Automatic gel permeation chromatography system

Abstract

The invention relates to the technical field of analysis and testing of high polymer materials, in particular to an automatic gel permeation chromatography system. The technical problem of improving the automation degree of analysis and detection is solved. According to the technical scheme, the automatic gel permeation chromatography system comprises an automatic sample injection unit, a detection unit and a control unit, the chromatographic separation unit comprises a constant flow infusion pump and a chromatographic column device; the chromatographic separation unit is used for receiving samples of the automatic sampling unit and performing chromatographic separation; the constant-flow liquid conveying pump is used for conveying samples to the chromatographic column device; the online detection unit comprises at least one differential detector; the differential detector is used for collecting electric signals of separated components of the chromatographic separation unit; the central control unit controls the automatic sample injection unit to inject a sample into the chromatographic separation unit; controlling a constant-flow infusion pump to convey a sample and controlling a chromatographic column device to perform chromatographic separation; and controlling the on-line detection unit to collect electric signals of components separated by the chromatographic separation unit.

Description

Technical Field

[0001] This invention relates to the field of polymer material analysis and testing technology, specifically to an automated gel permeation chromatography system. Background Technology

[0002] Gel permeation chromatography (GPC) works by utilizing the chemical inertness of gels to separate and identify them through a chromatographic system. This system comprises a pump, injector, column, detector, and data analysis system. However, with increasing testing demands, the original GPC system has revealed numerous problems, such as: cumbersome manual operation; high dependence on manual intervention for sample injection, system equilibration, and data post-processing; low automation of analysis and detection; reliance on manual monitoring for system stability; and low data analysis efficiency. Summary of the Invention

[0003] To address the technical problem of "improving the automation level of analysis and detection," this invention provides the following technical solution: An automated gel permeation chromatography system includes an automatic sample injection unit, a chromatographic separation unit, an online detection unit, a central control unit, and a data processing unit; An automatic sample introduction unit is used to receive samples and automatically introduce them. The chromatographic separation unit includes a constant flow pump and a chromatographic column; the chromatographic column receives sample injection from the automatic sample injection unit and performs chromatographic separation; the constant flow pump is used to deliver the sample to the chromatographic column. The online detection unit includes at least one differential detector; the differential detector is used to acquire electrical signals of the components separated by the chromatographic separation unit. The central control unit is communicatively connected to the automatic sample injection unit, the chromatographic separation unit, and the online detection unit. The central control unit is configured to: control the automatic sample injection unit to inject the sample into the chromatographic separation unit; control the constant flow infusion pump to transport the sample and control the chromatographic column device to perform chromatographic separation; and control the online detection unit to collect the electrical signals of the separated components from the chromatographic separation unit.

[0004] Furthermore, the chromatographic separation unit includes a column oven and at least one chromatographic column disposed within the column oven; the chromatographic separation unit also includes a degassing module, which is connected in series with a constant flow pump.

[0005] Furthermore, the automated gel permeation chromatography system includes sample vials and waste liquid vials, which are sequentially connected to a degassing module, a constant flow pump, an automatic injection unit, a chromatographic column, a differential detector, and a waste liquid vials through pipelines.

[0006] Furthermore, the automated sample delivery unit includes a sample tray for storing samples, reagent vials, a sample injection needle, and an XYZ axis motion assembly; the XYZ axis motion assembly includes an X-axis sliding assembly, a Y-axis sliding assembly, and a Z-axis sliding assembly; The X-axis sliding assembly is connected to the Z-axis sliding assembly, and the Z-axis sliding assembly is connected to an injection needle; the injection needle is movably positioned above the sample tray. The X-axis sliding assembly is connected to the sample tray via a drive system, enabling the sample tray to move along the X-axis.

[0007] Furthermore, the X-axis sliding assembly includes a slide rail slider assembly mounted above the sample tray in the X-axis direction; a first lead screw assembly drivenly connected to the slide rail slider assembly, and the first lead screw assembly is along the X-axis direction; a first belt gear transmission assembly drivenly connected to the first lead screw assembly; and an X-axis motor drivenly connected to the first belt gear transmission assembly, and the first lead screw assembly is connected to the Z-axis sliding assembly.

[0008] Furthermore, the Y-axis sliding assembly includes a slide plate mounted on the bottom of the sample tray; a slide table connected to the slide plate along the Y-axis; a second lead screw assembly driven by the slide plate along the Y-axis; a second belt gear drive assembly driven by the second lead screw assembly; and a Y-axis motor driven by the second belt gear drive assembly.

