System for dosing a liquid

Abstract

The application discloses a system for quantitatively processing liquid, which comprises at least one common pipeline and n through-flow pipelines, the through-flow pipelines extend from the inside of a container to distribution ports on the common pipeline, at least one through-flow pipeline is provided with a peristaltic pump, the common pipeline can selectively conduct one through-flow pipeline or none, the metering unit is connected in series in a first connecting pipeline through connecting channel ports arranged at the top and bottom thereof respectively, a second connecting pipeline is communicated with the connecting channel ports on the common pipeline or the metering unit and extends to the connecting channel ports, and a reaction-detection unit is connected in series in the first connecting pipeline through connecting channel ports arranged at the top and bottom thereof respectively. Through quantitative processing of liquid in the metering unit, the accuracy and precision of water quality detection can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of liquid processing, analysis or detection, and in particular, to a system for quantitatively processing liquid. BACKGROUND

[0002] Currently, in many technical fields, the processing and / or analysis of liquid is involved. For example, in the medical field, the detection of a sample to be tested requires quantitative or qualitative processing and analysis of the sample to be tested. For another example, in the field of environmental protection, water quality detection requires intercepting a small sample (0.05 to 0.5 milliliters) for quantitative detection and analysis.

[0003] In the field of liquid detection and analysis, the sample is usually small. Therefore, the accuracy of the amount of micro-liquid to be tested intercepted has a direct and crucial impact on the detection result. Once the small sample intercepted cannot be accurately obtained, a large error in the detection result will be caused.

[0004] In addition, a typical quantitative metering flow path commonly used in current analysis instruments and liquid processing fields is the "sequential injection" liquid metering technology: however, due to the need to apply a multi-channel switching valve (or valve group) and a liquid metering detection device, the cost of the flow path device in such a conventional device is relatively high.

[0005] At the same time, in view of the current automation demand in the field of liquid processing or analysis, how to design a system for processing liquid that is suitable for automated processing or analysis, has a low cost, a fast liquid inlet, and a high precision for micro-liquid quantity of 0.05 to 0.5 milliliters has become a technical problem to be solved in the field. SUMMARY

[0006] The purpose of the present application is to provide a system for quantitatively processing micro-liquid that is suitable for automated processing or analysis and has a relatively high accuracy.

[0007] In order to achieve the above object, the present application provides a system for quantitatively processing liquid, which comprises at least one common pipeline and n through pipelines, the through pipelines extending from the inside of a container to a distribution port on the common pipeline, n being a natural number equal to or greater than 2, at least one through pipeline being provided with a peristaltic pump, the common pipeline being selectively connected to one of the through pipelines or none of the through pipelines, the first connecting pipeline being in communication with connection port m on the common pipeline and extending to connection port t, the metering unit being connected in series in the first connecting pipeline through connection port v and connection port u provided at the top and bottom of the metering unit respectively, the second connecting pipeline being in communication with at least one of connection port d on the common pipeline, the first connecting pipeline and the metering unit and extending to connection port i, and the reaction-detection unit being connected in series in the first connecting pipeline through connection port a and connection port c provided at the top and bottom of the reaction-detection unit respectively.

[0008] Preferably, the metering unit is a combination of a fine channel and a local coarse channel, the fine channel having an inner diameter of 0.05 mm to 5 mm, and the coarse channel having an inner diameter greater than 5 mm.

[0009] Preferably, the fine channel has an inner diameter of 0.1 mm to 3 mm.

[0010] Preferably, the fine channel has an inner diameter of 0.5 mm to 2 mm.

[0011] Preferably, the through pipeline is also a fine channel; or, the through pipeline is a fine channel within a predetermined length range extending from the distribution port towards the container, the predetermined length range being at least 0.01 mm.

[0012] Preferably, the system comprises at least one external branch, the common pipeline being connected to the atmosphere through the external branch provided with a peristaltic pump, for pumping air in and / or out and / or discharging liquid.

[0013] Preferably, the metering unit is provided with at least one liquid detector.

[0014] Preferably, the metering unit is a container or a pipeline in communication with the atmosphere or a combination of the two, the metering unit being provided with at least one connection port w connected with an overflow pipeline, the overflow pipeline being provided with a peristaltic pump in series.

[0015] Preferably, a peristaltic pump is connected in series on the second connecting pipeline and / or the reaction-detection unit, and no device or a peristaltic pump and / or a stop valve is provided on the first connecting pipeline and / or the metering unit; or, a peristaltic pump is connected in series on the first connecting pipeline, and a peristaltic pump and / or a stop valve is provided on the second connecting pipeline.

