A large volume solid phase extraction device

Abstract

This invention belongs to the technical field of chemical analysis products, specifically relating to a large-volume solid-phase extraction device. It includes a large-volume sample vial with a flow guide hose, an adapter, and a solid-phase extraction column sequentially and sealed at its lower end. An annular tube is positioned above a tail liquid collection tank. Multiple solid-phase extraction column interfaces are evenly distributed circumferentially at the top of the annular tube, and multiple liquid guide tubes are located at its bottom. A liquid-collecting sealed cavity, divided into a first cavity and a second cavity by a partition, is located at the top of the tail liquid collection tank. A drainage gap is provided at the lower end of the partition. The lower end of the liquid guide tube is sealed and connected to the first cavity. The second cavity has a pressure regulating structure at its upper part and is connected to the tail liquid collection tank at its bottom via a drainage pipe. A flow control valve is installed on the drainage pipe. The annular tube is connected to a vacuum pump via a vacuum line, which includes a buffer cavity. This invention prevents liquid from entering the vacuum pump, provides rapid vacuuming, prevents blockage of the extraction column, and ensures continuous and smooth discharge of waste liquid.

Description

Technical Field

[0001] This invention belongs to the field of chemical analysis products technology, specifically relating to a large-volume solid-phase extraction device. Background Technology

[0002] Large-volume solid-phase extraction (SPE) is an essential sample preparation method for trace substance detection, often used for the detection of persistent pollutants in the environment and food, such as natural toxins, pesticide and veterinary residues, and heavy metals. Due to the very low concentrations (ppt~ppb levels), SPE is frequently required to enrich and purify the target analyte in large samples at trace levels. Fully automated large-volume SPE instruments are expensive, resulting in high experimental costs. Currently, laboratories use conventional SPE devices combined with vacuum pumps for large-volume sample pretreatment, but this method has several drawbacks: first, it cannot precisely control the sample flow rate, affecting extraction efficiency and the accuracy of results; second, when the extraction column becomes blocked, it is impossible to clear the blockage by adjusting the vacuum pressure in a timely manner. In existing large-volume solid-phase extraction technologies, to achieve multi-channel extraction and waste liquid collection, a large, sealed chamber is typically used for waste liquid collection. A vacuum device is installed on the side of the chamber to evacuate it. However, when the extraction column becomes blocked, the large chamber and buffering effect result in a long vacuuming time, making it difficult to quickly and accurately adjust the vacuum pressure, thus affecting the sample loading efficiency. Third, in large-volume solid-phase extraction, the large volume of waste liquid collected in the sealed chamber can easily lead to liquid from inside the chamber or splashes from the lower end of the drain pipe entering the vacuum channel, damaging the vacuum device. Fourth, due to the large size of the waste liquid collection chamber, sealing the cover and the main body is difficult, leading to air leakage. Furthermore, integration with the vacuum pump and external piping is challenging, making operation and use inconvenient. Summary of the Invention

[0003] To address the above problems, the purpose of this invention is to provide a large-volume solid-phase extraction device that is low-cost, simple and effective to operate, adaptable to multi-channel solid-phase extraction columns of different specifications, avoids liquid from entering the vacuum device, has a fast vacuuming speed, can quickly adjust and stabilize the vacuum level in the vacuum channel, prevents blockage of the extraction column, ensures continuous and smooth discharge of waste liquid, accurately and quickly controls and adjusts the flow rate of the sample liquid, and improves extraction efficiency and the validity of experimental results.

[0004] The objective of this invention is achieved through the following technical solution: a large-volume solid-phase extraction device, comprising a support, a large-volume sample bottle, a solid-phase extraction column, an annular tube, and a tail liquid collection tank. The large-volume sample bottle is suspended on the support, and a flow guiding hose is sealed to the lower end of the large-volume sample bottle. A flow guiding controller is provided on the flow guiding hose, and the lower end of the flow guiding hose is detachably and sealed to the solid-phase extraction column via an adapter. An annular tube is provided above the tail liquid collection tank, and multiple solid-phase extraction column interfaces are evenly arranged circumferentially at the top of the annular tube, and multiple liquid guiding tubes are evenly arranged circumferentially at the bottom. A liquid accumulation and sealing cavity is provided at the top of the tail liquid collection tank. The liquid accumulation sealing chamber is divided into chamber one and chamber two by a partition. A drainage gap is left between the lower end of the partition and the bottom of the liquid accumulation sealing chamber. The lower end of the liquid guide pipe is sealed and connected to chamber one. A pressure regulating structure is provided on the upper part of chamber two, and the bottom of chamber two is connected to the tail liquid collection tank through a drainage pipe. A flow control valve is provided on the drainage pipe. The annular pipe is connected to a vacuum pump through a vacuum pipeline. A buffer chamber is provided on the vacuum pipeline. A liquid collection pipeline is connected to the bottom of the buffer chamber. A control valve one is provided on the liquid collection pipeline. The lower end of the solid phase extraction column can be sealed and connected to the annular pipe through the solid phase extraction column interface. The interfaces of the multiple solid phase extraction columns that are not connected to the solid phase extraction column are provided with a detachable sealing connection structure. A drain port is provided at the bottom of the tail liquid collection tank. A control valve two is provided on the drain port.

