Liquid chromatography piston

Abstract

Disclosed in the present invention is a liquid chromatography piston, comprising: a connecting plate, two chromatographic columns being fixed below the connecting plate, and each chromatographic column being filled with a stationary phase packing material; two pistons respectively slidably arranged in the chromatographic columns, threaded tubes being fixed to the tops of the pistons; two nuts, which are respectively rotatably arranged on the connecting plate and are respectively threadedly connected to the two threaded tubes, wherein the positions of the pistons in the chromatographic columns can be adjusted by rotating the nuts, to change the column lengths and column pressures of the chromatographic columns; two connecting strips respectively fixed to the upper ends of the threaded tubes; and two liquid inlet tubes respectively slidable in the threaded tubes, the upper end of each liquid inlet tube passing through one connecting strip and being fixedly connected to a same flow guider. Compared with the prior art, the present invention achieves flexible regulation and control of column pressures, column lengths and packing amounts in chromatographic columns, thereby optimizing analysis time and resource utilization, and bringing significant progress to the field of liquid chromatography analysis.

Description

A liquid chromatography piston Technical Field

[0001] This invention relates to the technical field of detection devices, and specifically to a liquid chromatography piston. Background Technology

[0002] Liquid chromatography (LC), as a highly efficient and sensitive separation and analysis method, plays a vital role in various fields such as chemistry, biology, medicine, and environmental science. It comprises a chromatographic column, a high-pressure pump, an injector, a detector, and a data processing system. The chromatographic column is the core component of the LC apparatus, filled with a stationary phase. The sample solution (i.e., the mobile phase) is driven through the column under high pressure, and the different components are separated due to their different partition coefficients between the stationary and mobile phases. The high-pressure pump provides the necessary high pressure for the mobile phase to pass through the column. The stability and flow rate accuracy of the high-pressure pump are crucial to the separation effect. The injector injects the sample into the mobile phase, allowing it to enter the chromatographic column for separation. The detector detects the components eluting from the column and converts them into electrical signals for recording and analysis. Common detectors include ultraviolet detectors, fluorescence detectors, and mass spectrometry detectors. The data processing system collects, processes, and analyzes the signals output by the detectors to obtain the chromatogram of the sample, enabling qualitative and quantitative analysis.

[0003] After each separation, some sample and mobile phase residue remains in the chromatographic column. These residues may interfere with subsequent separations, leading to errors in the results. Therefore, the column needs to be cleaned after each separation to remove these residues. However, the cleaning process is not only time-consuming and labor-intensive but may also affect the column's lifespan and separation efficiency. Furthermore, incomplete cleaning can lead to column contamination and clogging, further impacting separation performance.

[0004] Most existing liquid chromatography (LC) devices operate intermittently, meaning they can only separate one sample at a time. After separating one sample, the system must be stopped for column cleaning and mobile phase replacement before the next sample can be separated. This not only reduces efficiency but also increases operational complexity and cost. Furthermore, the uncertainty of downtime can affect the stability and repeatability of separation results.

[0005] Therefore, it is necessary to provide a liquid chromatography piston to solve the problems mentioned in the background art. Summary of the Invention

[0006] To achieve the above objectives, the present invention provides a liquid chromatography stopcock, comprising:

[0007] A connecting plate has two chromatographic columns fixed below it. Each chromatographic column is filled with stationary phase packing material and has a liquid outlet at its lower end. The liquid outlet is connected to a continuous chromatograph.

[0008] Two pistons are slidably disposed inside the chromatographic column and located above the stationary phase packing. A threaded tube is fixed above each piston. The outer wall of the threaded tube is threaded, and its upper end extends upward through the connecting plate, while its lower end passes through the piston and is fixedly connected to the bottom of the piston.

[0009] Two nuts are rotatably mounted on the connecting plate and are threaded to the two threaded pipes respectively. By rotating the nuts, the position of the piston in the chromatographic column can be adjusted, thereby changing the column length and column pressure.

