A sample introduction device for ICP-MS

Abstract

The application discloses an instrument analysis technical field and a sampling device for ICP-MS, which comprises a liquid inlet mechanism and an atomizing mechanism; the liquid inlet mechanism is used for inputting liquid samples into the atomizing mechanism; the atomizing mechanism comprises a concentric atomizer and an atomizing chamber; the concentric atomizer is communicated with the atomizing chamber; the atomizing chamber is communicated with a waste liquid barrel and an ICP torch pipe; a self-cleaning mechanism is arranged on the communication path between the concentric atomizer and the atomizing chamber; the self-cleaning mechanism comprises a movable cylinder which is rotationally connected in a nozzle of the concentric atomizer; contact electrodes are symmetrically arranged in the movable cylinder; when the movable cylinder is blocked, the contact electrodes form a passage; the contact electrodes are electrically connected with a torsion mechanism and a back-blowing mechanism; the torsion mechanism is used for twisting the movable cylinder when the contact electrodes form the passage; the back-blowing mechanism is used for intercepting the carrier gas input into the concentric atomizer and blowing out from the nozzle of the concentric atomizer in the reverse direction. The application can perform self-cleaning when the sampling process is blocked, and can reduce the interruption of sample analysis caused by the blockage.

Description

Technical Field

[0001] This invention belongs to the field of instrumental analysis technology, specifically a sample introduction device for ICP-MS. Background Technology

[0002] Inductively coupled plasma mass spectrometry (ICP-MS), with its extremely low detection limit, high sensitivity, and rapid multi-element analysis capabilities, has become an indispensable analytical tool in fields such as environmental monitoring, food safety, geological exploration, biomedicine, and semiconductors. The analytical process of this technology mainly includes three core steps: sample introduction, ionization, and mass spectrometry detection. Among these, the sample introduction system (i.e., the sample introduction device), as the key link connecting the sample to the high-temperature plasma, directly determines the accuracy and reliability of the analytical results.

[0003] A typical ICP-MS sample introduction device consists of a peristaltic pump, a nebulizer, a spray chamber, and connecting tubing. Its main function is to convert liquid samples into fine aerosols and deliver them to the plasma for ionization. However, in actual analysis, clogging of the sample introduction system is a common and serious problem that affects continuous analysis, especially when processing complex samples with high salinity, suspended particles, or organic matrices.

[0004] Current techniques typically infer blockage indirectly by monitoring and analyzing anomalies in the data. For example, operators only suspect blockage in the injection system when a sudden drop in the signal intensity of the internal standard element, a significant deterioration in analytical precision (abnormally high RSD value), or a persistent deviation of the sample signal response from the calibration curve is observed. This method of judgment is severely retrospective and time-consuming.

[0005] Especially in the early stages of clogging (micro-clogging stage), only the nebulizer nozzle or capillary is partially blocked. The most direct manifestation is a slow decrease in atomization efficiency, leading to a slow and gradual decline in the sensitivity of all elements. Because this decline is gradual and may be misinterpreted as normal fluctuations in instrument status, plasma instability, or sample matrix effects, it is difficult to detect effectively through immediate observation of real-time signal data. Operators often fail to identify and intervene in the early stages of the problem.

[0006] When initial signs of blockage are ignored, and the blockage worsens until it becomes completely blocked, the sample signal may suddenly stop or disappear entirely. At this point, not only is the data from the currently analyzed sample rendered useless, but the sequence analysis usually needs to be interrupted for tedious maintenance operations such as shutdown, disassembly, cleaning, or replacement of parts. This not only wastes valuable samples and instrument time, but may also lead to the failure of the entire analytical sequence, severely impacting the laboratory's analytical efficiency and output quality.

[0007] Given the shortcomings of existing technologies, there is an urgent need to develop a sample introduction device with real-time monitoring and self-cleaning functions to enable early warning and automatic handling of blockages, thereby improving the analytical reliability, automation level and operating efficiency of ICP-MS. Summary of the Invention

[0008] To address the aforementioned problems, the present invention aims to provide a sample introduction device for ICP-MS that can self-clean when blockage occurs during the sample introduction process, thereby reducing sample analysis interruptions caused by blockage.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows:

[0010] A sample introduction device for ICP-MS includes a liquid inlet mechanism and an nebulization mechanism. The liquid inlet mechanism is used to input liquid samples into the nebulization mechanism, which includes a concentric nebulizer and a nebulization chamber. The concentric nebulizer is connected to the nebulization chamber, and the nebulization chamber is connected to a waste liquid tank and an ICP torch. A self-cleaning mechanism is provided on the communication path between the concentric nebulizer and the nebulization chamber. The self-cleaning mechanism includes a movable cylinder, which is rotatably connected to the nozzle of the concentric nebulizer. Contact electrodes are symmetrically arranged inside the movable cylinder. When the movable cylinder is blocked, the contact electrodes form a passage. The contact electrodes are electrically connected to a torsion mechanism and a backflush mechanism. The torsion mechanism is used to torsion the movable cylinder when the contact electrodes form a passage, and the backflush mechanism is used to intercept the carrier gas input to the concentric nebulizer and blow it out in reverse from the nozzle of the concentric nebulizer.