[0005] Furthermore, a vacuum valve and a pressure detection mechanism are provided on the vacuum pipeline between the buffer cavity and the vacuum pump.

[0006] Furthermore, the buffer cavity is located at the center of the annular tube, the sidewall of the buffer cavity is connected to the annular tube via a vacuum tube, and the top of the buffer cavity is connected to a vacuum pump via a vacuum line. Furthermore, the liquid accumulation sealing cavity is integrally connected to the bottom surface of the top cover of the tail liquid collection tank. The air pressure regulating structure includes a vent pipe installed on the second cavity, which extends out of the top cover of the tail liquid collection tank. A pressure relief structure is provided on the vent pipe to facilitate the adjustment of the vacuum pressure inside the second cavity, preventing excessive pressure difference between the second cavity and the tail liquid collection tank, which could lead to slow or even blocked liquid discharge from the drain pipe. During drainage, the flow control valve is first closed, allowing the waste liquid at the bottom of the liquid accumulation sealing cavity to overflow the drainage gap. The waste liquid seals the drainage gap, thus isolating the air pressure between the first and second cavities. Then, the flow control valve is opened, and the pressure difference between the second cavity and the tail liquid collection tank is adjusted through the pressure relief structure without affecting the air pressure inside the first cavity, ensuring smooth liquid discharge from the liquid accumulation sealing cavity.

[0007] Furthermore, the flow control valve includes a tapered tube integrally connected to the end of the drain pipe. A through hole is provided on the tail liquid collection tank opposite the tapered tube. A short pipe is installed in the through hole. A screw is threadedly connected to the short pipe. One end of the screw is a conical top that cooperates with the tapered tube. The other end of the screw is provided with a knob handle. A sealing structure is provided between the tapered tube and the conical top.

[0008] Furthermore, the pressure relief structure includes a second conical tube integrally connected to the vent pipe. The second conical tube is disposed within a housing fixed to the top of the liquid accumulation sealing cavity or the vent pipe. The housing and the sidewalls of the second conical tube are provided with air holes, and a through hole is provided at the top of the housing directly opposite the second conical tube. A short pipe is installed in the through hole, and a second lead screw is threadedly connected to the short pipe. One end of the second lead screw is a conical top that can seal with the inner wall of the second conical tube, and the other end of the second lead screw is provided with a knob handle. A second sealing structure is provided between the second conical tube and the second conical top.

[0009] Furthermore, both the sealing structure one and the sealing structure two are rubber layers provided on the inner wall of the conical tube and the top surface of the conical tube.

[0010] Furthermore, the sealing structure includes an annular groove disposed on the conical tube, and a sealing ring is provided in the annular groove. Furthermore, the liquid inlet at the upper end of the large-volume sample bottle is a variable-diameter funnel, the top of the funnel is provided with a sealing cap, the volume of the tail liquid collection tank is 1.5-1.8 times that of the large-volume sample bottle, and the volume of the liquid accumulation sealing chamber does not exceed 0.2 times the volume of the tail gas collection tank.

[0011] Furthermore, the drain gap is 4-8mm. Waste liquid flows into the liquid accumulation sealing cavity from the liquid guide pipe. When the liquid height is higher than the drain gap, the liquid will achieve liquid sealing of cavity one and cavity two. The air pressure in cavity two is adjusted by the air pressure regulating structure on the upper part of cavity two, reducing the pressure difference between cavity two and the tail liquid collection tank, making the draining smoother.

[0012] Furthermore, the bottom of the liquid-filled sealing cavity is sloping, and the drain pipe is located at the lowest point of the slope, which facilitates rapid liquid drainage. During drainage, the liquid easily fills the drain pipe opening, preventing air from entering the liquid-filled sealing cavity from the drain pipe opening and causing the vacuum pressure inside the liquid-filled sealing cavity to be lost rapidly.

[0013] Furthermore, each of the bottom of the annular tubes is provided with a liquid guide tube corresponding to the interface position of the solid phase extraction column, which allows the liquid to be quickly discharged from the corresponding liquid guide tube.

[0014] Furthermore, the first cavity is connected to the vacuum pipeline via a vacuum branch pipe. The vacuum branch pipe is equipped with a vacuum valve, which can quickly evacuate the first cavity as needed to better maintain the vacuum level in the annular tube. It can also quickly adjust the air pressure in the annular tube and the liquid-filled sealing cavity to ensure smooth liquid discharge from the liquid guide pipe. When it is necessary to accelerate the discharge rate of waste liquid, the liquid-filled sealing cavity can be evacuated through the vacuum branch pipe to allow the waste liquid to flow into the liquid-filled sealing cavity quickly.

