Method of quantitatively processing a liquid

Abstract

The application discloses a system and method for quantitatively processing liquid, which comprises a multi-channel switching unit, a through-flow metering pipeline and a reaction-detection unit. The multi-channel switching unit has one common port and N distribution ports. One end of the through-flow metering pipeline is communicated with the common port, and the other end extends to the first port. At least one connecting channel port is arranged on the wall of the through-flow metering pipeline, and a constant-volume pipeline is connected to the connecting channel port. The reaction-detection unit is connected in series in the through-flow metering pipeline between the first port and the connecting channel port through the first channel port and the second channel port arranged at the top and the bottom of the reaction-detection unit. A first peristaltic pump is arranged in series in the through-flow metering pipeline, and a second peristaltic pump is arranged in series in the constant-volume pipeline. The liquid can be quantitatively processed in the through-flow metering pipeline or the constant-volume pipeline, so that the accuracy and precision of water quality detection can be improved.

Description

Technical Field

[0001] This application relates to the field of liquid handling, analysis or detection, and more specifically, to a system and method for quantitatively handling liquids. Background Technology

[0002] Currently, the handling and / or analysis of liquids are involved in many technological fields. For example, in the medical field, the detection of test samples requires quantitative or qualitative processing and analysis. Similarly, in the environmental field of water quality testing, it is necessary to collect a small, quantitative sample (0.05 to 0.5 ml) and perform analysis on it.

[0003] In the field of liquid detection and analysis, samples are typically small. Therefore, the accuracy of the amount of the trace sample taken has a crucial and direct impact on the test results. Failure to accurately determine the small sample size can lead to significant errors in the test results.

[0004] Meanwhile, given the current demand for automation in the field of liquid handling or analysis, how to design a system and method for handling liquids that is suitable for automated processing or analysis, allows for rapid liquid inlet, and has high precision for micro-volume inlet of 0.05 to 0.5 ml has become a technical problem that needs to be solved in this field. Summary of the Invention

[0005] The purpose of this application is to provide a system and method for quantitative processing of micro-liquid volumes that is suitable for automated processing or analysis and has relatively high accuracy.

[0006] To achieve the above objectives, the present invention provides a system for quantitatively processing liquids, the system comprising a multi-channel switching unit, a flow metering pipeline, and a reaction-detection unit. The multi-channel switching unit has one common port and N distribution ports. The common port can selectively connect one of the distribution ports or de-connect all of them. The distribution ports are connected to liquid or air. One end of the flow metering pipeline is connected to the common port, and the other end extends to the first port. At least one connection channel is provided on the wall of the flow metering pipeline. The connection channel is connected to a constant volume pipeline. The reaction-detection unit is connected in series in the flow metering pipeline between the first port and the connection channel through the first channel and the second channel respectively provided at its top and bottom. A first peristaltic pump is connected in series in the flow metering pipeline, and a second peristaltic pump is connected in series in the constant volume pipeline. The flow metering pipeline is a thin tube or channel with an inner diameter of 0.05 to 4 mm, more preferably a thin tube or channel with an inner diameter of 0.1 mm to 3 mm, and even more preferably a thin tube or channel with an inner diameter of 0.5 mm to 2 mm.

[0007] Preferably, the reaction-detection unit is in communication with the atmosphere, and the first peristaltic pump is connected in series between the second channel port and the connecting channel port.

[0008] Preferably, the reaction-detection unit is not connected to the atmosphere, and the first peristaltic pump is connected in series between the first port and the first channel opening.

[0009] Preferably, the reaction-detection unit is in communication with the atmosphere, and the first peristaltic pump is connected in series between the common port of the multi-channel switching unit and the connection channel port.

[0010] Preferably, the multi-channel switching unit is a multi-channel directional valve, or a combination of other valves and / or pump devices consisting of multiple channels and multiple shut-off valves or peristaltic pumps.

[0011] Preferably, the flow metering pipeline and / or the constant volume pipeline are connected in series with a selectable shut-off valve.

[0012] Preferably, a liquid detector is connected in series in the flow metering pipeline or the constant volume pipeline.

