Filtering and sample adding assembly and sample pretreatment device

Abstract

The invention discloses a filtering and sample adding assembly and a sample pretreatment device, and belongs to the technical field of sample automatic analysis and liquid treatment. The filtering and sampling assembly comprises a sampling needle, a fixed base, a filtering head and an elastic supporting piece positioned between the sampling needle and the fixed base; the fixed base is provided with a fluid channel with a sealing ring, and the outlet end of the filter head is inserted into the fluid channel and matched with the sealing ring to form sealing. The elastic supporting piece is compressed to store energy when the filter head moves towards the fixed base, and resets after filtering is completed and pushes the filter head to be away from the fixed base, so that automatic ejection is achieved. The sample pretreatment device has the advantages of being simple in structure, reliable in sealing and capable of automatically ejecting the filter head after filtration, and the automation degree and the working efficiency of sample pretreatment are improved.

Description

Technical Field

[0001] This application relates to the field of automated sample analysis and liquid handling technology, specifically to a filter and sample dispensing assembly and a sample pretreatment device. Background Technology

[0002] With the continuous growth in demand for liquid handling in fields such as chemical engineering, pharmaceuticals, and environmental protection, traditional gravity filtration and centrifugation technologies face challenges due to their inability to accurately remove trace particles (<5μm), driving the iteration of microfiltration technology. As a commonly used microfiltration device in detection experiments, needle filters are primarily used for sample pretreatment and effectively protect precision instruments such as high-performance liquid chromatography (HPLC) and gas chromatography (GC) from particulate contamination. Existing needle filters have poor applicability; the filtered filtrate needs to be collected in a container before being supplied to analytical instruments for analysis. Furthermore, to form a sealed fluid filtration channel, existing needle filters typically fix the filter head by inserting a sample needle, with its outlet end inserted into the fluid channel of the lower fixed base, and sealed by a sealing ring. In actual use, to ensure no leakage during filtration, the sealing ring must remain tightly fitted under pressure, creating significant friction between the lower part of the filter head and the sealing ring. However, the connection between the sample needle and the upper part of the filter head relies mainly on a frictional fit, which has relatively low friction. Due to the significant difference in friction between the upper and lower parts, when the sample needle pulls the filter head out from the sealing ring, the sample needle may detach from the upper part of the filter head first, while the filter head remains "locked" in the base by the sealing ring, making it impossible to remove the used filter head smoothly. Summary of the Invention

[0003] This application provides a filtration and sample feeding assembly and a sample pretreatment device to solve the technical problems of poor applicability of existing filtration devices using filter heads, the inability to directly supply the filtrate to analytical instruments for analysis and detection and the need for transfer, and the difficulty in separating the filter head from the sealing ring.

[0004] According to one aspect of this application, a filtration and sample dispensing assembly is provided, including an injection needle, a fixed base, a filter head, and an elastic support member; the fixed base has a fluid channel, and a sealing ring is provided at the inlet of the fluid channel; the filter head has an inlet end for inserting and engaging with the injection needle and an outlet end for inserting into the fluid channel and engaging with the sealing ring; the elastic support member is used to withstand pressure and be compressed when the filter head is close to the fixed base, and to reset when the filter head is away from the fixed base, thereby applying a thrust to the filter head.

[0005] Optionally, the elastic support includes a top cover, a guide shaft, and a spring. The guide shaft includes a movable end and a fixed end. The fixed end is fixedly connected to the top cover, and the movable end is slidably engaged with the fixed base along the length direction. Alternatively, the fixed end is fixedly connected to the fixed base, and the movable end is slidably engaged with the top cover along the length direction.

[0006] Optionally, multiple guide shafts and corresponding springs are distributed along a circumferential direction.

[0007] Optionally, an annular support platform is formed on the filter head, which is used to contact the upper cover to transmit force.

[0008] Optionally, a limiting block is provided at the movable end of the guide shaft, and a limiting step is provided on the fixed base or the upper cover. The limiting block abuts against the limiting step when the spring is compressed to a preset stroke, thereby limiting the amount of spring compression.