[0009] Furthermore, the Z-axis sliding assembly includes a fixed plate connected to the first lead screw assembly; a third belt gear transmission assembly disposed above the fixed plate; a Z-axis motor driven by the third belt gear transmission assembly; and a third lead screw assembly driven by the third belt gear transmission assembly, wherein the third lead screw assembly is connected to an injection needle along the Z-axis direction.

[0010] Furthermore, the autosampler unit also includes a quantitative loop, a six-way valve, and a two-way assembly; The constant flow infusion pump is connected to the inlet of the two-way assembly via a pipeline, and the inlet of the two-way assembly is connected to port 4 of the six-way valve via a pipeline. The port of the six-way valve is connected to the outlet of the two-way assembly, and the outlet of the two-way assembly is connected to one end of the chromatographic column via a pipeline. The other end of the chromatographic column is connected to the differential detector via a pipeline, and the differential detector is connected to the waste liquid bottle via a pipeline.

[0011] Furthermore, Furthermore, the two ends of the quantitative loop are connected to ports 3 and 6 of the six-way valve respectively through pipes, the injection needle is connected to port 2 of the six-way valve through a pipe, the syringe is connected to port 1 of the six-way valve through a pipe, and the syringe is connected to an injection motor.

[0012] Furthermore, it also includes a sample tray transfer area and a robotic arm device. The sample tray transfer area is located on one side of the sample tray of the automatic sample feeding unit, and the differential detector is located between the sample tray transfer area and the robotic arm device.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This invention uses a central control system to coordinate and control the operation of the automatic sample injection unit, chromatographic separation unit, and online detection unit, thereby achieving fully automated operation throughout the entire process.

[0014] This invention combines the necessary modules of an automated gel permeation chromatography system with an automated robotic arm device equipped with grasping and placing functions, thereby achieving a higher degree of automation and intelligence, and improving the efficiency and reliability of analysis and detection.

[0015] This invention utilizes a sample tray transfer area and a robotic arm device to transfer completed sample trays and sample trays to be tested, achieving an automated sample transfer device that eliminates the need for manual operation and reduces operational errors.

[0016] Furthermore, the autosampler unit also includes a quantitative loop, a six-way valve, and a two-way assembly; The sample vial is connected to the autosampler unit to enable high-throughput automatic sample injection. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall external structure of the automated gel permeation chromatography system of the present invention.

[0018] Figure 2 This is a schematic diagram of the two-layer internal structure of the automated gel permeation chromatography system of the present invention, showing the automatic sample injection unit, differential detector, chromatographic column device, robotic arm device, and sample tray transfer area.

[0019] Figure 3 This is a schematic diagram of the overall structure of the automatic sample injection unit of the automated gel permeation chromatography system of the present invention.

[0020] Figure 4 This is a schematic diagram of the internal structure of the automatic sample injection unit from a first perspective of the automated gel permeation chromatography system of the present invention.

[0021] Figure 5 This is a schematic diagram of the internal structure of the automatic sample injection unit from a second perspective of the automated gel permeation chromatography system of the present invention.

[0022] Figure label: 1. Sample vials 2. Pump unit; 2-1. Degassing unit; 2-2. Constant flow infusion pump; 3. Automatic sample introduction unit; 3-1 Sample tray; 3-11 Tray pad; 3-2 First base; 3-3 Reagent bottle; 3-4, X-axis sliding assembly; 3-41, slide rail and slider assembly; 3-42, first lead screw assembly; 3-43, first belt and gear transmission assembly; 3-44, X-axis motor; 3-5. Y-axis sliding assembly; 3-51. Slide plate support; 3-52. Slide table; 3-53. Second lead screw assembly; 3-54. Second belt and gear transmission assembly; 3-55. Y-axis motor; 3-6, Z-axis sliding assembly; 3-61, fixed plate; 3-62, third belt gear transmission assembly; 3-63, third motor; 3-64, third lead screw assembly; 3-71. Metering loop; 3-72. Six-way valve; 3-73. Injection needle; 3-74. Syringe; 3-75. Two-way connector assembly; 3-76. Injection motor; 3-8. Cleaning solution tank; 4. Differential detector; 5. Chromatographic column apparatus; 5-1. Column oven; 5-2. Column; 6. Robotic arm device; 7. Waste liquid bottles; 8. Multi-layer cabinet; 8-1. Shelves; 9. Sample tray transfer area. Detailed Implementation