[0013] Preferably, the reaction-detection unit includes a reaction device and a detection device, which are either integrated or separable.

[0014] According to another aspect of this application, a method for use in the aforementioned system is proposed, wherein the first peristaltic pump is connected in series between the second channel port and the connecting channel port or between the first port and the first channel port. The liquid inlet steps of this system are as follows:

[0015] 1) Switch the multi-channel switching unit to the dispensing port that needs liquid inlet, and connect the common port of the multi-channel switching unit to it;

[0016] 2) The first peristaltic pump and / or the second peristaltic pump rotate counterclockwise, so that the head of the liquid to be injected (hereinafter referred to as "head" and "tail" in this application) approaches the connection port of the flow metering pipeline. Then, the first peristaltic pump remains stationary, and the second peristaltic pump rotates counterclockwise, and the liquid flows into the constant volume pipeline or overflows from the port of the constant volume pipeline.

[0017] 3) Switch the multi-channel switching unit to the air distribution port, keep the second peristaltic pump stationary, and rotate the first peristaltic pump counterclockwise. At this time, the liquid from the connection channel to the multi-channel switching unit flows into the reaction-detection unit.

[0018] According to another aspect of this application, a method for use in the aforementioned system is proposed, wherein the first peristaltic pump is connected in series between the second channel port and the connecting channel port or between the first port and the first channel port. The liquid inlet steps of this system are as follows:

[0019] 1) Switch the multi-channel switching unit to the dispensing port that needs liquid inlet, and connect the common port of the multi-channel switching unit to it;

[0020] 2) The first peristaltic pump and / or the second peristaltic pump rotate counterclockwise, so that the liquid head to be injected approaches the connection channel of the flow metering pipeline. Then, the first peristaltic pump stops moving, and the second peristaltic pump rotates counterclockwise, and the liquid flows into the constant volume pipeline or overflows from the port of the constant volume pipeline.

[0021] 3) With all the multi-channel switching units deactivated, the first peristaltic pump rotates counterclockwise, the second peristaltic pump rotates clockwise, and the flow rate of the first peristaltic pump is approximately equal to the flow rate of the second peristaltic pump. At this time, the liquid in the constant volume pipeline flows into the reaction-detection unit.

[0022] Alternatively, the multi-channel switching unit can be switched to the air distribution port, the first peristaltic pump rotates counterclockwise, the second peristaltic pump rotates clockwise, and the flow rate of the first peristaltic pump is greater than that of the second peristaltic pump. At this time, the liquid from the connecting channel to the multi-channel switching unit and the liquid in the constant volume pipeline flow into the reaction-detection unit.

[0023] According to another aspect of this application, a method for use in the aforementioned system is proposed, wherein the first peristaltic pump is connected in series between the common port of the multi-channel switching unit and the connection channel port. The liquid injection step of this system is as follows:

[0024] 1) Switch the multi-channel switching unit to the dispensing port that needs liquid inlet, and connect the common port of the multi-channel switching unit to it;

[0025] 2) The second peristaltic pump remains stationary, while the first peristaltic pump rotates counterclockwise. When the liquid reaches the position of the connection channel opening, the first peristaltic pump stops working or stops working after a delay, and the liquid remains above the connection channel opening.

[0026] 3) The first peristaltic pump remains stationary, while the second peristaltic pump rotates counterclockwise, causing the liquid above the connection channel to flow into the constant volume pipeline or flow out from the port of the constant volume pipeline;

[0027] 4) Switch the multi-channel switching unit to the air distribution port, keep the second peristaltic pump stationary, rotate the first peristaltic pump counterclockwise, and allow the liquid from the connection channel to the multi-channel switching unit to flow into the reaction-detection unit.

[0028] The above technical solution can utilize the working characteristics of pipelines, peristaltic pumps, and shut-off valves to capture a predetermined volume of liquid with high accuracy, thereby achieving a liquid processing solution with high accuracy suitable for automated processing or analysis.