[0009] According to another aspect of this application, a sample pretreatment apparatus is also provided, which includes the above-described filtering and sample dispensing assembly, wherein the moving assembly includes a moving mechanism and a separation mechanism disposed at the terminal of the moving mechanism.

[0010] Optionally, the separation mechanism includes a fixed plate, a push plate, and a driving member for driving the push plate to move in a linear direction; the fixed plate is used to mount the injection needle, and the push plate is used to push the filter head on the injection needle under the action of the driving member, so that the filter head is separated from the injection needle. Optionally, the driving component is a push rod motor, the body of which is mounted on a fixed plate, and the push rod of the push rod motor is connected to the push plate.

[0011] Optionally, the system also includes a workbench, which is provided with a filter sample loading assembly mounting plate and a filter head tray. The filter sample loading assembly mounting plate is provided with a plurality of mounting holes for placing the filter sample loading assembly, and the filter head tray is provided with a plurality of openings for placing the filter head.

[0012] Optionally, the workbench is provided with a recycling hole, and a recycling frame for receiving filter heads is provided below the recycling hole.

[0013] According to another aspect of this application, a sample pretreatment method using the above-described filtering and sample dispensing assembly is also provided, comprising the following steps: The control system controls the moving mechanism to move the injection needle to the filter head plate position, so that the injection needle can be inserted and connected to the filter head on the filter head plate; Move the injection needle with the filter head above the fixed base and press it down to insert the filter head into the fluid channel and form a tight fit with the sealing ring; The sample solution is fed into the filter head through the injection needle for filtration and then output through the fixed base; After filtration is complete, release the pressure on the injection needle and use the elastic support to reset the filter head and disengage it from the sealing ring. The drive separation mechanism pushes the injection needle to separate from the filter head; The control mechanism moves the injection needle above the recovery port, causing the filter head to fall into the recovery frame. The control system then resets the injection needle to its initial position to prepare for the next cycle.

[0014] In summary, this application includes at least one of the following beneficial technical effects: This application incorporates an elastic support between the filter head and the fixed base. During assembly, the filter head compresses a compressible spring to store energy, ensuring the sealing ring is fully compressed for reliable sealing. After filtration, when the pressure from the injection needle is released, the elastic support automatically resets under its elastic force, applying a reverse thrust to the filter head and pushing it away from the sealing ring's gripping area. This eliminates the need for the filter head to rely entirely on the injection needle's pulling force for separation, significantly reducing separation resistance and preventing failure due to needle detachment. This structure, while meeting high-pressure sealing requirements, achieves automatic ejection and smooth separation, fundamentally solving the problem of difficult separation caused by excessive friction from the sealing ring.

[0015] In addition to the purposes, features, and advantages described above, this application has other purposes, features, and advantages. A further detailed description of this application will be provided below with reference to the figures. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 An exploded view of the filtering and sampling assembly of this application; Figure 2 This is a front view of the filter feeding assembly of this application in the state when the filter head is to be inserted; Figure 3 A cross-sectional view of the filter feeding assembly of this application in the state when the filter head is to be inserted; Figure 4 This is a front view of the filter feeding assembly of this application in the state when the filter head is inserted; Figure 5 A cross-sectional view of the filter dispensing assembly of this application in the state when the filter head is inserted; Figure 6 This is a schematic diagram of the sample pretreatment device of this application; Figure 7 This is a schematic diagram of the structure of the mobile component of this application; Figure 8 This is a schematic diagram of the workbench structure of this application.

