A curved rotating ion transmission structure and mass spectrometer

Abstract

This invention relates to a curved rotating ion transport structure and a mass spectrometer incorporating the structure. The transport structure includes a sixteen-bar assembly having an inlet end and an outlet end. The sixteen-bar assembly includes eight inner bars and eight outer bars. The sixteen-bar assembly, formed by the inner and outer bars, has a central axis extending along its length, which is formed as a curved arc. Furthermore, the bars of the sixteen-bar assembly exhibit an overall rotational torsion along the curved central axis from the inlet end to the outlet end. This invention provides a curved rotating ion transport structure and a mass spectrometer incorporating the structure, enabling simultaneous and complete physical filtering of neutral noise and ultra-high-efficiency transport and focusing of the ion beam within a single integrated component.

Description

Technical Field

[0001] This invention relates to the field of analytical instrument technology, and in particular to an ion optical system for use in a mass spectrometer. More specifically, this invention relates to a curved-rotation ion transport structure and a mass spectrometer incorporating the structure. Background Technology

[0002] Mass spectrometry is an indispensable core technology in modern scientific research and industrial testing. It achieves qualitative and quantitative analysis of substances by accurately measuring the mass-to-charge ratio (m / z) of charged particles (ions). Among various mass spectrometry techniques, ICP-MS is widely used due to its high specificity and low detection limit. However, this type of instrument faces a core physical challenge: ions are generated in an environment of approximately one standard atmosphere (~10^5 Pa), while their final mass analysis and detection must be performed in an ultra-high vacuum environment (<10^-6 Pa). This huge pressure difference necessitates a precise, multi-stage differential vacuum interface and ion transport system between the ion source and the mass analyzer. The performance of this system directly determines the proportion of ions that can successfully "survive" and reach the analyzer. Furthermore, the ionized ion stream contains not only the analyte ions but also a large number of electrons, photons, and unionized neutral particles. These particles, upon reaching the detector, generate significant background interference, thus affecting the sensitivity and detection limit of the entire instrument. To address this challenge, the industry has developed various technical approaches over decades, such as photon baffles, off-axis lenses, and 90° quadrupole deflection. Currently, the mainstream approach involves using electrostatic quadrupoles or lenses to remove interference through deflection. However, these two mainstream approaches can only remove some interference and significantly impact particle transport efficiency. After the ions to be measured are deflected, they diverge and scatter severely, leading to low transport efficiency in subsequent stages and reduced sensitivity and detection limits. Summary of the Invention

[0003] To address the shortcomings and problems of existing technologies, the main objective of this invention is to resolve the technical contradiction of simultaneously achieving high ion transmission efficiency and background noise suppression capabilities by providing a novel ion transmission structure and a mass spectrometer incorporating this structure. This structure aims to achieve, through innovative geometric configuration and electric field design, complete physical filtering of neutral noise and ultra-high-efficiency transmission and focusing of the ion beam within a single integrated component. To achieve the above objectives, the core technical solution adopted by this invention is as follows: a curved and rotating ion transmission structure, comprising: A sixteen-bar assembly having an inlet end and an outlet end, the sixteen-bar assembly comprising: Eight concentrically arranged inner rods; and Eight outer rods arranged concentrically on the outside of the inner rod; The sixteen-bar assembly, consisting of inner and outer bars, has a central axis extending along its length, which is formed as a curved arc. Furthermore, the bars of the sixteen-bar assembly exhibit an overall rotational torsion along the curved central axis from the inlet to the outlet.

[0004] Furthermore, the central angle of the curved arc formed by the central axis is set to 60° to 120°.

[0005] Preferably, the central angle is 90°.

[0006] Furthermore, the entire rod system rotates and twists from the inlet end to the outlet end, with a total twist angle of 15° to 45°.

[0007] Preferably, the total torsion angle is 30°.

[0008] Furthermore, the eight inner rods are configured to collectively form an octet radio frequency electric field.

[0009] Preferably, the inner rod and the outer rod are configured to work together to form a sixteen-pole radio frequency electric field.

[0010] Furthermore, it also includes at least one insulating support member, through which the inner rod and the outer rod are precisely fixed to maintain their concentric arrangement and relative positional relationship.