[0011] Working principle: The symmetrically arranged contact electrodes inside the movable cylinder form an open circuit. During normal sample injection, the two electrodes are separated by a non-conductive carrier gas (such as argon) and the sample mist, and the circuit is in an open state. When micro-blockage occurs, a conductive sample liquid film or droplet (the sample liquid is generally pretreated with acid to form an acidic aqueous solution, thus possessing conductivity) gradually covers the electrodes, thereby forming a conductive path between the two contact electrodes, and the circuit is closed.

[0012] The circuit signal formed by the contact electrodes immediately triggers two parallel actuators—a torsion mechanism and a backflushing mechanism—initiating a brief but powerful automatic cleaning cycle:

[0013] After receiving an electrical signal, the torsion mechanism drives the movable cylinder to perform rapid, limited-angle reciprocating torsion at its connection point. The shearing and torsional forces generated by this reciprocating torsion effectively and mechanically peel away viscous liquid films or soft deposits adhering to the inner wall of the concentric atomizer and the nozzle.

[0014] Almost simultaneously, the backflushing mechanism activates. It first cuts off the normal flow of carrier air to the concentric atomizer, then redirects this high-pressure carrier airflow to blow it back into the nozzle of the concentric atomizer. This reverse high-speed airflow directly impacts the blockage loosened by the torsional force, blowing it away from the blockage and thus completely clearing the nozzle.

[0015] The above approach has the following beneficial effects:

[0016] 1. This solution overturns the traditional, lagging model that relies on indirect inference through signal analysis by directly detecting the earliest possible moment of a congestion event (the micro-congestion stage). It addresses the problem in its early stages, preventing micro-congestion from developing into complete congestion.

[0017] 2. This solution greatly improves analytical efficiency and automation, and avoids analytical interruptions: there is no need to pause the analysis sequence, disassemble and clean or replace the concentric nebulizer due to blockage, ensuring the continuity and integrity of long-term, large-batch sample analysis.

[0018] 3. In this solution, the cleaning process is completed automatically within the system without the need for disassembly or assembly, thus avoiding the risk of damage or secondary pollution caused by human operation.

[0019] Furthermore, the torsion mechanism includes a movable groove opened in the side wall of the concentric atomizer, a first electromagnet and an iron core are arranged in the movable groove, the iron core is slidably engaged with the movable groove, the iron core is fixedly connected to the movable cylinder, a spring is arranged between the iron core and the first electromagnet, and the first electromagnet is electrically connected to the contact electrode.

[0020] Beneficial effects: When the contact electrodes are disconnected, the first electromagnet is de-energized and loses its magnetism. At this time, the iron core is in its initial position under the preload of the spring (e.g., pushed to one end of the movable slot), and the connected movable cylinder is also in its default initial angle. When the contact electrodes form a circuit due to bridging by a blockage, the circuit is connected, and the first electromagnet is instantaneously energized, generating a strong magnetic field. The energized electromagnet generates magnetic force, attracting the iron core, overcoming the spring force, and causing the iron core to slide rapidly within the movable slot. The iron core drives the movable cylinder to rotate (i.e., torsion).

[0021] The first electromagnet has a energizing response time in the millisecond range, which can instantly provide a strong magnetic attraction force, thereby driving the iron core and the moving cylinder to produce a rapid and powerful torsional motion.

[0022] Furthermore, the backflushing mechanism includes a groove on the inner wall of the air inlet of the concentric nebulizer. A guide plate is rotatably connected to the side wall of the groove. A torsion spring is provided at the connection between the guide plate and the side wall of the groove. The torsion spring is used to support the guide plate to return to its original position. A second electromagnet is also provided in the side wall of the groove. The second electromagnet is positioned opposite to the guide plate. The guide plate is made of magnetic material. The second electromagnet is used to generate a magnetic field with the same magnetic properties as the guide plate. The groove is connected to a reverse channel. The outlet of the reverse channel faces the movable cylinder, and the gas flow direction in the reverse channel is opposite to the sample liquid flow direction.

[0023] Beneficial effects: When the second electromagnet is de-energized, it does not generate a magnetic field. Under the support of the torsion spring, the guide plate remains in its reset state, flat against and retracted into the side wall of the groove, its surface smoothly flush with the inner wall of the concentric nebulizer's air inlet. At this time, the carrier gas (such as Ar gas) from the gas source can flow unimpeded along the normal path through the air inlet, enter the core of the concentric nebulizer, mix with the sample liquid, and then be sprayed forward (towards the nozzle), forming a high-speed airflow for atomization.

