Online internal standard mixing sampling device

Abstract

The utility model discloses an on-line internal standard mixing sample introduction device which comprises a carrier liquid sample introduction unit, an internal standard sample introduction unit, a mixer and an atomizer, 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 so as to supply carrier liquid, and the atomizer is communicated with the other inlet end of the mixer through a second sample introduction pipe. The internal standard sample injection unit is communicated with the other inlet end of the mixer through a second sample injection pipe so as to supply internal standards, a common pipeline is arranged at the outlet end of the mixer, and the oscillator is arranged on the common pipeline through a connecting clamp; the atomizer is communicated with an outlet of the oscillator, and mixed liquid oscillated and mixed by the oscillator is fed into the atomizer. According to the utility model, the oscillator is arranged, 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 utility model relates to a kind of online internal standard mixed sample introduction devices. BACKGROUND

[0002] In ICP-MS (inductively coupled plasma mass spectrometer), ICP-OES (inductively coupled plasma optical emission spectrometer), HPLC (liquid chromatograph) and other analysis, the internal standard is a stable isotope or compound with known concentration, its chemical properties are similar to the element to be measured, but the mass spectrum or spectrum signal will not be disturbed. The main effects of internal standard include the following points: 1) correct matrix effect; 2) correct instrument drift; 3) compensate sample pretreatment error; 4) evaluate analysis accuracy. In general, ICP-MS, ICP-OES, HPLC and other internal standard addition can improve the accuracy, precision and reliability of analysis results, and it is a common quality control method.

[0003] At present, online internal standard addition system is widely used in ICP-MS, ICP-OES and other instrument analysis methods because of its convenient and fast use, without adding internal standard in each sample in advance. When using ICP-OES for measurement, the generally acceptable precision (i.e. relative standard deviation, RSD) is 1-2%. However, some applications require higher precision, such as analysis of main components of precious metals, battery materials and confirmation of matrix composition.

[0004] The prior art online internal standard sample introduction system is shown in Figure 1 It includes peristaltic pump 1, three-way valve 2, sample tube 3 and internal standard tube 4, which pumps liquid by peristaltic pump and uses the flow and diffusion effect of liquid in the tube to make the two liquids gradually mix. The mixing ratio is adjusted by selecting different pump tube diameters, and the mixing ratio of sample and internal standard is fixed after the tube diameter is determined. This method requires a long flow path and mixing time, and usually the sample and internal standard cannot be effectively mixed uniformly before the mixed liquid flows into the downstream atomizer.

[0005] It is found that the following factors affect the accuracy of the measurement: flicker noise, shot noise (i.e. counting statistics), and the choice and uniformity of the internal standard. Flicker noise is the noise in the analytical signal that originates from the plasma, and is caused mainly by the sample introduction process; these noise sources include pulses from the peristaltic pump, the generation and transport of aerosol into the plasma through the spray chamber, and processes occurring within the plasma. Typically, the peristaltic pump is the main contributor to flicker noise. In addition, in analyses such as ICP-MS and ICP-OES, the flow rate fluctuations and mixing uniformity of the internal standard are also critical to the accuracy of the results. The conventional mixing methods as described above often use a peristaltic pump to pump in, which is affected by the flow rate changes, the differences in density and viscosity of the sample and internal standard, the mixing time, the length of the flow path, etc., resulting in uneven mixing of the internal standard and the sample, large signal fluctuations, and affecting the parallelism and accuracy of the analysis results. Content of the utility model

[0006] In order to at least partially solve the deficiencies existing in the prior art, the main purpose of the present utility model is to provide an online internal standard mixing and sampling device with good mixing uniformity.