[0010] Two connecting strips are fixed to the upper end of the threaded pipe, respectively;

[0011] Two inlet tubes are slidable inside the threaded tube. The upper end of each inlet tube passes through a connecting strip and is fixedly connected to the same flow guide. The flow guide is fixed above the connecting plate. A sample tube and a cleaning agent tube are respectively arranged above the flow guide. The sample tube is used to introduce the mobile phase sample, and the cleaning agent tube is used to introduce the cleaning agent.

[0012] Furthermore, a sieve plate is provided at the lower end of the threaded tube, and a sieve plate is also provided at the liquid outlet.

[0013] Furthermore, two vertical guide rods are fixed above the connecting plate, and the two connecting strips are slidably sleeved on the two guide rods respectively.

[0014] Furthermore, each of the two nuts is fixedly fitted with a lifting gear, and the two lifting gears mesh with each other;

[0015] A drive gear is rotatably mounted on the connecting plate, and the drive gear meshes with one of the lifting gears.

[0016] A gear drive motor for driving the lifting gear to rotate is connected below the connecting plate.

[0017] Furthermore, each of the chromatographic columns is fixedly connected to a storage tank, which is filled with stationary phase packing material, and the lower part of the chromatographic column is connected to the corresponding storage tank through a connecting pipe.

[0018] Furthermore, a transfer screw is rotatably installed inside the connecting tube. The transfer screw is in contact with the inner wall of the connecting tube. One end of the transfer screw extends into the chromatographic column, and the other end rotatably passes through the storage tank and extends outside the storage tank.

[0019] The storage tank is equipped with a screw drive motor for driving the rotation of the transmission screw.

[0020] Furthermore, the flow guide is a cylindrical cavity with side cavities on both sides, and the two inlet pipes are respectively connected to the two side cavities;

[0021] The sample tube and the cleaning agent tube lead to the flow guide on the front and rear sides, respectively.

[0022] Furthermore, the flow guide is rotatably connected to the center of the flow guide, and two symmetrically arranged flow guide plates are fixed on both sides of the flow guide. The flow guide plates are fan-shaped and the arc length is greater than the inner diameter of the sample tube and the cleaning agent tube and the width of the side cavity. The two ends of the flow guide plates are respectively attached to the inner wall of the flow guide.

[0023] Furthermore, the lower end of the rotating shaft passes through the guide and extends from its underside, and a guide gear is fixed to the lower end of the rotating shaft, the guide gear being rotatably mounted above the connecting plate;

[0024] One of the lifting gears is fixed with a transmission gear ring, which meshes with the guide gear.

[0025] Furthermore, the rotation of the lifting gear will drive the rotating shaft to rotate, and when the piston of one of the chromatographic columns slides down to squeeze the stationary phase packing, the sample tube is connected to the inlet tube corresponding to that chromatographic column, while the cleaning agent tube is connected to the inlet tube corresponding to the other chromatographic column.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention allows for easy adjustment of the piston position within the chromatographic column, thereby altering the column pressure and column length. This enables the device to adapt to samples of varying structures and complexities, ensuring optimal separation for each sample. For simple samples, a short column and lower column pressure suffice, reducing analysis time and improving efficiency. For complex samples, a longer column and higher column pressure provide better separation efficiency and resolution, ensuring effective separation of all components within the sample.

[0028] In this invention, two chromatographic columns can slide synchronously in opposite directions, allowing one column to separate the sample while the other is being cleaned. This ensures continuous separation and purification of the sample, improving the efficiency of chromatographic analysis. When the piston slides upward to reduce column pressure, the cleaning agent can flow fully within the stationary phase packing, carrying away residual sample and thus improving cleaning efficiency.