[0024] When the contact electrodes form a circuit, the signal is simultaneously sent to the second electromagnet. The second electromagnet is instantly energized and, according to its design, generates a magnetic field with the same magnetic properties as the guide plate (i.e., like poles). Based on the principle of like poles repulsion, the magnetic field generated by the second electromagnet produces a strong repulsive force (pushing force) on the magnetic guide plate. This repulsive force overcomes the elasticity of the torsion spring, pushing the guide plate to quickly rotate and pop out of the groove, acting like a baffle across the airflow channel. The popped-out guide plate almost instantly cuts off the normal forward flow of carrier gas. At the same time, the pressurized carrier gas intercepted by the guide plate is forced into the reverse channel connected to the groove. The high-pressure gas is ejected at high speed from the outlet of the reverse channel. Because its outlet faces the movable cylinder and its direction is opposite to the sample flow direction, it forms a strong reverse purge airflow that rushes directly towards the nozzle area where blockage may occur.

[0025] When the cleaning pulse ends, the second electromagnet is de-energized, and the magnetic field disappears. The repulsive force on the guide plate disappears, and the elastic force of the torsion spring drives the guide plate to rotate in the opposite direction, causing it to retract into the groove and return to its flush position with the inner wall. The carrier gas flow path returns to normal, and the sample continues to be transported forward for atomization.

[0026] Furthermore, a light source emitter and a photodetector are also installed on the communication path between the concentric atomizer and the atomization chamber. The light source emitter is used to emit light into the atomized aerosol, and the photodetector is used to capture the Tyndall effect formed after the light passes through the aerosol. It also includes a control unit, which is used to determine the aerosol atomization status based on the Tyndall effect, and then determine whether the concentric atomizer is blocked, and control the operation of the torsion mechanism and the backflushing mechanism based on the judgment result.

[0027] Beneficial effects: According to the Tyndall effect, when light passes through a colloidal dispersion system (such as an aerosol), it is scattered by suspended microparticles, thus creating a light path that can be observed along the side of the light propagation path. The density and particle size distribution of the aerosol directly affect the intensity and shape of this light path.

[0028] Normal state: When atomization is good, the aerosol particles are small, uniform and dense, and have a strong scattering effect on light. The photodetector will capture a Tyndall spot with high intensity, stable shape and uniformity.

[0029] Abnormal state (early stage of blockage): When micro-blockage begins to occur in the concentric atomizer, the atomization efficiency decreases. The most direct manifestation is:

[0030] The reduced total amount of aerosols produced leads to a decrease in the overall intensity of scattered light.

[0031] Changes in the atomized particle size distribution (increase in the number of large droplets) lead to changes in the morphology and uniformity of scattered light.

[0032] The control unit receives and analyzes the image signals from the photodetector in real time. Through pre-set algorithms (such as comparing baseline intensity and analyzing the uniformity of light spot grayscale distribution), it can accurately identify the gradual trends in light intensity and shape.

[0033] Optical monitoring captures the direct physical manifestations of decreased atomization efficiency, and it may even detect anomalies earlier than electrode monitoring. This is because, in some cases, blockages may not yet be connected to the electrodes, but atomization performance has already deteriorated. This further advances the warning point, truly achieving prevention before problems arise.

[0034] Electrode monitoring may generate false signals due to changes in the conductivity of the sample itself (such as different acidities) or the occasional passage of air bubbles. Optical monitoring, on the other hand, verifies the signal from another physical dimension (optical properties).

[0035] Furthermore, the control unit is also used to determine whether the contact electrode is accidentally touched based on the Tyndall effect, and to control the circuit opening and closing of the torsion mechanism and the backflushing mechanism; if it is determined to be a true blockage, the circuit is immediately closed and the cleaning action is performed; if it is determined to be an accidental touch, the circuit is kept open and the cleaning action is not performed.

[0036] Beneficial effects: It fundamentally eliminates accidental cleaning, ensuring the absolute continuity and data integrity of the analytical sequence. The system can intelligently distinguish between real blockages and transient interference, avoiding sudden backflushing and torsion due to an accidental bubble or particle when it should not be interrupted (such as when collecting data from a valuable sample), thus ensuring a seamless and uninterrupted analytical process without human intervention.

[0037] Furthermore, the control unit determines the aerosol atomization status based on the following logic:

[0038] Analyze the intensity and uniformity of the Tyndall effect image;

[0039] The strength and uniformity are compared with preset strength reference range and preset uniformity reference range, respectively;

[0040] If the intensity is consistently below the preset intensity reference range and / or the uniformity consistently deviates from the preset uniformity reference range, the atomization state is determined to be abnormal, and blockage is determined to have occurred.

[0041] Beneficial effects: Simultaneous monitoring of two related but independent physical parameters (intensity and uniformity) provides dual evidence for diagnosis, which is much more accurate than judging by a single parameter (such as intensity alone) and greatly reduces the false positive rate.