[0017] Legend: 1. Injection needle; 2. Fixed base; 21. Fluid channel; 22. Sealing ring; 3. Filter head; 31. Inlet end; 32. Outlet end; 33. Annular support platform; 4. Elastic support component; 41. Top cover; 42. Guide shaft; 43. Spring; 44. Limiting block; 45. Limiting step; 5. Moving assembly; 51. Moving mechanism; 52. Separation mechanism; 521. Fixed plate; 522. Push plate; 523. Push rod motor; 6. Worktable; 61. Filter and sample feeding assembly mounting plate; 62. Filter head plate; 63. Recovery hole; 64. Recovery frame. Detailed Implementation

[0018] The embodiments of this application are described in detail below with reference to the accompanying drawings; however, this application may be implemented in a variety of different ways as defined and covered below.

[0019] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0020] like Figure 1 As shown, a filtration and sample dispensing assembly includes an injection needle 1, a fixed base 2, a filter head 3, and an elastic support 4 located between the two. This assembly is used to filter and guide the sample liquid in a closed loop during sample pretreatment, and features reliable sealing and smooth separation of the filter head.

[0021] The fixed base 2 has a through fluid channel 21 inside, and a sealing ring 22 is embedded at the inlet of the fluid channel 21. The sealing ring 22 is used to cooperate with the outlet end of the filter head 3 to form a seal during filtration, thereby preventing liquid leakage and ensuring the airtightness of the filtration channel.

[0022] The filter head 3 includes an upper inlet end 31 and a lower outlet end 32. During filtration, the upper inlet end 31 is inserted into the injection needle 1, which delivers the sample liquid to be filtered into the internal filter medium of the filter head 3. The lower outlet end 32 is inserted into the fluid channel 21 of the fixed base 2 and fits against the sealing ring 22 to form a closed flow path. The filtered sample liquid is output to the analytical device through the fluid channel 21 of the fixed base 2.

[0023] An elastic support 4 is provided between the filter head 3 and the fixed base 2. During filtration, the elastic support 4 is compressed under pressure when the filter head 3 is inserted downward into the fixed base 2 to store elastic potential energy. When the filtration operation is completed and the injection needle 1 is lifted to release the downward pressure, the elastic support 4 is reset under the action of elastic restoring force, and applies an upward pushing force to the filter head 3, thereby pushing the filter head 3 out of the clamping position of the sealing ring 22.

[0024] With the above structure, during the sample liquid filtration stage, the elastic support 4 is compressed to maintain sufficient sealing pressure on the sealing ring 22, achieving a high-pressure liquid channel seal to prevent liquid leakage. During the filter head separation stage, the reset thrust of the elastic support 4 effectively counteracts the high frictional clamping force between the sealing ring and the filter head, allowing the filter head 3 to smoothly detach from the fixed base 2, avoiding the problem of the injection needle 1 detaching from the filter head first due to frictional differences. This structure not only achieves reliable sealing during the filtration process but also significantly reduces the operational difficulty of filter head separation, improves the reusability of the components, and enhances the stability of automated handling.

[0025] like Figures 2 to 5 As shown, in this embodiment, the elastic support 4 includes an upper cover 41, a guide shaft 42, and a spring 43. The upper cover 41 has a through hole for the lower outlet end 32 of the filter head 3 to enter and exit. The spring 43 is used to be compressed and store energy when the filter head 3 is inserted downwards into the fixed base 2, and to provide a reset thrust to push out the filter head 3 after filtration. The guide shaft 42 is used to limit the direction of spring movement and maintain the axial guidance stability of the filter head 3. During the sample liquid filtration stage, the upper cover 41 contacts the annular support platform of the filter head 3, uniformly transmitting the downward pressure of the filter head 3 to the spring 43.

[0026] In one embodiment, the fixed end of the guide shaft 42 is fixedly connected to the upper cover 41, and the movable end passes through the fixed base 2 and slides along its length. Thus, when the filter head 3 is pressed down, the movable end of the guide shaft 42 can slide within the fixed base 2, causing the spring 43 to undergo controlled compression, moving the upper cover 41 closer to the fixed base 2, achieving stable axial guidance. In another embodiment, the fixed end of the guide shaft 42 is fixedly connected to the fixed base 2, and the movable end passes through the upper cover 41 and slides along its length. With this structure, the spring 43 maintains coaxial movement with the guide shaft 42 during compression and reset, effectively preventing the spring from tilting or shifting, ensuring uniform force distribution and smooth reset of the filter head 3.