[0029] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0030] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application, and the illustrative embodiments and descriptions thereof are used to explain this application. In the drawings:

[0031] Figures 1 to 5 These are schematic diagrams of preferred embodiments of the system for quantitative liquid processing according to this application;

[0032] Figure 6 This is a schematic diagram of a preferred embodiment of the multi-channel switching unit; and

[0033] Figure 7 This is a schematic diagram of a preferred embodiment of the reaction-detection unit. Detailed Implementation

[0034] The technical solution of this application will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] It should be noted that the terms "first" and "second" used in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, the peristaltic pump mentioned in this application is a device or combination of devices capable of driving liquid in either the forward or reverse direction, and which can shut off the pipeline when stationary, equivalent to a shut-off valve.

[0036] like Figures 1 to 5 As shown, according to one aspect of this application, a system for quantitatively processing liquids is proposed, the system comprising:

[0037] The multi-channel switching unit 16 has a common port h and N distribution ports g1, g2...gn. The common port h can selectively turn on one of the distribution ports g1, g2...gn or turn off all of them. The distribution ports g1, g2...gn are connected to liquids or air. The liquid can be water samples, reagents, waste liquids, etc. n is a natural number greater than or equal to 2.

[0038] A flow metering pipeline 11 is provided, one end of which is connected to a common port h and the other end extends to a first port a. At least one connection channel d is also provided on the pipe wall of the flow metering pipeline 11, and the connection channel d is connected to a constant volume pipeline 12 and a reaction-detection unit 14.

[0039] In the preferred embodiment, the orifice diameter of the flow metering pipe is 0.05 mm to 4 mm, more preferably 0.1 mm to 3 mm, and even more preferably 0.5 mm to 2 mm. If a pipe with an orifice diameter greater than 2 mm and less than 4 mm is used, bubbles and residual liquid are easily generated after the liquid passes through the pipe, which seriously affects the accuracy and precision of the detection. However, when a pipe with an orifice diameter of less than 2 mm (preferably less than 1 mm) is used, its inner diameter will be smaller than the diameter of the residual liquid, forming a liquid segment that naturally converges and then closes the thin tube. Therefore, it is possible to make up the volume and inject liquid with a smaller volume of liquid sample, achieving high-precision detection and analysis. At the same time, it reduces the amount of detection reagents used and lowers the cost.

[0040] Of course, without compromising the objective of this application, tubing with a larger aperture can be used locally to improve the speed of liquid processing and analysis. For example, a larger tube can be used to bring up a standard volume of more than 2 ml or to discharge waste liquid.

[0041] To further explain, multiple connection ports d can be provided on the wall of the flow metering pipeline 11, so that the flow metering pipeline 11 is connected to multiple volume control pipelines 12 and multiple peristaltic pumps P2, so as to perform high-precision volume control of different liquids, avoid cross-contamination between reagents and water samples, and enable simultaneous liquid injection. The number of volume control pipelines 12 can be set according to the actual situation.

[0042] The reaction-detection unit 14 is connected in series within a flow metering conduit 11 between a first port a and a connecting channel port d via a first channel port b and a second channel port c respectively disposed at its top and bottom. Preferably, the reaction-detection unit 14 includes a vessel 19 and a light source 181 and a photodetector 182 disposed adjacent to the vessel 19.

[0043] The flow metering pipeline 11 is equipped with a first peristaltic pump P1 connected in series, and the constant volume pipeline 12 is equipped with a second peristaltic pump P2 connected in series. The flow direction of the liquid can be simply controlled by the peristaltic pumps, which can significantly reduce the system cost.

[0044] Therefore, this system, through the cooperation of the flow metering pipeline 11 and the peristaltic pump, can achieve high-precision volume control and liquid injection, and has flexible liquid injection and drainage methods, high working efficiency and low cost.

[0045] like Figures 1 to 4 As shown, the first peristaltic pump P1 of this system can be connected in series in the flow metering line 11. Preferably, as... Figure 1 As shown, the first peristaltic pump P1 can be connected in series between the second channel port c and the connecting channel port d. Alternatively, as... Figure 2 As shown, the first peristaltic pump P1 is connected in series between the first port a and the first channel port b.