[0042] Furthermore, the control unit is also used to record the aerosol atomization status at each moment, and based on the changes in aerosol atomization status within continuous time nodes, analyze and judge the clogging trend, plot the degradation curve of the concentric atomizer performance, and predict the time node for thorough cleaning or replacement based on the degradation curve; it also includes a display unit for displaying the prediction results.

[0043] Beneficial effect: The control unit analyzes historical data and plots the changes in intensity and uniformity over time as curves. Under normal circumstances, this is a relatively stable straight line.

[0044] When performance begins to degrade, the curve exhibits a slow but continuous downward or worsening trend. The control unit can quantify this degradation rate using algorithms such as linear regression and moving average analysis. A predictive model is built based on the current performance value, the degradation rate, and a preset performance failure threshold (e.g., intensity falling below 50% of normal). This model extrapolates the performance degradation curve, thereby calculating when (e.g., after how many hours of operation) the performance is expected to reach a critical point requiring thorough cleaning or replacement, given this trend.

[0045] The performance degradation curve provides objective and quantitative data to assess the condition of concentric atomizers, eliminating the uncertainty of relying on operator experience and intuition. Predictive maintenance is based on the actual health of the equipment. Maintenance is only performed when absolutely necessary, maximizing the lifespan of the concentric atomizer while absolutely avoiding unexpected sudden failures.

[0046] Furthermore, the light source emitter is a laser diode, and the photodetector is a CCD or CMOS image sensor; the display unit is integrated into the control software interface of the ICP-MS host, and is used to visually display real-time Tyndall images, intensity and uniformity values, historical performance degradation curves, and predicted maintenance time nodes.

[0047] Beneficial effects: The laser light source ensures the stability and high intensity of the Tyndall effect signal, enabling it to be clearly captured even when the aerosol density begins to decrease slightly, greatly improving the sensitivity of monitoring and facilitating the earliest identification of micro-blockages.

[0048] Furthermore, the outlet end of the reverse channel is provided with a one-way mechanism, which only allows the carrier gas to flow out from the reverse channel.

[0049] Beneficial effects: When the instrument is operating normally, the pressure inside the concentric nebulizer (nozzle) is close to or slightly higher than atmospheric pressure. At this time, there is no airflow or the pressure is very low in the reverse channel, and the one-way mechanism remains tightly closed under its own structure or the action of external atmospheric pressure. This ensures that normally generated aerosols and sample droplets do not flow back into the reverse channel, thereby avoiding sample residue, cross-contamination, or crystallization that blocks the channel itself.

[0050] Furthermore, it also includes a pressure sensor, which is installed in the reverse channel of the concentric atomizer to monitor the carrier gas pressure; the control unit is also used to determine that the backflush mechanism is faulty or the reverse channel is blocked when the backflush mechanism is activated, if the pressure value monitored by the pressure sensor does not rise to the expected backflush pressure value within a preset time, and trigger an alarm message to be sent to the display unit.

[0051] Beneficial effects: A pressure sensor is precisely positioned inside the reverse channel to directly monitor pressure changes in this dedicated gas path. When the system is operating normally and there is no backflush action, the pressure in the reverse channel is atmospheric pressure (or a known baseline pressure value). When the backflush mechanism is triggered, the baffle plate cuts off the flow, and high-pressure carrier gas rushes into the reverse channel. Theoretically, this will cause the pressure there to rise sharply to a very high, predictable, expected backflush pressure value within a very short time (this value can be experimentally determined in advance and stored in the control unit).

[0052] If the pressure value fails to reach the expected backflushing pressure within the preset time, it indicates a potential malfunction in the reverse channel (such as a stuck guide plate or a blocked reverse channel). This prevents the micro-blockage from worsening due to backflushing failure and ensures the effectiveness of the self-cleaning mechanism. If the pressure remains zero or below the baseline, it may indicate a blocked reverse channel. If the pressure rises slowly or fails to reach the threshold, it may indicate a poor seal on the guide plate or insufficient magnetic force from the electromagnet. The control unit accurately determines the type of fault based on the pressure data, avoiding the need for operators to disassemble the entire sample introduction system for troubleshooting and improving maintenance efficiency. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the sample introduction device for ICP-MS according to the present invention.

[0054] Figure 2This is a schematic diagram of the internal structure of the concentric nebulizer in the sample introduction device for ICP-MS of the present invention.

[0055] Figure 3 for Figure 2 A magnified view of a portion of point M in the middle.

[0056] Figure 4 for Figure 3 A schematic diagram of the structure of the movable cylinder.

[0057] Figure 5 for Figure 2 A magnified view of a portion of point N in the middle.

