Time-of-flight mass spectrometer

Abstract

The time-of-flight mass spectrometer provided by the embodiment of the application comprises a flight tube, a detector and an ion focusing assembly, the detector and the ion focusing assembly are arranged in the flight tube, the ion focusing assembly is arranged at the front end of the detector, the flight tube is used for flight control of ions, the ion focusing assembly is used for focusing of the ions after flight, and the detector is used for detection of the focused ions. Through focusing of the ions after flight, the number of ions detected by the detector can be improved, and the sensitivity of the time-of-flight mass spectrometer is higher.

Description

Technical Field

[0001] This application belongs to the field of time-of-flight mass spectrometry technology, and particularly relates to a time-of-flight mass spectrometer. Background Technology

[0002] Time-of-flight mass spectrometry (TOF MS) is a commonly used instrument for measuring the mass-to-charge ratio of ions. TOF MS separates ions with different mass-to-charge ratios by utilizing the physical property of the flight time of ions in an electric field region and a non-electric field region. In existing TOF instruments, ions flying in the flight tube have a velocity component perpendicular to the flight plane, in addition to the vertical velocity component. The horizontal velocity component is often not uniform but exhibits a broadened velocity distribution. Due to the relatively long flight tube, after a period of flight, the spatial distribution of ions after reaching the microchannel plate (MCP) detector is much larger than the effective detection area of ​​the detector. Most ions exceeding the effective area of ​​the MCP detector will not be detected by the MCP detector, resulting in low sensitivity of the TOF MS instrument. Summary of the Invention

[0003] To address the aforementioned issues, this application provides a time-of-flight mass spectrometer that can improve the detection sensitivity of the time-of-flight mass spectrometer.

[0004] This application provides a time-of-flight mass spectrometer, including: a flight tube, a detector, and an ion focusing assembly. The detector and the ion focusing assembly are disposed inside the flight tube, with the ion focusing assembly located at the front end of the detector. The flight tube is used for flight control of ions, the ion focusing assembly is used for focusing the ions after flight, and the detector is used for detecting the focused ions.

[0005] In some embodiments, the ion focusing assembly includes an ion funnel, the ion funnel including a plurality of first annular electrodes, the plurality of first annular electrodes being coaxially arranged, and the inner diameter of the annular electrode at the inlet end of the ion funnel being larger than the inner diameter of the annular electrode at the outlet end of the ion funnel.

[0006] In some embodiments, the ion focusing assembly further includes an electrostatic lens, each of the electrostatic lenses comprising: two second annular electrodes, the two second annular electrodes being coaxially arranged, and the distance between the two second annular electrodes being less than a preset distance.

[0007] In some embodiments, the first annular electrode and the second annular electrode are coaxially arranged, and the second annular electrode is disposed between the two first annular electrodes.

[0008] In some embodiments, the time-of-flight mass spectrometer further includes: an orthogonal accelerator, an ion trap, and a first electrostatic lens group. The ion trap is disposed between the first electrostatic lens group and the orthogonal accelerator. The ion trap is used to capture, store, and manipulate ions output from the first electrostatic lens group and to send the ions into the orthogonal accelerator.

[0009] In some embodiments, the ion trap includes: two ion trap end electrodes, an intermediate storage region, and two ion trap field isolation electrodes. The intermediate storage region is disposed inside the two ion trap field isolation electrodes. One ion trap field isolation electrode corresponds to one ion trap end electrode, and one of the ion trap field isolation electrodes is disposed inside the corresponding ion trap end electrode.

[0010] In some embodiments, the inner surface of each ion trap end electrode has a conical space, the small end opening of the conical space is used for ion entry, and the large end opening of the conical space is disposed opposite to an ion trap field isolation electrode, the ion trap field isolation electrode having an opening that connects the conical space and the intermediate storage region.

[0011] In some embodiments, the intermediate storage region has an ion release port for delivering ions into the orthogonal accelerator.

[0012] In some embodiments, the intermediate storage region includes: a plurality of ion trap intermediate electrode plates, the plurality of ion trap intermediate electrode plates forming a ring-shaped storage region, and an ion release port on the ion trap intermediate electrode plate near the orthogonal accelerator.

[0013] In some embodiments, the time-of-flight mass spectrometer further includes a collision cell, a second electrostatic lens group, and a mass analyzer. The collision cell is provided with an ion focusing and collision fragmentation assembly, and the second electrostatic lens group is disposed between the collision cell and the mass analyzer.