[0016] Preferably, the metering unit is a container or a pipeline or a combination of the two, which is not in communication with the atmosphere, and is provided with at least one connecting channel port w, to which an overflow pipeline is connected, and the overflow pipeline is provided in series with a peristaltic pump or a stop valve.

[0017] Preferably, at least one of the metering unit, the reaction-detection unit, the first connecting pipeline and the second connecting pipeline is provided with a peristaltic pump, and the second connecting pipeline is provided with no device or a peristaltic pump and / or a stop valve.

[0018] Preferably, the metering unit and / or the reaction-detection unit is provided in series with a peristaltic pump and / or a stop valve, which can be selectively turned on or off.

[0019] Preferably, the reaction-detection unit comprises a reaction device and a detection device, which are integrated or separable.

[0020] By the above technical solution, the pipeline and the working characteristics of the peristaltic pump and the stop valve can be used to intercept a predetermined volume of liquid with high precision, thereby realizing a technical solution for processing liquid with high accuracy and suitable for automatic processing or analysis.

[0021] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve the purpose of explaining the present application. In the drawings:

[0023] Figures 1 to 9 are schematic diagrams of preferred embodiments of a quantitative liquid processing system according to the present application, respectively; and

[0024] Figure 10 is a schematic diagram of a preferred embodiment of a reaction-detection unit. DETAILED DESCRIPTION

[0025] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0026] It should be noted that the terms "first" and "second" mentioned in the present application are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features. In addition, the peristaltic pump mentioned in the present application is a device or combination of devices with peristaltic pump function that can drive liquid in forward or reverse direction, which can be closed when at rest, equivalent to a stop valve.

[0027] As shown in Figure 1 According to one aspect of the present application, a system for dosing a liquid is proposed, comprising at least one common line GL, n through lines PL, a first connecting line MT, a metering unit UV, a second connecting line DI and a reaction-detection unit CA, n being a natural number greater than or equal to 2.

[0028] The through lines PL extend from inside the containers Pz, Pr1...Prn, Ps, Py to the distribution ports z, r1...rn, s, y on the common line GL, at least one of the through lines PL being provided with a peristaltic pump, the common line GL being selectively conductive to one of the through lines PL or to none of them.

[0029] The first connecting line MT is in communication with the connecting port m on the common line GL and extends to the connecting port t.

[0030] The metering unit UV is in series in the first connecting line MT via the connecting ports v and u provided at the top and at the bottom of the metering unit UV, respectively.

[0031] The second connecting line DI is in communication with at least one of the connecting port d on the common line GL, the first connecting line MT and the metering unit UV and extends to the connecting port i.

[0032] The reaction-detection unit CA is in series in the first connecting line MT via the connecting ports a and c provided at the top and at the bottom of the reaction-detection unit CA, respectively.

[0033] Figure 1 The metering unit UV is a combination of a container and a line in communication with the atmosphere, a peristaltic pump Bd is in series on the second connecting line DI and / or on the reaction-detection unit CA, and the first connecting line MT can be provided with no device, or with a peristaltic pump and / or a shut-off valve. Of course, the present case is not limited thereto, and if a peristaltic pump is in series on the first connecting line MT and / or on the metering unit UV, a peristaltic pump and / or a shut-off valve can be provided on the second connecting line DI.

[0034] Further, the metering unit UV is a combination of a fine channel or a local coarse channel, the inner diameter of the fine channel is 0.05mm to 5mm, the inner diameter of the coarse channel is greater than 5mm, preferably, the inner diameter of the fine channel is 0.1mm to 3mm, more preferably, the inner diameter of the fine channel is 0.5mm to 2mm, if the pipe with a hole diameter greater than 2mm and less than 5mm is used, the liquid passing through the pipe is easy to produce bubbles and residual liquid, which seriously affects the detection accuracy and precision, and when the pipe with a hole diameter less than 2mm (most preferably less than 1mm) is used, the inner diameter is less than the diameter of the residual liquid, forming a liquid section that naturally converges and further seals the fine tube, therefore, a smaller volume of liquid sample can be used for constant volume and liquid feeding, realizing high-precision detection and analysis, at the same time, reducing the amount of detection reagent and reducing the cost.

[0035] Of course, without affecting the purpose of the present application, a larger diameter pipe can also be used locally to improve the speed of liquid processing and analysis. For example, a coarse pipe is used for constant volume of a conventional volume of more than 2ml, pumping liquid or discharging waste liquid.