[0046] This system can have the following liquid injection steps:

[0047] The steps for the first type of liquid injection operation are as follows:

[0048] 1) Switch the multi-channel switching unit 16 to the distribution ports g2, g3...gn that need liquid inlet, so that the common port h of the multi-channel switching unit 16 is connected to it;

[0049] 2) The second peristaltic pump P2 remains stationary, while the first peristaltic pump P1 rotates counterclockwise. At this time, the liquid enters the reaction-detection unit 14 under the drive of the first peristaltic pump P1.

[0050] The steps for the second liquid injection operation are as follows:

[0051] 1) Switch the multi-channel switching unit 16 to the distribution ports g2, g3...gn that need liquid inlet, so that the common port h of the multi-channel switching unit 16 is connected to it;

[0052] 2) The first peristaltic pump P1 and / or the second peristaltic pump P2 rotate counterclockwise, so that the liquid head to be injected approaches the connection channel d of the flow metering pipeline 11. Then, the first peristaltic pump P1 remains stationary, and the second peristaltic pump P2 rotates counterclockwise, and the liquid flows into the constant volume pipeline 12 or overflows from the port e of the constant volume pipeline 12.

[0053] 3) Switch the multi-channel switching unit 16 to the air distribution port g1. The second peristaltic pump P2 remains stationary, while the first peristaltic pump P1 rotates counterclockwise. At this time, the liquid connected to the channel port d to the multi-channel switching unit 16 flows into the reaction-detection unit 14.

[0054] The steps for the third liquid injection operation are as follows:

[0055] 1) Switch the multi-channel switching unit 16 to the distribution ports g2, g3...gn that need liquid inlet, so that the common port h of the multi-channel switching unit 16 is connected to it;

[0056] 2) The first peristaltic pump P1 and / or the second peristaltic pump P2 rotate counterclockwise, so that the liquid head to be injected approaches the connection channel d of the flow metering pipeline 11. Then, the first peristaltic pump P1 remains stationary, and the second peristaltic pump P2 rotates counterclockwise, and the liquid flows into the constant volume pipeline 12 or overflows from the port e of the constant volume pipeline 12.

[0057] 3) With all the multi-channel switching units 16 turned off, the first peristaltic pump P1 rotates counterclockwise and the second peristaltic pump P2 rotates clockwise, and the flow rate of the first peristaltic pump P1 is approximately equal to the flow rate of the second peristaltic pump P2. At this time, the liquid in the constant volume pipeline 12 flows into the reaction-detection unit 14.

[0058] The steps for the fourth liquid injection procedure are as follows:

[0059] 1) Switch the multi-channel switching unit 16 to the distribution ports g2, g3...gn that need liquid inlet, and connect the common port h of the multi-channel switching unit 16 to them;

[0060] 2) The first peristaltic pump P1 and / or the second peristaltic pump P2 rotate counterclockwise, so that the liquid head to be injected approaches the connection channel d of the flow metering pipeline 11. Then, the first peristaltic pump P1 remains stationary, and the second peristaltic pump P2 rotates counterclockwise, and the liquid flows into the constant volume pipeline 12 or overflows from the port e of the constant volume pipeline 12.

[0061] 3) Switch the multi-channel switching unit 16 to the air distribution port g1. The first peristaltic pump P1 rotates counterclockwise and the second peristaltic pump P2 rotates clockwise. The flow rate of the first peristaltic pump P1 is greater than the flow rate of the second peristaltic pump P2. At this time, the liquid in the connecting channel port d to the multi-channel switching unit 16 and the liquid in the constant volume pipeline 12 flow into the reaction-detection unit 14.

[0062] like Figure 5 As shown, the first peristaltic pump P1 of this system is connected in series between the common port h and the connection channel port d of the multi-channel switching unit 16.

[0063] This system can have the following liquid injection steps:

[0064] The steps for the first type of liquid injection operation are as follows:

[0065] 1) Switch the multi-channel switching unit 16 to the distribution ports g2, g3...gn that need liquid inlet, and connect the common port h of the multi-channel switching unit 16 to them;

[0066] 2) The second peristaltic pump P2 remains stationary, while the first peristaltic pump P1 rotates counterclockwise. At this time, the liquid enters the reaction-detection unit 14 under the drive of the first peristaltic pump P1.