[0014] The beneficial effects of the embodiments in this application compared with the prior art are:

[0015] The time-of-flight mass spectrometer provided in this application includes a flight tube, a detector, and an ion focusing assembly. The detector and the ion focusing assembly are disposed inside the flight tube, with the ion focusing assembly positioned at the front end of the detector. The flight tube is used for flight control of ions, the ion focusing assembly is used for focusing the ions after flight, and the detector is used for detecting the focused ions. By focusing the ions after flight, the number of ions detected by the detector can be increased, thereby making the time-of-flight mass spectrometer more sensitive. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the structure of a time-of-flight mass spectrometer in a related art, provided in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the structure of a time-of-flight mass spectrometer provided in an embodiment of this application;

[0019] Figure 3 A cross-sectional view of an ion funnel provided in an embodiment of this application;

[0020] Figure 4 A cross-sectional view of an ion focusing assembly provided in an embodiment of this application;

[0021] Figure 5 A schematic diagram showing the placement of an ion trap according to an embodiment of this application;

[0022] Figure 6 A schematic diagram of an ion trap provided in an embodiment of this application;

[0023] Figure 7 This is a schematic diagram of the structure of a trap field isolation electrode provided in an embodiment of this application;

[0024] Figure 8 A schematic diagram of the structure of an ion trap intermediate electrode plate near an orthogonal accelerator provided in this application embodiment;

[0025] 1. Flight tube; 11. Field-free flight zone of the flight tube; 12. Flight tube deflector; 2. Detector; 3. Ion focusing assembly; 31. First annular electrode; 32. Second annular electrode; 4. Orthogonal accelerator; 5. First electrostatic lens group; 6. Collision cell; 7. Second electrostatic lens group; 8. Mass analyzer; 9. Ion focusing and collision fragmentation assembly; 10. Ion trap; 101. Ion trap end electrode; 102. Intermediate storage region; 103. Ion trap field isolation electrode; 100. Ion trap equipotential line; 200. Ion confinement region. Detailed Implementation

[0026] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0027] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0028] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0029] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrases "if determined" or "if detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once detected," or "in response to detection."

[0030] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0032] Time-of-flight mass spectrometry (TOF MS) is a commonly used instrument for measuring the mass-to-charge ratio of ions. TOF MS separates ions with different mass-to-charge ratios by utilizing the physical property of the flight time of ions in an electric field region and a non-electric field region. The ions separated according to their mass-to-charge ratio are then detected by an MCP (multi-channel plane) detector. Since a longer flight tube results in higher relative resolution of ions, the electric field region in TOF systems is typically designed as an electric field deflector to change the direction of ion movement, thus doubling the flight path length. Figure 1 A schematic diagram of the structure of a time-of-flight mass spectrometer in a related art, as provided in an embodiment of this application, is shown below. Figure 1 As shown, flight tube 1 contains a field-free flight zone and a deflector. The deflecting electric field in flight tube 1 of TOF MS instruments typically employs a two-order electric field design to focus the temporal dispersion caused by ion energy dispersion. However, ions flying in flight tube 1 possess not only a vertical velocity component but also a velocity component perpendicular to the flight plane. Their horizontal velocity components are often not uniform but exhibit a broadened velocity distribution. Due to the relatively long length of the flight tube, after a period of flight, the spatial distribution of ions upon reaching the MCP detector is much larger than the effective detection area of ​​the MCP detector. Most ions exceeding the effective area of ​​the MCP detector will not be detected by the MCP, resulting in low sensitivity of the TOF instrument.

[0033] Based on the technical problems in related technologies, this application provides a time-of-flight mass spectrometer. Figure 2 This is a schematic diagram of the structure of a time-of-flight mass spectrometer provided in an embodiment of this application, as shown below. Figure 2 As shown, the time-of-flight mass spectrometer includes: a flight tube 1, a detector 2, and an ion focusing assembly 3. The detector 2 and the ion focusing assembly 3 are disposed inside the flight tube 1, with the ion focusing assembly 3 located at the front end of the detector 2. The flight tube 1 is used for flight control of ions, the ion focusing assembly 3 is used for focusing the ions after flight, and the detector 2 is used for detecting the focused ions.