[0015] Furthermore, both vacuum valve one and vacuum valve two are vacuum solenoid valves, and the pressure detection mechanism is a pressure sensor. Vacuum valve one, vacuum valve two, pressure sensor, and vacuum pump are all connected to the controller. The data detected by the pressure sensor is transmitted to the controller, and the controller controls the operation of the vacuum pump, vacuum valve one, and vacuum valve two, thereby realizing the automatic control and regulation of pressure in the annular pipe and the liquid-filled sealing cavity.

[0016] Furthermore, the liquid collection pipeline is connected to the liquid accumulation sealing cavity. After the liquid enters the vacuum tube, it will first enter the buffer cavity and then flow into the liquid accumulation sealing cavity through the liquid collection pipeline, thus preventing the liquid from entering the vacuum pipeline.

[0017] Furthermore, the vacuum tube is connected to the top of the annular tube, and the buffer cavity is a sealed conical cavity. After the liquid enters the conical cavity, it accumulates downwards and flows into the liquid-sealed cavity from the liquid collection pipe.

[0018] When using this invention, solid-phase extraction is performed according to the following steps: Activation: Place the tail liquid collection box on a horizontal platform so that the height of the annular tube is at a position that is easy to operate and observe the extraction column. Insert the lower end of the solid phase extraction column into the solid phase extraction column interface. Seal the unused solid phase extraction column interface with a detachable sealing connection structure. Close control valve 1, control valve 2, and flow control valve. Add activation liquid to the solid phase extraction column. Turn on the vacuum pump to evacuate the annular tube and the liquid accumulation sealing chamber (the liquid accumulation sealing chamber and the annular tube are connected through a liquid guide tube) so that the activation liquid flows into the liquid accumulation sealing chamber through the solid phase extraction column. Sample loading: Seal the large-volume sample vial with the flow guide hose, turn off the flow controller, insert the lower end of the flow guide hose into the adapter, so that the flow guide hose is detachably and sealed to the solid-phase extraction column through the adapter. Pour the sample loading solution into the large-volume sample vial and hang the large-volume sample vial on the bracket. Turn on the flow controller. The sample loading solution flows through the flow guide hose and through the solid-phase extraction column into the liquid accumulation sealing chamber. When the liquid in the liquid accumulation sealing chamber is higher than the drain gap, the liquid seals the drain gap, isolating chamber one and chamber two. Open the flow control valve to drain the liquid, and adjust the gas pressure in chamber two through the gas pressure regulating structure so that the liquid flows smoothly out of the drain pipe and into the tail liquid collection tank. Adjust the flow regulating valve to make the inflow and outflow of liquid in the liquid accumulation sealing chamber basically the same, to prevent the liquid from falling too fast below the drain gap. If the solid-phase extraction column is blocked or the flow rate is slow, start the vacuum pump to evacuate the annular tube and the liquid accumulation seal. Eluting: Remove the adapter, add eluent to the solid phase extraction column, and the eluent flows through the solid phase extraction column into the loop tube and the liquid accumulation sealing chamber into the tail liquid collection tank. Alternatively, the adapter can be left in place and the eluent can be poured directly into a large volume sample bottle for rinsing. Elution: Remove the solid-phase extraction column, place it at the top of the test tube, and add eluent to elute.