[0023] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0024] Example Combination Figures 1-5 As shown, the present invention provides an automated gel permeation chromatography system, including an automatic sample injection unit, a chromatographic separation unit, an online detection unit, a central control unit, and a data processing unit; An automatic sample introduction unit is used to receive samples and automatically introduce them. The chromatographic separation unit includes a constant flow pump 2-2 and a chromatographic column device 5; the chromatographic column device 5 receives the sample injection from the automatic injection unit 3 and performs chromatographic separation; the constant flow pump 2-2 is used to deliver the sample to the chromatographic column device 5. The online detection unit includes at least one differential detector 4; the differential detector is used to acquire the electrical signals of the components separated by the chromatographic separation unit. The central control unit is communicatively connected to the automatic sample injection unit, the chromatographic separation unit, and the online detection unit. The central control unit is configured to: control the automatic sample injection unit to inject the sample into the chromatographic separation unit; control the constant flow infusion pump to deliver the sample and control the chromatographic column device to perform chromatographic separation; and control the online detection unit to collect the electrical signals of the separated components from the chromatographic separation unit. The data processing unit, connected to the online detection unit, is used to receive the detection completion signal and automatically calculate the molecular weight and sample distribution parameters of the sample.

[0025] The following description, in conjunction with the accompanying drawings, details an automated gel permeation chromatography system of the present invention, comprising a multi-layer cabinet 8, a sample vial 1, an automatic sample injection unit 3, a chromatographic separation unit, an online detection unit, a robotic arm device 6, and a waste liquid bottle 7 disposed within the multi-layer cabinet 8.

[0026] The chromatographic separation unit includes a pump unit 2 and a chromatographic column unit 5.

[0027] The sample vial 1, pump device 2, automatic injection unit 3, chromatographic column device 5, differential detector 4, and waste liquid vial 7 are connected in sequence by pipelines.

[0028] The central control unit includes a controller, which is communicatively connected to the pump unit 2, the automatic injection unit 3, the differential detector 4, the chromatographic column unit 5, and the robotic arm unit 6. The controller is used to coordinate and control the operation of the pump unit 2, the automatic injection unit 3, the differential detector 4, the chromatographic column unit 5, and the robotic arm unit 6 to achieve fully automated operation.

[0029] The pump device 2 includes a degassing module 2-1 and at least one constant flow infusion pump 2-2, with the degassing module and the constant flow infusion pump 2-2 connected in series.

[0030] The chromatographic column apparatus 5 includes a chromatographic column oven 5-1 and three identical chromatographic columns 5-2 arranged in series within the chromatographic column oven 5-1.

[0031] The multi-layer cabinet 8 has a two-layer structure, with a partition 8-1 on the bottom layer. A waste liquid bottle 7 is located on the bottom layer of the multi-layer cabinet 8. A sample bottle 1 is placed on the partition 8-1 above the waste liquid bottle 7. A degassing module 2-1 and a constant flow infusion pump 2-2 are located on one side of the sample bottle 1. The sample bottle 1 is connected to the degassing module 2-1 and the constant flow infusion pump 2-2 sequentially via pipelines.

[0032] The automatic sample injection unit 3 is located on the second floor of the multi-layer cabinet 8. The automatic sample injection unit 3 also includes a quantitative loop 3-71, a six-way valve 3-72, an injection needle 3-73, a syringe 3-74, and a two-way assembly 3-75.

[0033] The constant flow infusion pump is connected to the inlet of the two-way assembly 3-75 through a pipeline, and the inlet of the two-way assembly 3-75 is connected to port 4 of the six-way valve 3-72 through a pipeline. Port 5 of the six-way valve 3-72 is connected to the outlet of the two-way assembly 3-75, and the outlet of the two-way assembly 3-75 is connected to one end of the chromatographic column 5-2 through a pipeline.

[0034] The other end of the chromatographic column 5-2 is connected to the differential detector 4 via a tubing, and the differential detector 4 is connected to the waste liquid bottle 7 via a tubing. Under the action of the constant flow pump 2-2, the liquid in the sample bottle 1 enters the chromatographic column 5-2 through the tubing via the automatic injection unit 3 for separation, and then enters the differential detector 4 for detection. The detected sample is then recovered to the waste liquid bottle 7.

