Sample introduction system for capillary electrophoresis and water quality ion detection device thereof

Abstract

The utility model relates to the technical field of water quality detection, and discloses a sample introduction system for capillary electrophoresis and a water quality ion detection device thereof. The sample introduction system comprises a sample reagent bottle and a buffer solution reagent bottle. And the sample reagent bottle and the buffer solution reagent bottle are simultaneously connected into the capillary tube and the waste liquid bottle through a multi-way joint. And an electromagnetic valve is arranged at the joint of the waste liquid bottle and the multi-way joint. Peristaltic pumps for conveying liquid in the bottles into the multi-way joint are arranged at the joints of the reagent bottles and the multi-way joint, so that buffer solution or sample solution can be injected into the capillary tubes. The capillary rapid sample injection device is simple in structure, economical and practical, meanwhile, rapid sample injection can be conducted on the capillary only by manually controlling or automatically controlling the start-stop time and sequence of the peristaltic pump and the electromagnetic valve according to a specific program, and therefore capillary electrophoresis is convenient to detect water quality.

Description

Technical Field

[0001] The utility model relates to the technical field of water quality detection, in particular to a sample injection system for capillary electrophoresis and a water quality ion detection device using the sample injection system. Background Art

[0002] At present, most of the ion detection technologies are carried out in the laboratory. It is necessary to collect samples on site and then transport them back to the laboratory for determination through specific detection methods (such as spectrophotometry, ion chromatography, etc.). However, in the process of collecting and transporting samples, the water samples to be tested may be contaminated, thereby affecting the accuracy of water sample determination. In addition, changes in the environment may also cause changes in the morphology and concentration of the target to be measured during the transfer process. Therefore, the measurement results of this method may not truly reflect the actual situation of water quality.

[0003] In recent years, a variety of micro-instruments for on-site water quality detection have emerged, most of which are based on electrochemical methods and spectrophotometry. As for the electrochemical detection method, there are inherent disadvantages of electrochemical detection, and the long-term stability of the sensor is still difficult to be applied to long-term on-site operation. For example, the on-site analysis instrument that combines spectrophotometry with flow injection analysis technology can quickly complete the on-site automated detection of water samples, but most of the inorganic ions in the water samples need to react with the corresponding reagents to generate colored compounds for sensitive detection by spectrophotometry. Therefore, in order to realize the detection of multiple ions in natural water samples, multiple or multi-channel detection is required, which not only consumes a large amount of reagents, but also makes the structure of the entire instrument very complicated, affecting the stability of the system. In order to detect multiple ions in water samples at the same time on site, ion chromatography instruments for on-site analysis have appeared, but they often require the use of high-pressure plunger pumps. The price of such pumps is relatively expensive and not suitable for on-site use, resulting in their inability to be widely promoted and used in on-site water quality detection.

[0004] In response to the above problems, relevant researchers have proposed capillary electrophoresis technology, which has the characteristics of fast separation speed, low reagent usage and high separation efficiency. Therefore, it is urgent to provide a water quality ion detection device based on capillary electrophoresis technology to solve the technical problems of the existing on-site water quality detection instruments, which have cumbersome detection steps, complex structure and high cost. Utility Model Content

[0005] In order to avoid and overcome the technical problems existing in the prior art, the utility model provides a sample injection system for capillary electrophoresis and a water quality ion detection device thereof. The utility model can realize rapid sample injection by setting a capillary electrophoresis sample injection system with a simple structure and economical and practicality, thereby facilitating capillary electrophoresis to detect water quality.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] The utility model discloses a sample injection system for capillary electrophoresis, comprising a sample reagent bottle and a buffer reagent bottle. The sample reagent bottle and the buffer reagent bottle are simultaneously connected to a capillary and a waste liquid bottle through a multi-way connector. A solenoid valve is provided at the connection between the waste liquid bottle and the multi-way connector. A peristaltic pump for conveying liquid in the bottle to the inside of the multi-way connector is provided at the connection between each reagent bottle and the multi-way connector, so as to inject a buffer or a sample liquid into the capillary.

[0008] As a further improvement of the above solution, the injection system includes two sets of one-way valves, the inlets of which are respectively connected to the sample reagent bottle and the buffer reagent bottle, and the outlets of which are connected to the multi-way connector.