[0027] A support surface is formed between the upper cover 41 and the filter head 3 to withstand the downward pressure of the filter head 3 and transmit the force to the spring 43. When the filter head 3 is pressed down and inserted into the fluid channel 21 of the fixed base 2, the annular support platform of the filter head 3 contacts the upper surface of the upper cover 41, causing the spring 43 to be compressed and store elastic potential energy. When the injection needle 1 is lifted after filtration to release the downward pressure, the spring 43 returns to its original state, driving the upper cover 41 to move upward, thereby pushing the filter head 3 out of the position of the sealing ring 22, realizing the automatic ejection function. Through the above structure, the elastic support 4 achieves balanced force and smooth separation of the filter head 3 while ensuring sealing reliability, further reducing the difficulty of separating the sealing ring and the filter head, and improving the reusability stability and automatic adaptation capability of the filter assembly.

[0028] like Figures 2 to 5 As shown, to further improve the uniformity of force and guiding stability of the elastic support 4 during the pressing and resetting process of the filter head 3, the guide shaft 42 and the corresponding spring 43 adopt a multi-point distribution structure. Specifically, multiple guide shafts 42 and springs 43 are evenly arranged along the circumferential direction surrounding the outlet end 32 of the filter head 3. They can usually be set in two, four, or six groups symmetrically distributed, or multiple groups evenly distributed at equal intervals in the circumferential direction. When the filter head 3 is inserted downward into the fluid channel 21 of the fixed base 2, multiple springs 43 are simultaneously pressed and compressed, and the movable ends of multiple guide shafts 42 move simultaneously relative to the upper cover 41 or the fixed base 2 along their respective sliding engagement directions, thereby ensuring that the movement posture of the filter head 3 always remains parallel and will not tilt or jam due to uneven force on one side. The movable end of each guide shaft 42 has an independent sliding hole in the fixed base 2 or the upper cover 41, which gives it a good independent guiding effect during the compression stroke.

[0029] After filtration, when spring 43 releases its stored energy to push filter head 3 upward, the combined action of multiple springs 43 balances the thrust, preventing filter head 3 from being eccentrically ejected or rotating when it disengages from sealing ring 22. This circumferentially distributed support not only ensures smooth and precise up-and-down movement of filter head 3 but also effectively reduces local friction and wear, improving the overall reliability and service life of the assembly. This multi-guide structure also has assembly tolerance absorption capabilities; when some guide shafts 42 or springs 43 have slight stroke deviations due to manufacturing errors, the remaining guide components can automatically compensate, ensuring the repeatability and consistency of the assembly during long-term operation, thus meeting the high repeatability positioning requirements of automated equipment.

[0030] In one embodiment, to ensure stable and reliable force transmission between the filter head 3 and the elastic support 4, an annular support platform 33 is formed on the outer surface of the filter head 3. The annular support platform 33 is located above the outlet end 32 of the filter head 3, and its outer diameter is larger than that of the filter head body, for contacting the upper cover 41 of the elastic support 4. When the filter head 3 is inserted into the fixed base 2, the lower surface of the annular support platform 33 abuts against the upper surface of the upper cover 41, thereby uniformly transmitting the downward pressure of the filter head 3 to the spring 43, causing the spring 43 to be compressed axially and store elastic potential energy. Because the annular support platform 33 is a continuous ring structure, it can effectively disperse the concentrated load applied by the filter head 3, avoiding eccentric compression caused by single-point force on the spring.

[0031] In one embodiment, to prevent the spring 43 from undergoing excessive plastic deformation during repeated compression, a limiting structure is provided on the guide shaft 42. Specifically, a limiting block 44 is provided on the movable end of the guide shaft 42, and a limiting step 45 is provided at a corresponding position on the fixed base 2 or the upper cover 41. When the filter head 3 is inserted downward into the fixed base 2 and the spring 43 is compressed, the guide shaft 42 slides along its axial direction until the limiting block 44 abuts against the limiting step 45. At this time, the spring 43 is compressed to a preset stroke, forming a reliable mechanical limit.

