Online internal standard mixed sampling system

Abstract

The invention discloses an online internal standard mixing sample introduction system which comprises a carrier liquid sample introduction unit, an internal standard sample introduction unit, a mixer and an oscillator, the mixer is provided with two inlet ends and an outlet end, the carrier liquid sample introduction unit is communicated with one inlet end of the mixer through a first sample introduction pipe, the internal standard sample introduction unit is communicated with the other inlet end of the mixer through a second sample introduction pipe, a shared pipeline is arranged at the outlet end of the mixer, and the oscillator is arranged on the shared pipeline; carrier liquid supplied by the carrier liquid sample introduction unit and internal standard supplied by the internal standard sample introduction unit are mixed in the mixer according to a set proportion and then discharged through the common pipeline, and meanwhile, the oscillator is used for oscillating and mixing flowing liquid. The oscillator is arranged in the mixer, so that the mixing time can be shortened while the mixing uniformity is improved, and the length of a flow path can be reduced.

Description

Technical Field

[0001] The invention relates to an online internal standard mixed sampling system. Background Art

[0002] In ICP-MS (Inductively Coupled Plasma Mass Spectrometer), ICP-OES (Inductively Coupled Plasma Emission Spectrometer), HPLC (Liquid Chromatography) and other analyses, the internal standard is a stable isotope or compound of known concentration, whose chemical properties are similar to the element to be measured, but the mass spectrum or spectral signal will not be interfered with. The functions of the internal standard mainly include the following: 1) Correcting matrix effects; 2) Correcting instrument drift; 3) Compensating for sample pretreatment errors; 4) Evaluating analytical accuracy. In general, adding internal standards to ICP-MS, ICP-OES, HPLC, etc. can improve the accuracy, precision and reliability of analytical results, and is a commonly used quality control method.

[0003] At present, the online internal standard addition system is widely used in instrumental analysis methods such as ICP-MS and ICP-OES because it is convenient and quick to use, and does not require the addition of internal standards to each sample in advance. When using ICP-OES for measurement, the generally acceptable accuracy (i.e., relative standard deviation, RSD) is 1-2%. However, some applications require higher accuracy, such as the main component analysis of precious metals, battery materials, etc. and the confirmation of matrix composition.

[0004] The online internal standard injection system of the prior art is as follows Figure 1 As shown, it includes a peristaltic pump 1, a three-way valve 2, a sample tube 3 and an internal standard tube 4, which pumps liquid through a peristaltic pump and utilizes the liquid to flow in the tube and diffuse so that the two liquids are gradually mixed, and the mixing ratio is adjusted by selecting pump tubes of different diameters, and the ratio of sample and internal standard mixed is fixed after the diameter is determined. This method requires a long flow path and mixing time, and usually fails to effectively achieve uniform mixing of the sample and the internal standard before the mixed liquid flows into the downstream atomizer.

[0005] The study found that the following factors will affect the accuracy of the measurement: flicker noise, shot noise (i.e., counting statistics), and the selection and uniformity of the internal standard. Among them, flicker noise is the noise in the analytical signal originating from the plasma, which is mainly caused by the sample introduction process; these noise sources include pulses from the peristaltic pump, the generation and transportation of aerosols entering the plasma through the spray chamber, and the processes occurring inside the plasma. Usually, the peristaltic pump is the main factor causing flicker noise. In addition, in analyses such as ICP-MS and ICP-OES, the flow rate fluctuation and mixing uniformity of the internal standard are also crucial to the accuracy of the results. For example, the traditional mixing method mentioned above often uses a peristaltic pump to pump in, which is affected by changes in flow rate, differences in sample and internal standard density, viscosity, etc., mixing time, flow path length, etc., resulting in uneven mixing of the internal standard and sample, large signal fluctuations, and affecting the parallelism and accuracy of the analysis results. Summary of the invention

[0006] In order to at least partially solve the deficiencies in the prior art, the main purpose of the present invention is to provide an online internal standard mixing injection system with good mixing uniformity.

[0007] In order to achieve the above main purpose, the present invention discloses an online internal standard mixed injection system, which comprises:

[0008] a mixer having two inlet ports and one outlet port;

[0009] A carrier liquid injection unit, which is connected to an inlet end of the mixer through a first injection tube;

[0010] an internal standard injection unit, which is connected to the other inlet end of the mixer through a second injection tube;

[0011] A common pipeline is provided on the outlet end of the oscillator and the mixer, and the oscillator is arranged on the common pipeline;

[0012] A common pipeline is provided on the outlet end of the mixer, and an oscillator is provided on the common pipeline. The carrier liquid supplied by the carrier liquid injection unit and the internal standard supplied by the internal standard injection unit are mixed in the mixer according to a set ratio and discharged through the common pipeline. At the same time, the oscillator is used to oscillate and mix the liquid flowing through; wherein the oscillator can oscillate and mix the liquid flowing through by means of mechanical vibration or ultrasound.