[0007] In order to achieve the above main purpose, the utility model discloses an online internal standard mixing and sampling device, which comprises a carrier liquid sampling unit, an internal standard sampling unit, a mixer, an oscillator and an atomizer, the mixer has two inlet ends and an outlet end, the carrier liquid sampling unit is connected with one inlet end of the mixer through a first sampling pipe to supply carrier liquid, the internal standard sampling unit is connected with the other inlet end of the mixer through a second sampling pipe to supply internal standard, a common pipeline is arranged on the outlet end of the mixer, and the oscillator is arranged on the common pipeline through a connecting clamp; the atomizer is connected with the outlet of the oscillator, and the mixed liquid oscillated by the oscillator is sent into the atomizer.

[0008] According to a specific embodiment of the utility model, the oscillator comprises an oscillator shell and an oscillation motor, the oscillation motor is installed in the oscillator shell, and the connecting clamp is arranged on the oscillator shell and can be clamped to the common pipeline.

[0009] According to a specific embodiment of the utility model, the connecting clamp is a U-shaped elastic clamp.

[0010] According to a specific embodiment of the utility model, the inner surface of the connecting clamp in contact with the common pipeline is provided with an anti-skid layer.

[0011] According to a specific embodiment of the utility model, the oscillator further comprises a fixing clamp, and the oscillator shell is installed through the fixing clamp; wherein a connecting arm is arranged between the fixing clamp and the oscillator shell, and the connecting arm can be bent and shaped to adjust the installation position of the oscillator shell.

[0012] According to one of the specific embodiments of the utility model, the carrier liquid sampling unit includes an automatic sampler assembly, a carrier liquid sampling assembly, a circulating liquid assembly 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 assembly is communicated with the circulating liquid assembly to sample the inner pipeline of the valve module, and the carrier liquid sampling assembly is communicated with the first sampling tube to clean the first sampling tube, when the valve module is in the second passage state, the carrier liquid sampling assembly is communicated with the first sampling tube through the inner pipeline of the valve module to sample.

[0013] According to one of the specific embodiments of the utility model, the carrier liquid sampling assembly includes a carrier liquid container and a drive pump, the liquid in the carrier liquid container is communicated with the sampling port of the valve module through the carrier liquid sampling tube, and is sampled under the control of the drive pump.

[0014] According to one of the specific embodiments of the utility model, the drive pump is a syringe pump, a carrier liquid sampling three-way valve is arranged on the carrier liquid sampling tube, when the carrier liquid sampling three-way valve is in the first position, the liquid in the carrier liquid container is pumped into the drive pump through the carrier liquid sampling tube, when the carrier liquid sampling three-way valve is in the second position, the liquid in the drive pump is pumped into the sampling port of the valve module through the carrier liquid sampling tube.

[0015] According to one of the specific embodiments of the utility model, the internal standard sampling unit includes an internal standard container, a syringe pump, an internal standard sampling tube and an internal standard sampling three-way valve, when the internal standard sampling three-way valve is in the first position, the liquid in the internal standard container is pumped into the syringe pump through the internal standard sampling tube, when the carrier liquid sampling three-way valve is in the second position, the liquid in the syringe pump is pumped into the mixer through the second sampling tube.

[0016] According to one of the specific embodiments of the utility model, the valve module is a six-way valve, which has a sampling port, a sample outlet port, a cleaning liquid port, a circulating liquid port and two conversion ports, and an inner pipeline is formed between the two conversion ports; wherein the sampling port, the sample outlet port, the cleaning liquid port and the circulating liquid port are communicated with the conversion ports to provide the first passage state and the second passage state when the valve module is switched.

[0017] The utility model has the advantages that an online internal standard mixing sampling device with good mixing uniformity and adjustable mixing ratio is provided, an oscillator is arranged in the device, the carrier liquid supplied by the carrier liquid sampling unit and the internal standard supplied by the internal standard sampling unit can be mixed in the mixer according to the set ratio, and the oscillator is used for oscillating and mixing the liquid flowing therethrough; the arrangement of the oscillator in the utility model can improve the mixing uniformity and shorten the mixing time, thereby helping to reduce the flow path length.