[0032] This limiting structure ensures that the filter head 3 is fully pressed down to achieve a seal while preventing the spring 43 from being over-compressed, thus effectively avoiding fatigue and permanent deformation of the spring under long-term operation. This design not only guarantees the service life of the spring 43 but also maintains stable movement between the filter head 3 and the fixed base 2, ensuring consistent action of the filter head 3 during each insertion and separation process. Through this limiting structure design, the filter feeding assembly maintains stable elastic return characteristics during long-term cyclic operation, ensuring that the filter head 3 can still be smoothly inserted and ejected under the high friction conditions of the sealing ring 22, significantly improving the reliability and durability of the entire machine.

[0033] like Figure 6 As shown in this embodiment, a sample pretreatment device is disclosed. This device is used to automatically complete sample liquid filtration, filtrate transportation and waste filter head recovery, and can realize unmanned and highly repeatable sample pretreatment operations.

[0034] The moving component 5 includes a moving mechanism and a separation mechanism 52 disposed at its end. The moving mechanism 51 is used to drive the injection needle 1 and its connected filter head to achieve spatial positioning and path control. The separation mechanism 52 is installed at the end of the moving mechanism 51 and is used to separate the filter head 3 from the injection needle 1 after the filtration operation is completed.

[0035] The separation mechanism 52 includes a fixed plate 521, a push plate 522, and a drive component 523 for driving the push plate 522 to move linearly. The fixed plate 521 is used to mount the injection needle 1. When the injection needle 1 needs to be disengaged from the filter head 3, the drive component 523 is activated to push the push plate 522 forward. The push plate 522 contacts the filter head 3 and applies a separation force, causing the injection needle 1 to disengage from the filter head 3. In this way, the injection needle 1 can be completely withdrawn from the filter head 3. The above actions can be automatically completed by the control system without manual intervention. This sample pretreatment device realizes a fully automatic process of "insertion of the fluid channel between the filter head and the fixed base - filtration - separation of the filter head and the sealing ring - disengagement of the injection needle from the filter head" through mechanical coordination. This ensures the sealing reliability during the filtration process and effectively solves the problem of high separation resistance between the filter head and the sealing ring. Through the cooperation of the moving mechanism and the separation mechanism, precise positioning and controllable separation of the injection needle and the filter head can be achieved, thereby improving the stability and repeatability of sample processing.

[0036] The moving mechanism 51 is the spatial positioning unit of this device. Optionally, the moving mechanism 51 is a three-axis sliding mechanism used to achieve precise movement of the injection needle 1 and its connecting components in the X, Y, and Z directions. This mechanism typically consists of three mutually orthogonal linear motion modules, each corresponding to the displacement control of a coordinate axis. During operation, the X-axis module is responsible for driving the injection needle 1 to move left and right in the horizontal plane, used to achieve lateral switching between different workstations; the Y-axis module is used to achieve positioning movement in the forward and backward directions, controlling the alignment accuracy of the injection needle 1 in the horizontal direction; the Z-axis module is used to achieve vertical lifting and lowering movements, controlling the insertion, pressing down, and lifting of the injection needle 1 and the filter head 3. The three-axis sliding mechanism is typically driven by a servo motor or stepper motor, achieving precise displacement through transmission components such as ball screws, guide rails, sliders, or synchronous belts. The stroke and speed of each axis can be adjusted in real time by the control system, thereby ensuring that the motion path of the injection needle 1 in the three-dimensional spatial range is controllable and has high repeatability. The above-mentioned moving mechanism has low cost and occupies less space. In another embodiment, the moving mechanism 51 is a multi-axis robotic arm.

[0037] like Figure 8 As shown, the sample pretreatment device in this embodiment also includes a worktable 6 for supporting and arranging the various functional components. The worktable 6 serves as the mounting base for the entire machine and mainly supports the filter sample dispensing assembly, filter head plate, and moving mechanism.