[0013] The carrier liquid injection unit includes an automatic sampler component, a carrier liquid injection component, a circulating liquid component and a valve module. The valve module has a first passage state and a second passage state. When the valve module is in the first passage state, the automatic sampler component is connected to the circulating liquid component to load samples into the inner pipeline of the valve module, and the carrier liquid injection component is connected to the first injection tube to clean the first injection tube; when the valve module is in the second passage state, the carrier liquid injection component is connected to the first injection tube via the inner pipeline of the valve module for injection.

[0014] According to a specific embodiment of the present invention, the carrier liquid injection assembly includes a carrier liquid container and a driving pump. The liquid in the carrier liquid container is connected to the injection port of the valve module through a carrier liquid injection tube and is injected under the control of the driving pump.

[0015] According to a specific embodiment of the present invention, the driving pump is an injection pump, and a carrier liquid injection three-way valve is provided on the carrier liquid injection tube. When the carrier liquid injection three-way valve is in a first position, the liquid in the carrier liquid container is drawn into the driving pump through the carrier liquid injection tube. When the carrier liquid injection three-way valve is in a second position, the liquid in the driving pump is pumped into the injection port of the valve module through the carrier liquid injection tube.

[0016] Furthermore, the syringe pump is an electrically driven syringe pump, and the amount of liquid entering the injection port of the valve module is controlled by setting the pumping rate of the syringe pump.

[0017] According to a specific embodiment of the present invention, the valve module is a six-way valve, which has an injection port, a sample outlet port, a cleaning liquid port, a circulating liquid port and two conversion ports, and an internal pipeline is formed between the two conversion ports; wherein the injection port, the sample outlet port, the cleaning liquid port and the circulating liquid port are respectively connected to the conversion port to provide a first passage state and a second passage state when the valve module is switched.

[0018] According to a specific embodiment of the present invention, the internal standard injection unit includes an internal standard container, a syringe pump, an internal standard injection tube and an internal standard injection three-way valve. When the internal standard injection three-way valve is in a first position, the liquid in the internal standard container is drawn into the syringe pump through the internal standard injection tube. When the carrier liquid injection three-way valve is in a second position, the liquid in the syringe pump is pumped into the mixer through the second injection tube.

[0019] According to a specific embodiment of the present invention, the automatic sampler assembly includes a cleaning liquid container, a sample tube and a robotic arm, one end of the sample tube is connected to the cleaning liquid container, the other end of the sample tube is connected to the cleaning liquid port of the valve module, and the robotic arm is connected to the sample tube to position the sample tube, automatically aspirate and discharge liquid.

[0020] According to a specific embodiment of the present invention, the oscillator includes an oscillator housing, an oscillation motor, a connecting clamp and a fixing clamp, the oscillator housing is installed by the fixing clamp, the oscillation motor is installed in the oscillator housing, and the connecting clamp is arranged on the oscillator housing and can be clamped to a common pipeline.

[0021] Furthermore, the connecting clamp is a U-shaped elastic clamp, and an anti-slip layer is provided on the inner surface of the U-shaped elastic clamp in contact with the common pipeline.

[0022] Furthermore, a connecting arm is provided between the fixing fixture and the vibrator housing, and the connecting arm can be bent and shaped to adjust the installation position of the vibrator housing.

[0023] The present invention has the following beneficial effects: provides an online internal standard mixing injection system with good mixing uniformity and adjustable mixing ratio, wherein an oscillator is arranged in the system, a carrier liquid supplied by a carrier liquid injection unit and an internal standard supplied by an internal standard injection unit are mixed in a mixer according to a set ratio and discharged through a common pipeline, and the oscillator is used to oscillate and mix the liquid flowing through, and the oscillator in the present invention can improve the mixing uniformity and shorten the mixing time, thereby helping to reduce the flow path length.