[0029] In this invention, the flow guide plate design inside the flow guide allows the sample and cleaning agent to flow to different chromatographic columns respectively, and can automatically select which chromatographic column to deliver the sample or cleaning agent according to the current piston position, ensuring the continuity and efficiency of sample separation and cleaning. Attached Figure Description

[0030] Figure 1 is a schematic diagram of the overall structure of a liquid chromatography piston;

[0031] Figure 2 is a schematic diagram of the liquid chromatography piston after the chromatographic column has been cut open;

[0032] Figure 3 is a schematic diagram of the front cross-sectional structure of the two chromatographic columns;

[0033] Figure 4 is a schematic diagram of the side cross-sectional structure of a chromatographic column;

[0034] Figure 5 is a schematic diagram of the flow guide;

[0035] In the diagram: 1. Connecting plate; 2. Chromatographic column; 21. Outlet; 22. Piston; 3. Threaded tube; 31. Nut; 32. Lifting gear; 33. Drive gear; 34. Transmission gear ring; 35. Guide gear; 4. Connecting strip; 5. Inlet tube; 6. Flow guide; 61. Sample tube; 62. Cleaning agent tube; 63. Side cavity; 64. Flow guide plate; 7. Guide rod; 8. Storage tank; 81. Connecting tube; 82. Transfer screw; 83. Screw drive motor; 9. Gear drive motor; 10. Shaft. Detailed Implementation

[0036] Please refer to Figures 1-5. The liquid chromatography piston in this embodiment of the invention includes:

[0037] The connecting plate 1 has two chromatographic columns 2 fixed below it. Each chromatographic column 2 is filled with stationary phase packing material and has a liquid outlet 21 at its lower end, which is connected to a continuous chromatograph.

[0038] Two pistons 22 are slidably disposed inside the chromatographic column 2 and located above the stationary phase packing. A threaded tube 3 is fixed above each piston 22. The outer wall of the threaded tube 3 is threaded, its upper end extends upward through the connecting plate 1, and its lower end passes through the piston 22 and is fixedly connected to the bottom of the piston 22.

[0039] Two nuts 31 are respectively rotatably mounted on the connecting plate 1 and respectively threadedly connected to the two threaded pipes 3. By rotating the nuts 31, the position of the piston 22 in the chromatographic column 2 can be adjusted, thereby changing the column length and column pressure of the chromatographic column 2.

[0040] Two connecting strips 4 are respectively fixed to the upper end of the threaded tube 3;

[0041] Two inlet pipes 5 are slidable within the threaded pipe 3. The upper end of each inlet pipe 5 passes through a connecting strip 4 and is fixedly connected to the same flow guide 6. The flow guide 6 is fixed above the connecting plate 1. A sample tube 61 and a cleaning agent tube 62 are respectively arranged above the flow guide 6. The sample tube 61 is used to introduce the mobile phase sample, and the cleaning agent tube 62 is used to introduce the cleaning agent.

[0042] By rotating the two nuts 31 respectively, the piston 22 can slide downward to squeeze the stationary phase packing in the corresponding chromatographic column 2, thereby adjusting the column length of the stationary phase packing in the chromatographic column 2. The longer the column length, the longer the distance the mobile phase sample flows through the stationary phase packing.

[0043] For samples with simple structures and few components, shorter chromatographic columns are usually sufficient for separation. Although the separation efficiency of short columns is relatively low, it is enough for simple samples. Short columns can also shorten analysis time and improve analytical efficiency. For samples with complex structures and many components, longer chromatographic columns are required to achieve better separation results. Longer columns have higher separation efficiency and resolution, and therefore can better separate the individual components in the sample.

[0044] Simultaneously, the compression of the stationary phase packing increases the column pressure of column 2, thereby increasing the packing density. Higher packing density increases the contact area between the packing material and sample molecules, thus improving resolution. This helps to better separate the components in the mixture, but it reduces the flow rate of the mobile phase sample and requires higher pump pressure to drive the mobile phase sample through column 2.

[0045] When piston 22 slides upward, reducing the column pressure of column 2, cleaning agent can be introduced into column 2. Here, due to the low packing density of the stationary phase packing, the cleaning agent can flow sufficiently within the stationary phase packing to remove residual sample, thereby improving cleaning efficiency.