[0058] The reference numerals in the accompanying drawings of the instruction manual include: 1. Sample; 2. Peristaltic pump; 3. Concentric atomizer; 4. Atomization chamber; 5. Waste liquid tank; 6. ICP torch tube; 301. Air inlet; 302. Light source emitter; 303. Photodetector; 304. Nozzle; 305. Movable cylinder; 306. Contact electrode; 307. Reverse channel; 308. Guide plate; 309. Groove; 310. Second electromagnet; 311. Movable groove; 312. Spring; 313. Iron core; 314. First electromagnet. Detailed Implementation

[0059] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0060] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "vertical", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0061] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0062] The following detailed description illustrates the specific implementation method:

[0063] The basic implementation examples are as follows: Figures 1-5 The diagram shows a sample introduction device for ICP-MS, mainly comprising a liquid inlet mechanism and an nebulization mechanism. The liquid inlet mechanism is used to input liquid sample 1 into the nebulization mechanism, which includes a concentric nebulizer 3 and an nebulization chamber 4. The concentric nebulizer 3 is a Meinhard type concentric nebulizer 3, which is connected to the nebulization chamber 4. The nebulization chamber 4 is connected to a waste liquid tank 5 and an ICP torch tube 6. Preferably, the liquid inlet mechanism includes a peristaltic pump 2, a sample 1 tube, and an injection needle. The peristaltic pump 2 is set to a speed of 2 mL / min, and pumps sample 1 from the sample 1 tube into the sample 1 capillary of the concentric nebulizer 3 through a silicone tube (this is prior art and will not be described in detail here).

[0064] A self-cleaning mechanism is provided on the communication path between the concentric atomizer 3 and the atomization chamber 4. The self-cleaning mechanism includes a movable cylinder 305, combined with an attached... Figure 2 and attached Figure 3 As shown, the nozzle 304 of the concentric atomizer 3 (the nozzle 304 is where gas and liquid mix to form a high-speed airflow that atomizes the liquid) has an annular groove, and the movable cylinder 305 is rotatably connected to the annular groove, combined with the attached... Figure 3 and attached Figure 4 As shown, contact electrodes 306 are symmetrically embedded in the movable cylinder 305. Preferably, the contact electrodes 306 have an arc-shaped structure. When the movable cylinder 305 is blocked, the conductive medium (the blockage generated by the sample liquid) adheres and connects between the contact electrodes 306, forming a passage between the two contact electrodes 306. The contact electrodes 306 are electrically connected to a torsion mechanism and a backflush mechanism. The torsion mechanism is used to torsion the movable cylinder 305 when the contact electrodes 306 form a passage. Specifically, the torsion mechanism includes an arc-shaped movable groove 311 opened in the side wall of the concentric atomizer 3. The movable groove 311 is embedded with a first electromagnet 314 and an iron core 313. The iron core 313 slides in the movable groove 311. The iron core 313 is welded and fixed to the movable cylinder 305. A spring 312 is bonded and fixed between the iron core 313 and the first electromagnet 314. The first electromagnet 314 is electrically connected to the contact electrodes 306 through a wire.

[0065] The backflush mechanism is used to intercept the carrier gas entering the concentric atomizer 3 and blow it out in reverse from the nozzle 304 of the concentric atomizer 3. Specifically, in conjunction with the attached... Figure 2 and attached Figure 5As shown, the backflush mechanism includes a groove 309 on the inner wall of the inlet end 301 (the location of the carrier gas input; in this embodiment, the carrier gas is 99.999% pure argon) of the concentric atomizer 3. A guide plate 308 is rotatably connected to the side wall of the groove 309 via a rotating shaft. A torsion spring is sleeved on the rotating shaft, with its two ends embedded in the guide plate 308 and the side wall of the groove 309, respectively. The torsion spring is used to support the guide plate 308 to return to its original position. A second electromagnet 310 is also embedded in the side wall of the groove 309. The second electromagnet 310 is positioned opposite the guide plate 308, which is made of magnetic material. The second electromagnet 310 is used to generate a magnetic field with the same magnetic properties as the guide plate 308. The groove 309 is connected to a reverse channel 307. The outlet of the reverse channel 307 faces the movable cylinder 305, and the gas flow direction in the reverse channel 307 is opposite to the flow direction of the sample liquid (see attached diagram). Figure 3 (As shown). Preferably, the outlet end of the reverse channel 307 is provided with a one-way mechanism (e.g., a one-way valve, umbrella valve, etc.), which only allows the carrier gas to flow out of the reverse channel 307. In this embodiment, the one-way mechanism is a rotating plate (not shown in the figure). The rotating plate is also rotatably connected to the outlet end of the reverse channel 307 via a rotating shaft, on which a torsion spring is also sleeved. When the sample injection device is working normally, the pressure inside the nozzle 304 is close to or slightly higher than atmospheric pressure. At this time, there is no airflow or the pressure is very low in the reverse channel 307, and the rotating plate remains tightly closed (i.e., tightly against the inner wall of the nozzle 304) under the action of external atmospheric pressure. When high-pressure carrier gas is introduced into the reverse channel 307, the pressure inside the channel rises sharply. When this pressure exceeds the opening pressure (torsion spring force) of the one-way mechanism and the external atmospheric pressure, the rotating plate is pushed open, allowing the high-pressure gas to be successfully ejected, forming a reverse purge airflow.