[0011] Preferably, the inner rod and the outer rod are configured to be connected to independent radio frequency power supplies and DC power supplies, respectively.

[0012] Furthermore, it also includes a mass spectrometer comprising the aforementioned bent-rotating ion transport structure.

[0013] Compared with the prior art, the beneficial effects of this invention are significant and multifaceted: 1. Fundamentally resolves the contradiction between transmission efficiency and noise suppression, achieving a balance between the two: The core innovation of this invention lies in organically combining the seemingly contradictory elements of the ultra-strong radial confinement capability of a sixteen-pole field and a large-angle curved path into a single structure. On one hand, the large-angle (e.g., 90°) non-linear curved path physically and geometrically blocks the channels of all neutral particles and photons moving in straight lines, ensuring unparalleled background noise suppression capabilities and achieving an extremely "clean" mass spectrometry baseline. On the other hand, the sixteen-pole radio frequency electric field generated by the synergy of the inner and outer rod systems provides a pseudopotential trap that is wider, flatter, and has stronger confinement than the four-pole, eight-pole, or even twelve-pole fields in existing technologies. This ultra-strong confinement force is sufficient to overcome the huge centrifugal effect generated when the ion beam passes through the large-angle curved path at high speed, ensuring that the ions are firmly bound near the central axis, thereby achieving extremely high ion transmission efficiency and avoiding the ion loss problem of traditional curved conduits.

[0014] 2. Superior Ion Beam Confinement and Focusing Performance, Enhancing Subsequent Analysis Quality: The superior wide-range confinement performance of the hexapole field makes it particularly suitable for capturing and guiding ion beams with extremely large initial divergence angles formed by the violent gas expansion when entering a vacuum from an atmospheric pressure interface. Furthermore, the overall rotating torsional structure designed along a curved path imparts a helical motion component to the ions during their propagation. This motion mode continuously modulates and compresses the radial position of the ions, effectively reducing the volume of the ion beam in phase space. The direct effect is that the ion beam formed at the structure's exit not only has high flux but also a smaller spatial divergence angle and a more concentrated energy distribution, meaning a higher "quality" ion beam. This significantly reduces the difficulty for subsequent mass analyzers (such as quadrupole mass analyzers or time-of-flight analyzers) to receive the ion beam, contributing to improved overall system quality resolution and signal stability.

[0015] 3. Highly Integrated Structure, Significantly Simplifying the Instrument System: This invention ingeniously integrates the three core functions of ion guidance, powerful focusing, and neutral particle filtration into a compact, single component. This replaces the complex combination of multiple independent optical elements (such as the entrance lens group, deflectors or fan-shaped electric fields for deflection, and linear multipole rods for transmission) that may be required in traditional high-performance instruments. This highly integrated design not only makes the internal structure of the mass spectrometer simpler and more compact, significantly reducing the size and weight of the instrument, but also greatly reduces the system's manufacturing cost, assembly difficulty, and the complexity of subsequent maintenance. At the same time, reducing the number of independently tuned electrical components also simplifies the instrument's operation and optimization process.

[0016] 4. Comprehensive Improvement of Core Instrument Analytical Performance: Because this invention can stably provide the mass spectrometer with a "pure" ion beam with extremely high throughput and virtually no background noise, its improvement on the instrument's final analytical performance is direct and comprehensive. The instrument's signal-to-noise ratio (S / N ratio) will be improved by several times or even orders of magnitude, meaning that at the same sample concentration, the target signal will be more easily highlighted from the background. This directly translates to a significant reduction in the instrument's limit of detection (LOD) and limit of quantitation (LOQ), making it possible to accurately detect trace and even ultra-trace substances in complex matrices, greatly expanding the application areas and analytical capabilities of the mass spectrometer. Attached Figure Description

[0017] To enable those skilled in the art to more clearly and comprehensively understand the technical solutions of the present invention, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the accompanying drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings: Figure 1This is a three-dimensional schematic diagram of a curved and rotating ion transport structure provided in a preferred embodiment of the present invention; Figure 2 This is a side view schematic diagram of a bent-rotation ion transport structure provided in a preferred embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the working principle of a bent-rotating ion transport structure according to a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the simulation model of the sixteen-pole structure used in the embodiments of the present invention; Figure 5 This is a simulation diagram of the ion trajectory of a traditional 90-degree off-axis lens used for comparison; Figure 6 This is a simulation diagram of the ion trajectory of the bent rotating sixteen-pole electrode in an embodiment of the present invention; Figure 7 This is a comparison chart of experimental data of the embodiments of the present invention and the comparative examples at the mass number 59; Figure 8 This is a comparison chart of experimental data of the embodiments of the present invention and the comparative examples at the mass number 115.

