Liquid chromatography piston

Abstract

The present invention discloses a liquid chromatography piston, comprising: a connecting plate, under which two chromatographic columns are fixed, each of which is filled with a stationary phase filler; two pistons, which are respectively slidably arranged in the chromatographic columns, and threaded tubes are fixed above the pistons; two nuts, which are respectively rotatably arranged on the connecting plate and are respectively threadedly connected to the two threaded tubes, and the position of the piston in the chromatographic column can be adjusted by rotating the nuts, thereby changing the column length and column pressure of the chromatographic column; two connecting strips, which are respectively fixed to the upper ends of the threaded tubes; two liquid inlet pipes, which are respectively slidably arranged in the threaded tubes, and the upper ends of each of the liquid inlet pipes pass through the connecting strips and are fixedly connected to the same flow guide; compared with the prior art, the present invention realizes flexible regulation of column pressure, column length and filler amount in the chromatographic column, can optimize analysis time and resource utilization, and brings significant progress to the field of liquid chromatography analysis.

Description

Technical Field

[0001] The invention relates to the technical field of detection devices, in particular to a liquid chromatography piston. Background Art

[0002] As an efficient and sensitive separation and analysis method, liquid chromatography technology plays an important role in many fields such as chemistry, biology, medicine, and environmental science. It includes: Chromatographic column: The chromatographic column is the core component of the liquid chromatography device, which is filled with stationary phase filler. The sample solution (i.e., mobile phase) passes through the chromatographic column under high pressure, and the different components in it are separated due to the different distribution coefficients between the stationary phase and the mobile phase. High-pressure pump: used to provide the high pressure required for the mobile phase to pass through the chromatographic column. The stability and flow accuracy of the high-pressure pump are crucial to the separation effect. Injector: used to inject the sample into the mobile phase so that it enters the chromatographic column with the mobile phase for separation. Detector: used to detect the components flowing out of the chromatographic column and convert them into electrical signals for recording and analysis. Common detectors include ultraviolet detectors, fluorescence detectors, mass spectrometers, etc. Data processing system: used to collect, process and analyze the signals output by the detector to obtain the chromatogram of the sample, and then perform qualitative and quantitative analysis on the sample.

[0003] After each separation, some sample and mobile phase will remain in the chromatographic column. These residues may interfere with the next separation, resulting in errors in the separation results. Therefore, the chromatographic column needs to be cleaned after each separation to remove the residues. However, the cleaning process is not only time-consuming and laborious, but may also affect the service life and separation efficiency of the chromatographic column. In addition, incomplete cleaning may also cause contamination and blockage of the chromatographic column, further affecting the separation effect.

[0004] Most existing liquid chromatography devices use intermittent working mode, that is, only one sample can be separated at a time. After completing the separation of one sample, it is necessary to stop the machine to clean the chromatographic column and replace the mobile phase before starting the separation of the next sample. This working mode not only reduces work efficiency, but also increases operational complexity and cost. In addition, due to the uncertainty of downtime, it may also affect the stability and repeatability of the separation results.

[0005] Therefore, it is necessary to provide a liquid chromatography piston to solve the problems raised in the above background technology. Summary of the invention

[0006] To achieve the above object, the present invention provides the following technical solution: a liquid chromatography piston, comprising:

[0007] A connecting plate, under which two chromatographic columns are fixed, each of which is filled with a stationary phase filler and has a liquid outlet at the lower end, and the liquid outlet is connected to a continuous chromatograph;

[0008] Two pistons are respectively slidably arranged in the chromatographic column and located above the stationary phase filler. A threaded tube is fixed above each of the pistons. The outer wall of the threaded tube is provided with threads. The upper end of the threaded tube passes through the connecting plate and extends upward. The lower end passes through the piston and is fixedly connected to the bottom of the piston.

[0009] Two nuts are rotatably arranged on the connecting plate and are respectively threadedly connected with the two threaded pipes. The position of the piston in the chromatographic column can be adjusted by rotating the nuts, thereby changing the column length and column pressure of the chromatographic column.