[0019] In this invention, a large volume of sample solution is added to the large volume sample vial. The lower end of the large volume sample vial is sealed with a flow guide hose, which is equipped with a flow controller to control the liquid flow rate. The lower end of the solid-phase extraction column is sealed to a ring tube via the solid-phase extraction column interface. The ring tube is connected to a vacuum pump via a vacuum line. When the liquid in the solid-phase extraction column is blocked or the flow rate is too slow, the vacuum pump is activated to evacuate the ring tube. Due to the small internal volume of the ring tube, the vacuum pump can quickly change the vacuum pressure inside the ring tube, rapidly clearing the liquid blockage and increasing the liquid flow rate. A buffer chamber is provided on the vacuum line. This design prevents liquid from being drawn into the vacuum line and damaging the vacuum device due to rapid pressure changes within the annular tube. If liquid does enter the vacuum tube, it first flows into the buffer chamber and then out through the collection pipe, thus preventing liquid from being drawn into the vacuum line. A vacuum valve and pressure detection mechanism are installed between the buffer chamber and the vacuum pump. The pressure detection mechanism can promptly detect the vacuum pressure within the annular tube and quickly open and close the vacuum line as needed via the vacuum valve. Liquid flows into the annular tube from the lower end of the solid-phase extraction column and into the liquid accumulation sealing chamber through the nearest liquid guide pipe. The liquid guide pipe away from the solid-phase extraction column allows for ventilation with the liquid accumulation sealing chamber. This design ensures that the pressure inside the annular tube and the liquid-sealed cavity is the same, allowing for smooth liquid flow in the guide tube. The liquid-sealed cavity is divided into cavity one and cavity two by a partition. A drainage gap is left between the lower end of the partition and the bottom of the liquid-sealed cavity. When the sample is first loaded, if the waste liquid level is lower than the drainage gap, the air pressure inside cavity one and cavity two is the same, creating a pressure difference with the air pressure inside the tail liquid collection box. This can easily cause slow or even blocked drainage from the drain tube. If the liquid is not drained in time, it may accumulate in the annular tube or even enter the vacuum tube. In addition, if the amount of liquid is small during drainage, it may not fill the drain tube completely, causing air leakage and allowing gas from the tail liquid collection box to enter. When liquid enters the accumulating liquid sealing chamber, it alters the vacuum pressure within. Therefore, the flow control valve is first closed to raise the liquid level in the accumulating liquid sealing chamber above the height of the drain gap. At this point, the liquid creates a liquid seal on the drain gap, isolating the air pressure in chamber one and chamber two. By adjusting the air pressure regulating structure at the top of chamber two, the air pressure inside chamber two is adjusted, reducing the pressure difference between it and the tail liquid collection tank. The flow control valve is then opened, allowing the waste liquid to continuously and smoothly drain from the accumulating liquid sealing chamber into the tail liquid collection tank. Through the adjustment of the air pressure inside chamber two and the control of the flow rate by the flow control valve, the flow rate and velocity of the liquid flowing into and out of the accumulating liquid sealing chamber are kept stable, thus maintaining a stable liquid level in the accumulating liquid sealing chamber. This maintains a liquid seal on the drain gap.

[0020] Beneficial effects: This invention is used for large-volume solid-phase extraction and can be used in conjunction with multi-channel solid-phase extraction columns of different specifications. It avoids liquid from entering the vacuum device, has a fast vacuuming speed, can quickly adjust and stabilize the vacuum level in the vacuum channel, prevents blockage of the extraction column, accurately and quickly controls and adjusts the flow rate of the sample liquid, ensures continuous and smooth discharge of waste liquid, and improves extraction efficiency and the validity of test results. Attached Figure Description

[0021] The specific structure of this application is given by the following figures and embodiments: Figure 1 : A three-dimensional structural schematic diagram of Embodiment 1 of the present invention; Figure 2 : Schematic diagram of the vibration acceleration spring mounting structure of Embodiment 2 of the present invention; Figure 3 : Schematic diagram of the connection structure between the test tube fixing sleeve and the vibration rod in Embodiment 3 of the present invention; Figure 4 : A schematic diagram of the flow control valve in Embodiment 1 of the present invention; Figure 5 : A schematic diagram of the pressure-releasing structure of Embodiment 2 of the present invention; Figure 6 : Schematic diagram of the connection structure between the annular tube and the liquid-sealing cavity in Embodiment 3 of the present invention.

[0022] In the diagram: 01. Support, 02. Large-volume sample vial, 03. Flow guide hose, 04. Flow controller, 05. Adapter, 1. Solid phase extraction column, 2. Loop tube, 3. Tail liquid collection tank, 4. Solid phase extraction column interface, 5. Liquid guide tube, 6. Liquid accumulation sealing chamber, 7. Gas pressure regulating structure, 20. Vacuum tube, 21. Vacuum pipeline, 22. Vacuum pump, 23. Buffer chamber, 24. Vacuum valve one, 25. Pressure detection mechanism, 26. Liquid collection pipeline, 27. Control valve one, 31. Control valve two, 60. Partition plate, 6 1. Cavity 1; 62. Cavity 2; 63. Drainage gap; 64. Drainage pipe; 65. Flow control valve; 71. Vent pipe; 72. Pressure relief structure; 211. Vacuum branch pipe; 212. Vacuum valve 2; 251. Pressure sensor; 651. Conical tube; 652. Through hole; 653. Short tube; 654. Lead screw; 655. Conical top; 656. Sealing structure 1; 720. Conical top 2; 721. Conical tube 2; 722. Shell; 723. Vent hole; 724. Lead screw 2; 725. Sealing structure 2. Implementation

[0023] The following provides specific embodiments of the present invention to further explain the invention in detail. This is not intended to limit the scope of the patent; any equivalent structural or procedural modifications made based on the description and drawings of this invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this invention.

[0024] In this invention, for ease of description, the relative positional relationships of each component are described according to the layout of the accompanying drawings. For example, the positional relationships of top, bottom, left, right, etc., are determined according to the layout direction in the accompanying drawings.