[0067] The steps for the second liquid injection operation are as follows:

[0068] 1) Switch the multi-channel switching unit 16 to the distribution ports g2, g3...gn that need liquid inlet, and connect the common port h of the multi-channel switching unit 16 to them;

[0069] 2) The second peristaltic pump P2 remains stationary, while the first peristaltic pump P1 rotates counterclockwise. When the liquid reaches the position of the connection channel opening d, the first peristaltic pump P1 stops working or stops working after a delay, and the liquid remains above the connection channel opening d.

[0070] 3) The first peristaltic pump P1 remains stationary, while the second peristaltic pump P2 rotates counterclockwise, causing the liquid above the connection channel d to flow into the constant volume pipe 12 or out from port e of the constant volume pipe 12.

[0071] 4) Switch the multi-channel switching unit 16 to the air distribution port g1, keep the second peristaltic pump P2 stationary, rotate the first peristaltic pump P1 counterclockwise, and the liquid flowing from the channel port d to the multi-channel switching unit 16 into the reaction-detection unit 14.

[0072] To further explain, after processing and analyzing the liquid using this system, the multi-channel switching unit 16 can be switched to the waste liquid distribution port g8, the first peristaltic pump P1 and / or the second peristaltic pump P2 rotate clockwise, and the reacted solution is discharged from the reaction-detection unit 14. Then, the multi-channel switching unit 16 can be switched to the distilled water distribution port g2 to clean the reaction-detection unit 14 and the corresponding pipelines.

[0073] like Figure 4 and Figure 5 As shown, the flow metering line 11 and / or the constant volume line 12 are connected in series with a selectable on / off shut-off valve Z or a liquid detector S. The shut-off valve Z reduces the influence of negative pressure in the system for quantitative liquid processing on the detection results, reducing detection errors and improving detection accuracy. The shut-off valve can be a diaphragm valve, a clamp valve, or a rotary ball valve, etc. Of course, this shut-off valve can also be replaced by a peristaltic pump. The liquid detector is used to sense whether the liquid has reached the designated part in the flow path, thereby accurately locating the head and tail positions of the liquid, which can improve metering accuracy, avoid over-flushing and waste of reagents during liquid inlet, and improve liquid inlet efficiency. Preferably, the shut-off valve Z or the liquid detector S is located near the bifurcation point a.

[0074] like Figure 6 As shown, the multi-channel switching unit 16 can be a multi-channel directional valve, or a combination of other valves and / or pump devices consisting of multiple channels and multiple shut-off valves Z or peristaltic pumps P. Of course, this application is not limited to this; it can be adjusted to other reasonable structures according to actual needs.

[0075] like Figure 7As shown, the reaction-detection unit 14 includes a reaction device 17 and a detection device 18. The reaction device 17 and the detection device 18 can be integrated, sharing the same container 19. A light source 181 and a photodetector 182 are positioned adjacent to the container 19. Alternatively, the reaction device 17 and the detection device 18 can be separate, with the light source 181 and the photodetector 182 positioned adjacent to the container 19 of the detection device 18. Of course, this application is not limited to these configurations and can be adjusted to other reasonable structures according to actual needs. For example, the reaction-detection unit 14 may also include a high-pressure valve, a shut-off valve, or a peristaltic pump.

[0076] According to one embodiment of the quantitative liquid processing system of this application, water quality pollution indicators such as COD, ammonia nitrogen, and hexavalent chromium in water samples can be detected separately. Figure 1 In the configuration, the connections for ports g1, g2...gn are as follows:

[0077] ●COD:

[0078] port g1: Air port; port g2: Distilled water; port g3: Potassium dichromate solution; port g4: Concentrated sulfuric acid + silver sulfate solution; port g5: Water sample port; port g8: Waste liquid port.

[0079] ●Ammonia nitrogen:

[0080] g1 port: Air port; g2 port: Distilled water; g3 port: Potassium sodium tartrate solution; g4 port: Nessler's reagent; g5 port: Water sample port; g8 port: Waste liquid port. ● Hexavalent chromium:

[0081] g1 port: Air port; g2 port: Distilled water; g3 port: Mixed acid solution; g4 port: Chromogenic reagent solution; g5 port: Water sample port; g8 port: Waste liquid port.