[0066] Preferably, a light source emitter 302 and a light detector 303 are also provided on the communication path between the concentric atomizer 3 and the atomization chamber 4. Preferably, they are installed outside the observation window (quartz material) on the left side of the atomization chamber 4, and the light detectors 303 are symmetrically installed on the right side of the atomization chamber 4. In this embodiment, the light source emitter 302 is a laser diode, and the light detector 303 is a CCD or CMOS image sensor. The light source emitter 302 is used to emit light into the atomized aerosol, and the light detector 303 is used to capture the Tyndall effect formed after the light passes through the aerosol.

[0067] It also includes a control unit, which is used to determine the aerosol atomization status based on the Tyndall image. Specifically, it analyzes the intensity and uniformity of the Tyndall image; compares the intensity and uniformity with a preset intensity reference range and a preset uniformity reference range, respectively; if the intensity is continuously lower than the preset intensity reference range and / or the uniformity is continuously deviating from the preset uniformity reference range, it is determined that the atomization status is abnormal; then it determines whether the concentric atomizer 3 is blocked, and controls the operation of the torsion mechanism and the backflush mechanism based on the judgment result.

[0068] The control unit is also used to determine whether the contact electrode 306 is a false contact based on the Tyndall effect, and to control the circuit opening and closing of the first electromagnet 314 and the second electromagnet 310; if it is determined to be a true blockage, the circuit is immediately closed and the self-cleaning program is started; if it is determined to be a false contact, the circuit is kept open and the cleaning action is not performed.

[0069] The control unit is also used to record the aerosol atomization status at each moment, and based on the changes in aerosol atomization status over continuous time points, analyze and judge the clogging trend, plot the performance degradation curve of the concentric atomizer 3, and predict the time point for thorough cleaning or replacement based on the degradation curve; it also includes a display unit, which is integrated into the control software interface of the ICP-MS host, for visually displaying real-time Tyndall images, intensity and uniformity values, historical performance degradation curves, and predicted maintenance time points.

[0070] Preferably, it also includes a pressure sensor, which is embedded in the reverse channel 307 of the concentric atomizer 3 to monitor the carrier gas pressure; the control unit is also used to determine that the electromagnet is faulty or the reverse channel 307 is blocked when the second electromagnet 310 is energized, if the pressure value monitored by the pressure sensor does not rise to the expected backflush pressure value within a preset time, and trigger an alarm message to be sent to the display unit.

[0071] The specific implementation process is as follows:

[0072] Normal sample introduction stage:

[0073] Start the ICP-MS instrument and continuously introduce carrier gas (high-purity argon) into the carrier gas inlet of the concentric nebulizer 3 at a set flow rate (usually 0.8-1.2 L / min).

[0074] The peristaltic pump 2 is activated to pump the liquid sample 1 into the capillary of the concentric nebulizer 3 at a constant flow rate. At the nebulizer nozzle 304, the high-speed gas flow meets the liquid to form a uniform and fine aerosol. After these aerosols enter the nebulization chamber 4, larger droplets are separated and discharged, while fine droplets are transported with the carrier gas to the isotropic ICP torch 6, where they are ionized in high-temperature plasma for mass spectrometry detection.

[0075] During this period, the laser beam emitted by the laser diode penetrates the aerosol cloud ejected from nozzle 304, producing a significant Tyndall effect. The CCD image sensor continuously captures images of this optical path and transmits them to the control unit. The control unit calculates the average grayscale value (intensity) and standard deviation (uniformity) of the image in real time and compares them with the preset reference range set during the initialization phase. If the values ​​are within the normal range, the system determines that the atomization state is good.

[0076] At this time, the contact electrodes 306 are separated by airflow and droplets, and the circuit is in an open state. Under the action of the torsion spring, the guide plate 308 is tightly closed within the groove 309, flush with the inner wall of the concentric atomizer 3, and does not obstruct normal airflow. The one-way valve (rotary plate) at the outlet of the reverse channel 307 is closed due to the lack of internal pressure.

[0077] The process of micro-blockage occurrence and intelligent identification:

[0078] When processing high-salt or complex matrix sample 1, dissolved substances or microparticles in sample 1 may begin to gradually deposit on the inner wall of the movable cylinder 305 at nozzle 304, forming micro-blockage.

[0079] The most direct impact of this process is a slow decrease in atomization efficiency. This manifests as:

[0080] a) The total amount of aerosols produced decreases -> the overall intensity of the Tyndall image shows a slow and continuous downward trend.

[0081] b) The atomized particle size distribution deteriorates, and the number of large droplets increases -> the uniformity of the Tyndall spot (such as the standard deviation of image gray level) continues to deteriorate, and the spot shows irregular light and dark distribution.

[0082] At the same time, the conductive liquid film or deposit of sample 1 will adhere to the inner wall of the movable cylinder 305, bridging the two symmetrical contact electrodes 306 to form a circuit and generate an electrical signal.