[0009] As a further improvement of the above scheme, the multi-way connector is composed of a three-way connector 1 and a three-way connector 2. The two inlets of the three-way connector 1 are respectively used to connect the sample reagent bottle and the buffer reagent bottle. The outlet of the three-way connector 1 is fixedly installed with the inlet of the three-way connector 2. The two outlets of the three-way connector 2 are respectively used to connect the capillary and the waste liquid bottle.

[0010] As a further improvement of the above solution, the multi-way connector adopts a four-way connector with an integrated structure.

[0011] As a further improvement of the above solution, a detachable syringe is provided on the pipeline where the multi-way connector and the solenoid valve are connected, and the syringe includes a barrel and a needle portion that are fixed and connected to each other. One of the barrel and the needle portion is connected to the multi-way connector through a pipeline, and the other is connected to the liquid inlet end of the solenoid valve through a pipeline.

[0012] As a further improvement of the above solution, the pipes used in the sample reagent bottle, the buffer reagent bottle, the peristaltic pump, the multi-way connector, the capillary, the solenoid valve and the connection points in the waste liquid bottle are all made of polytetrafluoroethylene tubes.

[0013] The utility model also discloses a water quality ion detection device, comprising: an injection system, an electrophoresis system, a capillary, a detector and a conductivity detection cell. The injection system adopts the above-mentioned injection system for capillary electrophoresis. The electrophoresis system comprises a power supply and an electrolytic cell. One end of the capillary away from the multi-way connector is connected to the electrolytic cell. The first electrode of the power supply is connected to the electrolytic cell, and the second electrode is connected to the pipeline at the connection between the multi-way connector and the electromagnetic valve, thereby forming a closed loop when the pipeline, the multi-way connector and the interior of the capillary are all filled with liquid. The detector is located in the middle of the capillary and is used to detect ion signals, and the detector and the conductivity detection cell are electrically connected.

[0014] As a further improvement of the above scheme, the water quality ion detection device also includes a control system. The control system includes a flow control module. The flow control module is electrically connected to the solenoid valve and two peristaltic pumps in the injection system, thereby controlling the injection system to inject buffer and sample solution into the capillary in a specified order.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. The sample injection system of the utility model can deliver the liquid in the reagent bottle to the capillary by arranging a multi-way connector and a peristaltic pump. While having a simple structure and being economical and practical, it only needs to manually control or automatically control the start and stop time and sequence of the peristaltic pump and the solenoid valve according to a specific program to quickly inject samples into the capillary, thereby facilitating capillary electrophoresis to detect water quality.

[0017] 2. The sample injection system of the utility model is provided with a one-way valve, which can prevent the liquids delivered from the two reagent bottles from flowing back into each other's pipelines during the process of forming buffer solution-sample-buffer solution in the capillary, thereby ensuring the accuracy of water quality detection.

[0018] 3. The sampling system of the utility model designs the multi-way connector into two structures: an integrated structure of a four-way connector and a composite structure assembled from two three-way connectors; the integrated structure can bring higher strength and durability to the instrument; the composite structure can reduce the influence of the branch where the reagent bottle is located, the branch where the capillary is located, and the branch where the waste liquid bottle is located on each other during disassembly and assembly.

[0019] 4. The sample injection system of the utility model is provided with a detachable syringe on the waste liquid discharge branch. Since the barrel and the needle can be plugged and fixed like a traditional drug syringe, it is convenient to replace and disassemble the components on the pipeline. At the same time, the needle made of conductive material also facilitates the "non-invasive" access to the electrodes in the electrophoresis system, for example, the needle can be clamped by an electrode clamp.

[0020] 5. The water quality ion detection device of the present invention can produce the same beneficial effects as the above-mentioned injection system by applying the above-mentioned injection system, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the water quality ion detection device in a preferred embodiment of the utility model.

[0022] Figure 2 for Figure 1 Schematic diagram of the structure of the multi-way connector.

[0023] In the figure: 1. injection system; 11. sample reagent bottle; 12. buffer reagent bottle; 13. multi-way connector; 131. three-way connector one; 132. three-way connector two; 130. interface; 15. waste liquid bottle; 16. solenoid valve; 17. peristaltic pump; 18. one-way valve; 19. syringe; 191. barrel; 192. needle head; 2. electrophoresis system; 21. power supply; 211. first electrode; 212. second electrode; 22. electrolytic cell; 3. capillary; 4. detector; 5. conductivity detection cell; 6. control system; 61. flow control module. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] See also Figure 1 and Figure 2 The embodiment of the utility model provides a water quality ion detection device, including: a sample injection system 1, an electrophoresis system 2, a capillary 3, a detector 4 and a conductivity detection cell 5, and may also include a control system 6.

