A high throughput automatic sampling plasma mass spectrometer

Abstract

The utility model discloses a kind of high-flux automatic sample introduction plasma mass spectrometer, the device includes the precision ceramic substrate with V-shaped locating slot, corrosion-resistant slider with permanent magnet array and electromagnet being sealed inside, stator coil assembly fixed to the outside of substrate and controller, stator coil assembly non-contact drive slider high-speed movement, when slider reaches target position vicinity, controller disconnects drive current and connects electromagnet, make the locating pin of slider bottom and the V-shaped locating slot on substrate forced engagement locking.The utility model separates high-speed drive and mechanical locking completely, uses high-rigidity, corrosion-resistant mechanical structure as final precision anchor point, fundamentally solves the positioning overshoot and vibration problem under high speed, and has excellent chemical corrosion resistance, significantly improves the operation efficiency, positioning accuracy and long-term reliability of device.

Description

Technical Field

[0001] This utility model relates to the field of analytical instrument technology, and in particular to a high-throughput, high-precision, and corrosion-resistant automatic sample introduction device for plasma mass spectrometers. Background Technology

[0002] In the field of modern chemical analysis, especially in plasma mass spectrometry, autosamplers are key equipment for realizing automated analysis of large batches of samples. In the existing technology, autosamplers generally adopt a three-axis XYZ Cartesian coordinate robot based on synchronous belt or ball screw drive as a known structure. However, with the continuous improvement of the requirements for analytical efficiency, such a known structure has exposed irreconcilable systemic defects.

[0003] First, to achieve high throughput, the no-load speed of the XY axes must be greater than 500 mm / s. Under such high-speed start-stop conditions, the traditional synchronous belt / ball screw drive structure and the high precision required by analytical chemistry form an inherent electromechanical deadlock. Specifically, the huge inertia brought about by high-speed motion causes the start-stop control of the drive motor to produce a positioning overshoot of ≥0.5 mm and end-effector chatter lasting ≥100 ms. This overshoot and chatter make the slender sampling needle extremely susceptible to collision damage when inserted into the sample tube, or cross-contamination due to droplet shedding during high-speed movement between samples, seriously affecting the accuracy of the analytical results and the reliability of the equipment.

[0004] Secondly, the internal working environment of the ICP-MS instrument is extremely harsh, with a continuous presence of strong acid vapor. This environment will cause irreversible chemical corrosion to the metal guide rails and bearings that serve as positioning references. This constitutes a structural-environment deadlock. That is, after approximately 500 hours of cumulative operation, corrosion will cause the moving pair, namely the guide rail and the slider, to have a clearance of ≥0.2mm and become stuck, completely destroying the long-term positioning accuracy of the system and ultimately leading to complete positioning failure.

[0005] The applicant found a prior art document CN208766081U, which discloses a high-throughput micro-volume automated sample introduction system. This system uses a linear motor for direct drive and a ceramic guide rail to suppress end vibration under high-speed movement. However, this system has significant flaws and cannot be directly applied to the scenario in this case: 1) Environmental adaptability: Its electrical components and sensors are completely exposed and designed for ultra-clean environments, making it unable to withstand the strong acid vapor corrosion in this case; 2) Application scenario-specific issues: The system does not address the anti-collision strategy for the sampling needle and the cross-contamination problem between samples; 3) Cost mismatch: The air bearings and high-resolution grating rulers used are too expensive and lack commercial viability in the field of analytical instruments.

[0006] Therefore, how to provide an automated sample delivery device that can meet the requirements of high-throughput operation, ensure sub-millimeter positioning accuracy, and operate stably for a long time in a highly corrosive environment is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0007] The purpose of this invention is to provide a high-throughput automated sample introduction plasma mass spectrometer to solve the technical problems of the contradiction between high speed and high precision and the failure of precision due to corrosion in the above-mentioned background technology.

[0008] To achieve the above objectives, this utility model provides a high-throughput automated sample introduction plasma mass spectrometer, which includes a substrate, a slider, a permanent magnet array, positioning pins, an electromagnet, a stator coil assembly, a position sensor, and a controller. The specific technical solution is as follows: A high-throughput automated sample introduction plasma mass spectrometer includes: The substrate has a series of V-shaped positioning grooves on its upper surface along a preset motion path; A slider that can move relative to the substrate along the preset motion path, and the interior of the slider is a sealed cavity; The permanent magnet array is sealed within the sealed cavity of the slider; A positioning pin is fixed to the bottom of the slider and configured to mechanically engage with any of the V-shaped positioning grooves on the substrate; An electromagnet is sealed within the sealed cavity of the slider and configured to generate magnetic force when energized, driving the positioning pin to engage and lock with the V-shaped positioning groove. The stator coil assembly is fixed to the outside of the substrate and cooperates with the permanent magnet array inside the slider to drive the slider to move along the preset motion path in a non-contact manner. A position sensor is used to detect the position of the slider; The controller is electrically connected to the stator coil assembly, the electromagnet, and the position sensor, respectively.