[0082] Taking the measurement of ammonia nitrogen as an example, the steps of the quantitative liquid processing system of this application are as follows:

[0083] 1) Drain the liquid in the reaction-detection unit 14 through the waste liquid port g8.

[0084] 2) First, use the aforementioned liquid injection operation to inject 4 ml of water sample into the reaction-detection unit 14.

[0085] 3) Using the aforementioned liquid injection operation, 0.5 ml of shielding agent sodium potassium tartrate solution is injected into the reaction-detection unit 14.

[0086] 4) Switch the multi-channel switching unit 16 to the air distribution port g1. The second peristaltic pump P2 remains stationary, while the first peristaltic pump P1 rotates counterclockwise. The reagents can be mixed evenly by the air bubbles drawn in.

[0087] 5) After the liquid has settled, measure the colorimetric background voltage at this point.

[0088] 6) Using the aforementioned liquid injection operation, 0.5 ml of Nessler's reagent, a colorimetric reagent, is then introduced into the reaction-detection unit 14.

[0089] 7) Switch the multi-channel switching unit 16 to the air distribution port g1. The second peristaltic pump P2 remains stationary, while the first peristaltic pump P1 rotates counterclockwise. The color developer and solution can be mixed evenly by the air intake, and the mixture begins to develop color.

[0090] 8) After a fixed colorimetric time, once the liquid has settled, measure the voltage after colorimetry.

[0091] 9) The concentration of ammonia nitrogen in the water is calculated by measuring the background voltage and the voltage after colorimetry.

[0092] 10) Discharge the reaction-detection unit 14 after the reaction and rinse the reaction-detection unit 14 and the corresponding pipelines with distilled water.

[0093] To further explain, the number of reagent feeds in the quantitative liquid processing system can be expanded or reduced by increasing or decreasing the number of distribution ports g1, g2...gn of the multi-channel switching unit 16. For example, the extra distribution ports of the multi-channel switching unit 16 can be connected to potassium dichromate solution, concentrated sulfuric acid solution and COD range calibration solution required for COD detection, so that the detection of two water quality monitoring indicators can be achieved in one system.

[0094] The extra distribution ports of the redundant multi-channel switching unit 16 can also be connected to other reaction-detection vessels, such as titration-based detection vessels. In this case, the flow path system design is similar to that based on sequential injection technology.

[0095] The above technical solution utilizes the thin tube characteristics and internal volume space attributes of the flow metering pipe 11 and the constant volume pipe 12, as well as the physical characteristics such as the working characteristics and rotation time attributes of the peristaltic pumps P1 and P2, to accurately extract a predetermined micro-volume of liquid. At the same time, it achieves fast liquid inlet efficiency and high stability. The accuracy of liquid inlet metering depends only on the internal volume space attributes of the flow metering pipe 11 and the constant volume pipe 12, as well as the speed and rotation time of the peristaltic pumps P1 and P2, thus realizing a technical solution for processing liquids with high accuracy suitable for automated processing or analysis.

[0096] The preferred embodiments of this application have been described in detail above. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0097] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0098] Furthermore, various different embodiments of this application can be combined in any way, as long as they do not violate the spirit of this application, they should also be regarded as the content disclosed by this invention.