[0024] At the same time, the carrier liquid injection unit in the present invention is provided with a valve module, and the valve module has a first passage state and a second passage state. By controlling the valve module and the automatic sampler assembly, the carrier liquid injection assembly, and the circulating liquid assembly, the actions of aspirating, discharging, pumping, and cleaning the carrier liquid can be realized. The front-end carrier liquid injection part can be cleaned synchronously when the downstream spectrometer is reading, thereby saving equipment cleaning time and maintaining the cleanliness of the equipment.

[0025] In order to more clearly illustrate the purpose, technical solutions and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flow chart of the prior art;

[0027] Figure 2 It is a first flow chart of an embodiment of an online internal standard mixed injection system of the present invention;

[0028] Figure 3 is a second flow chart of an embodiment of an online internal standard mixed injection system of the present invention;

[0029] Figure 4 1 is a mixing flow chart before and after the vibrator in an embodiment of the online internal standard mixing injection system of the present invention;

[0030] Figure 5 This is a comparison chart of the signal fluctuations generated by the peristaltic pump and the syringe pump;

[0031] Figure 6 It is a schematic diagram of the recovery rate of online internal standard Ge, In, Re, and Rh in the embodiment;

[0032] Figure 7 It is a schematic diagram of the recovery rate of Ge, In, Re, and Rh using the traditional peristaltic pump online internal standard;

[0033] Figure 8 It is the structural diagram of the oscillator;

[0034] Fig. 9 This is a typical circuit diagram of an oscillator. DETAILED DESCRIPTION

[0035] In the following description, many specific details are explained in conjunction with the embodiments to facilitate a full understanding of the present invention. However, it should be understood that the following embodiments and detailed descriptions are only for illustrative purposes and do not limit the scope of protection of the present invention.

[0036] The online internal standard mixing injection system of the embodiment of the present invention can be used for online internal standard injection of samples of ICP-MS, ICP-OES, HPLC, etc., and can especially achieve constant flow rate, continuously adjustable mixing ratio of sample and internal standard, fast mixing speed and good mixing uniformity, thereby effectively improving the accuracy and stability of internal standards and detection results when ICP-MS and ICP-OES adopt online internal standard method.

[0037] The online internal standard mixed injection system of the embodiment is as follows Figure 2-3 As shown, it includes a carrier liquid injection unit 10, an internal standard injection unit 20, a mixer 30 and an oscillator 40. The carrier liquid injection unit 10 is used to supply a specific sample liquid, the internal standard injection unit 20 is used to supply an internal standard, the mixer 30 is used to mix the sample liquid and the internal standard, and the oscillator 40 is used to improve the effect after mixing; wherein, the mixed liquid after passing through the oscillator 40 is sent to the nebulizer A for subsequent measurement.

[0038] The mixer 30 has two inlet ends and one outlet end, the carrier liquid injection unit 10 is connected to one inlet end of the mixer 30 through a first injection tube 50, the internal standard injection unit 20 is connected to the other inlet end of the mixer 30 through a second injection tube 60, a common pipeline 70 is provided on the outlet end of the mixer 30, and an oscillator 40 is provided on the common pipeline 70. The carrier liquid supplied by the carrier liquid injection unit 10 and the internal standard supplied by the internal standard injection unit 20 are mixed in the mixer 30 according to a set ratio and discharged through the common pipeline 70, while the oscillator 40 is used to oscillate and mix the liquid flowing through; Figure 4 As shown, the period before the mixer 30 belongs to the infusion or liquid intake stage, the period between the mixer 30 and the oscillator 40 belongs to the blending stage, and the period after the oscillator 40 belongs to the mixing stage.

[0039] Please continue reading Figure 2-3 The carrier liquid injection unit 10 includes an automatic sampler component 11, a carrier liquid injection component 12, a circulating liquid component 13 and a valve module 14. The valve module 14 has a first passage state and a second passage state. When the valve module 14 is in the first passage state, the automatic sampler 11 is connected to the circulating liquid component 13 to load the inner pipeline of the valve module 14, and the carrier liquid injection component 12 is connected to the first injection tube 50 to clean the first injection tube; when the valve module 14 is in the second passage state, the carrier liquid injection component 12 is connected to the first injection tube 50 through the inner pipeline of the valve module 14 for injection.

[0040] Specifically, the valve module 14 is a six-way valve, which has an injection port, a sample outlet port, a cleaning liquid port, a circulating liquid port and two conversion ports, the two conversion ports are respectively a first conversion port and a second conversion port, and an internal pipeline is formed between the two, and the internal pipeline is also the sample loop of the valve module 14; wherein the injection port, the sample outlet port, the cleaning liquid port, and the circulating liquid port are respectively connected to the conversion port to provide a first passage state and a second passage state when the valve module 14 is switched.