[0009] Preferably, the substrate is made of zirconia ceramic or silicon nitride ceramic material.

[0010] Preferably, the locating pin is made of cemented carbide material.

[0011] Preferably, the slider includes a housing and a cover plate made of PEEK material, and the cover plate is sealed to the housing by an O-ring to form the sealed cavity.

[0012] Preferably, the position sensor is a Hall sensor array, which is arranged along the preset motion path to non-contactly sense the magnetic field of the permanent magnet array inside the slider to determine the position of the slider.

[0013] Preferably, the controller is configured to: when receiving a signal from the position sensor indicating that the movement of the slider has stopped within a predetermined capture area of ​​any of the V-shaped positioning slots, cut off the power supply to the stator coil assembly and turn on the power supply to the electromagnet.

[0014] Preferably, it also includes a sampling needle fixing arm mounted on the slider, the sampling needle fixing arm being made of PEEK material.

[0015] Compared with the prior art, the present invention has the following significant advantages: This invention fundamentally breaks the electromechanical deadlock, achieving a balance between high throughput and high precision. The solution uses a linear motor for high-speed transport and a passive mechanical locking mechanism for precise positioning, completely decoupling the two actions. The inertia and vibration of high-speed motion are instantly eliminated by the mechanical locking action, achieving performance that traditional transmission methods cannot match.

[0016] This invention achieves full-path corrosion resistance, ensuring long-term stability. The core precision reference ceramic substrate and the moving part PEEK slider are both made of acid-resistant materials or have a fully sealed structure. The drive source is physically isolated, which completely solves the problem of long-term precision failure caused by corrosion from a structural perspective.

[0017] This invention significantly reduces system complexity and cost, and improves reliability. It replaces the expensive, environmentally sensitive high-resolution grating ruler and closed-loop servo system in the prior art with extremely reliable mechanical hard tolerances, resulting in a simpler structure, higher reliability, and longer service life. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model; Figure 2 This is an exploded view of the slider in an embodiment of this utility model; Figure 3 This is a three-dimensional sectional view of the engagement state of the positioning pin and the V-shaped positioning groove in an embodiment of this utility model; Figure 4 yes Figure 3 A side sectional view showing the meshing state. Detailed Implementation

[0019] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0020] Please see Figures 1-4This utility model provides a high-throughput automated sample introduction plasma mass spectrometer.

[0021] The device includes a base mounting plate 1 for fixing the entire device to the mass spectrometer body. A precision ceramic V-shaped positioning array substrate 2, which serves as the core accuracy reference, is fixed on the base mounting plate 1 by M3 socket head cap screws 15 made of PEEK material. The substrate 2 is preferably integrally sintered from zirconium oxide (ZrO2) material, which has extremely high hardness, dimensional stability and excellent acid resistance. A series of V-shaped positioning grooves are machined on the upper surface of the substrate 2 along a preset linear motion path, and each groove precisely corresponds to the center position of a sample tube.

[0022] Below the substrate 2, a segmented stator coil assembly 3 is mounted on a stator coil fixing bracket 4 made of PEEK material. The coil assembly 3 is completely encapsulated with epoxy resin, which physically isolates it from the corrosive environment inside the instrument.

[0023] Above the substrate 2, a movable slider 5 is provided. The main body of the slider 5 is made of 30% glass fiber reinforced PEEK material to ensure its strength and corrosion resistance. The slider 5 forms a completely sealed internal cavity through the cover plate 6 and the O-ring 7 of perfluoroether FFKM material. The cavity encapsulates the permanent magnet array 8 as the mover of the linear motor and the miniature electromagnet 9 for locking. A V-shaped positioning pin 10 made of tungsten carbide YG8 hard alloy is firmly fixed at the bottom of the slider 5. The tip shape of the pin is precisely matched with the V-shaped positioning groove on the substrate 2.

[0024] Above the slider 5 is a sampling needle fixing arm 11, also made of PEEK material, used to hold the sampling needle. To detect the position of the slider 5, a Hall sensor PCB board 12 is also set along the movement path and fixed by a PVC sensor fixing strip 13. The power supply cable of the electromagnet 9 on the slider 5 is led out through a flexible drag chain 14. All components are assembled with fasteners such as M2 socket head cap screws 16 made of PEEK material.