[0010] Two connecting strips are respectively fixed to the upper ends of the threaded pipes;

[0011] Two liquid inlet tubes are slidably arranged in the threaded tubes respectively. The upper end of each liquid inlet tube passes through the 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 detergent tube are respectively arranged above the flow guide. The sample tube is used to pass the mobile phase sample, and the detergent tube is used to pass the detergent.

[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 respectively slidably sleeved in the two guide rods.

[0014] Furthermore, a lifting gear is fixedly sleeved outside the two nuts, and the two lifting gears are meshed with each other;

[0015] A driving gear is rotatably provided on the connecting plate, and the driving gear is meshed 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 chromatographic column is fixedly connected to a storage tank at the rear, the storage tank is filled with a stationary phase filler, and the lower part of the chromatographic column is connected to the corresponding storage tank through a connecting pipe.

[0018] Furthermore, a transmission screw is rotatably arranged in the connecting tube, the transmission screw is in contact with the inner wall of the connecting tube, one end of the transmission screw extends into the chromatographic column, and the other end rotates and penetrates outside the storage tank;

[0019] A screw drive motor for driving the transmission screw to rotate is arranged outside the storage tank.

[0020] Furthermore, the deflector is a cylindrical cavity, with side cavities on both sides, and the two liquid inlet pipes penetrate into the two side cavities respectively;

[0021] The sample tube and the cleaning agent tube penetrate into the front and rear of the flow guide respectively.

[0022] Furthermore, the center of the guide is rotatably connected to a rotating shaft, and two symmetrically arranged guide plates are fixed on both sides of the rotating shaft. The guide plates are fan-shaped and the arc lengths are greater than the inner diameters of the sample tube and the detergent tube and the width of the side cavity, and the two ends of the guide plates are respectively in contact with the inner wall of the guide.

[0023] Furthermore, the lower end of the rotating shaft passes through the lower part of the deflector, and a deflector gear is fixed to the lower end of the rotating shaft, and the deflector gear is rotatably mounted above the connecting plate;

[0024] A transmission gear ring is fixed on one of the lifting gears, and the transmission gear ring is meshed with the guide gear.

[0025] Furthermore, when the lifting gear rotates, the rotating shaft is driven to rotate, and when the piston of one of the chromatographic columns slides downward to squeeze the stationary phase filler, the sample tube is connected to the liquid inlet tube corresponding to the chromatographic column, and the detergent tube is connected to the liquid inlet tube corresponding to the other chromatographic column.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] In the present invention, the position of the piston in the chromatographic column can be easily adjusted, thereby changing the column pressure and column length. The device can adapt to samples of different structures and complexities, ensuring that each sample can achieve the best separation effect. For simple samples, a short column and a lower column pressure can meet the separation requirements, thereby shortening the analysis time and improving the analysis efficiency. For complex samples, a long column and a higher column pressure can provide better separation efficiency and resolution, ensuring that each component in the sample can be effectively separated.

[0028] In the present invention, the two chromatographic columns can slide synchronously in opposite directions, so that one chromatographic column can separate samples while the other chromatographic column can clean them. This ensures continuous separation and purification of samples and improves the efficiency of chromatographic analysis. When the piston slides upward to reduce the column pressure, the detergent can fully flow in the stationary phase filler and take away the residual sample, thereby improving the cleaning efficiency.

[0029] In the present invention, the guide plate design in the guide device enables the sample and the detergent to flow to different chromatographic columns respectively, and can automatically select which chromatographic column to deliver the sample or detergent to according to the current piston position, thereby ensuring the continuity and efficiency of sample separation and cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0032] Figure 3 Schematic diagram of the front cross-section structure of two chromatographic columns;

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

[0034] Figure 5 is a schematic diagram of the structure of the deflector;