[0018] Meanwhile, the liquid-carrying sample input unit is provided with a valve module, the valve module has a first passage state and a second passage state, liquid suction, liquid discharge, pumping, cleaning and other actions of the liquid-carrying sample are realized by controlling the valve module, the automatic sample input component, the liquid-carrying sample input component and the circulating liquid component, synchronous cleaning of the front end liquid-carrying sample input part during reading of the downstream spectrometer can be realized, and the cleaning time of the equipment is saved and the cleanliness of the equipment is maintained.

[0019] In order to more clearly illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a flow chart of the prior art;

[0021] Figure 2 is a first flow chart of the online internal standard mixed sample input device embodiment of the present application;

[0022] Figure 3 is a second flow chart of the online internal standard mixed sample input device embodiment of the present application;

[0023] Figure 4 is a mixed flow chart before and after the oscillator in the online internal standard mixed sample input device embodiment of the present application;

[0024] Figure 5 is a signal fluctuation comparison chart generated by the peristaltic pump and the injection pump;

[0025] Figure 6 is a schematic diagram of the recovery rate of online internal standard Ge, In, Re and Rh in the embodiment;

[0026] Figure 7 is a schematic diagram of the recovery rate of online internal standard Ge, In, Re and Rh of the traditional peristaltic pump;

[0027] Figure 8 is a structure diagram of the oscillator;

[0028] Figure 9 is a typical circuit diagram of the oscillator. DETAILED DESCRIPTION

[0029] In the following description, many specific details are set forth in order to fully understand the present application, but it should be understood that the following embodiments and detailed description are only for illustrative purposes and do not limit the protection scope of the present application.

[0030] The online internal standard mixing sample injection device can be used for sample online internal standard injection of ICP-MS, ICP-OES, HPLC and the like, and in particular, can realize constant flow rate, continuous adjustable mixing ratio of the sample and the internal standard, fast mixing speed and good mixing uniformity, thereby effectively improving the accuracy and stability of the internal standard and detection results when ICP-MS and ICP-OES and the like adopt the online internal standard method.

[0031] The online internal standard mixing sample injection device of the embodiment is shown in Figures 2-3 The online internal standard mixing sample injection device of the embodiment is shown in

[0032] The mixing device 30 has two inlet ends and one outlet end, the carrier liquid injection unit 10 is connected with one inlet end of the mixing device 30 through the first injection pipe 50, the internal standard injection unit 20 is connected with the other inlet end of the mixing device 30 through the second injection pipe 60, the outlet end of the mixing device 30 is provided with a common pipeline 70, one inlet of the atomizer A is connected with the common pipeline 70, the oscillator 40 is arranged 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 mixing device 30 according to the set ratio, and are discharged through the common pipeline 70 at the same time, the oscillator 40 is used for oscillating and mixing the liquid flowing through, and finally the liquid is sent into the atomizer A. Figure 4 As shown in Figure 4 , the stage before the mixing device 30 belongs to a liquid conveying or liquid injection stage, the stage between the mixing device 30 and the oscillator 40 belongs to a mixing stage, and the stage after the oscillator 40 belongs to a mixing stage.

[0033] Please continue to refer to Figures 2-3 The carrier liquid injection unit 10 includes an automatic injector assembly 11, a carrier liquid injection assembly 12, a circulating liquid assembly 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 injector 11 is connected with the circulating liquid assembly 13 to sample the inner pipeline of the valve module 14, and the carrier liquid injection assembly 12 is connected with the first injection pipe 50 to clean the first injection pipe; when the valve module 14 is in the second passage state, the carrier liquid injection assembly 12 is connected with the first injection pipe 50 through the inner pipeline of the valve module 14 to inject.

[0034] Specifically, valve module 14 is a six-way valve, which has an inlet port, an outlet port, a cleaning fluid port, a circulating fluid port, and two switching ports, namely the first switching port and the second switching port, which form an internal pipeline, which is also the sample loop of valve module 14; wherein, the inlet port, the outlet port, the cleaning fluid port, and the circulating fluid port are respectively connected to the switching ports to provide a first passage state and a second passage state when valve module 14 switches.