[0034] In this embodiment, the flight tube 1 is the core component for ion free flight and mass separation. The main function of the flight tube 1 is to control the flight process of ions within it. By applying appropriate electric fields and other conditions, the ions are guided to fly along a predetermined path, ensuring that the ions do not deviate from their flight trajectory due to diffusion, collisions, or other factors during flight. The flight tube 1 includes a field-free flight region 11 and a flight tube deflector 12. The field-free flight region 11 is the ion flight region in the time-of-flight mass spectrometer that remains electrically neutral and is free from electric or magnetic fields. It is the core functional area for mass separation. The field-free flight region 11 is typically a cylindrical metal cavity. The flight tube deflector 12 is an active control device for controlling the ion flight trajectory. The flight tube deflector is located at the end of the field-free flight region 11. After being deflected by the flight tube deflector 12, the ions re-enter the field-free flight region 11 to continue their flight.

[0035] In this embodiment, detector 2 is a component in a time-of-flight mass spectrometer used to detect ion signals. It converts the ion signal into a measurable electrical signal or other form of signal for subsequent data processing and analysis. The detector is typically a microchannel plate (MCP) detector. An MCP consists of numerous tiny channels. When ions collide with the surface of the microchannel plate, secondary electron emission occurs within the channels. These secondary electrons are accelerated by the electric field within the channels and collide with the channel walls, generating more electrons and creating an electron avalanche effect. This amplifies the single ion signal into a measurable electrical pulse signal. Microchannel plate detectors have advantages such as high sensitivity and fast response speed.

[0036] In this embodiment, the ion focusing component 3 is disposed at the front end of the detector 2 to focus the ions after they have passed through the flight tube 1, enabling the ions to reach the detector 2 more concentratedly and improving the detection efficiency and sensitivity of the detector 2. Since ions may diffuse during flight due to various factors (such as initial kinetic energy dispersion, space charge effect, etc.), the ion beam becomes dispersed when it reaches the detector. The function of the ion focusing component 3 is to refocus the dispersed ions into a narrower ion beam by applying a suitable electric or magnetic field, allowing more ions to reach the effective detection area of ​​the detector 2.

[0037] In this embodiment, the ion focusing component 3 focuses the ions after flight by means of spatial focusing and / or temporal focusing. Spatial focusing reduces the spatial dispersion of the ion beam, while temporal focusing compensates for the initial kinetic energy difference.

[0038] In this embodiment of the application, the ion focusing component 3 may include: an ion funnel and / or an electrostatic lens.

[0039] The time-of-flight mass spectrometer of this application includes a flight tube, a detector, and an ion focusing assembly. The detector and the ion focusing assembly are disposed inside the flight tube, with the ion focusing assembly located at the front end of the detector. The flight tube is used for flight control of ions, the ion focusing assembly is used for focusing the ions after flight, and the detector is used for detecting the focused ions. By focusing the ions after flight, the number of ions detected by the detector can be increased, thereby making the time-of-flight mass spectrometer more sensitive.

[0040] In some embodiments, the ion focusing assembly includes an ion funnel. The ion funnel includes a plurality of first annular electrodes 31, which are coaxially arranged, wherein the inner diameter of the annular electrode at the inlet end of the ion funnel is larger than the inner diameter of the annular electrode at the outlet end of the ion funnel.

[0041] In some embodiments, the inner diameter of the plurality of first annular electrodes 31 in the ion funnel gradually decreases from the inlet end to the outlet end of the ion funnel. For example, there are 9 first annular electrodes, the inner diameter of the first annular electrode at the inlet end is 10 mm, and the inner diameter of the first annular electrode from the inlet end to the outlet end decreases by 1 mm in sequence.

[0042] In the embodiments of this application, Figure 3 A cross-sectional view of an ion funnel provided in an embodiment of this application, as shown below. Figure 3 As shown, the ion funnel is typically conical or funnel-shaped and consists of a series of first annular electrodes 31 with a central hole. The first annular electrode 31 is a ring-shaped electrode that serves as a key component in the ion funnel. It generates an electric field by applying voltage, thereby exerting a force on the ions and influencing their trajectory. The first annular electrode 31 can be made of materials with good conductivity and mechanical strength, such as stainless steel or copper. Coaxial arrangement means that the central axes of multiple first annular electrodes 31 coincide, and they are arranged around the same central axis. This arrangement helps to form a stable and regular electric field distribution, facilitating precise control and focusing of ions. The distance between the multiple first annular electrodes 31 can be set according to design requirements, and the distance between the first annular electrodes 31 needs to be uniform. The inlet end of the ion funnel is the area where ions enter the ion funnel; this area has a relatively large space to facilitate the smooth entry of ions into the ion funnel. The outlet end of the ion funnel is the area where ions exit the ion funnel; this area has a relatively small space, which helps to output the focused ion beam in a narrower shape. By setting a larger inner diameter at the inlet, ions can enter the ion funnel more easily, reducing ion loss at the inlet. Simultaneously, due to the difference in inner diameter between the inlet and outlet, ions are subjected to a gradually increasing radial electric field constraint after entering the ion funnel, thus achieving initial ion focusing and guiding the dispersed ions towards the central axis.