[0038] The workbench 6 is equipped with a filter sample dispensing assembly mounting plate 61 and a filter head tray 62. The filter sample dispensing assembly mounting plate 61 has multiple mounting holes for mounting multiple filter sample dispensing assemblies and ensuring the vertical positioning accuracy of each assembly. The number and distribution of the mounting holes can be adjusted according to the processing throughput of the automated equipment. Multiple filter sample dispensing assemblies can be arranged in parallel to achieve simultaneous filtration of multiple samples. The filter head tray 62 is located above the workbench 6 and has multiple openings for placing the filter heads 3 to be used. In a preferred embodiment, the filter head tray 62 can be detachably connected to the workbench 6 via positioning pins or guide grooves for easy maintenance and batch replacement; the bottom of the openings in the filter head tray 62 can be provided with positioning steps and / or flexible pads to limit the insertion depth of the filter heads 3 and reduce mechanical impact.

[0039] like Figure 8 As shown, in this embodiment, to achieve centralized collection after the used filter head 3 automatically detaches, a recovery hole 63 is provided on the worktable 6, and a recovery frame 64 is provided below the recovery hole 63. After the filtration operation is completed, the moving component 5, under the command of the control system, moves the injection needle 1 along with the filter head 3, which has been completely separated from the fluid channel 21 of the fixed base 2, to above the recovery hole 63. At this time, the drive component 523 is activated to push the push plate 522 forward. The push plate 522 contacts the filter head 3 and applies a separation force, causing the injection needle 1 to detach from the filter head 3. After the filter head 3 detaches from the insertion end of the injection needle 1, it falls into the recovery frame 64 through the recovery hole 63 under its own gravity. In this way, the filter head 3 can automatically detach from the injection needle 1 and enter the recovery frame 64 after completing one filtration, without manual intervention. This avoids the risk of operators coming into contact with contaminated samples, improves the continuous operation capability of the automated equipment, and enhances the safety and efficiency of the system.

[0040] like Figure 8 As shown, in this embodiment, the recovery hole 63 is preferably located in the area between the filter sample feeding assembly mounting plate 61 and the filter head plate 62. This layout is based on the principle of optimizing the device's operating path, minimizing the movement path of the moving assembly 5 between the three stations of filter head picking, filtering, and filter head recovery, thereby significantly reducing operation time and minimizing the accumulation of movement errors.

[0041] During operation, the moving mechanism 51 first drives the injection needle 1 to move above the filter head plate 62. The injection needle 1 descends via the Z-axis to connect with the filter head 3, thus completing the filter head retrieval action. It then moves horizontally to the filter sample loading assembly mounting plate 61, causing the filter head 3 to be pressed down and inserted into the fluid channel 21 of the fixed base 2 for filtration. After filtration, the injection needle 1 rises to release the downward pressure and then moves along a preset path to a position above the recovery hole 63. At this point, the driving component 523 activates, pushing the push plate 522 forward. The push plate 522 contacts the filter head 3 and applies a separation force, causing the injection needle 1 to disengage from the filter head 3. After the filter head 3 detaches from the insertion end of the injection needle 1, it enters the recovery hole 63 under its own gravity and finally falls into the recovery frame 64. By arranging the recovery hole 63 between the mounting plate 61 and the filter head plate 62, the moving component 5 can complete the entire operation cycle without large-scale displacement, which not only improves the equipment's working efficiency but also reduces the mechanical load and energy consumption of the moving mechanism. In a preferred embodiment, the edge of the recovery hole 63 may also be provided with a guide bevel or chamfer to guide the filter head 3 to fall smoothly and prevent jamming or deflection.