[0035] To elaborate, in valve module 14 at Figure 2 In the first path state shown, the cleaning fluid in the autosampler 11 flows into the valve module 14 through the cleaning fluid port, and then sequentially flows through the first conversion port, the inner tubing, the second conversion port, and finally out through the circulating fluid port to the circulating fluid assembly 13, completing the sample loading operation in the inner tubing. Excess circulating fluid can be treated as waste and discharged directly. At this time, the sample liquid in the liquid-carrying injection assembly 12 flows into the valve module 14 through the injection port and flows out through the sample outlet port. The flow of liquid in both paths can be achieved by their own designed power source.

[0036] When valve module 14 is in Figure 3 In the second pathway state shown, the circulating fluid flows into the valve module 14 through the circulating fluid port and flows out to the autosampler assembly 11 through the cleaning fluid port. Similarly, the circulating fluid here can also be treated as waste fluid and discharged directly. Additionally, the sample liquid in the liquid-carrying injection assembly 12 flows into the valve module 14 through the injection port, and sequentially flows through the second conversion port, the inner tubing, the first conversion port, and finally out through the sample outlet port, completing the injection. Likewise, the flow of liquid in both pathway states can be achieved using their own designed power sources.

[0037] The valve module 14 controls the loading, drainage, pumping, and cleaning of the sample liquid by switching between the first and second path states.

[0038] Furthermore, the liquid-carrying sample introduction assembly 12 includes a liquid-carrying container 121 and a drive pump 122. The liquid in the liquid-carrying container 121 is connected to the sample introduction port of the valve module 14 via a liquid-carrying sample introduction tube 123, and is introduced under the control of the drive pump 122. The drive pump 122 is an injection pump, and a liquid-carrying sample introduction three-way valve 124 is provided on the liquid-carrying sample introduction tube 123. When the liquid-carrying sample introduction three-way valve 124 is in the first position, the liquid in the liquid-carrying container 121 is drawn into the drive pump 122 via the liquid-carrying sample introduction tube 123. When the liquid-carrying sample introduction three-way valve 124 is in the second position, the liquid in the drive pump 122 is pumped into the sample introduction port of the valve module 14 via the liquid-carrying sample introduction tube 123. Preferably, the drive pump 122 is an electrically driven injection pump, and the amount of liquid entering the sample introduction port of the valve module 14 is controlled by setting the pumping rate of the electrically driven injection pump.

[0039] Optionally, the circulating liquid assembly 13 in the embodiment is completely identical in structure with the carrier liquid sampling assembly 12, which will not be described here. The automatic sampler assembly 11 includes a cleaning liquid container 111, a sample tube 112 and a mechanical arm 113. One end of the sample tube 112 is in communication with the cleaning liquid container 111, and the other end of the sample tube 112 is in communication with a cleaning liquid port of the valve module 14. The cleaning liquid container 111 has a plurality of small tubes. The mechanical arm 113 is movable relative to the cleaning liquid container 111 to realize automatic liquid suction and discharge of the sample tube 112 in cooperation with the corresponding small tubes.

[0040] Similarly, the internal standard sampling unit 20 includes an internal standard container 21, a syringe pump 22, an internal standard sampling tube 23 and an internal standard sampling three-way valve 24. When the internal standard sampling three-way valve 24 is in the first position, the liquid in the internal standard container 21 is drawn into the syringe pump 22 through the internal standard sampling tube 23. When the carrier liquid sampling three-way valve 124 is in the second position, the liquid in the syringe pump 22 is pumped into the mixer 30 through the second sampling tube 60.

[0041] In the embodiment, the sample liquid and internal standard sampling mode adopts a syringe pump scheme, which can effectively reduce the fluctuation of the flow rate. In cooperation with the valve module 14 and the components connected thereto, the online internal standard can be quickly loaded and cleaned, and the sample residue is less. The spectral instrument reading can also be synchronized with the cleaning to save the equipment cleaning time and maintain the cleanliness of the equipment.