[0046] In this embodiment, a sieve plate is provided at the lower end of the threaded tube 3, and a sieve plate is also provided at the liquid outlet 21 to prevent the stationary phase packing from flowing out.

[0047] In this embodiment, two vertical guide rods 7 are fixed above the connecting plate 1, and two connecting strips 4 are slidably sleeved on the two guide rods 7 respectively. The guide rods 7 can restrict the rotation of the connecting strips 4, thereby preventing the threaded tube 3 from rotating.

[0048] In this embodiment, lifting gears 32 are fixedly sleeved on both nuts 31, and the two lifting gears 32 mesh with each other.

[0049] A drive gear 33 is rotatably mounted on the connecting plate 1, and the drive gear 33 meshes with one of the lifting gears 32.

[0050] A gear drive motor 9 for driving the lifting gear 32 to rotate is connected below the connecting plate 1.

[0051] In other words, the gear-driven motor 9 can drive the nut 31 to rotate, thereby causing the piston 22 to slide. Since the two lifting gears 32 mesh with each other, the two nuts 31 always rotate synchronously in opposite directions, and thus the two pistons 22 always slide synchronously in opposite directions. This allows the other column 2 to reduce its column pressure and introduce a mobile phase sample for separation while the other column 2 reduces its column pressure and introduces a cleaning agent for cleaning. As a result, the two columns 2 can output the separated samples sequentially, thus enabling continuous input of mobile phase samples and continuous output of separated samples, achieving continuous separation and purification of samples and improving the efficiency of chromatographic analysis.

[0052] In this embodiment, a storage tank 8 is fixedly connected to the rear of each chromatographic column 2. The storage tank 8 is filled with stationary phase packing material, and the lower part of the chromatographic column 2 is connected to the corresponding storage tank 8 through a connecting pipe 81.

[0053] In this embodiment, a transmission screw 82 is rotatably disposed inside the connecting tube 81. The transmission screw 82 is in contact with the inner wall of the connecting tube 81. One end of the transmission screw 82 extends into the chromatographic column 2, and the other end rotatably penetrates the storage tank 8.

[0054] The storage tank 8 is equipped with a screw drive motor 83 for driving the transmission screw 82 to rotate.

[0055] The screw drive motor 83 drives the transmission screw 82 to rotate, which can exchange the stationary phase packing in the corresponding storage tank 8 with the stationary phase packing in the chromatographic column 2, thereby increasing or decreasing the stationary phase packing in the chromatographic column 2, and thus further adjusting the column pressure under a fixed column length.

[0056] Different samples may require different column pressures to achieve optimal separation. Adjustable column pressure allows column 2 to be suitable for a wider range of sample types and analytical needs, helping to improve the separation between different components, helping to form good chromatographic peak shapes in the chromatograph, avoiding undesirable phenomena such as peak expansion and tailing, and improving the accuracy and reliability of analytical results.

[0057] In this embodiment, the flow guide 6 is a cylindrical cavity with side cavities 63 on both sides, and the two liquid inlet pipes 5 respectively pass through the two side cavities 63.

[0058] The sample tube 61 and the cleaning agent tube 62 are respectively connected to the flow guide 6 on the front and rear sides.

[0059] In this embodiment, the center of the flow guide 6 is rotatably connected to a rotating shaft 10. Two symmetrically arranged flow guide plates 64 are fixed on both sides of the rotating shaft 10. The flow guide plates 64 are fan-shaped and their arc lengths are all greater than the inner diameter of the sample tube 61 and the cleaning agent tube 62 and the width of the side cavity 63. The two ends of the flow guide plates 64 are respectively attached to the inner wall of the flow guide 6.