[0083] Upon receiving the electrode signal, the control unit does not immediately trigger cleaning, but instead initiates a dual verification mechanism:

[0084] It immediately retrieves and analyzes the current and previous optical monitoring data (i.e., Tyndall images).

[0085] If the optical signal (intensity and uniformity) also shows a trend of continuous deterioration starting from the same point in time, the control unit determines it to be a true blockage.

[0086] If only the electrode path signal is received, and the optical signal is stable and normal, the control unit determines that this is a false trigger (possibly caused by a single bubble or particle passing by accidentally), ignores the signal, records only the event log, and the system continues to inject samples normally, thereby effectively preventing malfunctions.

[0087] Self-cleaning triggering and execution process (taking true blockage determination as an example):

[0088] Once the control unit confirms that a blockage has occurred, it immediately sends a brief pulse current to both the first electromagnet 314 of the torsion mechanism and the second electromagnet 310 of the backflush mechanism.

[0089] Torsional Action: The first electromagnet 314 is momentarily energized, generating a strong magnetic force that attracts the iron core 313, causing it to slide rapidly within the movable groove 311, overcoming the elastic force of the spring 312. Since the iron core 313 is fixedly connected to the movable cylinder 305, this linear motion is converted into a rapid torsion of the movable cylinder 305. This action generates a powerful mechanical shearing force on the blockages adhering to the inner wall, loosening and peeling them off. After the pulse current ends (or the blockage is cleared), the first electromagnet 314 is de-energized, and the elastic force of the spring 312 pushes the iron core 313 and causes the movable cylinder 305 to twist and reset in the opposite direction. This rapid, alternating torsion effectively breaks up and peels away deposits.

[0090] At the same moment, the second electromagnet 310 is energized, generating a magnetic field with the same magnetism as the guide plate 308. According to the principle of like poles repulsion, the strong magnetic repulsion force instantly pushes the guide plate 308, causing it to overcome the elastic force of the torsion spring and quickly pop out of the groove 309 to the center of the airflow channel, completely cutting off the normal forward flow of the carrier air.

[0091] The interrupted high-pressure carrier gas has nowhere to go, causing its pressure to rise sharply. It is forced to rush into the reverse channel 307, which connects to the groove 309. The high-pressure gas pushes the rotating plate at the outlet of the reverse channel 307 to open, forming a high-speed, pulsed reverse purge airflow that sprays out from the outlet and directly hits the inner wall of the movable cylinder 305. This reverse airflow works in conjunction with the torsional motion: the torsional mechanism scrapes off the blockage, and the reverse purge airflow then blows it out, completely clearing the nozzle 304.

[0092] After the cleaning pulse ends, the first and second electromagnets 310 are de-energized. The guide plate 308, under the action of the torsion spring, quickly rotates back into the groove 309 to reset, restoring the airflow channel. The one-way valve (rotating plate) closes under its own torsion spring and external atmospheric pressure, sealing the reverse channel 307. The system immediately resumes normal sample injection.

[0093] The control unit continuously monitors the subsequent optical signals. If the intensity and uniformity of the Tyndall image quickly return to the normal reference range, the cleaning is considered successful, and the system records a successful cleaning event.

[0094] During the backflushing operation, the control unit reads data from the pressure sensor in the reverse channel 307. If the pressure value fails to rise as expected, it determines that there may be a fault in the backflushing mechanism (such as electromagnet failure, baffle 308 jamming, or blockage of the reverse channel 307), and immediately generates a clear alarm message on the display unit (such as "Backflushing failed, please check and maintain") to prompt the operator to intervene, thereby preventing the system from operating silently in a faulty state.

[0095] Predictive maintenance process:

[0096] The control unit continuously records nebulization health data (intensity and uniformity values) during each analysis. After long-term operation, the system software can plot the performance degradation curve of the concentric nebulizer 3 (such as the slow decrease in sensitivity over time). By analyzing this trend through algorithms, the system can predict when the performance will drop to an unacceptable level and issue an early warning to the operator via the display unit (e.g., "Concentric nebulizer 3 is expected to need cleaning in 70 hours"). This allows laboratory managers to schedule maintenance during instrument downtime, achieving predictive maintenance, maximizing instrument operating efficiency and lifespan, and avoiding interruptions due to sudden complete blockage during critical analytical tasks.

[0097] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific structures and / or characteristics in the solutions are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A sample injection device for ICP-MS, comprising a liquid inlet mechanism and an atomization mechanism; the liquid inlet mechanism is used for inputting a liquid sample (1) to the atomization mechanism, the atomization mechanism comprises a concentric atomizer (3) and an atomization chamber (4), the concentric atomizer (3) is communicated with the atomization chamber (4), and the atomization chamber (4) is communicated with a waste liquid tank (5) and an ICP torch pipe (6); characterized in that: A self-cleaning mechanism is arranged on a communication path between the concentric atomizer (3) and the atomization chamber (4), and the self-cleaning mechanism comprises a movable cylinder (305) which is rotationally connected in a nozzle (304) of the concentric atomizer (3), and symmetrical contact electrodes (306) are arranged in the movable cylinder (305), and the contact electrodes (306) form a passage when the movable cylinder (305) is blocked; the contact electrodes (306) are electrically connected with a torsion mechanism and a back-blowing mechanism, the torsion mechanism is used for torsion of the movable cylinder (305) when the contact electrodes (306) form the passage, and the back-blowing mechanism is used for intercepting carrier gas input into the concentric atomizer (3) and reversely blowing out from the nozzle (304) of the concentric atomizer (3).