[0035] The two ends of the metering loop 3-71 are connected to ports 3 and 6 of the six-way valve 3-72 via pipes, respectively. The injection needle 3-73 is connected to port 2 of the six-way valve 3-72 via a pipe, and the syringe 3-74 is connected to port 1 of the six-way valve 3-72 via a pipe. The syringe 3-74 is connected to the injection motor 3-76.

[0036] The automatic sample injection unit 3 includes a first base 3-2, a sample tray 3-1 for storing samples, and a reagent bottle 3-3, with the sample tray 3-1 and reagent bottle 3-3 positioned on the first base 3-2. The automatic sample injection unit 3 has three injection modes via the quantitative loop 3-71: full quantitative loop 3-71 injection, partial destructive injection, and partial non-destructive injection.

[0037] The automatic sample feeding unit 3 can simultaneously accommodate two sets of sample trays 3-1, which are used to hold multiple sample vials.

[0038] The automatic sample introduction unit 3 also includes XYZ axis motion components, which include an X-axis sliding component 3-4, a Y-axis sliding component 3-5, and a Z-axis sliding component 3-6; wherein, The X-axis sliding assembly 3-4 includes a slide rail slider assembly 3-41 mounted above the sample tray 3-1 in the X-axis direction; a first lead screw assembly 3-42 driven by the slide rail slider assembly 3-41, and the first lead screw assembly 3-42 is along the X-axis direction; a first belt gear transmission assembly 3-43 driven by the first lead screw assembly 3-42; and an X-axis motor 3-44 driven by the first belt gear transmission assembly 3-43, and the first lead screw assembly 3-42 is connected to the Z-axis sliding assembly 3-6. The X-axis motor 3-44 drives the first belt gear transmission assembly 3-43 to rotate, which in turn drives the first lead screw assembly 3-42 to rotate, causing the Z-axis sliding assembly 3-6 to slide in the X-axis direction.

[0039] The Y-axis sliding assembly 3-5 includes a sliding plate support 3-51 mounted on the bottom of two sets of sample trays 3-1; a slide table 3-52 connected to the sliding plate support 3-51 along the Y-axis direction, the slide table 3-52 being disposed on the second layer of the multi-layer cabinet 8; a second lead screw assembly 3-53 driven by the sliding plate support 3-51 along the Y-axis direction; a second belt gear transmission assembly 3-54 driven by the second lead screw assembly 3-53; and a Y-axis motor 3-55 driven by the second belt gear transmission assembly 3-54. The Y-axis motor 3-55 drives the second belt gear transmission assembly 3-54 to rotate, thereby driving the second lead screw assembly 3-53 to rotate, causing the sliding plate support 3-51 to slide, and thus moving the two sets of sample trays 3-1.

[0040] The Z-axis sliding assembly 3-6 includes a fixed plate 3-61 connected to the first lead screw assembly 3-42; a third belt gear transmission assembly 3-62 disposed above the fixed plate 3-61; a Z-axis motor 3-63 driven by the third belt gear transmission assembly 3-62 and disposed below the fixed plate 3-61; and a third lead screw assembly 3-64 driven by the third belt gear transmission assembly 3-62, with the third lead screw assembly 3-64 along the Z-axis direction. A sample injection needle 3-73 is connected to the third lead screw assembly 3-64. The Z-axis motor 3-63 drives the third belt gear transmission assembly 3-62 to rotate, which in turn drives the third lead screw assembly 3-64 to rotate, thereby moving the sample injection needle 3-73 along the Z-axis direction.

[0041] The X-axis sliding assembly 3-4 allows the injection needle 3-73 to move along the Y-axis, and under the influence of the Z-axis sliding assembly 3-6, it moves along the Z-axis. The Y-axis sliding assembly 3-5 ensures that the sample vial to be sampled in the sample tray 3-1 is directly below the injection needle 3-73, allowing the injection needle 3-73 to extract the sample from the sample vial in the sample tray 3-1. After passing through the injection needle 3-73, the six-way valve 3-72, the quantitative loop 3-71, and the syringe 3-74, the sample finally enters the chromatographic column 5-2 for separation, and then enters the differential detector 4 for detection. The detected sample is then recovered to the waste liquid bottle 7.

[0042] It also includes a sample tray transfer area 9, which is located on one side of the sample tray 3-1 of the automatic sample feeding unit 3. A differential detector 4 is located between the sample tray transfer area 9 and the robotic arm device 6.