[0042] In the embodiment, by adjusting the pumping rate of each syringe pump, the continuous adjustable mixing ratio of the sample and the internal standard can also be realized. In this way, the direct sampling of high-salinity samples (such as seawater, sewage and soy sauce) can be realized without the need for pre-dilution treatment of the sample, which is of great significance to the smooth progress of the experiment.

[0043] Under the traditional online internal standard addition mode: through the rotation and extrusion of the peristaltic pump, the liquid is pushed forward. Assuming that the rotation speed of the peristaltic pump is 0.1 rps, the pump tube pumping volume = π × pump tube inner radius 2 × peristaltic pump pumping distance. When the rotation speed of the peristaltic pump is constant, the internal standard and the sample peristaltic pump pumping distance are consistent, and the ratio of the internal standard and the sample pumping volume is equal to the ratio of the square of the pump tube radius. Assuming that the sample tube inner diameter is 1.02 mm and the internal standard tube inner diameter is 0.19 mm, the sample solution pumping amount: internal standard solution pumping amount = π × (1.02 / 2) 2 × peristaltic pump pumping distance: π × (0.19 / 2) 2 × peristaltic pump pumping distance ≈ 28.8:1. As a comparison, the syringe pump pumping volume = π × syringe radius 2 × syringe pump pumping rate. When the syringe is fixed, the syringe pump pumping volume ∝ syringe pump pumping rate, and the syringe pump pumping rate is continuously adjustable. For example,Figure 5 The signal fluctuation comparison chart of the peristaltic pump and the injection pump shows that the injection pump flow rate is smoother, and can greatly eliminate the influence of flicker noise on the subsequent measurement accuracy.

[0044] As a further comparison, as shown in Figures 6-7 The recovery rate of the traditional online internal standard Ge, In, Re, Rh in ICP-MS analysis fluctuates in the range of 80-120%, the recovery rate is dispersed and wide, while the recovery rate of the online internal standard mixed system Ge, In, Re, Rh in this embodiment fluctuates in the range of 90-110%, the recovery rate dispersion range is narrowed, the fluctuation amplitude is reduced, effectively reducing the detection data fluctuation caused by the flow rate change of the sampling system and the uneven mixing of the internal standard and the sample solution, thereby improving the accuracy and parallelism of the internal standard and the sample analysis results.

[0045] An exemplary structure of the oscillator 40 is shown in Figure 8 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 by the fixing clamp 44, the oscillation motor 42 is installed in the oscillator housing 41, and the connecting clamp 43 is arranged on the oscillator housing 41 and can be clamped to the common pipeline 70.

[0046] The oscillator housing 41 is, for example, a hollow cylindrical shape, and the oscillation motor 42 is vertically installed to the inside of the oscillator housing 41; the oscillation motor 42 is, for example, a controllable vibration motor, and when in use, the corresponding swing amplitude and frequency can be obtained by controlling the oscillation motor 42 to achieve different mixing effects, and a typical circuit diagram of an exemplary oscillation motor 42 is shown in Figure 9 To reduce the vibration influence of the oscillation motor 42, a damping sheet 45 can also be arranged at the bottom of the oscillation motor 42 in the oscillator housing 41.

[0047] The connecting clamp 43 is specifically a U-shaped elastic clamp, which can adapt to common pipelines 70 of more pipe diameters, and also has the advantage of convenient installation. The inner surface of the U-shaped elastic clamp in contact with the common pipeline 70 is provided with an anti-skid layer 431 to ensure that the common pipeline 70 and the connecting clamp 43 will not slide relative to each other after installation, and the stability of the connection is ensured. At the same time, a mark is arranged on the surface of the connecting clamp 43, which is, for example, an arrow with directional indication, and the mark is used to indicate the correct installation position and direction of the common pipeline 70, so as to avoid problems caused by installation errors.