[0042] This application also discloses a sample pretreatment method based on the above-mentioned sample pretreatment device, used to achieve full-process control of automatic sampling, filtering, collection, and recovery. This method is uniformly managed by a control system, and through the coordinated actions of the injection needle 1, the filtering and sample application component, the moving component 5, and the worktable 6, it can achieve fully unattended operation under a preset program. The specific steps are as follows: Step S1: Positioning and Automatic Loading of the Filter Head to be Inserted. The control system activates the moving mechanism, and the injection needle 1 moves along a preset path to the designated position above the filter head tray 62. The injection needle 1 is then lowered so that its tip is aligned with and inserted into the upper inlet end 31 of the designated filter head 3 placed in the filter head tray 62. The injection needle 1 and the filter head 3 are automatically connected through insertion, completing the filter head retrieval action. This process is automatically completed by program control without manual intervention.

[0043] Step S2: Automatic Insertion and Sealing Filtration. After the injection needle 1 is connected to the filter head 3, the moving mechanism moves the injection needle 1 and filter head 3 above the fixed base 2. The injection needle 1 and filter head 3 are then lowered so that the lower outlet end 32 of the filter head 3 inserts into the fluid channel 21 of the fixed base 2 and engages with the sealing ring 22 to form a sealed flow path. The elastic support 4 is compressed and stores energy during the downward pressure to maintain the tight fit of the sealing ring 22. Subsequently, the control system filters the sample liquid through the internal filter medium of the filter head 3 and outputs it through the fluid channel 21 of the fixed base 2 to the analytical instrument or collection container. The entire filtration process is executed automatically under set pressure and flow parameters.

[0044] Step S3: Filtration End and Automatic Pressure Relief. After the filtration process is completed, the control system controls the moving mechanism to raise the injection needle 1 and the filter head 3 to release the downward pressure of the injection needle 1 on the filter head 3. At this time, the elastic support 4 automatically resets under the elastic force of the spring 43, applying an upward pushing force to the filter head 3, causing it to disengage from the clamping area of ​​the sealing ring 22, providing a pilot displacement for the separation action of the filter head 3 and the sealing ring 22.

[0045] Step S4: Automatic Filter Head Retrieval. After the filter head 3 has completely exited the fluid channel 21 of the fixed base 2, the control system controls the moving mechanism to move the injection needle 1 and the filter head 3 above the retrieval hole 63. The control system activates the push rod motor 523, and the push plate 522 moves axially toward the filter head 3, applying a controllable separation force to the filter head 3. The filter head gradually disengages from the insertion part between the filter head 3 and the injection needle 1, thus achieving automatic and smooth separation of the filter head and the injection needle. The filter head 3 automatically falls under the action of gravity and enters the retrieval frame 64 through the retrieval hole 63 to complete the retrieval. This step requires no manual intervention; the system can automatically detect the retrieval status and record the operating data.

[0046] Step S5: System Reset and Next Cycle. After the recovery operation is completed, the control system resets the injection needle 1 to the initial position of the filter head plate 62 and automatically removes a new filter head 3 according to the preset program, then re-enters Step 1. All actions are executed cyclically by the control system according to predetermined logic, allowing for the continuous processing of multiple sets of samples.

[0047] The sample pretreatment control process of this application can adopt the following two control modes depending on the sampling method, and either mode can realize unattended automated sample pretreatment.

[0048] The first method involves a continuously connected injection needle to the sample tubing. In this implementation, the injection needle is connected to the sample container or sample tubing system via a connecting tube, and filtration is driven by a negative or positive pressure provided by an injection pump. In this mode, the system controls the injection pump to start, introducing the sample liquid through the injection needle into the filter head for filtration. The filtered liquid is then discharged to the analytical instrument or collection container through a fixed base.

[0049] The second method involves inserting the injection needle into the sample container as needed for sampling. In this implementation, the injection needle is not always connected to the sample container. Instead, when sampling is required, the control system drives a moving mechanism to lower the injection needle and insert it into the sample container to extract the sample. After sampling, the injection needle rises and moves to the filter head plate position, where it is inserted and connected to the filter head on the filter head plate. It then moves to the fixed base position, and the filtration, separation, and recovery operations are performed according to the above-described filtration steps.