[0043] The robotic arm device 6 can transfer the sample tray 3-1 that has been tested in the automatic sample feeding unit 3 to the sample tray transfer area 9, and transfer a set of untested sample trays 3-1 from the sample tray transfer area 9 to the automatic sample feeding unit 3 without manual operation.

[0044] It also includes a cleaning solution tank 3-8 set on the first base 3-2. After one injection is completed, the controller controls the automatic injection unit 3 to enter the needle washing state, and the injection needle 3-73 enters the cleaning solution tank 3-8 to clean the inner and outer walls of the injection needle 3-73.

[0045] The workflow of this automated gel permeation chromatography system is described below. ① The degassing module 2-1 and the constant flow pump 2-2 are activated. The sample in sample vial 1 is sequentially introduced into the degassing module 2-1 and the constant flow pump 2-2 through the tubing under the action of the constant flow pump 2-2. The degassing module 2-1 removes dissolved gases from the mobile phase, thereby improving the column separation efficiency and maintaining the baseline stability of the differential detector 4. Under the action of the constant flow pump 2-2, the mobile phase is kept at a constant flow rate as it enters the autosampler unit 3. Using the constant flow pump 2-2 ensures that the mobile phase passes uniformly through the column 5-2, avoiding differences in separation effect caused by pressure fluctuations. It also allows for optimization of the separation effect of different components by adjusting the flow rate, while reducing mechanical wear.

[0046] ② The autosampler unit 3 begins operation, precisely controlling the injection volume via the quantitative loop 3-71 and the injection needle 3-73 to process samples in batches, ensuring the stability and reliability of the analytical results. Specifically, driven by the X-axis, Y-axis, and Z-axis motors respectively, the injection needle 3-73 is inserted into the target sample vial in the sample tray 3-1. Subsequently, the syringe 3-74, controlled by the injection motor 3-76, extracts the sample according to a predetermined volume and draws it into the quantitative loop 3-71. Under the action of the injection motor 3-76, the syringe 3-74 pushes the sample in the quantitative loop 3-71 into the chromatographic column 5-2 through the six-way valve 3-72, completing the injection. The sample then enters the differential detector 4 for detection. After one injection, the autosampler unit 3 enters the needle washing state to clean the inner and outer walls of the injection needle 3-73.

[0047] ③ The sample enters the chromatographic column 5-2 through the tubing from the automatic injection unit 3, and the sample is separated in the chromatographic column 5-2. During this process, the temperature control function of the column oven 5-1 is activated. The column oven 5-1 accurately and stably controls the operating temperature of the chromatographic column 5-2 in the oven according to the experimental requirements, which can improve the resolution of chromatographic peaks, shorten retention time, reduce back pressure, and ensure the repeatability of the analysis results.

[0048] ④ Differential detector 4 is activated. After the sample is separated from column 5-2, it enters differential detector 4 through a tubing. By comparing the refractive index difference between the sample and the mobile phase, the optical signal is converted into an electrical signal for detection, thus achieving substance separation and analysis. After detection, the sample flows into waste liquid bottle 7 through a tubing.

[0049] ⑤ The robotic arm device 6 is started. After the sample tray 3-1 in the automatic sampling unit 3 is injected and detected by the differential detector 4, the controller transmits the detection completion signal to the robotic arm device 6. The robotic arm device 6 identifies the sample tray 3-1 that has been detected. Driven by the Y-axis motor, the automatic sampling unit 3 moves the sample tray 3-1 that has been detected to the gripping area of ​​the robotic arm device 6. The robotic arm device 6 grips the sample tray 3-1 from directly above it and transfers it to the sample tray transfer area 9 by axial rotation. Then, the undetected sample tray 3-1 is transferred from the sample tray transfer area 9 to the tray pad 3-11 of the automatic sampling unit 3. Driven by the Y-axis motor, the undetected sample tray 3-1 is moved to the detection area in the automatic sampling unit 3 to start a new round of detection operations.

[0050] The above technical features constitute the preferred embodiment of the present invention, which has strong adaptability and optimal implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the needs of different situations.