[0060] In other words, by rotating the shaft 10, the guide plate 64 can be rotated. When the guide plate 64 rotates to the point where the sample tube 61 is connected to one inlet tube 5, the cleaning agent tube 62 is connected to another inlet tube 5, thereby allowing one chromatographic column 2 to separate the sample while the other chromatographic column 2 is cleaned.

[0061] In this embodiment, the lower end of the rotating shaft 10 passes through the flow guide 6 and extends from its lower side, and a flow guide gear 35 is fixed to the lower end of the rotating shaft 10. The flow guide gear 35 is rotatably mounted above the connecting plate 1.

[0062] One of the lifting gears 32 is fixed with a transmission gear ring 34, which meshes with the guide gear 35.

[0063] When the lifting gear 32 rotates, it will drive the rotating shaft 10 to rotate. When the piston 22 of one of the chromatographic columns 2 slides down to squeeze the stationary phase packing, the sample tube 61 is connected to the inlet tube 5 corresponding to that chromatographic column 2, while the cleaning agent tube 62 is connected to the inlet tube 5 corresponding to the other chromatographic column 2.

[0064] In other words, the flow guide 6 can automatically deliver the mobile phase sample to one of the chromatographic columns 2 where the stationary phase packing is squeezed, and deliver the cleaning agent to one of the chromatographic columns 2 where it is loosened, so that the chromatographic columns 2 can separate the sample and clean it in turn, thereby improving the purity of the separation.

[0065] The specific implementation includes the following steps:

[0066] Sample separation process:

[0067] The gear-driven motor 9 reciprocates to drive the nut 31 to rotate, which in turn drives the piston 22 to slide inside the chromatographic column 2. Since the two lifting gears 32 mesh with each other, the two pistons 22 will slide synchronously in opposite directions.

[0068] When piston 22 slides downward, it squeezes the stationary phase packing material inside column 2, thereby increasing the column pressure. The increase in column pressure increases the packing density of the stationary phase packing material, which in turn increases the contact area between the packing material and sample molecules, thus improving the resolution.

[0069] While adjusting the column pressure, the mobile phase sample is introduced into the flow guide 6 through the sample tube 61. The flow guide 6 will automatically select which column 2 to deliver the sample to based on the current position of the piston 22.

[0070] While one chromatographic column 2 is separating the sample, the other chromatographic column 2 is being cleaned. Cleaning agent is introduced into the flow guide 6 through the cleaning agent tube 62 to clean the residual sample in the chromatographic column 2. The separated sample will flow out from the outlet 21 of the chromatographic column 2 and enter the continuous chromatogram for further analysis or collection.

[0071] Adjustment of stationary phase packing:

[0072] When it is necessary to adjust the amount of stationary phase packing in column 2, the screw drive motor 83 is started to drive the transmission screw 82 to rotate. The rotation of the transmission screw 82 will exchange the stationary phase packing in storage tank 8 with the packing in column 2, thereby adjusting the amount of packing in column 2. Before adjusting the amount of stationary phase packing in column 2, the stationary phase packing in column 2 should be cleaned and no new mobile phase sample should enter.

[0073] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A liquid chromatography piston, characterized by, The utility model relates to a continuous chromatography device, including: A connecting plate (1) is fixed with two chromatographic columns (2) below, each of the chromatographic columns (2) is filled with stationary phase filler inside and is equipped with a liquid outlet (21) at the lower end, and the liquid outlet (21) is connected with a continuous chromatograph; Two pistons (22) are respectively slidably arranged in the chromatographic columns (2) and above the stationary phase filler, the upper part of the piston (22) is fixed with a threaded tube (3), the outer wall of the threaded tube (3) is provided with a thread, the upper end of the threaded tube (3) extends upwardly through the connecting plate (1), and the lower end of the threaded tube (3) penetrates the piston (22) and is fixedly connected with the bottom of the piston (22); Two nuts (31) are respectively rotatably arranged on the connecting plate (1) and are respectively threadedly connected with the two threaded tubes (3), the position of the piston (22) in the chromatographic column (2) can be adjusted by rotating the nut (31), so that the column length and column pressure of the chromatographic column (2) are changed; Two connecting strips (4) are respectively fixed to the upper end of the threaded tube (3); Two liquid inlet tubes (5) are respectively slidably arranged in the threaded tube (3), the upper end of each of the liquid inlet tubes (5) penetrates the connecting strip (4) and is fixedly connected to the same flow guide (6), the flow guide (6) is fixed above the connecting plate (1), the flow guide (6) is provided with a sample tube (61) and a cleaning agent tube (62) above, the sample tube (61) is used for introducing a mobile phase sample, and the cleaning agent tube (62) is used for introducing a cleaning agent.