[0043] In this embodiment, by applying an appropriate voltage to the first annular electrode, a radial electric field is formed, causing ions to be subject to radial constraint after entering the ion funnel, thereby focusing them onto the central axis of the funnel and achieving the function of ion focusing. The voltage applied to the first annular electrode can be precisely controlled by an electronic control system. Devices such as microprocessors or programmable logic controllers (PLCs) can be used to adjust the voltage magnitude and polarity of each annular electrode according to a preset program or real-time feedback signals to achieve the best ion focusing effect. For example, when ions enter the ion funnel, the voltage of the annular electrode at the inlet end is appropriately adjusted to allow the ions to enter smoothly and begin the focusing process; during the ion movement, the voltage of each annular electrode is dynamically adjusted according to the ion's position and velocity information to ensure that the ions always move along the central axis and are effectively focused.

[0044] The time-of-flight mass spectrometer provided in this application improves the number of ions detected by the detector by setting an ion funnel to focus the ions after flight, thereby making the time-of-flight mass spectrometer more sensitive.

[0045] Since the addition of an ion funnel can lead to a decrease in the time-of-flight resolution of ions, in order to improve the time resolution, in some embodiments, the ion focusing assembly further includes an electrostatic lens, each of which includes two second annular electrodes, the distance between the two second annular electrodes being less than a preset distance.

[0046] In this embodiment, the ion funnel is used to radially constrain and initially focus the ions, while the electrostatic lens can further optimize the focusing effect of the ion beam.

[0047] In this embodiment, the preset distance is the spacing between the two second annular electrodes. For example, Figure 4 A cross-sectional view of an ion focusing assembly provided in an embodiment of this application, as shown below. Figure 4 As shown, the two second annular electrodes 32 are relatively close together, and an electrostatic lens effect can be achieved by applying a voltage to the second annular electrodes 32. In the ion funnel, by adjusting the distance between specific annular electrodes, a specific electric field distribution is formed in the corresponding area, thereby achieving the focusing effect on ions.

[0048] In this embodiment, the first annular electrode 31 and the second annular electrode 32 can be coaxially arranged. Alternatively, two second annular electrodes 32 can be coaxially arranged, with the second annular electrodes disposed on two of the first annular electrodes.

[0049] By placing the second ring electrode between the two first ring electrodes, better time resolution can be achieved before ions reach the ion detector, allowing different ions to arrive at the detector at closer times. The second ring electrode can be placed between any two first ring electrodes.

[0050] In some embodiments, the second annular electrode is disposed between the two first annular electrodes near the outlet of the ion funnel.

[0051] In this embodiment of the application, by inserting a second annular electrode between the two first annular electrodes near the exit end, the temporal focusing performance of the ion beam can be significantly improved, thereby improving the temporal resolution of ions arriving at the detector.

[0052] In this embodiment, the voltage applied to the first and second annular electrodes can be precisely controlled by an electronic control system. A microprocessor or programmable logic controller (PLC) can be used to adjust the voltage magnitude and polarity of each annular electrode according to a preset program or real-time feedback signals to achieve optimal ion focusing. For example, when ions enter the ion funnel, the voltage of the first annular electrode at the inlet is appropriately adjusted to allow ions to enter smoothly and begin the focusing process; when ions move to the electrostatic lens, the voltage of the second annular electrode is adjusted to generate a suitable electric field strength, thereby improving the quality of time resolution; when ions leave the ion funnel, the voltage of the first annular electrode at the outlet is adjusted to ensure stable ion output.

[0053] The time-of-flight mass spectrometer provided in this application includes an ion focusing component comprising an ion funnel and an electrostatic lens, which enables spatial and temporal focusing of ions entering the MCP, thereby achieving better temporal resolution of the MCP and allowing the detector to detect more ions, thus improving the sensitivity of the TOF while ensuring the time resolution of the TOF.