[0041] Specifically, when the valve module 14 is in Figure 2 In the first passage state shown, the cleaning liquid in the automatic sampler 11 flows into the valve module 14 through the cleaning liquid port, and sequentially flows through the first conversion port, the inner pipeline, the second conversion port until it flows out from the circulating liquid port to the circulating liquid component 13, completing the sample loading operation of the inner pipeline, wherein the excess circulating liquid here can be directly treated as waste liquid. At this time, the sample liquid in the carrier liquid injection component 12 flows into the valve module 14 through the injection port, and flows out through the sample outlet port. Among them, the above two passage conditions can realize the flow of liquid according to its own designed power source.

[0042] When the valve module 14 is in Figure 3 In the second passage state shown, the circulating liquid flows into the valve module 14 through the circulating liquid port, and flows out to the automatic sampler assembly 11 through the cleaning liquid port. Similarly, the circulating liquid here can also be directly treated as waste liquid. In addition, the sample liquid in the carrier liquid injection assembly 12 flows into the valve module 14 through the injection port, and sequentially flows through the second conversion port, the internal pipeline, the first conversion port until it flows out from the sample outlet port to complete the injection. Similarly, the above two passage conditions can also realize the flow of liquid according to its own designed power source.

[0043] The valve module 14 realizes the loading, discharge, pumping and cleaning of the sample liquid through the switching and coordination control between the first passage state and the second passage state.

[0044] Further, the carrier liquid injection assembly 12 includes a carrier liquid container 121 and a driving pump 122. The liquid in the carrier liquid container 121 is connected to the injection port of the valve module 14 through the carrier liquid injection tube 123, and is injected under the control of the driving pump 122. The driving pump 122 is a syringe pump, and a carrier liquid injection three-way valve 124 is provided on the carrier liquid injection tube 123. When the carrier liquid injection three-way valve 124 is in a first position, the liquid in the carrier liquid container 121 is drawn into the driving pump 122 through the carrier liquid injection tube 123. When the carrier liquid injection three-way valve 124 is in a second position, the liquid in the driving pump 122 is pumped into the injection port of the valve module 14 through the carrier liquid injection tube 123. Preferably, the driving pump 122 is preferably an electrically driven syringe pump, and the amount of liquid entering the injection port of the valve module 14 is controlled by setting the pumping rate of the electrically driven syringe pump.

[0045] Optionally, the structure of the circulating liquid component 13 in the embodiment is completely the same as that of the carrier liquid injection component 12, which will not be expanded here. Among them, the automatic sampler component 11 includes a cleaning liquid container 111, a sample tube 112 and a mechanical arm 113, one end of the sample tube 112 is connected to the cleaning liquid container 111, and the other end of the sample tube 112 is connected to the cleaning liquid port of the valve module 14. There are multiple small tubes in the cleaning liquid container 111, and the mechanical arm 113 can move relative to the cleaning liquid container 111 to achieve automatic liquid suction and discharge in coordination with different small tubes on the sample tube 112.

[0046] Similarly, the internal standard injection unit 20 includes an internal standard container 21, an injection pump 22, an internal standard injection tube 23 and an internal standard injection three-way valve 24. When the internal standard injection three-way valve 24 is in a first position, the liquid in the internal standard container 21 is drawn into the injection pump 22 via the internal standard injection tube 23. When the carrier liquid injection three-way valve 124 is in a second position, the liquid in the injection pump 22 is pumped into the mixer 30 via the second injection tube 60.

[0047] In this embodiment, the injection method of the sample liquid and the internal standard adopts a syringe pump solution, which can effectively reduce the fluctuation of the flow rate. In conjunction with the valve module 14 and the components connected thereto, rapid loading and cleaning of the online internal standard can be achieved. At the same time, less sample residues can be obtained, and synchronous cleaning can be performed when the spectrometer is reading, thereby saving equipment cleaning time and maintaining the cleanliness of the equipment.

[0048] In the embodiment, by adjusting the pumping rate of each injection pump, the mixing ratio of the sample and the internal standard can be continuously adjusted, so that high-salt samples (such as seawater, sewage, soy sauce, etc.) can be directly injected without diluting the samples in advance, which is of great significance to the smooth progress of the experiment.