[0036] Preferably, the through pipe PL is a fine channel, but the through pipe PL can also be adjusted according to the actual situation, for example, the through pipe PL is a fine channel within a predetermined length range extending from the distribution port z, r1...rn, s, y to the container P, and the predetermined length range is at least 0.01mm.

[0037] By designing the through pipe PL as a fine channel within a predetermined length range extending from the distribution port z, r1...rn, s, y to the container P, the through pipe PL has better reliability and accuracy when the remaining part of the through pipe PL is a relatively coarse pipe, and the metering unit UV can accurately intercept a predetermined volume of liquid, especially avoiding the situation that at least part of the liquid flows into the through pipe PL or even backflows into the container P when the liquid flows through the distribution port z, r1...rn, s, y.

[0038] In addition, the system for quantitatively processing liquid also includes at least one external branch WZ1, WL2, and the common pipe GL is connected to the atmosphere through the external branch WZ1, WL2 provided with a peristaltic pump Bq, Bf, for pumping in and / or pumping out air, and / or discharging liquid.

[0039] In all application flow paths of the present application, the constant volume of the liquid when the liquid is fed can be achieved by positioning the liquid section head at a certain position near the liquid detector S, or by controlling the speed and time of each liquid feeding peristaltic pump.

[0040] Figure 1The flow path shown, at least one liquid detector S is provided at the metering unit UV to realize the metering of liquid, the liquid detector S can be various sensors suitable for judging whether there is liquid, to judge whether there is liquid or reach the position where the liquid detector S is located. By setting the liquid detector S, the liquid sample of the more flexible volume segment connected to the channel port near the liquid detector S can be intercepted flexibly. At the same time, due to the overflow of liquid, it can prevent waste.

[0041] Next, we will Figure 1 The high-precision liquid feeding of the reaction flow path shown is briefly described as follows: if water sample is needed, the peristaltic pump By first rotates counterclockwise, the water sample stops when passing through the liquid detector S, and then the peristaltic pump By is stationary. Then, the peristaltic pump Bd of the second connecting pipeline DI rotates counterclockwise, and the water sample between the connecting channel port m and the liquid detector S is injected into the reaction-detection unit CA, thereby completing the high-precision feeding of a micro-liquid volume (such as 0.005-2 milliliters). The water sample from the connecting channel port y to the connecting channel port m can be discharged through the outer branch WZ1, or as part of the constant volume metering into the reaction-detection unit CA, then the peristaltic pump Bd is stationary, the peristaltic pump Br1 or Brn rotates counterclockwise, the reagent stops when passing through the liquid detector S, then the peristaltic pump Bd of the second connecting pipeline DI rotates counterclockwise, and the reagent between the connecting channel port m and the liquid detector S is injected into the reaction-detection unit CA, and the reagent from the connecting channel port r1 or rn to the connecting channel port m can be discharged through the outer branch WZ1, or as part of the constant volume metering into the reaction-detection unit CA. Other liquids and reagents in the flow path can be metered and fed in this way. According to the operation, the determined volume of different liquids in different containers can be pushed into the reaction-detection unit CA in a predetermined order, and then the reaction and / or analysis in the reaction-detection unit CA can be carried out.

[0042] It should be noted that the rotation speed of each peristaltic pump described in the present application and the rotation speed difference of different peristaltic pumps can be adjusted according to the direction and path of the liquid to be conveyed, so that the liquid can move at a set speed and path during the liquid feeding, constant volume, dilution and liquid discharge process. For example, Figure 1 The peristaltic pump By and the peristaltic pump Bd in the connecting pipeline DI can rotate counterclockwise at the same time, but the speed of the peristaltic pump Bd is greater than that of the peristaltic pump By, so that the liquid can be directly sent into the reaction-detection unit CA, if the peristaltic pump By rotates counterclockwise without the peristaltic pump Bd, the liquid can be directly sent into the metering unit UV and the first connecting pipeline MT.

[0043] Figure 2 The flow path shown is in Figure 1Based on this, the liquid detector S is replaced with an overflow pipe WL to achieve liquid metering. The metering unit UV is equipped with at least one connection port w, which is connected to the overflow pipe WL. A peristaltic pump Bw is connected in series in the overflow pipe WL. The volume is determined by the liquid flowing out of the overflow pipe WL, and the flow direction of the liquid can be easily controlled by the peristaltic pump, which can significantly reduce the system cost.