[0026] The feeding system 1 includes a sample reagent bottle 11 and a buffer reagent bottle 12 , and may also include two sets of one-way valves 18 .

[0027] The sample reagent bottle 11 and the buffer reagent bottle 12 are used to pre-fill the water sample to be tested and the buffer solution, respectively. In order to facilitate on-site water quality testing, the sample reagent bottle 11 can be set to a structure that is easy to disassemble, such as the bottle body and the bottle cap are separated. When testing, a certain amount of water quality sample is first filled into the bottle body, and then the bottle body and the bottle cap on the device body are tightened.

[0028] The sample reagent bottle 11 and the buffer reagent bottle 12 are simultaneously connected to the capillary 3 and the waste liquid bottle 15 through a multi-way connector 13. A solenoid valve 16 is provided at the connection between the waste liquid bottle 15 and the multi-way connector 13. A peristaltic pump 17 is provided at the connection between each reagent bottle and the multi-way connector 13 for transporting the liquid in the bottle to the inside of the multi-way connector 13, so as to inject the buffer solution or sample solution into the capillary 3.

[0029] In this embodiment, two sets of one-way valves 18 are respectively arranged on the pipelines where the multi-way connector 13 is connected with the sample reagent bottle 11 and the buffer reagent bottle 12, and the liquid outlet ends of the two sets of one-way valves 18 are both facing the multi-way connector 13. Therefore, when one of the peristaltic pumps 17 delivers liquid to the multi-way connector 13, it is ensured that the liquid in the multi-way connector 13 will not flow back to the pipeline and reagent bottle where the other peristaltic pump 17 is located.

[0030] The multi-way connector 13 has four interconnected interfaces 130, two of which are used to connect to the sample reagent bottle 11 and the buffer reagent bottle 12, and the other two interfaces 130 are used to connect to the capillary 3 and the waste liquid bottle 15. In some embodiments, the multi-way connector 13 can directly adopt an integrated four-way connector with a cross structure, which can extend the service life of the device.

[0031] In order to reduce the influence of the branch where the reagent bottle is located, the branch where the capillary tube 3 is located and the branch where the waste liquid bottle 15 is located on each other during assembly and disassembly, in this embodiment, the multi-way connector 3 is configured to have a structure formed by splicing two three-way connectors.

[0032] In this embodiment, the multi-way connector 13 is composed of a three-way connector 1 131 and a three-way connector 132. The two inlets of the three-way connector 1 131 serve as two interfaces 130. The outlet of the three-way connector 1 131 is fixedly installed with the inlet of the three-way connector 132. The two outlets of the three-way connector 132 serve as the other two interfaces 130.

[0033] In addition, a detachable syringe 19 is provided on the pipeline where the multi-way connector 13 and the solenoid valve 16 are connected, and the syringe 19 includes a barrel 191 and a needle head 192 that are fixed and connected to each other. One of the barrel 191 and the needle head 192 is connected to the multi-way connector 13 through a pipeline, and the other of them is connected to the liquid inlet end of the solenoid valve 16 through a pipeline. Since the barrel 191 and the needle head 192 can be plugged and fixed like traditional drug syringes, it is convenient to replace and disassemble the devices on the pipeline. At the same time, the needle head 192 made of conductive material also facilitates "non-invasive" access to the electrodes in the electrophoresis system 2, for example, the needle head 192 can be clamped by an electrode clamp.

[0034] In this embodiment, the pipes used in the connections of the sample reagent bottle 11, the buffer reagent bottle 12, the peristaltic pump 17, the multi-way connector 13, the capillary 3, the solenoid valve 16 and the waste liquid bottle 15 can all be made of polytetrafluoroethylene tubes, which are resistant to acids, alkalis and various organic solvents.

[0035] The electrophoresis system 2 includes a power source 21 and an electrolytic cell 22. The end of the capillary 3 away from the multi-way connector 13 is connected to the electrolytic cell 22. The first electrode 211 of the power source 21 is connected to the electrolytic cell 22, and the second electrode 212 is connected to the pipeline at the connection between the multi-way connector 13 and the electromagnetic valve 16, thereby forming a closed loop when the pipeline, the multi-way connector 13 and the interior of the capillary 3 are all filled with liquid. The detector 4 is located in the middle of the capillary 3 and is used to detect the ion signal. The detector 4 is electrically connected to the conductivity detection cell 5.