[0025] Example 1, referring to Figure 1 , Figure 2 , Figure 3 , Figure 4 A large-volume solid-phase extraction device includes a support 01, a large-volume sample bottle 02, a solid-phase extraction column 1, an annular tube 2, and a tail liquid collection tank 3. The large-volume sample bottle 02 is suspended on the support 01. A flow guide hose 03 is sealed to the lower end of the large-volume sample bottle 02. A flow guide controller 04 is provided on the flow guide hose 03. The flow guide hose 03 is also provided with an exhaust structure. The lower end of the flow guide hose 03 is detachably and sealed to the solid-phase extraction column 1 through an adapter 05. An annular tube 2 is provided above the tail liquid collection tank 3. Multiple solid-phase extraction column interfaces 4 are evenly arranged circumferentially on the top of the annular tube 2, and multiple liquid guide tubes 5 are evenly arranged circumferentially on the bottom. A liquid accumulation sealing cavity 6 is provided at the top of the tail liquid collection tank 3. The liquid accumulation sealing chamber 6 is divided into chamber one 61 and chamber two 62 by a partition 60. A drainage gap 63 is left between the lower end of the partition 60 and the bottom of the liquid accumulation sealing chamber 6. The lower end of the liquid guide pipe 5 is sealed and connected to chamber one 61. A pressure regulating structure 7 is provided on the upper part of chamber two 62, and the bottom of chamber two 62 is connected to the tail liquid collection tank 3 through a drainage pipe 64. A flow control valve 65 is provided on the drainage pipe 64. The annular pipe 2 is connected to the vacuum pump 22 through a vacuum pipeline 21. A buffer chamber 2 is provided on the vacuum pipeline 21. 3. A vacuum valve 24 and a pressure detection mechanism 25 are provided on the vacuum pipeline 21 between the buffer chamber 23 and the vacuum pump 22. A liquid collection pipeline 26 is connected to the bottom of the buffer chamber 23. A control valve 27 is provided on the liquid collection pipeline 26. The lower end of the solid phase extraction column 1 can be sealed and connected to the annular tube 2 through the solid phase extraction column interface 4. Sealing rods are provided on the other interfaces of the multiple solid phase extraction column interfaces 4 that are not connected to the solid phase extraction column 1. A liquid discharge port is provided at the bottom of the tail liquid collection tank 3. A control valve 31 is provided on the liquid discharge port.

[0026] The buffer chamber 23 is located at the center of the annular tube 2. The sidewall of the buffer chamber 23 is connected to the annular tube 2 via a vacuum tube. The top of the buffer chamber 23 is connected to the vacuum pump 22 via a vacuum tube 21. The liquid accumulation sealing cavity 6 is integrally connected to the bottom surface of the top cover of the tail liquid collection tank 3. The air pressure regulating structure 7 includes a vent pipe 71 installed on the second cavity 62. The vent pipe 71 extends out of the top cover of the tail liquid collection tank 3, and a pressure relief structure 72 is installed on the vent pipe 71 to facilitate the adjustment of the vacuum pressure in the second cavity 62, preventing the pressure difference between the second cavity 62 and the tail liquid collection tank 3 from being too large, which could lead to slow or even blocked liquid discharge from the self-draining pipe 64. During drainage, the flow control valve 65 is closed first, allowing the waste liquid at the bottom of the liquid accumulation sealing cavity 6 to overflow the drainage gap 63. The waste liquid seals the drainage gap 63, thereby isolating the air pressure between the first cavity 61 and the second cavity 62. Then, the flow control valve 65 is opened, and the pressure difference between the second cavity 62 and the tail liquid collection tank 3 is adjusted through the pressure relief structure 72, without affecting the air pressure in the first cavity 61, so that the liquid in the liquid accumulation sealing cavity can be discharged smoothly.

[0027] The flow control valve 65 includes a tapered tube 651 integrally connected to the end of the drain pipe 64. A through hole 652 is provided on the tail liquid collection tank 3 opposite to the tapered tube 651. A short pipe 653 is installed in the through hole 652. A lead screw 654 is threadedly connected to the short pipe 653. One end of the lead screw 654 is a conical top 655 that cooperates with the tapered tube 651. The other end of the lead screw 654 is provided with a knob handle. A sealing structure 656 is provided between the tapered tube 651 and the conical top 655.

[0028] The sealing structure 656 includes an annular groove on the conical tube, a sealing ring in the annular groove, a variable diameter funnel at the upper end of the large volume sample 02, a sealing cap at the top of the funnel, a tail liquid collection box 3 with a volume of 1.5-1.8 times that of the large volume sample bottle 02, and a liquid accumulation sealing cavity 6 with a volume not exceeding 0.2 times the volume of the tail gas collection box 3.