[0018] In the above figures, the same reference numerals denote parts that are the same or have similar functions; the names of the parts represented by each reference numeral are as follows: 100- Bending and Rotating Ion Transport Structure 10-16 bar assembly 10a-Entry Terminal 10b-Exit End 12-Inner Rod 14-Outer rod 20-Insulating support A-Center Axis P-ion movement trajectory Trajectory of N-neutral particles. Detailed implementation method. The present invention will now be described in detail with reference to the accompanying drawings: To make the objectives, technical solutions, and advantages of this invention clearer, several preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings. It should be understood that the embodiments described herein are merely for explaining the invention and do not constitute any limitation on its scope of protection. Any modifications, equivalent substitutions, or improvements made based on the spirit and principles of this invention should be included within the scope of protection of this invention.

[0019] Example 1 Please see Figures 1 to 3This embodiment provides a curved-rotation ion transport structure 100. This structure 100 is designed to be installed inside the vacuum system of a mass spectrometer, serving as a core bridge connecting the atmospheric pressure ion source and the high vacuum mass analyzer.

[0020] The curved rotating ion transport structure 100 includes: a sixteen-bar assembly 10 having an inlet end 10a and an outlet end 10b; the sixteen-bar assembly 10 includes: eight concentrically arranged inner bars 12; and eight concentrically arranged outer bars 14 outside the inner bars 12; wherein the sixteen-bar assembly 10, formed by the inner bars 12 and the outer bars 14, has a central axis A extending along its length direction, the central axis A being formed as a curved arc; and the bars of the sixteen-bar assembly 10 have an overall rotational torsion along the curved central axis A from the inlet end 10a to the outlet end 10b.

[0021] Regarding "a sixteen-bar assembly 10": This is the core functional component of the invention. It is a precision assembly consisting of sixteen independent, slender rod-shaped electrodes. (The overall length, inner diameter, and outer diameter of this assembly, etc., can be adapted to the vacuum chamber size and ion beam energy of the mass spectrometer being used. For example, its total length may be between 100 mm and 200 mm, and the diameter of the inscribed circle of the channel enclosed by the inner rods may be between 4 mm and 8 mm.) Its function is to generate a pseudopotential trap in its central axial region by applying a radio frequency (RF) electric field, which is used to confine charged ions radially.

[0022] Regarding "Inlet 10a and Outlet 10b": This clarifies the directionality of this component. Inlet 10a faces the ion source and receives a mixed beam containing ions and neutral particles from the pre-vacuum interface. Outlet 10b faces the mass analyzer and outputs a purified ion beam after transmission, purification, and focusing.

[0023] • Regarding the “eight concentrically arranged inner rods 12” and the “eight concentrically arranged outer rods 14 outside the inner rods 12”: This is a specific definition of the internal structure of the sixteen-bar assembly 10, and is also the key difference between this invention and traditional single-layer multi-pole rods. For example... Figure 1 and 2As shown, eight inner rods 12 are evenly distributed on a smaller concentric circle, collectively forming the internal ion channels. Eight outer rods 14 are evenly distributed on a larger concentric circle, enclosing the inner rods 12. (The cross-sections of all sixteen rods are preferably perfect circles to obtain a high-quality electric field. Their diameters can be the same, for example, all 1 mm. To ensure the accuracy of the electric field, the straightness, roundness, and surface finish (e.g., mirror-level through electrolytic polishing) of all rods are subject to extremely high requirements. The radial distance between the inner rods 12 and the outer rods 14, as well as the angular spacing between the rods, must be ensured through high-precision assembly, with tolerances typically at the micrometer level.) This double-layered structure is the basis for generating higher-order, stronger-constraint sixteen-pole fields.