[0044] To further explain, the metering unit UV is equipped with multiple connection channels w, which facilitates high-precision volume determination of different liquids, avoids cross-contamination between reagents and water samples, and allows for simultaneous liquid inlet. The number of overflow pipes WL can be set according to actual conditions.

[0045] Below, we will... Figure 2 The high-precision liquid injection in the reaction flow path shown is briefly described as follows: If a water sample is required, peristaltic pumps By and Bw first rotate counterclockwise. After the water sample flows out from the overflow pipe WL, peristaltic pumps By and Bw come to a stop. Then, peristaltic pump Bd of the second connecting pipe DI rotates counterclockwise, injecting the water sample between the connecting channel port m and peristaltic pump Bw into the reaction-detection unit CA, thereby completing a high-precision liquid injection of a micro-volume (e.g., 0.005-2 ml). Liquid flowing from connection port y to connection port m can be drained through external branch WZ1 or fed into reaction-detection unit CA as a volume-controlled portion. Then, peristaltic pump Bd stops, peristaltic pump Br1 or Brn rotates counterclockwise, and peristaltic pump Bw rotates counterclockwise. After reagent flows out from overflow line WL, peristaltic pumps By and Bw stop, and peristaltic pump Bd in the second connection line DI rotates counterclockwise, injecting reagent from connection port m to peristaltic pump Bw into reaction-detection unit CA. Liquid flowing from connection port r1 or rn to connection port m can be drained through external branch WZ1 or fed into reaction-detection unit CA as a volume-controlled portion. Other liquids and reagents within the flow path can also be metered and injected in this manner. Following this operation, predetermined volumes of different liquids from different containers can be pushed into reaction-detection unit CA in a predetermined sequence for reaction and / or analysis.

[0046] Figure 3 The flow path shown is in Figure 2 Based on this, a peristaltic pump Bd is added to the first connecting pipeline MT, converting the metering unit UV into a pipeline connected to atmospheric air. Its liquid inlet method is the same as... Figure 2 The implementation methods shown are similar and will not be described in detail here.

[0047] Figure 4 The metering unit UV shown is a container or pipe or a combination of both that is not open to the atmosphere; some flow passages may be shut-off valves. Figure 4At least one of the metering unit UV, the reaction-detection unit CA, the first connecting pipe MT, and the second connecting pipe DI is equipped with a peristaltic pump, and the second connecting pipe DI has no device or is equipped with a peristaltic pump and / or a shut-off valve.

[0048] Below, we will... Figure 4 The high-precision liquid inlet of the reaction flow path is briefly described as follows: If water sample is required, peristaltic pumps By and Bt first rotate counterclockwise, stopping when the water sample passes the liquid detector S. Then, peristaltic pumps By and Bt come to a standstill. Next, peristaltic pump Bt rotates clockwise, and peristaltic pump Bd in the second connecting pipe DI rotates counterclockwise, injecting the water sample between the connecting channel port m and the liquid detector S into the reaction-detection unit CA, thus completing a high-precision liquid inlet of a micro-volume (e.g., 0.005-2 ml). The liquid from connecting channel port y to connecting channel port m can be drained through the external branch WZ1 or sent to the reaction-detection unit CA as part of the volumetric metering. If cleaning solution / distilled water is required, peristaltic pump Bt rotates counterclockwise, the shut-off valve Fz opens, the cleaning solution / distilled water stops when it passes the liquid detector S, and then the shut-off valve Fz closes. Then, peristaltic pump Bt rotates clockwise, and peristaltic pump Bd of the second connecting pipe DI rotates counterclockwise, injecting the cleaning solution / distilled water between the connecting channel port m and the liquid detector S into the reaction-detection unit CA. The liquid between connecting channel ports z and m can be drained through the external branch WZ1, or sent into the reaction-detection unit CA as a volume-controlled portion. By operating in this way, a predetermined volume of different liquids from different containers can be pushed into the reaction-detection unit CA in a predetermined sequence, and then reacted and / or analyzed within the reaction-detection unit CA.

[0049] Figure 5 The metering unit UV shown is a container or pipe or a combination of both that is not open to the atmosphere. The metering unit UV is provided with at least one connection channel port w, and the connection channel port w is connected to an overflow pipe WL. A peristaltic pump Bw or a shut-off valve Fw is connected in series in the overflow pipe WL.