[0029] The drain gap 63 is 4-8mm. Waste liquid flows into the liquid accumulation sealing chamber 6 from the liquid guide pipe 5. When the liquid height is higher than the drain gap 63, the liquid will achieve liquid sealing of the first chamber 61 and the second chamber 62. The air pressure in the second chamber 62 is adjusted by the air pressure regulating structure 7 on the upper part of the second chamber 62 to reduce the pressure difference between the second chamber 62 and the tail liquid collection tank 3, so that the draining is smoother.

[0030] The cavity 61 is connected to the vacuum branch pipe 211 through the vacuum port. The vacuum branch pipe 211 is equipped with a vacuum valve 212. The vacuum branch pipe 211 is connected to the vacuum pipeline 21. It can quickly evacuate the cavity 61 as needed to better maintain the vacuum level in the annular pipe 2. It can also quickly adjust the air pressure in the annular pipe 2 and the liquid accumulation sealing cavity 6 to ensure smooth liquid discharge from the liquid guide pipe 5. When it is necessary to accelerate the discharge speed of waste liquid, the liquid accumulation sealing cavity 6 can be evacuated through the vacuum branch pipe 211 to allow the waste liquid to flow into the liquid accumulation sealing cavity 6 quickly.

[0031] Vacuum valve 24 and vacuum valve 212 are both vacuum solenoid valves. The pressure detection mechanism 25 is a pressure sensor 251. Vacuum valve 24, vacuum valve 212, pressure sensor 251, and vacuum pump 22 are all connected to the controller. The data detected by pressure sensor 251 is transmitted to the controller. The controller controls the operation of vacuum pump 22, vacuum valve 24, and vacuum valve 212, thereby realizing automatic pressure control and regulation in the annular pipe 2 and the liquid accumulation sealing cavity 6.

[0032] When using this invention, solid-phase extraction is performed according to the following steps: Activation: Place the tail liquid collection box 3 on a horizontal platform so that the height of the annular tube 2 is at a position that is convenient for operation and observation of the extraction column. Insert the lower end of the solid phase extraction column 1 into the solid phase extraction column interface 4. Seal the unused solid phase extraction column interface 4 with a sealing rod. Close control valve 1 27, control valve 2 31, and flow control valve 65. Add activation liquid to the solid phase extraction column 1. Turn on the vacuum pump 22 to evacuate the annular tube 2 and the liquid accumulation sealing chamber 6 (the liquid accumulation sealing chamber 6 and the annular tube 2 are connected through the liquid guide tube 5) so that the activation liquid flows into the liquid accumulation sealing chamber 6 through the solid phase extraction column 1. Sample loading: Seal the large-volume sample vial 02 to the flow guide hose 03, close the flow controller 04, insert the lower end of the flow guide hose 03 into the adapter 05, so that the flow guide hose 03 is detachably and sealed to the solid-phase extraction column 1 through the adapter 05, pour the sample loading solution into the large-volume sample vial 02, and hang the large-volume sample vial 02 on the bracket 01. Turn on the flow controller 04, and the sample loading solution flows through the flow guide hose 03 through the solid-phase extraction column 1 and into the liquid accumulation sealing chamber 6. When the liquid in the liquid accumulation sealing chamber 6 is higher than the drainage gap 63, The liquid seals the drain gap 63, isolating chamber 1 61 and chamber 2 62. The flow control valve 65 is opened to drain the liquid, and the gas pressure in chamber 2 62 is adjusted by the gas pressure regulating structure 7 so that the liquid flows smoothly out of the drain pipe and into the tail liquid collection box 3. The flow regulating valve 65 is adjusted to make the liquid entering and exiting the liquid accumulation sealing chamber 6 basically the same, preventing the liquid from falling too fast below the drain gap 63. If the solid phase extraction column 1 is blocked or the flow rate is slow, the vacuum pump 22 is started to evacuate the annular tube 2 and the liquid accumulation sealing chamber 6. Washing: Remove adapter 05, add washing solution to solid phase extraction column 1, and the washing solution flows into tail liquid collection tank 3 through solid phase extraction column 1 into ring tube 2 and liquid accumulation sealing chamber 6. Alternatively, adapter 05 can be left in place and the washing solution can be poured directly into large volume sample bottle 02 for washing. Elution: Remove solid phase extraction column 1, place it at the top of the test tube, and add eluent to elute.

