Automatic sampling device

Abstract

An automatic sample injection device comprises an injection pump (1), a three-way valve (2), a six-way sample injection valve (3), a bubble sensor (4) and a controller (5), the injection pump (1) is connected with the three-way valve (2), the injection pump is provided with a selector valve, one of different sample channels, the three-way valve (2), the six-way sample injection valve (3) and a waste liquid port can be selected, the three-way valve (2) selects one of cleaning liquid and air, and the bubble sensor (4) is connected with the controller (5). The six-way sample injection valve (3) is connected with the injection pump (1), a pump of the liquid chromatograph and a chromatographic column, the bubble sensors (4) are located on pipelines of all channels of the injection pump (1), and the automatic sample injection device has the advantages of being capable of executing in-situ degassing, infinite sample injection, efficient cleaning and emptying and the like.

Description

Technical Field

[0001] The invention relates to an automatic sample injection device, belonging to the fields of medicine and food, and in particular to an automatic sample injection device for preparative liquid chromatography. Background Art

[0002] Preparative liquid chromatography (LC) is an analytical instrument used to separate and purify individual components within a sample. Separation is achieved by dissolving the sample in a mobile phase and pumping it through a chromatographic column containing a stationary phase. Components are separated based on their varying interactions with the stationary phase. A preparative liquid chromatograph primarily consists of a pump, injector, chromatographic column, detector, and data system.

[0003] Preparative liquid chromatography (HPLC) is characterized by its high separation efficiency and ability to prepare high-purity samples. Compared to traditional distillation, crystallization, or extraction methods, preparative liquid chromatography (HPLC) can more precisely separate and purify compounds, making it suitable for the preparation of rare or precious products.

[0004] In preparative liquid chromatography applications, due to the limited sample loading capacity of the column, a batch of samples often requires multiple repeated injections. Traditional liquid chromatography typically estimates the required number of injections by dividing the total sample volume by the injection volume per injection. The injection volume and number of injections are then set in the liquid chromatography method to perform repeated injections. This method requires measuring the total sample volume and is often not very accurate. This can result in residual sample not being fully injected or insufficient sample, leading to an empty sample being injected.

[0005] In addition, traditional liquid chromatographs usually draw more samples when injecting samples, and pre-discharge a small amount of samples before injection to remove bubbles and ensure the accuracy of the injection volume, which results in the loss of valuable samples. Summary of the Invention

[0006] In response to the above-mentioned defects of the existing processing methods, the purpose of the present invention is to provide an automatic sampling device that can perform unlimited sampling of the user's samples until there is no residual sample. In addition, the present invention can perform in-situ sample degassing, which not only ensures the accuracy of the injection volume but also does not cause sample loss.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An automatic sampling device comprises a syringe pump (1), a three-way valve (2), a six-way injection valve (3), a bubble sensor (4) and a controller (5), wherein the syringe pump (1) is connected to the three-way valve (2), the syringe pump is provided with a selection valve, which can select one of different sample channels, the three-way valve (2), the six-way injection valve (3) and a waste liquid port, the three-way valve (2) selects one of a cleaning liquid and air, the six-way injection valve (3) is connected to the syringe pump (1) and a pump and a chromatographic column of a liquid chromatograph, the bubble sensor (4) is located on the pipeline of each channel of the syringe pump (1), and the controller (5) performs sample degassing, repeated injection, cleaning and emptying operations according to a user-set program.

[0009] Preferably, the automatic sampling device further comprises a sample needle (6), which is inserted into the bottom of the sample and can completely extract the sample.

[0010] Preferably, the automatic sampling device further comprises a mechanical motion mechanism, which can insert the sample needle (6) into different sample bottles to achieve the sampling of multiple samples.

[0011] Preferably, the automatic sampling device can perform in-situ sample degassing by slowly extracting liquid and rapidly pushing it out to fill the pipeline with liquid, thereby ensuring the accuracy of the subsequent injection volume, and ensuring the complete removal of gas by continuous monitoring of the bubble sensor (4) during extraction and pushing.