[0050] Below, we will... Figure 5The high-precision liquid feeding of the reaction flow path is briefly described as follows: if water sample needs to be fed, the peristaltic pump By is rotated counterclockwise, one of the stop valves Fw is opened, the water sample flows out from the corresponding overflow pipeline WL, then the peristaltic pump By is stopped, and the stop valve Fw is closed. Then, the stop valve Fd of the second connecting pipeline DI is opened, the water sample between the connecting channel port m and the stop valve Fw is injected into the reaction-detection unit CA, thereby completing the high-precision liquid feeding of a micro-liquid volume (e.g. 0.005-2 ml), the liquid between the connecting channel port y and the connecting channel port m can be discharged through the outer branch WZ1, or sent into the reaction-detection unit CA as part of the constant-volume measurement. Then, the stop valve Fd is closed, the peristaltic pump Br1 or Brn is rotated counterclockwise, one of the stop valves Fw is opened, the reagent flows out from the corresponding overflow pipeline WL, then the peristaltic pump Br1 or Brn is stopped, and the stop valve Fw is closed. Then, the stop valve Fd of the second connecting pipeline DI is opened, the reagent between the connecting channel port m and the stop valve Fw is injected into the reaction-detection unit CA, the liquid between the connecting channel port r1 or rn and the connecting channel port m can be discharged through the outer branch WZ1, or sent into the reaction-detection unit CA as part of the constant-volume measurement. The other liquids and reagents in the flow path can be measured and fed in this way. According to the operation, the determined volume of different liquids in different containers can be pushed into the reaction-detection unit CA in a predetermined order, and then the reaction and / or analysis in the reaction-detection unit CA can be performed.

[0051] Figures 5 to 7 As shown, the outer branch includes a first outer branch WZ1 and a second outer branch WZ2.

[0052] The first outer branch WZ1 is connected to the air / waste liquid bottle or the air / rinse water bottle from the common pipeline GL. The common pipeline GL is connected to the atmosphere through the outer branch WZ1 for pumping in and / or pumping out air, and the liquid after reaction can also be discharged.

[0053] Preferably, the first outer branch WZ1 can be connected to the portion of the common pipeline GL1 between the end portion away from the reaction-detection unit CA and the node connecting the reagent distilled water (i.e. between the q point and the z point in Figure 6 ; or the first outer branch WZ1 is connected to the portion of the common pipeline GL1 between the end portion away from the reaction-detection unit CA and the node connecting the reagent container (e.g. between the q point and the rn point after the cleaning liquid / distilled water bottle Pz and the reagent bottle Prn are interchanged on the basis of Figure 6 ). In a preferred embodiment, the first outer branch WZ1 is connected to the end portion of the common pipeline GL away from the reaction-detection unit CA, as shown in Figure 6 .

[0054] The second external branch WZ2 extends from at least one of the metering unit UV, the first connecting pipeline MT and the second connecting pipeline DI to the waste liquid bottle Pf. Preferably, the second external branch WZ2 is communicated in the second connecting pipeline DI, as shown in Figure 6 Alternatively, the second external branch WZ2 is communicated in the first connecting pipeline MT, as shown in Figure 7 With the second external branch WZ2 arranged separately, the waste liquid can be collected separately, thereby avoiding the cross contamination of the waste liquid to other water samples and reagents.

[0055] Figure 7 The flow path shown in Figure 5 is based on that the second external branch WZ2 is combined into the overflow pipeline WL, which can realize overflow by overflow and can also drain waste liquid, thereby reducing the use of devices. In addition, the metering unit UV can adopt a spiral pipeline, which is convenient for constant volume metering of large volume liquid. The liquid inlet mode is similar to the embodiment shown in Figure 1 , which will not be described here.

[0056] Figure 8 The flow path shown in Figure 5 is based on that the second connecting pipeline DI and the reaction-detection unit CA are combined as a whole, communicated with the first connecting pipeline MT and the metering unit UV through the connecting channel port d and the connecting channel port i, and form a parallel connection with the liquid level detector S. The peristaltic pump Bt can be selectively communicated with the liquid level detector S and the reaction-detection unit CA through the setting of the stop valve Ft and the stop valve Fi. The stop valve Ft and the stop valve Fi here can be replaced by a peristaltic pump or a three-way valve. Figure 8 The liquid inlet mode is similar to the embodiment shown in Figure 1 , which will not be described here.

[0057] Figure 9 The flow path shown in Figure 4 is based on a simple transformation that the second connecting pipeline DI and the reaction-detection unit CA are combined as a whole and connected in series in the first connecting pipeline (MT) through the connecting channel port d and the connecting channel port i. Figure 9 The liquid inlet mode is similar to the aforementioned embodiments, which will not be described here.