[0051] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. An automated gel permeation chromatography system, characterized in that, It includes an automatic sample injection unit, a chromatographic separation unit, an online detection unit, a central control unit, and a data processing unit; An automatic sample introduction unit is used to receive prepared samples and automatically introduce them; The chromatographic separation unit includes a constant flow pump and a chromatographic column; the chromatographic column receives sample injection from the automatic sample injection unit and performs chromatographic separation; the constant flow pump is used to deliver the sample to the chromatographic column. The online detection unit includes at least one differential detector; the differential detector is used to acquire electrical signals of the components separated by the chromatographic separation unit. The central control unit communicates with the automatic sample injection unit, chromatographic separation unit, and online detection unit. The central control unit is configured to: control the automatic injection unit to inject the sample into the chromatographic separation unit; control the constant flow infusion pump to transport the sample and control the chromatographic column device to perform chromatographic separation; and control the online detection unit to collect the electrical signals of the separated components of the chromatographic separation unit.

2. The automated gel permeation chromatography system according to claim 1, characterized in that, The chromatographic separation unit includes a column oven and at least one column disposed inside the column oven; the chromatographic separation unit also includes a degassing module connected in series with a constant flow pump.

3. The automated gel permeation chromatography system according to claim 2, characterized in that, The automated gel permeation chromatography system includes sample vials and waste liquid vials. The sample vials are connected in sequence to the degassing module, constant flow pump, automatic injection unit, chromatographic column, differential detector, and waste liquid vials through pipelines.

4. The automated gel permeation chromatography system according to claim 3, characterized in that, The automated sample delivery unit includes a sample tray for storing samples, reagent vials, a sample injection needle, and an XYZ axis motion assembly; the XYZ axis motion assembly includes an X-axis sliding assembly, a Y-axis sliding assembly, and a Z-axis sliding assembly. The X-axis sliding assembly is connected to the Z-axis sliding assembly, and the Z-axis sliding assembly is connected to the injection needle. The injection needle is movable and positioned above the sample tray; The X-axis sliding assembly is connected to the sample tray via a drive system, enabling the sample tray to move along the X-axis.

5. The automated gel permeation chromatography system according to claim 4, characterized in that, The X-axis sliding assembly includes a slide rail slider assembly mounted above the sample tray in the X-axis direction; a first lead screw assembly driven by the slide rail slider assembly and the first lead screw assembly being driven by the X-axis direction; a first belt gear drive assembly driven by the first lead screw assembly; and an X-axis motor driven by the first belt gear drive assembly, and the first lead screw assembly being connected to the Z-axis sliding assembly.

6. The automated gel permeation chromatography system according to claim 4, characterized in that, The Y-axis sliding assembly includes a slide plate mounted on the bottom of the sample tray; a slide table connected to the slide plate along the Y-axis; a second lead screw assembly driven by the slide plate along the Y-axis; and a second belt gear drive assembly driven by the second lead screw assembly. And a Y-axis motor that is connected to the second belt gear drive assembly.

7. The automated gel permeation chromatography system according to claim 5, characterized in that, The Z-axis sliding assembly includes a fixed plate connected to the first lead screw assembly; and a third belt gear transmission assembly disposed above the fixed plate. A Z-axis motor is driven by the third belt gear transmission assembly; and a third lead screw assembly is driven by the third belt gear transmission assembly, wherein the third lead screw assembly is along the Z-axis direction and is connected to an injection needle.

8. An automated gel permeation chromatography system according to claim 4, characterized in that, The automated sample delivery unit also includes a quantitative loop, a six-way valve, and a two-way assembly; The constant flow infusion pump is connected to the inlet of the two-way assembly via a pipeline, and the inlet of the two-way assembly is connected to port 4 of the six-way valve via a pipeline. The port of the six-way valve is connected to the outlet of the two-way assembly, and the outlet of the two-way assembly is connected to one end of the chromatographic column via a pipeline. The other end of the chromatographic column is connected to the differential detector via a pipeline, and the differential detector is connected to the waste liquid bottle via a pipeline.

9. An automated gel permeation chromatography system according to claim 8, characterized in that, The two ends of the quantitative loop are connected to ports 3 and 6 of the six-way valve through pipes, respectively. The injection needle is connected to port 2 of the six-way valve through a pipe, and the syringe is connected to port 1 of the six-way valve through a pipe. The syringe is connected to an injection motor.

10. An automated gel permeation chromatography system according to claim 4, characterized in that, It also includes a sample tray transfer area and a robotic arm device. The sample tray transfer area is located on one side of the sample tray of the automatic sample feeding unit, and the differential detector is located between the sample tray transfer area and the robotic arm device.

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