[0012] Preferably, the automatic sampling device can also perform sampling and cleaning between different samples. Between different samples, the three-way valve (2) selects the cleaning liquid, the injection pump (1) draws the cleaning liquid and discharges it from the six-way injection valve to the waste liquid, and this is repeated to clean the injection pump (1) and the six-way injection valve (3) to ensure that the previous sample does not remain in the next sample. Beneficial effects

[0013] (1) Infinite injection can be performed until the sample is completely injected, and there is no residual sample or empty sample injection.

[0014] (2) The present invention can perform in-situ degassing, reducing unnecessary loss of valuable samples.

[0015] (3) The system has little residue and can be fully cleaned between different samples.

[0016] (4) The system can be thoroughly cleaned and emptied to avoid dilution of the sample in the next experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of embodiment 1 of the automatic sampling device of the present invention

[0018] In the figure: 1. Syringe pump, 2. Three-way valve, 3. Six-way injection valve, 4. Bubble sensor, 5. Controller, 6. Sample needle, 7. Air, 8. Cleaning fluid, 9. Waste liquid port, 10. Waste liquid port, 11. Liquid phase pump, 12. Liquid chromatography column. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Example

[0020] like Figure 1 As shown, an automatic sampling device includes a syringe pump, a three-way valve, a six-way injection valve, a bubble sensor, an injection needle, and a controller.

[0021] The working procedure of the automatic sample injection device is as follows:

[0022] Cleaning before injection: The three-way valve (2) is connected to the cleaning liquid, and the injection pump (1) draws the cleaning liquid and discharges it through the six-way injection valve (3). This process is repeated several times to perform system cleaning.

[0023] Sample degassing: The syringe pump (1) slowly draws the sample solution through the sample needle (6), and then quickly pushes the sample back from the sample needle (6). The bubble sensor (4) continuously monitors, and this process is repeated until the pipeline is filled with liquid.

[0024] Sample injection: The syringe pump (1) slowly extracts a set volume of sample solution through the sample needle (6) and injects it into the six-way injection valve (3). Large volume injection can be performed repeatedly. Then the controller (5) switches the six-way injection valve and triggers an external signal to indicate that the injection is completed.

[0025] Cleaning: The three-way valve (2) allows the cleaning liquid to pass through, the injection pump (1) draws the cleaning liquid and discharges it through the six-way injection valve (3), the injection pump (1) draws the cleaning liquid and discharges it through the sample needle (6) of each channel, and this is repeated several times to perform system cleaning.

[0026] Emptying: The three-way valve (2) allows air to pass through, the injection pump (1) draws air and discharges it through the six-way injection valve (3), the injection pump (1) draws air and discharges it through the sample needles (6) of each channel, and this process is repeated several times to empty the system.

Claims

1. An automatic sample injection device, characterized in that: The invention comprises an injection pump (1), a three-way valve (2), a six-way injection valve (3), a bubble sensor (4) and a controller (5), wherein the injection pump (1) is connected to the three-way valve (2), the injection pump is provided with a selection valve, which can select one of different sample channels, the three-way valve (2), the six-way injection valve (3) and a waste liquid port, the three-way valve (2) selects one of a cleaning liquid and air, the six-way injection valve (3) is connected to the injection pump (1) and a pump and a chromatographic column of a liquid chromatograph, and the bubble sensor (4) is located on the pipeline of each channel of the injection pump (1).

2. The automatic sample injection device according to claim 1, characterized in that: The automatic sampling device further comprises a sample needle (6), which is inserted into the bottom of the sample and can completely extract the sample.

3. An automatic sample injection device according to claim 1 or 2, characterized in that: The automatic sampling device further comprises a mechanical motion mechanism, which can insert the sample needle (6) into different sample bottles to achieve the sampling of multiple samples.

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