[0049] In the traditional online internal standard addition method: the peristaltic pump rotates and squeezes the pump tube to push the liquid forward. Assuming the peristaltic pump speed is 0.1rps, the pumping volume of the pump tube = the inner diameter cross-sectional area of ​​the pump tube × the peristaltic pump pumping distance = π × the inner radius of the pump tube 2 × peristaltic pump pumping distance. When the peristaltic pump speed is constant, the internal standard and sample peristaltic pump pumping distances are the same, and the ratio of the internal standard to sample pumping volume is equal to the ratio of the square of the pump tube radius. Assumption: the inner diameter of the sample tube is 1.02mm, the inner diameter of the internal standard tube is 0.19mm, the sample solution pumping volume: internal standard solution pumping volume = π × (1.02 / 2) 2 ×Peristaltic pump pumping distance: π×(0.19 / 2) 2 × peristaltic pump pumping distance ≈ 28.8: 1. In contrast, syringe pump pumping volume = syringe tube cross-sectional area × syringe pump pumping rate = π × syringe radius 2 × Injection pump pumping rate. When the syringe is fixed, the injection pump pumping volume ∝ injection pump pumping rate, and the injection pump pumping rate can be adjusted continuously. Figure 5 From the comparison of signal fluctuations generated by the peristaltic pump and the syringe pump, it can be seen that the syringe pump has a smoother flow rate and can greatly eliminate the influence of flicker noise on subsequent measurement accuracy.

[0050] As a further comparison, Figure 6-7 As shown, in the ICP-MS analysis, the recovery rates of Ge, In, Re, and Rh using the traditional online internal standard fluctuate within the range of 80-120%, and the recovery rates are dispersed and wide, while the recovery rates of Ge, In, Re, and Rh using the online internal standard mixing system of this embodiment fluctuate within the range of 90-110%, and the dispersion range of the recovery rates is narrowed, and the fluctuation amplitude is reduced, which effectively reduces the detection data fluctuations caused by the flow rate changes of the injection system and the uneven mixing of the internal standard and the sample solution, thereby improving the accuracy and parallelism of the internal standard and sample analysis results.

[0051] An exemplary structure of the oscillator 40 is as follows Figure 8 As shown, it includes an oscillator housing 41, an oscillation motor 42, a connecting clamp 43 and a fixing clamp 44. The oscillator housing 41 is installed to a fixed position such as a workbench frame through the fixing clamp 44. The oscillation motor 42 is installed in the oscillator housing 41. The connecting clamp 43 is arranged on the oscillator housing 41 and can be clamped to the common pipeline 70.

[0052] The oscillator housing 41 is, for example, a hollow cylinder, and the oscillating motor 42 is vertically mounted inside the oscillator housing 41; the oscillating motor 42 is, for example, an adjustable vibration motor, and when in use, the oscillating motor 42 can be controlled to obtain the corresponding swing amplitude and frequency to achieve different mixing effects. A typical circuit diagram of an exemplary oscillating motor 42 is shown in FIG. Fig. 9To reduce the vibration effect of the oscillating motor 42 , a shock absorbing sheet 45 may be provided at the bottom of the oscillating motor 42 in the oscillator housing 41 .

[0053] The connection clamp 43 is specifically a U-shaped elastic clamp, which can adapt to the common pipeline 70 of more pipe diameters and has the advantage of easy installation. Among them, an anti-slip layer 431 is provided on the inner surface of the U-shaped elastic clamp in contact with the common pipeline 70 to ensure that the common pipeline 70 and the connection clamp 43 will not slide relative to each other after installation, thereby ensuring the stability of the connection. At the same time, a mark is provided on the surface of the connection clamp 43, such as an arrow with a directional indication, which is used to indicate the correct installation position and direction of the common pipeline 70 to avoid problems caused by installation errors.

[0054] The fixing fixture 44 adopts an external hanging design of a press-type clamping base, which is easy to operate, making the process of installing and removing the online internal standard mixing device more convenient and quick. Among them, a connecting arm 46 is further provided between the fixing fixture 44 and the vibrator housing, and the connecting arm 46 can be bent and shaped to adjust the installation position of the vibrator housing. This bendable and height-adjustable installation method is very convenient to use, and can also reduce the influence of the oscillation motor 42 on the fixing fixture 44 and its installation structure.

[0055] In the embodiment, the main components of the oscillator 40 are preferably made of PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxy resin), which has the advantages of corrosion resistance, wear resistance, aging resistance, light weight and high strength, ensuring that the fixture can work stably and reliably during ICP-OES and ICP-MS analysis.