[0024] For example Figure 1 As shown, the entire sixteen-bar assembly 10 is not macroscopically straight, but rather forms a smooth curve along its central axis A. The sole and fundamental purpose of this non-linear path design is to achieve the physical filtering of neutral noise. Figure 3 As shown, when a neutral particle (trajectory N) enters the curved inlet end 10a in a straight line, since its motion is unaffected by the electric field, it will inevitably collide with the inner wall of the curved channel (i.e., the surface of one of the inner rods 12 or outer rods 14) within a very short distance. Once the collision occurs, its kinetic energy is exhausted, and it is subsequently pumped away by the vacuum pump, thus being completely removed from the ion beam. In contrast, charged ions (trajectory P) are constrained by a strong radio frequency electric field, forcing their trajectory to bend, thus enabling them to pass smoothly through the entire channel. This design fundamentally solves the problem that existing straight conduits cannot filter out neutral noise.

[0025] As described above, the overall rotational twisting means that these sixteen rods are not simply bent; they rotate as a whole while advancing along the curved path. Looking from the inlet 10a to the outlet 10b, it can be seen that the position of each rod has undergone an angular deflection. (This twisting can be linear, meaning that the angle of rotation is the same for every unit arc length advanced.) This DNA double helix-like twisted structure applies a continuously changing transverse electric field component to the ions. As the ions move within it, their radial oscillations couple with this rotation, producing a compression effect that continuously focuses the ion beam towards the central axis A during transmission. This not only counteracts the space charge repulsion effect between ions but also effectively reduces the volume of the ion beam in phase space, ultimately forming a high-quality ion beam with a smaller divergence angle and finer beam spot at the outlet 10b, greatly improving the receiving efficiency and performance of the subsequent mass analyzer.

[0026] Preferably, the central angle of the curved arc formed by the central axis A is set to 60° to 120°.

[0027] The above defines an optimal angle range. The rationale for this range is that when the angle is less than 65°, especially close to 60°, for some large-aperture, short-length designs, some high-speed neutral particles may "graze" through, making 100% physical blocking impossible and resulting in insufficient noise reduction. On the other hand, an angle greater than 120° would lead to an overly curved and bulky structure, making it difficult to place within a compact vacuum cavity, and also imposing more stringent, even impractical, requirements on the constraint of the RF electric field. Therefore, 60° to 120° is an optimal range that strikes the best balance between ensuring thorough noise reduction, maintaining high transmission efficiency, and ensuring structural compactness.

[0028] Furthermore, the central angle is specifically 90°.

[0029] The choice of 90° as the optimal value is based on rigorous analysis of geometric optics. For a channel with a defined inner diameter and length, a 90° bend mathematically guarantees that no straight line can pass through from the inlet to the outlet without collision. This means that it can theoretically achieve 100% neutral particle and photon filtration efficiency, thereby maximizing the purification of the ion beam and providing the most reliable physical guarantee for obtaining the ultimate signal-to-noise ratio. Therefore, 90° is the best technical choice to achieve the core objective of this invention.

[0030] In one embodiment, the rod system rotates and twists as a whole from the inlet end 10a to the outlet end 10b, with a total twist angle of 15° to 45°.

[0031] A total twist angle of 15° is sufficient to significantly compress and focus the ion beam's phase space, improving ion beam quality at the exit point. Increasing the twist angle to 45° further enhances this focusing effect, with more pronounced results for higher-energy ion beams or those with particularly large initial divergence angles. However, beyond 45°, the marginal performance improvement diminishes, while the requirements for machining and assembly precision of the rod system increase dramatically, leading to a corresponding increase in manufacturing costs. Therefore, 15° to 45° is an economical and efficient preferred range for achieving effective focusing.

[0032] More preferably, the total torsion angle is specifically 30°.

[0033] This angle provides a specific torsion angle that achieves the optimal balance between performance and cost. A 30° torsion is relatively easy to manufacture, and the assembly tolerance requirements can be well met within the range of existing precision machining technologies. Meanwhile, the phase space compression effect it provides is perfectly sufficient for most conventional mass spectrometry applications. It is an optimal choice that combines excellent technical performance with good engineering feasibility. To further demonstrate the beneficial effects of this invention, this application provides the following simulation experiments and actual test data, and compares them with existing technologies.