[0033] In this invention, a large volume of sample solution is added to the large volume sample vial 02. Since the lower end of the large volume sample vial 02 is sealed with a flow guide hose 03, and the flow guide hose 03 is equipped with a flow controller 04, the liquid flow rate is controlled by the flow controller 04. The lower end of the solid-phase extraction column 1 is sealed to the annular tube 2 through the solid-phase extraction column interface 4. The annular tube 2 is connected to the vacuum pump 22 through a vacuum line 21. When the liquid in the solid-phase extraction column 1 is blocked or the flow rate is too slow, the vacuum pump 22 is activated to evacuate the annular tube 2. Because the annular tube 2 has a small internal volume, the vacuum pump 22 can quickly change the vacuum pressure inside the annular tube 2, quickly removing the liquid blockage and increasing the liquid flow rate. The vacuum line 21 is equipped with a buffer chamber 2. 3. To prevent liquid from being drawn into the vacuum line 21 and damaging the vacuum device due to rapid pressure changes within the annular tube 2, when liquid does enter the vacuum tube 20, it first flows into the buffer chamber 23 and then is discharged through the collection pipe 26, thus preventing liquid from being drawn into the vacuum line 21. A vacuum valve 24 and a pressure detection mechanism 25 are provided between the buffer chamber 23 and the vacuum pump 22. The pressure detection mechanism 25 can detect the vacuum pressure within the annular tube 2 in a timely manner and quickly open and close the vacuum line 21 as needed through the vacuum valve 24. Liquid flows into the annular tube 2 from the lower end of the solid-phase extraction column 1 and flows into the liquid accumulation sealing chamber 6 from the nearest liquid guide pipe 5. The liquid guide pipe 5, which is away from the solid-phase extraction column 1, can act as a seal between the liquid accumulation chamber and the liquid accumulation sealing chamber. The ventilation function ensures that the pressure inside the annular tube 2 and the liquid accumulation sealing cavity 6 is the same, allowing for smooth liquid flow in the liquid guide tube 5. The liquid accumulation sealing cavity 6 is divided into cavity one 61 and cavity two 62 by a partition. A drainage gap 63 is left between the lower end of the partition 60 and the bottom of the liquid accumulation sealing cavity 6. When the sample is first loaded, if the waste liquid level is lower than the drainage gap 63, the air pressure inside cavity one 61 and cavity two 62 is the same, creating a pressure difference with the air pressure inside the tail liquid collection box 3. This can easily cause slow or even blocked drainage from the drainage pipe 64. If the liquid is not drained in time, it may accumulate in the annular tube 2 or even enter the vacuum tube. In addition, if the amount of liquid is small during drainage, it may not fill the drainage pipe 64, causing air leakage in the drainage pipe and gas in the tail liquid collection box 3. Entering the liquid-sealed cavity 6 alters its vacuum pressure. Therefore, the flow control valve 65 is first closed to raise the liquid level in the cavity 6 above the drain gap 63. This creates a liquid seal on the drain gap 63, isolating the air pressure in cavity 1 61 and cavity 2 62. The air pressure in cavity 2 62 is adjusted by regulating the air pressure regulating structure 7 at the top of cavity 2 62, reducing the pressure difference between cavity 2 62 and the tail liquid collection tank 3. The flow control valve 65 is then opened, allowing the waste liquid to flow smoothly and continuously from the liquid-sealed cavity 6 into the tail liquid collection tank 3. By regulating the air pressure in cavity 2 62 and controlling the flow rate of the flow control valve 65, the flow rate and velocity of the liquid flowing into and out of the liquid-sealed cavity 6 are kept stable, thus maintaining a stable liquid level in the cavity 6. This maintains a liquid seal on the drain gap 63.

[0034] Example 2, refer to Figure 5 The pressure relief structure 72 includes a second conical tube 721 integrally connected to the vent pipe 71. The second conical tube 721 is disposed in a housing 722 fixed to the vent pipe 71. The housing 722 and the side wall of the second conical tube 721 are provided with air holes 723. The top of the housing 722 is provided with a through hole directly opposite the second conical tube 721. A short tube is installed in the through hole. A second lead screw 724 is threadedly connected to the short tube. One end of the second lead screw 724 is a conical top 720 that can seal with the inner wall of the second conical tube 721. The other end of the second lead screw 724 is provided with a knob handle. A second sealing structure 725 is provided between the second conical tube 721 and the second conical top 720. Both the second sealing structure 725 and the first sealing structure 656 are rubber layers provided on the inner wall of the conical tube and the surface of the conical top.

[0035] The bottom of the liquid-filled sealing cavity 6 is sloping. The drain pipe 64 is located at the lowest point of the slope, which facilitates rapid liquid drainage. During drainage, the liquid easily fills the drain pipe opening, preventing air from entering the liquid-filled sealing cavity 6 from the drain pipe 64 opening and causing the vacuum pressure in the liquid-filled sealing cavity 6 to be lost rapidly.