Claims

1. A method of dosing a liquid, characterized in that, The method is applied to a system for quantitatively processing liquid, the system comprising: a multi-channel switching unit (16) having one common port (h) and N distribution ports (g1, g2...gn), the common port (h) being selectively conductive to one of the distribution ports (g1, g2...gn) or none of them, the distribution ports (g1, g2...gn) being connected with liquid or air, n being a natural number greater than or equal to 2; a through-flow metering pipeline (11) having one end in communication with the common port (h) and the other end extending to a first port (a), the through-flow metering pipeline (11) further having at least one connection channel opening (d) provided on the wall thereof, the connection channel opening (d) being connected with a constant-volume pipeline (12); and a reaction-detection unit (14) being connected in series in the through-flow metering pipeline (11) between the first port (a) and the connection channel opening (d) through a first channel opening (b) and a second channel opening (c) provided respectively at the top and bottom thereof; wherein a first peristaltic pump (P1) is connected in series in the through-flow metering pipeline (11), and a second peristaltic pump (P2) is connected in series in the constant-volume pipeline (12), the through-flow metering pipeline (11) being a thin tube or channel having an inner diameter of 0.05 to 4 mm; wherein the first peristaltic pump (P1) is connected in series between the first port (a) and the connection channel opening (d), the method for quantitatively processing liquid comprising the following liquid feeding steps: 1) switching the multi-channel switching unit (16) to the distribution port (g2, g3...gn) requiring liquid feeding, so that the common port (h) of the multi-channel switching unit (16) is in communication therewith; 2) rotating the first peristaltic pump (P1) and / or the second peristaltic pump (P2) counterclockwise, so that the liquid to be fed has a water head close to the connection channel opening (d) of the through-flow metering pipeline (11), then keeping the first peristaltic pump (P1) stationary and rotating the second peristaltic pump (P2) counterclockwise, so that the liquid flows into the constant-volume pipeline (12) or overflows from the port (e) of the constant-volume pipeline (12); 3) switching the multi-channel switching unit (16) to the distribution port (g1) connected with air, keeping the second peristaltic pump (P2) stationary and rotating the first peristaltic pump (P1) counterclockwise, at this time, the liquid from the connection channel opening (d) to the multi-channel switching unit (16) flows into the reaction-detection unit (14).

2. The method of dosing a liquid according to claim 1, characterized in that, The through-flow metering pipeline (11) is a thin tube or channel having an inner diameter of 0.1 mm to 3 mm.

3. The method of dosing a liquid according to claim 2, characterized in that, The through-flow metering pipeline (11) is a thin tube or channel having an inner diameter of 0.5 mm to 2 mm.

4. The method of dosing a liquid according to claim 1, characterized in that, The multi-channel switching unit (16) is a multi-channel selector valve, or a combination of other valve and / or pump devices composed of multiple channels and multiple shut-off valves or peristaltic pumps (P).

5. The method of dosing a liquid according to claim 1, characterized in that, The through-flow metering pipeline (11) and / or the constant-volume pipeline (12) is connected in series with a shut-off valve (Z) which can be selectively turned on or off.

6. The method of dosing a liquid according to claim 1, wherein, The throughflow metering pipeline (11) or the constant volume pipeline (12) is provided with a liquid detector (S) in series.

7. The method of dosing a liquid according to claim 1, wherein, The reaction-detection unit (14) comprises a reaction device (17) and a detection device (18), which are integrated or separable.

8. A method of dosing a liquid, characterized in that The method is applied to the system for quantitatively processing liquid as claimed in claim 1, and the first peristaltic pump (P1) is connected in series between the second channel port (c) and the connecting channel port (d); or the first peristaltic pump (P1) is connected in series between the first port (a) and the first channel port (b). The liquid inlet step is: 1) Switch the multi-channel switching unit (16) to the distribution port (g2, g3, ……gn) requiring liquid inlet, so that the common port (h) of the multi-channel switching unit (16) is connected thereto; 2) The first peristaltic pump (P1) and / or the second peristaltic pump (P2) rotate counterclockwise, so that the liquid to be inlet has a water head close to the connecting channel port (d) of the throughflow metering pipeline (11), then the first peristaltic pump (P1) is stationary, and the second peristaltic pump (P2) rotates counterclockwise, so that the liquid flows into the constant volume pipeline (12) or overflows from the port (e) of the constant volume pipeline (12); 3) Switch the multi-channel switching unit (16) to the distribution port (g1) connected to air, the first peristaltic pump (P1) rotates counterclockwise, the second peristaltic pump (P2) rotates clockwise, and the flow rate of the first peristaltic pump (P1) is greater than that of the second peristaltic pump (P2), at this time, the liquid from the connecting channel port (d) to the multi-channel switching unit (16) and the liquid in the constant volume pipeline (12) flow into the reaction-detection unit (14).

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