[0025] The working principle of this utility model consists of the following two steps: Step 1: Core Mechanical Principle. The final positioning accuracy and long-term stability of this device are entirely guaranteed by its core mechanical structure. Specifically, when the slider 5 moves above the target V-shaped positioning groove, the hard alloy positioning pin 10 at its bottom physically engages with the ceramic V-shaped positioning groove on the substrate 2. Because both the positioning pin 10 and the V-shaped groove are made of ultra-high hardness materials and have extremely high machining precision, this forced engagement of V-shapes can instantly eliminate all gaps on the XY plane, forming an extremely stable rigid lock. The final positioning accuracy depends entirely on the manufacturing tolerances of these two core mechanical components and is completely unrelated to dynamic factors such as previous movement speed, acceleration, and system vibration. This constitutes the core principle of this utility model.

[0026] Step 2, Electrically Controlled Auxiliary Process: The role of the electrical control system is to efficiently and automatically drive the slider to the predetermined position and trigger the aforementioned mechanical locking process. The process is as follows: The controller first drives the stator coil assembly 3 to generate a traveling wave magnetic field. This magnetic field penetrates the ceramic substrate 2 and drives the permanent magnet array 8 inside the slider 5 non-contactly, causing the slider to slide at high speed along the substrate towards the target position. During this process, the Hall sensor array 12 monitors the position of the slider in real time. When the controller receives a signal from the sensor 12 and determines that the slider has entered the capture area of ​​the target V-groove and decelerated to a stop, the controller immediately cuts off the power supply to the stator coil assembly 3 and simultaneously energizes the electromagnet 9 inside the slider. After the electromagnet 9 is energized, it generates a strong attraction force, forcibly pulling the entire slider along with the positioning pin 10 towards the substrate 2, causing the positioning pin 10 to wedge into the V-groove with great force, completing the final, highly reliable mechanical positioning. After sampling is completed, the controller de-energizes the electromagnet 9, the locking is released, and the slider 5 is driven to the next position.

[0027] It must be emphasized again that the high-precision and corrosion-resistant positioning technology claimed by this invention is ultimately achieved and physically guaranteed by the unique and forced physical fit between the precision ceramic V-shaped positioning array substrate 2 and the hard alloy V-shaped positioning pin 10. The role of the electronic control unit is only to optimize the triggering timing of the mechanical engagement process and to achieve automated protection. It does not participate in or can correct the final technical effect determined by the core mechanical structure. Even in the power-off state, the core function of this device can still be achieved by manually operating the mechanical structure.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-throughput automated sample introduction plasma mass spectrometer, characterized in that, include: The substrate (2) has a series of V-shaped positioning grooves on its upper surface along a preset motion path; Slider (5), the slider can move relative to the substrate along the preset motion path, and the inside of the slider is a sealed cavity; The permanent magnet array (8) is sealed within the sealed cavity of the slider; A positioning pin (10) is fixed to the bottom of the slider and configured to mechanically engage with any of the V-shaped positioning grooves on the substrate; An electromagnet (9) is sealed in the sealed cavity of the slider and is configured to generate magnetic force when energized, driving the positioning pin to engage and lock with the V-shaped positioning groove; The stator coil assembly (3) is fixed to the outside of the substrate and cooperates with the permanent magnet array inside the slider to drive the slider to move along the preset motion path in a non-contact manner. Position sensor (12) is used to detect the position of the slider; The controller is electrically connected to the stator coil assembly, the electromagnet, and the position sensor, respectively.

2. The high-throughput automated sample introduction plasma mass spectrometer according to claim 1, characterized in that, The substrate (2) is made of zirconium oxide ceramic or silicon nitride ceramic material.

3. A high-throughput automated sample introduction plasma mass spectrometer according to claim 1, characterized in that, The locating pin (10) is made of cemented carbide material.

4. A high-throughput automated sample introduction plasma mass spectrometer according to claim 1, characterized in that, The slider (5) includes a shell and a cover plate (6) made of PEEK material. The cover plate is sealed to the shell by an O-ring (7) to form the sealed cavity.

5. A high-throughput automated sample introduction plasma mass spectrometer according to claim 1, characterized in that, The position sensor (12) is a Hall sensor array arranged along the preset motion path to non-contactly sense the magnetic field of the permanent magnet array inside the slider to determine the position of the slider.

6. A high-throughput automated sample introduction plasma mass spectrometer according to claim 1, characterized in that, The controller is configured to: when it receives a signal from the position sensor (12) indicating that the movement of the slider has stopped within a predetermined capture area of ​​any of the V-shaped positioning slots, cut off the power supply to the stator coil assembly (3) and turn on the power supply to the electromagnet (9).

7. A high-throughput automated sample introduction plasma mass spectrometer according to claim 6, characterized in that, It also includes a sampling needle fixing arm (11) mounted on the slider, the sampling needle fixing arm being made of PEEK material.

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