[0036] Example 3, referring to Figure 6 The bottom of the annular tube 2 is provided with a liquid guide tube 5 corresponding to the position of the solid phase extraction column interface 4, which allows the liquid to be discharged quickly from the corresponding liquid guide tube 5. The liquid collection pipe 26 is connected to the liquid accumulation sealing cavity 6. After the liquid enters the vacuum tube 20, it will first enter the buffer cavity 23, and then flow into the liquid accumulation sealing cavity 6 through the liquid collection pipe 26, preventing the liquid from entering the vacuum pipe 21. The vacuum tube 20 is connected to the top of the annular tube 2. The buffer cavity 23 is a sealed conical cavity. After the liquid enters the conical cavity, it accumulates downward and flows into the liquid accumulation sealing cavity 6 from the liquid collection pipe 26.

Claims

1. A large volume solid phase extraction device, characterized in that, The device includes a support, a large-volume sample vial, a solid-phase extraction column, a ring tube, and a tail liquid collection tank. The large-volume sample vial is suspended on the support, and a flow guide hose is sealed to the lower end of the large-volume sample vial. A flow guide controller is installed on the flow guide hose, and the lower end of the flow guide hose is detachably and sealed to the solid-phase extraction column via an adapter. A ring tube is provided above the tail liquid collection tank. Multiple solid-phase extraction column interfaces are evenly arranged circumferentially on the top of the ring tube, and multiple liquid guide tubes are evenly arranged circumferentially on the bottom. A liquid accumulation and sealing cavity is provided at the top of the tail liquid collection tank. The liquid accumulation sealing chamber is divided into chamber one and chamber two by a partition. A drainage gap is left between the lower end of the partition and the bottom of the liquid accumulation sealing chamber. The lower end of the liquid guide pipe is sealed and connected to chamber one. A pressure regulating structure is provided on the upper part of chamber two, and the bottom of chamber two is connected to the tail liquid collection tank through a drainage pipe. A flow control valve is provided on the drainage pipe. The annular pipe is connected to a vacuum pump through a vacuum pipeline. A buffer chamber is provided on the vacuum pipeline. A liquid collection pipeline is connected to the bottom of the buffer chamber. A control valve one is provided on the liquid collection pipeline. The lower end of the solid phase extraction column can be sealed and connected to the annular pipe through the solid phase extraction column interface. The interfaces of the multiple solid phase extraction columns that are not connected to the solid phase extraction column are provided with a detachable sealing connection structure. A drain port is provided at the bottom of the tail liquid collection tank. A control valve two is provided on the drain port.

2. A device for large volume solid phase extraction according to claim 1, characterized in that A vacuum valve and a pressure detection mechanism are provided on the vacuum pipeline between the buffer cavity and the vacuum pump.

3. A device for large volume solid phase extraction according to claim 1, wherein, The liquid accumulation sealing cavity is integrally connected to the bottom surface of the tail liquid collection tank top cover. The air pressure regulating structure includes a vent pipe disposed on the cavity second, the vent pipe extends out of the tail liquid collection tank top cover, and a pressure relief structure is disposed on the vent pipe.

4. A device for large volume solid phase extraction according to claim 3, wherein, The flow control valve includes a tapered tube integrally connected to the end of the drain pipe. A through hole is provided on the tail liquid collection tank opposite the tapered tube. A short pipe is installed in the through hole. A screw is threadedly connected to the short pipe. One end of the screw is a conical top that cooperates with the tapered tube. The other end of the screw is provided with a knob handle. A sealing structure is provided between the tapered tube and the conical top.

5. A device for large volume solid phase extraction according to claim 4, wherein, The pressure relief structure includes a second conical tube integrally connected to the vent pipe. The second conical tube is disposed in a housing fixed to the top of the liquid accumulation sealing cavity or the vent pipe. The housing and the side wall of the second conical tube are provided with air holes, and the top of the housing is provided with a through hole directly opposite the second conical tube. A short tube is installed in the through hole, and a second lead screw is threadedly connected to the short tube. One end of the second lead screw is a conical top that can seal with the inner wall of the second conical tube, and the other end of the second lead screw is provided with a knob handle. A second sealing structure is provided between the second conical tube and the second conical top.

6. A device for large volume solid phase extraction according to claim 1, wherein, The bottom of the liquid-sealed cavity is sloping, and the drain pipe is located at the lowest point of the slope.

7. A device for large volume solid phase extraction according to claim 1, wherein, Each of the annular tubes has a liquid guide tube at the bottom corresponding to the interface position of the solid phase extraction column.

8. A device for large volume solid phase extraction according to claim 2, wherein, The cavity one is connected to the vacuum pipeline through a vacuum branch pipe, and a vacuum valve two is provided on the vacuum branch pipe.

9. A device for large volume solid phase extraction according to claim 8, wherein, Both vacuum valve one and vacuum valve two are vacuum solenoid valves, the pressure detection mechanism is a pressure sensor, and vacuum valve one, vacuum valve two, pressure sensor and vacuum pump are all connected to the controller.

10. A device for large volume solid phase extraction according to claim 1, wherein, The liquid collection pipeline is connected to the liquid accumulation sealing cavity.

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