[0034] Comparative example: A traditional 90-degree off-axis lens is used as the ion transport and deflection element. Its basic working principle is to deflect ions through an electrostatic field, thereby separating them from neutral particles that are flying in a straight line.

[0035] This invention employs the sixteen-pole ion transport structure with 90° bending and 30° torsion as described in Example 1. Its simulation model is attached. Figure 4 As shown.

[0036] 1. Simulation Comparison Please see the appendix Figure 5 and attached Figure 6 These are simulation diagrams of ion trajectories for a conventional off-axis lens and the sixteen-pole lens of this invention, respectively.

[0037] In the appendix Figure 5 In this process, after passing through the 90-degree deflection region, the ion beam (bright white trajectory) experiences severe divergence due to the lack of continuous radial confinement, resulting in a significant increase in beam diameter. This divergence effect causes a large number of ions to be lost during subsequent transport due to collisions with electrodes or chamber walls, thus severely reducing ion transport efficiency.

[0038] In comparison, as shown in the appendix Figure 6 As shown, when the ion beam (bright white trajectory) of this invention passes through the curved and rotating hexapole, the strong radial constraint force provided by the hexapole radio frequency field (RF field) firmly binds the ion beam near the central axis, effectively overcoming the centrifugal effect caused by the path curvature. Simultaneously, the 30° torsion structure of the rod system continuously compresses and focuses the ion beam, resulting in a smaller diameter, lower divergence angle, and higher ion beam "quality" at the exit end. This greatly benefits the subsequent reception and detection by the mass analyzer.

[0039] 2. Comparison of experimental data To verify its performance in actual equipment, the 90-degree off-axis lens of the comparative example and the bent rotating sixteen-pole sensor of the present invention were respectively installed in the same ICP-MS (Inductively Coupled Plasma Mass Spectrometry) system for testing, with all other conditions such as the ion source and back-end detector kept completely consistent. The experimental results are shown in Table 1 below. Table 1: Comparison of Experimental Data (Lens vs. Sixteen-Pole Sensor) (Note: CPS, Counts Per Second, is a direct reflection of signal strength.) The data in Table 1 clearly show that when testing ions with different mass numbers (Li-7, Co-59, In-115, U-238), the sixteen-pole structure of the present invention is significantly superior to the traditional lens structure in terms of ion transport flux (in tens of thousands of CPS).

[0040] To demonstrate this effect more intuitively, see attached... Figure 7 and attached Figure 8 Signal intensity comparison graphs at mass numbers of 59 and 115 are given respectively. The upper part of the graph shows the signal peak of the comparative example (lens), and the lower part shows the signal peak of the embodiment of this invention (hexadecimal pole). It can be seen that the signal response value (vertical axis) of this invention is much higher than that of the comparative example, proving that its ion transport efficiency is higher. 3. Tolerance Verification In addition, the transmission performance under different ion incident angles was simulated, and the results are shown in Table 2. Ion distribution (%) refers to the proportion of ions that finally fall within a circle with a radius of 0.5 mm at the exit, reflecting the focusing effect. Table 2: Effect of different ion incident angles on ion transmission Table 2 shows that the sixteen-pole structure of this invention maintains high transmission efficiency (71.2%) and good focusing performance (45.7%) over a large incident angle range (e.g., up to 8.0 degrees). In contrast, the performance of conventional lenses deteriorates rapidly with increasing angle, with a transmission efficiency of only 11.6% at 8.0 degrees and complete ion beam divergence (distribution of 0). This demonstrates that this invention has stronger capture and guidance capabilities for ion beams with larger initial divergence angles, i.e., better ion reception. Conclusion: In summary, both simulations and actual experimental data have confirmed that, compared with existing technologies, this invention can simultaneously achieve efficient filtering of neutral particles (through a 90° curved structure) and efficient transmission and focusing of ion beams (through a curved and rotating sixteen-pole field), fundamentally solving the technical problem of the contradiction between transmission efficiency and noise suppression in the prior art.