[0036] The control system 6 may include a flow control module 61. The flow control module 61 is electrically connected to the solenoid valve 16 and the two peristaltic pumps 17 in the injection system 1, thereby controlling the injection system 1 to inject the buffer solution and the sample solution into the capillary 3 in a specified order. The flow control module 61 may use an existing controller, and the specific circuit principle is not the focus of improvement of the present utility model, and will not be described here. Of course, in some embodiments, the control system 6 can also control components such as the power supply 21, the detector 4, and the conductivity detection cell 5 in the electrophoresis system 2.

[0037] When testing water samples, the upper computer may first send a control, and the lower computer receives the command to control the injection system 1 to fill the capillary 3 in the injection step, so that the buffer solution-sample-buffer solution appears in the injection end of the capillary 3 in the order of time. The specific steps are as follows:

[0038] Before step (1), the electrolytic cell 22 may be cleaned and decontaminated to ensure that there is no solution in the electrolytic cell 22 .

[0039] (1) Control the solenoid valve 16 and the peristaltic pump 17 corresponding to the buffer reagent bottle 12 to start for a preset time of one, so as to fill the multi-way connector 13 and the flow path of the subsequent pathway with the buffer.

[0040] (2) Control the solenoid valve 16 to close, keep the peristaltic pump 17 corresponding to the buffer reagent bottle 12 open for a preset time of two to accumulate a certain pressure at the liquid inlet end of the capillary 3, then close the peristaltic pump 17 and wait for a preset time of three, so that the buffer solution is pressed into the capillary 3 by pressure and filled.

[0041] (3) Control the solenoid valve 16 to open to release the pressure, and at the same time control the peristaltic pump 17 corresponding to the sample reagent bottle 11 to open for a preset time of four, so as to fill the multi-way connector 13 and the flow path of the subsequent pathway with the water sample to be tested.

[0042] (4) Control the solenoid valve 16 to close, control the peristaltic pump 17 corresponding to the sample reagent bottle 11 to open for a preset time of five to accumulate a certain pressure at the liquid inlet end of the capillary 3, then close the peristaltic pump 17 and wait for a preset time of six, thereby pressing a certain amount of water sample to be tested into the capillary 3 by pressure, and then close the peristaltic pump 17 corresponding to the sample reagent bottle 11.

[0043] (5) Keep the solenoid valve 16 closed, and control the peristaltic pump 17 corresponding to the buffer reagent bottle 12 to start for a preset time of seven, so that the buffer fills the multi-way connector 13 and the flow path of the subsequent path again, and then continuously fills the buffer into the capillary 3 by pressure until the quantitative water sample to be tested in step four is squeezed into the electrolytic cell 22.

[0044] After step (5), the solenoid valve 16 and the peristaltic pump 17 corresponding to the buffer reagent bottle 12 are controlled to remain open, so that the water sample to be tested remaining in the flow path before the liquid inlet end of the capillary 3 is discharged to the waste liquid bottle 15, and then the solenoid valve 16 and the peristaltic pump 17 corresponding to the buffer reagent bottle 12 are closed, and step (6) is executed.

[0045] (6) The control power supply 21 is turned on to perform electrophoresis in a closed loop, and during the electrophoresis, the detector 4 is used to collect the ion signal in the middle of the capillary 3 and transmit it to the conductivity detection cell 5, so as to realize ion detection of the water sample to be tested according to the ion signal.

[0046] When the utility model performs electrophoresis separation, a high voltage electric field is applied to the closed loop through the power supply 21, so that the ions in the sample inside the capillary 3 migrate at different speeds to achieve ion separation. When the separated ions pass through the conductivity detector 4, the conductivity changes, and the non-contact conductivity detection cell 5 collects data. It should be understood that the conductivity detector 4 is equivalent to a probe, which is used to collect the electrical signal when the ions pass through, and the function of the conductivity detection cell 5 is to receive and process the electrical signal to generate a digital value.

[0047] The detection system composed of the detector 4 and the conductivity detection cell 5 adopts C4D technology, which detects the changes in conductivity caused by different ions passing through the detector 4, converts the changes into voltage data and records them, so as to facilitate qualitative and quantitative analysis of the ions contained in the sample.

[0048] After the electrophoresis is finished, the capillary 3 can be flushed again by controlling the peristaltic pump 17 to prepare for the next electrophoresis detection.