2. The sample introduction device for ICP-MS according to claim 1, characterized by: The torsion mechanism comprises a movable groove (311) which is arranged in a side wall of the concentric atomizer (3), a first electromagnet (314) and an iron core (313) are arranged in the movable groove (311), the iron core (313) is in sliding fit with the movable groove (311), the iron core (313) is fixedly connected with the movable cylinder (305), a spring (312) is arranged between the iron core (313) and the first electromagnet (314), and the first electromagnet (314) is electrically connected with the contact electrodes (306).

3. The sample introduction device for ICP-MS of claim 1, wherein: The back-blowing mechanism comprises a groove (309) which is arranged in a side wall of an air inlet end (301) of the concentric atomizer (3), a guide plate (308) is rotationally connected in the side wall of the groove (309), a torsion spring is arranged at a connection position of the guide plate (308) and the side wall of the groove (309) and is used for supporting the guide plate (308) to reset, a second electromagnet (310) is further arranged in the side wall of the groove (309), the second electromagnet (310) is arranged opposite to the guide plate (308), the guide plate (308) is made of a magnetic material, and the second electromagnet (310) is used for generating a magnetic field which has the same magnetism as the guide plate (308); and the groove (309) is communicated with a reverse channel (307), an outlet of the reverse channel (307) faces the movable cylinder (305), and a gas flow direction in the reverse channel (307) is opposite to a sample (1) liquid flow direction.

4. The sample introduction device for ICP-MS according to claim 3, characterized by: The concentric atomizer (3) and the atomization chamber (4) are further communicated with a light source emitter (302) and a light detector (303), the light source emitter (302) is used for emitting light to the atomized aerosol, and the light detector (303) is used for capturing a Tyndall image formed after the light passes through the aerosol; and a control unit is further arranged, and the control unit is used for judging the aerosol atomization condition based on the Tyndall image, judging whether the concentric atomizer (3) is blocked, and controlling operation of the torsion mechanism and the back-blowing mechanism based on a judgment result.

5. The sample introduction device for ICP-MS of claim 4, wherein: The control unit is further used for judging whether the contact electrodes (306) are false touch based on the Tyndall image, and controlling on-off of a circuit of the torsion mechanism and the back-blowing mechanism; if it is judged that the concentric atomizer (3) is blocked, the circuit is immediately closed, and a cleaning action is performed; if it is judged that the contact electrodes (306) are false touch, the circuit is kept off, and the cleaning action is not performed.

6. The sample introduction device for ICP-MS of claim 4, wherein: The control unit judges the aerosol atomization condition based on the following logic: intensity and uniformity of the Tyndall image are analyzed; the intensity and the uniformity are compared with a preset intensity reference range and a preset uniformity reference range, respectively; If the intensity continuously falls below the preset intensity reference range and / or the uniformity continuously deviates from the preset uniformity reference range, it is determined that the atomization state is abnormal, and it is determined that clogging occurs.

7. The sample introduction device for ICP-MS of claim 6, wherein: The control unit is also used to record the aerosol atomization condition at each moment, analyze and determine the clogging trend based on the change of the aerosol atomization condition within the continuous time nodes, draw the degradation curve of the performance of the atomizer, and predict the time node of complete cleaning or replacement based on the degradation curve; and further comprising a display unit, which is used to display the prediction results.

8. The sample introduction device for ICP-MS of claim 7, wherein: The light source emitter (302) is a laser diode, and the light detector (303) is a CCD or CMOS image sensor; the display unit is integrated in the control software interface of the ICP-MS host, and is used to visually display the real-time Tyndall image, intensity and uniformity values, historical performance degradation curve and predicted maintenance time node.

9. The sample introduction device for ICP-MS of claim 3, wherein: The outlet end of the reverse channel (307) is provided with a one-way mechanism that only allows the carrier gas to flow out of the reverse channel (307).

10. The sample introduction device for ICP-MS of claim 7, wherein: Further comprising a pressure sensor arranged in the reverse channel (307) of the concentric atomizer (3) for monitoring the carrier gas pressure; the control unit is also used to determine that the back flushing mechanism fails or the reverse channel (307) is clogged and trigger an alarm information to be sent to the display unit if the pressure value monitored by the pressure sensor does not rise to the expected back flushing pressure value within a preset time when the back flushing mechanism is actuated.

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