[0050] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A filter sample loading assembly, characterized in that: comprising a sample injection needle (1), a fixed base (2), a filter head (3) and an elastic support (4); the fixed base (2) has a fluid channel (21), and an inlet of the fluid channel (21) is provided with a sealing ring (22); the filter head (3) has an inlet end (31) for plug-in cooperation with the sample injection needle (1) and an outlet end (32) for insertion into the fluid channel (21) and cooperation with the sealing ring (22); and the elastic support (4) is used to bear pressure and be compressed when the filter head (3) is close to the fixed base (2), and is used to reset and apply a pushing force to the filter head (3) when the filter head (3) is away from the fixed base (2).

2. The filter sample loading assembly according to claim 1, characterized in that: the elastic support (4) comprises a cover (41), a guide shaft (42) and a spring (43), the guide shaft (42) comprises a movable end and a fixed end, the fixed end is fixedly connected with the cover (41), and the movable end is slidingly connected with the fixed base (2) in a length direction, or the fixed end is fixedly connected with the fixed base (2), and the movable end is slidingly connected with the cover (41) in a length direction.

3. The filter sample loading assembly according to claim 2, characterized in that: a plurality of the guide shafts (42) and corresponding springs (43) are distributed in an annular direction.

4. The filter sample loading assembly according to claim 3, characterized in that: an annular support table (33) is formed on the filter head (3), and the annular support table (33) is used to contact the cover (41) to transmit a force.

5. The filter sample loading assembly according to claim 2, characterized in that: a limiting block (44) is arranged on the movable end of the guide shaft (42), a limiting step (45) is arranged on the fixed base (2) or the cover (41), and the limiting block (44) abuts against the limiting step (45) when the spring (43) is compressed to a preset stroke, so as to limit the compression amount of the spring (43).

6. A sample pretreatment device, characterized in that: comprising a moving assembly (5) and the filter sample loading assembly according to any one of claims 1-5; and the moving assembly (5) comprises a moving mechanism and a separation mechanism (52) arranged at a terminal end of the moving mechanism (51).

7. The sample pretreatment device according to claim 6, characterized in that: the separation mechanism (52) comprises a fixed plate (521), a push plate (522) and a driving member for driving the push plate (522) to move in a linear direction; the fixed plate (521) is used to mount the sample injection needle (1), and the push plate (522) is used to push the filter head (3) on the sample injection needle (1) under the action of the driving member, so that the filter head (3) is separated from the sample injection needle (1).

8. The sample pretreatment device according to claim 7, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The workbench (6) is provided with a filter sampling assembly mounting plate (61) having a plurality of mounting holes for placing filter sampling assemblies and a filter head disc (62) having a plurality of openings for placing filter heads (3).

9. The sample pretreatment device according to claim 8, characterized in that: The workbench (6) is provided with a recovery hole below which a recovery frame for receiving the filter head (3) is arranged.

10. A sample pretreatment method using the filter sample application assembly according to any one of claims 1 to 4, characterized by, The steps include: The control system controls the moving mechanism to move the sampling needle (1) to the position of the filter head disc (62) to connect the sampling needle (1) with the filter head (3) on the filter head disc (62) through plug-in connection; The sampling needle (1) with the filter head (3) is moved above the fixed base (2) and is pressed down to insert the filter head (3) into the fluid channel (21) and form airtight cooperation with the sealing ring (22); The sample liquid is sent into the filter head (3) through the sampling needle (1) for filtration and is output through the fixed base (2); After the filtration is completed, the downward pressure of the sampling needle (1) is released, the filter head (3) is separated from the sealing ring (22) by using the elastic supporting member (4) to reset the pushing force; The separation mechanism (52) is driven to push the sampling needle (1) and the filter head (3) to separate; The control system controls the moving mechanism to move the sampling needle (1) above the recovery hole to make the filter head (3) fall into the recovery frame, and then resets the sampling needle (1) to the initial position to prepare for the next cycle.

Images