[0035] In the figure: 1. connecting plate; 2. chromatographic column; 21. liquid outlet; 22. piston; 3. threaded tube; 31. nut; 32. lifting gear; 33. driving gear; 34. transmission gear ring; 35. guide gear; 4. connecting strip; 5. liquid inlet pipe; 6. guide; 61. sample tube; 62. detergent tube; 63. side cavity; 64. guide plate; 7. guide rod; 8. storage tank; 81. connecting tube; 82. transmission screw; 83. screw drive motor; 9. gear drive motor; 10. rotating shaft. DETAILED DESCRIPTION

[0036] See also Figure 1-Figure 5 In an embodiment of the present invention, a liquid chromatography piston comprises:

[0037] A connecting plate 1, under which two chromatographic columns 2 are fixed, each of which is filled with a stationary phase filler and has a liquid outlet 21 at the lower end, and the liquid outlet 21 is connected to a continuous chromatograph;

[0038] Two pistons 22 are respectively slidably disposed in the chromatographic column 2 and are located above the stationary phase filler. A threaded tube 3 is fixed above each of the pistons 22. The outer wall of the threaded tube 3 is provided with threads. The upper end of the threaded tube 3 penetrates the connecting plate 1 and extends upward. The lower end penetrates the piston 22 and is fixedly connected to the bottom of the piston 22.

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

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

[0041] Two liquid inlet tubes 5 are slidably arranged in the threaded tube 3 respectively. The upper end of each liquid inlet tube 5 passes through 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. A sample tube 61 and a detergent tube 62 are respectively arranged above the flow guide 6. The sample tube 61 is used to pass the mobile phase sample, and the detergent tube 62 is used to pass the detergent.

[0042] By rotating the two nuts 31 respectively, the piston 22 can slide downward to squeeze the stationary phase filler in the corresponding chromatographic column 2, so that the column length of the stationary phase filler in the chromatographic column 2 can be adjusted. The longer the column length, the longer the distance the mobile phase sample flows in the stationary phase filler.

[0043] For samples with simple structures and fewer components, shorter chromatographic columns can usually meet the separation requirements. Although the separation efficiency of short columns is relatively low, it is sufficient for simple samples. Short columns can also shorten the analysis time and improve the analysis efficiency. For samples with complex structures and more components, longer chromatographic columns are required to achieve better separation effects. Long columns have higher separation efficiency and resolution, and can better separate the components in the sample.

[0044] At the same time, the squeezing of the stationary phase filler will increase the column pressure of the chromatographic column 2 to increase the filling density of the stationary phase filler. The greater the filling density, the larger the contact area between the filler and the sample molecules, thereby improving the separation degree, which helps to better separate the components in the mixture, but will reduce the flow rate of the mobile phase sample, and require a higher pump pressure to drive the mobile phase sample to flow in the chromatographic column 2.

[0045] When the piston 22 slides upward to reduce the column pressure of the chromatographic column 2, the detergent can be introduced into the chromatographic column 2. Since the packing density of the stationary phase filler is relatively low, the detergent can fully flow in the stationary phase filler to take away the residual sample, thereby improving the 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 , which can prevent the stationary phase filler from passing through the sieve plate.

[0047] In this embodiment, two vertical guide rods 7 are fixed above the connecting plate 1, and the two connecting strips 4 are respectively slidably sleeved in the two guide rods 7. The connecting strips 4 can be limited to rotate by the guide rods 7, thereby preventing the threaded tube 3 from rotating.

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

[0049] A driving gear 33 is rotatably provided on the connecting plate 1, and the driving gear 33 is meshed 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] That is to say, the gear-driven motor 9 can drive the nut 31 to rotate so that the piston 22 slides, and because the two lifting gears 32 are meshed with each other, the two nuts 31 always rotate synchronously in opposite directions, and the two pistons 22 always slide synchronously in opposite directions, so that when one chromatographic column 2 increases the column pressure and passes the mobile phase sample for separation, the other chromatographic column 2 reduces the column pressure and passes the detergent for cleaning, so that the two chromatographic columns 2 can output the separated samples in turn, so that the mobile phase sample can be continuously input and the separated sample can be continuously output, thereby realizing continuous separation and purification of the sample 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 , and the storage tank 8 is filled with a stationary phase filler. 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 in the connecting tube 81, and 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 rotates to penetrate the outside of the storage tank 8.