[0056] Although the present invention has been described above through embodiments, the above embodiments are only used to exemplarily describe the feasible implementation schemes of the present invention, and are not used to limit the protection scope of the present invention. Any equivalent substitutions or changes made by those skilled in the art in accordance with the present invention should also be covered by the protection scope defined by the claims of the present invention.

Claims

1. An online internal standard mixed injection system, characterized in that include: a mixer having two inlet ports and one outlet port; A carrier liquid injection unit, which is connected to an inlet end of the mixer through a first injection tube; an internal standard injection unit, which is connected to the other inlet end of the mixer through a second injection tube; An oscillator, a common pipeline is provided on the outlet end of the mixer, and the oscillator is arranged on the common pipeline; The carrier liquid supplied by the carrier liquid injection unit and the internal standard supplied by the internal standard injection unit are mixed in the mixer according to a set ratio and discharged through the common pipeline. At the same time, the oscillator is used to oscillate and mix the liquid passing through. The carrier liquid injection unit includes an automatic sample injector component, a carrier liquid injection component, a circulating liquid component and a valve module, wherein the valve module has a first passage state and a second passage state. When the valve module is in the first passage state, the automatic sample injector component is connected to the circulating liquid component to load samples into the inner pipeline of the valve module, and the carrier liquid injection component is connected to the first injection tube to clean the first injection tube; when the valve module is in the second passage state, the carrier liquid injection component is connected to the first injection tube via the inner pipeline of the valve module for injection.

2. The online internal standard mixed injection system according to claim 1, characterized in that: The carrier liquid injection assembly comprises a carrier liquid container and a driving pump. The liquid in the carrier liquid container is connected to the injection port of the valve module through a carrier liquid injection tube, and is injected under the control of the driving pump.

3. The online internal standard mixed sample injection system according to claim 2, characterized in that: The driving pump is an injection pump, and a carrier liquid injection three-way valve is provided on the carrier liquid injection tube. When the carrier liquid injection three-way valve is in a first position, the liquid in the carrier liquid container is drawn into the driving pump through the carrier liquid injection tube. When the carrier liquid injection three-way valve is in a second position, the liquid in the driving pump is pumped into the injection port of the valve module through the carrier liquid injection tube.

4. The online internal standard mixed sample injection system according to claim 3, characterized in that: The syringe pump is an electrically driven syringe pump, and the amount of liquid entering the injection port of the valve module is controlled by setting the pumping rate of the syringe pump.

5. The online internal standard mixed injection system according to claim 1, characterized in that: The valve module is a six-way valve, which has an injection port, an outlet port, a cleaning liquid port, a circulating liquid port and two conversion ports, and an internal pipeline is formed between the two conversion ports; wherein the injection port, the outlet port, the cleaning liquid port and the circulating liquid port are respectively connected to the conversion ports to provide a first passage state and a second passage state when the valve module is switched.

6. The online internal standard mixed injection system according to claim 1, characterized in that: The internal standard injection unit comprises an internal standard container, a syringe pump, an internal standard injection tube and an internal standard injection three-way valve. When the internal standard injection three-way valve is in a first position, the liquid in the internal standard container is drawn into the syringe pump through the internal standard injection tube. When the carrier liquid injection three-way valve is in a second position, the liquid in the syringe pump is pumped into the mixer through the second injection tube.

7. The online internal standard mixed injection system according to claim 1, characterized in that: The automatic sampler assembly includes a cleaning liquid container, a sample tube and a robotic arm, one end of the sample tube is connected to the cleaning liquid container, the other end of the sample tube is connected to the cleaning liquid port of the valve module, and the robotic arm is connected to the sample tube to position, automatically aspirate and discharge the sample tube.

8. The online internal standard mixed injection system according to claim 1, characterized in that: The oscillator comprises an oscillator housing, an oscillation motor, a connection fixture and a fixing fixture, the oscillator housing is installed by the fixing fixture, the oscillation motor is installed in the oscillator housing, and the connection fixture is arranged on the oscillator housing and can be clamped to the common pipeline.

9. The online internal standard mixed injection system according to claim 8, characterized in that: The connecting clamp is a U-shaped elastic clamp, and an anti-slip layer is provided on the inner surface of the U-shaped elastic clamp in contact with the common pipeline.

10. The online internal standard mixed injection system according to claim 8, characterized in that: A connecting arm is provided between the fixing fixture and the vibrator housing, and the connecting arm can be bent and shaped to adjust the installation position of the vibrator housing.

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