[0058] As shown in Figure 10The reaction-detection unit CA includes a reaction device 17 and a detection device 18, which can be integrated, and the reaction device 17 and the detection device 18 share the same vessel 19, and the light source 181 and the light detector 182 are arranged adjacent to the vessel 19. The reaction device 17 and the detection device 18 can be separated, and the light source 181 and the light detector 182 are arranged adjacent to the vessel 19 of the detection device 18. Of course, the present application is not limited thereto, and can be adjusted to other reasonable structures according to actual needs, for example, the metering unit UV and / or the reaction-detection unit CA are provided with a peristaltic pump and / or a stop valve which can be selectively turned on and off in series.

[0059] By the above technical solution, the predetermined micro-liquid volume of liquid can be intercepted with high precision by using the physical properties such as the fine tube characteristics and the content volume space properties, and the working characteristics and the rotation time properties of the peristaltic pump, so as to realize the technical solution of processing liquid with high accuracy which is suitable for automatic processing or analysis, and the system has high stability and fast liquid inlet efficiency.

[0060] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application (for example Figure 9 It should be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations. In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, it should also be considered as disclosed in the present application.

Claims

1. A system for dosing a liquid, characterized in that The system comprises: at least one common line (GL) and n through lines (PL) extending from the inside of the container to a distribution port on the common line (GL), n being a natural number greater than or equal to 2, at least one through line (PL) being provided with a peristaltic pump, the common line (GL) being able to conduct one of the through lines (PL) or none of them; a first connection line (MT) communicating with a connection channel mouth m on the common line (GL) and extending to a connection channel mouth t; a metering unit (UV) connected in series in the first connection line (MT) through a connection channel mouth v provided at the top thereof and a connection channel mouth u provided at the bottom thereof; a second connection line (DI) communicating with a connection channel mouth m on the common line (GL) and extending to a connection channel mouth i; and a reaction-detection unit (CA) connected in series in the second connection line (DI) through a connection channel mouth a provided at the top thereof and a connection channel mouth c provided at the bottom thereof; in the case where the metering unit (UV) is in communication with the atmosphere, a peristaltic pump (Bd) is connected in series on the second connection line (DI); in the case where the peristaltic pump (Bd) is at rest, the peristaltic pumps on the through lines (PL) are rotated counterclockwise to make the liquid in the corresponding containers reach the metering unit (UV); then the peristaltic pumps on the through lines (PL) are at rest, and the peristaltic pump (Bd) connected in series on the second connection line (DI) is rotated counterclockwise to make the liquid from the connection channel mouth m to the metering unit (UV) be sent into the reaction-detection unit (CA); in the case where the metering unit (UV) is not in communication with the atmosphere, a peristaltic pump (Bt) is connected in series on the first connection line (MT), and a peristaltic pump is provided on the second connection line (DI); in the case where the through lines (PL) are conducted and the second connection line (DI) is not conducted, the peristaltic pump (Bt) connected in series on the first connection line (MT) is rotated counterclockwise to make the liquid in the corresponding containers of the through lines (PL) reach the metering unit (UV); in the case where the through lines (PL) are not conducted and the second connection line (DI) is conducted, the peristaltic pump (Bt) connected in series on the first connection line (MT) is rotated clockwise to make the liquid from the connection channel mouth m to the metering unit (UV) be sent into the reaction-detection unit (CA), the metering unit (UV) is a fine channel, the inner diameter of the fine channel being 0.5 mm to 2 mm, the through lines (PL) are also fine channels.

2. The system for dosing a liquid according to claim 1, characterized in that, The system comprises at least one external branch (WZ1, WL2) through which the common line (GL) is communicated to the atmosphere by means of an external branch (WZ1, WL2) provided with a peristaltic pump (Bq, Bf) for pumping in and / or pumping out air and / or discharging liquid.

3. The system for dosing a liquid according to claim 2, characterized in that, The metering unit (UV) is provided with at least one liquid detector (S).

4. The system for dosing a liquid according to claim 2, characterized in that, The metering unit (UV) is provided with at least one connecting channel port w, which is connected with an overflow pipeline (WL), and a peristaltic pump (Bw) is connected in series in the overflow pipeline (WL).

5. The system for dosing a liquid of claim 1, wherein, The reaction-detection unit (CA) comprises a reaction device (17) and a detection device (18), which are integrated or separable.

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