[0054] A screw drive motor 83 for driving the transmission screw 82 to rotate is disposed outside the storage tank 8 .

[0055] By driving the transmission screw 82 to rotate through the screw drive motor 83, the stationary phase filler in the corresponding storage tank 8 can be exchanged with the stationary phase filler in the chromatographic column 2, thereby increasing or decreasing the stationary phase filler in the chromatographic column 2, thereby further adjusting the column pressure under a fixed column length.

[0056] Different samples may require different column pressures to achieve optimal separation. The adjustable column pressure enables chromatographic column 2 to be applicable to a wider range of sample types and analysis requirements, helps to improve the separation between different components, helps to form a good chromatographic peak shape in the chromatograph, avoids undesirable phenomena such as peak expansion and tailing, and improves the accuracy and reliability of the analysis results.

[0057] In this embodiment, the flow guide 6 is a cylindrical cavity, and has side cavities 63 on both sides thereof, and the two liquid inlet pipes 5 are respectively connected to the two side cavities 63;

[0058] The sample tube 61 and the cleaning agent tube 62 are respectively passed through the front and rear of the flow guide 6;

[0059] In this embodiment, the guide plate 6 is centrally rotatably connected to a rotating shaft 10, and two symmetrically arranged guide plates 64 are fixed on both sides of the rotating shaft 10. The guide plates 64 are fan-shaped and the arc lengths are greater than the inner diameters of the sample tube 61 and the detergent tube 62 and the width of the side cavity 63. The two ends of the guide plates 64 are respectively in contact with the inner wall of the guide plate 6.

[0060] That is, the guide plate 64 can be rotated by rotating the rotating shaft 10. When the guide plate 64 rotates until the sample tube 61 is connected to one liquid inlet tube 5, the detergent tube 62 is connected to another liquid inlet tube 5, so that one chromatographic column 2 separates 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 lower part of the deflector 6, and a deflector gear 35 is fixed to the lower end of the rotating shaft 10, and the deflector gear 35 is rotatably mounted above the connecting plate 1;

[0062] A transmission gear ring 34 is fixed on one of the lifting gears 32 , and the transmission gear ring 34 is meshed with the guide gear 35 .

[0063] When the lifting gear 32 rotates, the rotating shaft 10 is driven to rotate, and when the piston 22 of one of the chromatographic columns 2 slides downward to squeeze the stationary phase filler, the sample tube 61 is connected to the liquid inlet tube 5 corresponding to the chromatographic column 2, and the detergent tube 62 is connected to the liquid inlet tube 5 corresponding to the other chromatographic column 2.

[0064] That is, the flow guide 6 can automatically deliver the mobile phase sample to a chromatographic column 2 where the stationary phase filler is squeezed, and deliver the cleaning agent to a chromatographic column 2 that is loosened, so that the chromatographic column 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 drive motor 9 reciprocates to drive the nut 31 to rotate, thereby driving the piston 22 to slide in the chromatographic column 2. Since the two lifting gears 32 are meshed with each other, the two pistons 22 will slide synchronously in opposite directions.

[0068] When the piston 22 slides downward, it squeezes the stationary phase filler in the chromatographic column 2, thereby increasing the column pressure. The increase in column pressure increases the packing density of the stationary phase filler, thereby increasing the contact area between the filler and the sample molecules and improving the separation degree.

[0069] While adjusting the column pressure, the mobile phase sample is introduced into the flow guide 6 through the sample tube 61 , and the flow guide 6 automatically selects which chromatographic column 2 to deliver the sample to according to the current position of the piston 22 .

[0070] While one chromatographic column 2 is separating samples, the other chromatographic column 2 is in a cleaning state. 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 liquid outlet 21 of the chromatographic column 2 and enter the continuous chromatograph for further analysis or collection.