[0049] In the present invention, in a complete round of detection method, the first time the buffer solution is added is to flush the capillary 3. In some embodiments, after the first time the buffer solution is added, the solution in the electrolytic cell 22 can be discharged continuously for a period of time, so that the capillary 3 and the electrolytic cell 22 are flushed with the buffer solution to maintain a relatively stable solution environment in the electrolytic cell 22. The second time the buffer solution is added is to ensure that the quantitative water samples to be tested are completely squeezed into the electrolytic cell 22 before the electrophoresis begins, rather than remaining in the capillary 3 and other flow paths, so that the detection conditions remain the same.

[0050] The above description 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 within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A sample injection system for capillary electrophoresis, characterized in that: The invention comprises a sample reagent bottle (11) and a buffer reagent bottle (12); the sample reagent bottle (11) and the buffer reagent bottle (12) are simultaneously connected to a capillary (3) and a waste liquid bottle (15) via a multi-way connector (13); a solenoid valve (16) is provided at the connection between the waste liquid bottle (15) and the multi-way connector (13); and a peristaltic pump (17) is provided at the connection between each reagent bottle and the multi-way connector (13) for conveying liquid in the bottle to the inside of the multi-way connector (13), so as to inject the buffer solution and / or the sample liquid into the capillary (3).

2. The sample injection system for capillary electrophoresis according to claim 1, characterized in that: It also includes two groups of one-way valves (18); the inlets of the two groups of one-way valves (18) are respectively connected to the sample reagent bottle (11) and the buffer reagent bottle (12), and the outlets of the two groups of one-way valves (18) are connected to the multi-way connector (13).

3. The sample injection system for capillary electrophoresis according to claim 1, characterized in that: The multi-way connector (13) is composed of a three-way connector 1 (131) and a three-way connector 2 (132); the two inlets of the three-way connector 1 (131) are respectively used to connect to the sample reagent bottle (11) and the buffer reagent bottle (12); the outlet of the three-way connector 1 (131) is fixedly installed with the inlet of the three-way connector 2 (132); the two outlets of the three-way connector 2 (132) are respectively used to connect to the capillary (3) and the waste liquid bottle (15).

4. The sample injection system for capillary electrophoresis according to claim 1, characterized in that: The multi-way connector (13) adopts a four-way connector with an integrated structure.

5. The sample injection system for capillary electrophoresis according to any one of claims 1 to 4, characterized in that: A detachable syringe (19) is arranged on the pipeline at the connection point between the multi-way connector (13) and the electromagnetic valve (16), and the syringe (19) comprises a barrel (191) and a needle head (192) which are fixed to and communicate with each other; one of the barrel (191) and the needle head (192) is connected to the multi-way connector (13) through a pipeline, and the other is connected to the liquid inlet end of the electromagnetic valve (16) through a pipeline.

6. The sample injection system for capillary electrophoresis according to claim 5, characterized in that: The pipes used in the connection parts of the sample reagent bottle (11), the buffer reagent bottle (12), the peristaltic pump (17), the multi-way connector (13), the capillary (3), the electromagnetic valve (16) and the waste liquid bottle (15) are all made of polytetrafluoroethylene tubes.

7. A water quality ion detection device, characterized in that: include: An injection system (1), an electrophoresis system (2), a capillary (3), a detector (4) and a conductivity detection cell (5); the injection system (1) adopts the injection system for capillary electrophoresis as claimed in claim 6; the electrophoresis system (2) comprises a power supply (21) and an electrolytic cell (22); the end of the capillary (3) away from the multi-way connector (13) is connected to the electrolytic cell (22); the first electrode (211) of the power supply (21) is connected to the electrolytic cell (22), and the second electrode (212) is connected to the pipeline at the connection between the multi-way connector (13) and the electromagnetic valve (16), thereby forming a closed loop when the pipeline, the multi-way connector (13) and the interior of the capillary (3) are all filled with liquid; the detector (4) is located in the middle of the capillary (3) and is used to detect ion signals, and the detector (4) and the conductivity detection cell (5) are electrically connected.

8. The water quality ion detection device according to claim 7, characterized in that: The system also includes a control system (6); the control system (6) includes a flow control module (61); the flow control module (61) is electrically connected to the solenoid valve (16) and two peristaltic pumps (17) in the injection system (1), thereby controlling the injection system (1) to inject buffer solution and sample solution into the capillary (3) in a specified order.

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