2. The liquid chromatography piston of claim 1, wherein, The lower end of the threaded tube (3) is provided with a sieve plate, and the sieve plate is also arranged at the liquid outlet (21).

3. The liquid chromatography piston of claim 1, wherein, The connecting plate (1) is fixed with two vertical guide rods (7) above, and the two connecting strips (4) are respectively slidably sleeved on the two guide rods (7).

4. The liquid chromatography piston of claim 1, wherein, The outer part of each of the two nuts (31) is fixedly sleeved with a lifting gear (32), and the two lifting gears (32) are meshed with each other; A driving gear (33) is rotatably arranged on the connecting plate (1), and the driving gear (33) is meshed with one of the lifting gears (32); The connecting plate (1) is connected with a gear driving motor (9) below for driving the lifting gear (32) to rotate.

5. The liquid chromatography piston of claim 1, wherein, Each of the chromatographic columns (2) is fixedly connected with a storage tank (8) behind, the storage tank (8) is filled with stationary phase filler, and the lower part of the chromatographic column (2) is communicated with the corresponding storage tank (8) through a connecting pipe (81).

6. The liquid chromatography piston of claim 5, wherein, A transmission screw (82) is rotatably arranged in the connecting pipe (81), the transmission screw (82) is attached to the inner wall of the connecting pipe (81), one end of the transmission screw (82) extends into the chromatographic column (2), and the other end of the transmission screw (82) rotatably penetrates the storage tank (8) and extends out of the storage tank (8); The storage tank (8) is provided with a screw driving motor (83) outside for driving the transmission screw (82) to rotate.

7. The liquid chromatography piston of claim 4, wherein, The flow guide (6) is a cylindrical cavity, and two side cavities (63) are respectively arranged on the two sides of the flow guide (6), and the two liquid inlet tubes (5) respectively pass into the two side cavities (63); The sample tube (61) and the cleaning agent tube (62) respectively pass into the flow guide (6) from the front side and the back side.

8. The liquid chromatography piston of claim 7, wherein, The flow director (6) is rotationally connected with a rotating shaft (10) in the center, two symmetrical flow guide plates (64) are fixed on both sides of the rotating shaft (10), the flow guide plates (64) are fan-shaped and the arc length is greater than the inner diameter of the sample tube (61) and the cleaner tube (62) and the width of the side cavity (63), and the two ends of the flow guide plates (64) are respectively attached to the inner wall of the flow director (6).

9. The liquid chromatography piston of claim 8, wherein, The lower end of the rotating shaft (10) penetrates through the flow director (6) and extends from the lower side, and a flow guide gear (35) is fixed on the lower end of the rotating shaft (10), which is rotationally arranged above the connecting plate (1). One of the lifting gears (32) is fixed with a transmission gear ring (34), which is engaged with the flow guide gear (35).

10. The liquid chromatography piston of claim 9, wherein, The rotation of the lifting gear (32) drives the rotating shaft (10) to rotate, and when the piston (22) of one of the chromatographic columns (2) slides downward to press the stationary phase filler, the sample tube (61) is communicated with the liquid inlet pipe (5) corresponding to the chromatographic column (2), and the cleaner tube (62) is communicated with the liquid inlet pipe (5) corresponding to the other chromatographic column (2).

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