[0071] Stationary phase filler adjustment:

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

[0073] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A liquid chromatography piston, characterized in that: include: A connecting plate (1) with two chromatographic columns (2) fixed thereunder, each of the chromatographic columns (2) being filled with a stationary phase filler and having a liquid outlet (21) at the lower end, the liquid outlet (21) being connected to a continuous chromatograph; Two pistons (22) are respectively slidably disposed in the chromatographic column (2) and are located above the stationary phase filler. A threaded tube (3) is fixed above each of the pistons (22). The outer wall of the threaded tube (3) is provided with threads. The upper end of the threaded tube (3) passes through the connecting plate (1) and extends upward, while the lower end passes through the piston (22) and is fixedly connected to the bottom of the piston (22). Two nuts (31) are rotatably mounted on the connecting plate (1) and are respectively threadedly connected to the two threaded tubes (3); the position of the piston (22) in the chromatographic column (2) can be adjusted by rotating the nuts (31), thereby changing the column length and column pressure of the chromatographic column (2); Two connecting strips (4) are respectively fixed to the upper ends of the threaded tubes (3); Two liquid inlet pipes (5) are respectively slidably arranged in the threaded pipe (3), the upper end of each liquid inlet pipe (5) passes through 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), and 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 pass a mobile phase sample, and the cleaning agent tube (62) is used to pass a cleaning agent; The flow guide (6) is a cylindrical cavity, with side cavities (63) on both sides thereof, and the two liquid inlet pipes (5) respectively penetrate into the two side cavities (63); The sample tube (61) and the cleaning agent tube (62) are respectively connected to the front and rear of the flow guide (6); The center of the flow guide (6) is rotatably connected to a rotating shaft (10), and 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 have arc lengths greater than the inner diameters of the sample tube (61) and the detergent tube (62) and the width of the side cavity (63). The two ends of the flow guide plates (64) are respectively in contact with the inner wall of the flow guide (6).

2. A liquid chromatography piston according to claim 1, characterized in that: 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).

3. A liquid chromatography piston according to claim 1, characterized in that: Two vertical guide rods (7) are fixed above the connecting plate (1), and the two connecting strips (4) are respectively slidably sleeved in the two guide rods (7).

4. A liquid chromatography piston according to claim 1, characterized in that: A lifting gear (32) is fixedly sleeved outside the two nuts (31), and the two lifting gears (32) are meshed with each other; A driving gear (33) is rotatably provided on the connecting plate (1), and the driving gear (33) is meshed with one of the lifting gears (32); A gear drive motor (9) for driving the lifting gear (32) to rotate is connected below the connecting plate (1).

5. A liquid chromatography piston according to claim 4, characterized in that: A storage tank (8) is fixedly connected to the rear of each chromatographic column (2), the storage tank (8) being filled with a stationary phase filler, and the lower part of the chromatographic column (2) is connected to the corresponding storage tank (8) via a connecting pipe (81).

6. A liquid chromatography piston according to claim 5, characterized in that: A transmission screw (82) is rotatably disposed in the connecting tube (81), the transmission screw (82) being in contact with the inner wall of the connecting tube (81), one end of the transmission screw (82) extending into the chromatographic column (2), and the other end of the transmission screw (82) being rotatably penetrated to the outside of the storage tank (8); A screw drive motor (83) for driving the transmission screw (82) to rotate is arranged outside the storage tank (8).

7. A liquid chromatography piston according to claim 6, characterized in that: The lower end of the rotating shaft (10) passes through the lower part of the deflector (6), and a deflector gear (35) is fixed to the lower end of the rotating shaft (10), and the deflector gear (35) is rotatably mounted above the connecting plate (1); A transmission gear ring (34) is fixed on one of the lifting gears (32), and the transmission gear ring (34) is meshed with the guide gear (35).

8. A liquid chromatography piston according to claim 7, characterized in that: When the lifting gear (32) rotates, the rotating shaft (10) is driven to rotate, and when the piston (22) of one of the chromatographic columns (2) slides downward to squeeze the stationary phase filler, the sample tube (61) is connected to the liquid inlet tube (5) corresponding to the chromatographic column (2), and the cleaning agent tube (62) is connected to the liquid inlet tube (5) corresponding to the other chromatographic column (2).

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