[0041] Furthermore, the eight inner rods 12 are configured to collectively form an octupole radio frequency electric field. This feature reveals the fundamental structure of the electric field. When positive and negative phase radio frequency voltages are alternately applied to the eight inner rods 12 (e.g., adjacent rods have opposite RF phases), they generate a pure octupole electric field in the central region. The key advantage of the octupole field is that the pseudopotential well it generates in the central region is much wider than that of a conventional quadrupole field, and the potential energy distribution is much flatter. This means that ions can exist stably over a larger radial range, rather than being strongly pushed towards the central axis as in a quadrupole field. This "gentle" confinement characteristic is highly advantageous for capturing ion beams with wide initial position and velocity distributions, effectively reducing initial ion loss.

[0042] Preferably, the inner rod 12 and the outer rod 14 are configured to work together to form a sixteen-pole radio frequency electric field.

[0043] When radio frequency voltages are applied simultaneously to both the inner and outer rod systems (e.g., one set of RF voltages is applied to the inner rod, and another set of RF voltages of the same frequency but different amplitudes or phases are applied to the outer rod), the electric fields they generate will superimpose and interfere, ultimately forming a high-order multipole field in the central region with a hexadecapole field as the main component. The hexadecapole field is the physical basis for this invention's core function of "high-efficiency transmission under large-angle bending." Compared to the octapole field, the pseudopotential well of the hexadecapole field is wider and flatter in the central region, meaning it can accommodate larger and more divergent ion beams. More importantly, the "well walls" of its pseudopotential well—that is, the repulsive potential energy far from the central axis—rise much steeper than in the octapole field. This "wide-bottomed, steep-walled" potential well shape provides unparalleled strong radial confinement. When the ion beam attempts to escape to the outside of the bend due to centrifugal effect, it immediately encounters a sharply increased repulsive potential energy and is forcefully pushed back to the central region. It is this super-strong confinement that allows the ion beam to "easily" pass through a 90° sharp turn with almost no loss.

[0044] In one embodiment, during actual production and manufacturing, the inner rod 12 and the outer rod 14 are precisely fixed by an insulating support 20 to maintain their concentric arrangement and relative positional relationship.

[0045] This is a necessary component for realizing the entire precision structure. For example... Figure 1 and 2As shown, an insulating support 20 is typically installed at both the inlet end 10a and the outlet end 10b. These supports 20 are usually designed as end caps or flanges, with sixteen through holes precisely machined on them corresponding to the cross-section of the rod system. The ends of the sixteen rods are precisely inserted into these through holes and fixed in place. Their core functions are twofold: first, mechanical positioning, which ensures the relative positions of all sixteen rods with extremely high precision (micrometer level), including concentricity, radial distance, and angular spacing—a prerequisite for forming a high-quality sixteen-pole field; second, electrical insulation, which ensures electrical isolation between the rods and between the rod system and the external vacuum chamber, preventing short circuits. (Preferably, the insulating support 20 is made of ceramic (such as alumina ceramic) or high-performance engineering plastic PEEK (polyetheretherketone). These materials are chosen because they simultaneously possess extremely high volume resistivity, excellent mechanical strength and rigidity, extremely low vacuum outgassing rate, and good high-temperature resistance and chemical corrosion resistance, making them ideal structural and insulating materials for high vacuum and high-voltage environments.) Preferably, the inner rod 12 and the outer rod 14 are configured to be connected to independent radio frequency power supplies and DC power supplies, respectively.

[0046] By providing independent power supplies to the inner and outer rod systems, the operator can: 1) independently adjust the amplitude of the radio frequency (RF) voltage applied to the inner and outer rods. By changing the voltage ratio between the two, the weights of the octet and hexadecimal components in the hexadecimal field can be finely adjusted, thereby changing the shape of the pseudopotential trap to optimize ion transport within a specific m / z range; 2) independently adjust the phase relationship of the RF voltages of the inner and outer rod systems to further fine-tune the electric field morphology; 3) based on the RF voltage, superimpose different DC bias voltages on the inner and outer rod systems to establish an axial DC electric field gradient within the entire curved and rotating ion transport structure, used to guide and accelerate / decelerate ions and control their flight time. This high degree of electrical control freedom allows the structure to be precisely tuned to adapt to various ion types and application scenarios, achieving optimal performance.