[0048] The fixed clamp 44 adopts an external hanging type design of pressing the clamp base, has strong operability, and makes the installation and disassembly of the online standard mixing device more convenient and fast. Further, a connecting arm 46 is arranged between the fixed clamp 44 and the oscillator shell, the connecting arm 46 can be bent and shaped to adjust the installation position of the oscillator shell, the installation mode of the bendable and height-adjustable is very convenient to use, and meanwhile, the influence of the oscillation motor 42 on the fixed clamp 44 and the installation structure thereof can be reduced.

[0049] In the embodiment, the main components in the oscillator 40 are preferably made of PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxy resin) materials, have the advantages of corrosion resistance, wear resistance, aging resistance, light weight, high strength and the like, and ensure that the clamp can work stably and reliably in the ICP-OES and ICP-MS analysis process.

[0050] Although the utility model is described above through the embodiment, the above embodiment is only used for exemplarily describing the implementable scheme of the utility model, and is not used for limiting the protection scope of the utility model, and any equivalent replacement or change made by the person skilled in the art according to the utility model should be covered by the protection scope defined by the claims of the utility model.

Claims

1. An online internal standard mixing injection device, characterized by The device comprises a carrier liquid injection unit, an internal standard injection unit, a mixer, an oscillator and an atomizer, the mixer has two inlet ends and one outlet end, the carrier liquid injection unit is connected to one inlet end of the mixer through a first injection tube to supply carrier liquid, the internal standard injection unit is connected to the other inlet end of the mixer through a second injection tube to supply internal standard, the outlet end of the mixer is provided with a common pipeline, and the oscillator is arranged on the common pipeline through a connecting clamp.

2. The online internal standard mixed injection device of claim 1, wherein: The oscillator comprises an oscillator shell and an oscillation motor, the oscillation motor is installed in the oscillator shell, and the connecting clamp is arranged on the oscillator shell and can be clamped to the common pipeline.

3. The online internal standard mixed injection device of claim 2, wherein: The connecting clamp is a U-shaped elastic clamp.

4. The online internal standard mixed injection device of claim 2, wherein: An inner surface of the connecting clamp in contact with the common pipeline is provided with an anti-skid layer.

5. The online internal standard mixed injection device of claim 2, wherein: The oscillator further comprises a fixing clamp, and the oscillator shell is installed through the fixing clamp; wherein a connecting arm is arranged between the fixing clamp and the oscillator shell, and the connecting arm can be bent and shaped to adjust the installation position of the oscillator shell.

6. The online internal standard mixed injection device of claim 1, wherein: The carrier liquid injection unit comprises an automatic injector assembly, a carrier liquid injection assembly, a circulating liquid assembly 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 injector assembly is connected to the circulating liquid assembly to inject the inner pipeline of the valve module, and the carrier liquid injection assembly 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 assembly is connected to the first injection tube through the inner pipeline of the valve module to inject.

7. The online internal standard mixed injection device of claim 6, wherein: The carrier liquid injection assembly comprises a carrier liquid container and a drive 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 drive pump.

8. The online internal standard mixed injection device of claim 7, wherein: The drive pump is a syringe pump, a carrier liquid injection three-way valve is arranged 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 drive pump through the carrier liquid injection tube, and when the carrier liquid injection three-way valve is in a second position, the liquid in the drive pump is pumped into the injection port of the valve module through the carrier liquid injection tube.

9. The online internal standard mixed injection device of claim 8, wherein: 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, and 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.

10. The online internal standard mixed injection device of claim 6, wherein: The valve module is a six-way valve, which has a sample inlet port, a sample outlet port, a washing liquid port, a circulating liquid port and two switching ports, and an inner pipeline is formed between the two switching ports; wherein the sample inlet port, the sample outlet port, the washing liquid port and the circulating liquid port are communicated with the switching ports to provide a first passage state and a second passage state when the valve module is switched.

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