample is a suspension or slurry of nano-zero ferric iron or a suspension or slurry of nano-zero ferric iron loaded with heavy metal composite material. The filter paper / membrane (3) in the filtration funnel (1) of the filtration device realizes solid-liquid separation of the sample. After filtration, the filtrate is collected by the small volume collection tube (4) of the filtration device, and nano-zero ferric iron solid phase or nano-zero ferric iron loaded with heavy metal solid phase is obtained by the filter paper / membrane (3).

8. A method for filtration of small-volume samples, characterized in that, The process of using a batch rapid filtration device for small volume samples according to any one of claims 1-6 is as follows: add the small volume sample into the filtration funnel (1), start the vacuum pump (9) to form a negative pressure, and the filtrate is filtered through the filter paper / membrane (3) in the filtration funnel (1) and then directly enters the small volume collection tube (4); after the filtration is completed, turn off the vacuum pump (9), take out the small volume collection tube (4), pour out the filtrate and rinse or replace it and insert it again to continue the next small volume sample filtration, without the need to frequently clean the filtration bottle (7).

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