[0047] Example 2 This embodiment provides a high-performance mass spectrometer, the core improvement of which is that it adopts the bent-rotating ion transport structure 100 described in detail in Embodiment 1.

[0048] The overall structure of the mass spectrometer includes, in sequence: an atmospheric pressure ion source (e.g., an ESI source), a multi-stage differential vacuum system, a bending and rotating ion transport structure 100 disposed in the vacuum system, a mass analyzer (e.g., a triple quadrupole or time-of-flight analyzer), and an ion detector.

[0049] Its workflow is as follows: 1. Ion generation: The sample solution is atomized and ionized through the ESI source, generating a large number of charged ions and neutral solvent molecules at near atmospheric pressure.

[0050] 2. Ion introduction and preliminary transport: A mixed beam containing ions and neutral interfering substances enters the first stage of the vacuum system through a capillary or orifice, driven by a pressure gradient.

[0051] 3. Core Transport and Purification: The mixed beam then enters the inlet 10a of the curved rotating ion transport structure 100 of the present invention. Here, as in Example 1, neutral particles and photons are completely filtered out because they cannot bend. Simultaneously, the target ions are transported efficiently and without loss in a strong, curved, torsional sixteen-pole field and focused into a high-quality ion beam that exits from the outlet 10b.

[0052] 4. Mass Analysis and Detection: This extremely pure and well-focused ion beam then enters a mass analyzer under high vacuum conditions, where it is separated according to its mass-to-charge ratio. The separated ions sequentially reach the detector, are converted into electrical signals, and finally form a mass spectrum.

[0053] In the mass spectrometer of this embodiment, due to the introduction of the bent and rotating ion transport structure 100, the final mass spectrum exhibits an unprecedentedly clean baseline and extremely high target signal intensity, which fundamentally improves the signal-to-noise ratio, detection limit, and accuracy of quantitative analysis of the entire instrument.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bent-rotating ion transport structure (100), characterized in that, include: A sixteen-bar assembly (10) having an inlet end (10a) and an outlet end (10b), the sixteen-bar assembly (10) comprising: Eight concentrically arranged inner rods (12); and Eight outer rods (14) arranged concentrically on the outside of the inner rod (12); The sixteen-bar assembly (10), which is composed of the inner rod (12) and the outer rod (14), has a central axis (A) extending along its length direction, which is formed as a curved arc; and the rod system of the sixteen-bar assembly (10) has an overall rotational torsion along the curved central axis (A) from the inlet end (10a) to the outlet end (10b).

2. The bent-rotation ion transport structure (100) according to claim 1, characterized in that, The central angle of the curved arc formed by the central axis (A) is set to 60° to 120°.

3. The bent-rotation ion transport structure (100) according to claim 2, characterized in that, The central angle is 90°.

4. The bent-rotation ion transport structure (100) according to claim 1, characterized in that, The entire rod system rotates and twists from the inlet end (10a) to the outlet end (10b), with a total twist angle of 15° to 45°.

5. The bent-rotation ion transport structure (100) according to claim 4, characterized in that, The total torsion angle is 30°.

6. The bent-rotation ion transport structure (100) according to claim 1, characterized in that, The eight inner rods (12) are configured to together form an octagonal radio frequency electric field.

7. The bent-rotation ion transport structure (100) according to claim 6, characterized in that, The inner rod (12) and the outer rod (14) are configured to work together to form a sixteen-pole radio frequency electric field.

8. The bent-rotation ion transport structure (100) according to claim 1, characterized in that, It also includes at least one insulating support (20), through which the inner rod (12) and the outer rod (14) are fixed to maintain their concentric arrangement and relative positional relationship.

9. The bent-rotation ion transport structure (100) according to claim 1, characterized in that, The inner rod (12) and the outer rod (14) are respectively configured to be connected to independent radio frequency power supply and DC power supply.

10. A mass spectrometer, characterized in that, Includes the bent-rotation ion transport structure (100) as described in any one of claims 1 to 9.

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