[0054] In some embodiments, one or more electrostatic lenses may be provided to achieve spatial and temporal focusing of ions.

[0055] In some embodiments, Figure 5 This is a schematic diagram of an enlarged ion trap provided in an embodiment of this application. See also... Figure 2 and Figure 5 The time-of-flight mass spectrometer also includes an orthogonal accelerator 4, an ion trap 10, and a first electrostatic lens group 5. The ion trap 10 is disposed between the first electrostatic lens group 5 and the orthogonal accelerator 4. The ion trap 10 is used to capture, store, and manipulate ions output from the first electrostatic lens group 5 and send the ions into the orthogonal accelerator 4.

[0056] In this embodiment, the orthogonal accelerator 4 is used to orthogonally accelerate ions and send the orthogonally accelerated ions into the flight tube 1.

[0057] In this embodiment, the orthogonal accelerator 4 enables ions to gain additional kinetic energy in a direction perpendicular to their initial direction of motion, thereby altering their flight trajectory and velocity to meet the requirements of subsequent time-of-flight analysis. The orthogonal accelerator 4 includes: an orthogonal accelerator body, an orthogonal accelerator ion detection end lens group, and an orthogonal accelerator incident lens group. The orthogonal accelerator body generally consists of one or more sets of electrodes. By rationally designing the electrode layout and the voltage applied to the electrodes, an electric field perpendicular to the initial direction of ion motion is generated.

[0058] An ion trap 10 is a device capable of capturing, storing, and manipulating ions. It confines ions within a defined spatial region using a specific electric field and allows for precise control over the ion's motion and energy, enabling pre-processing such as ion enrichment and mass selection. The ion trap 10 needs to be able to introduce ions from a first electrostatic lens group into the ion trap and release ions to an orthogonal accelerator at appropriate times. For example, during ion introduction, the voltage of certain electrodes is reduced to allow ions to smoothly enter the trap; during ion release, the electrode voltage is adjusted to give the ions sufficient energy to escape from the trap. The first electrostatic lens group is used to focus, guide, and shape the ion beam using an electrostatic field, ensuring that the ions move along a predetermined path.

[0059] In some embodiments, Figure 6 This is a schematic diagram of the structure of an ion trap provided in an embodiment of this application, as shown below. Figure 6 As shown, the ion trap 10 includes: two ion trap end electrodes 101, an intermediate storage region 102, and two ion trap field isolation electrodes 103. The intermediate storage region 102 is disposed inside the two ion trap field isolation electrodes 103. One ion trap field isolation electrode 103 corresponds to one ion trap end electrode 101, and one of the ion trap field isolation electrodes 103 is disposed inside the corresponding ion trap end electrode 101.

[0060] In some embodiments, each ion trap end electrode 101 has a conical space on its inner surface. The small end opening of the conical space is used for ion entry, and the large end opening of the conical space is disposed opposite to an ion trap field isolation electrode 103. The ion trap field isolation electrode has an opening that connects the conical space and the intermediate storage region 102. The intermediate storage region 102 has an ion release port for sending ions into the orthogonal accelerator.

[0061] In this embodiment, the ion trap end electrode 101 has a spatially shaped structure on its inner surface to generate an electric field that facilitates ion capture and guidance. The intermediate storage region 102, located between two ion trap field isolation electrodes 103, is the space within the ion trap used for actual ion storage. Ions remain relatively stable within this region, awaiting subsequent release and further processing. The ion trap field isolation electrodes 103 isolate the internal and external electric fields of the ion trap, reducing interference from the external electric field on ion movement and storage within the ion trap, and ensuring the stability of the internal electric field and the accuracy of ion manipulation. The special spatial shape of the inner surface of the ion trap end electrode, with its cross-sectional area gradually changing from one end to the other, features a small opening for ion entry and a large opening opposite to the ion trap field isolation electrodes. This shape facilitates the guidance and focusing of ions upon entering the ion trap. The ion release port, an opening on the intermediate storage region, releases ions stored within the intermediate storage region for further acceleration and analysis by subsequent components such as orthogonal accelerators.

[0062] In this embodiment, the ion trap end electrode 101 is typically made of a metallic material, such as stainless steel or copper. The conical space on its inner surface can be achieved through precision machining (such as CNC milling or EDM) to ensure the shape accuracy and surface quality of the conical space. An electronic control system (such as a microprocessor or programmable logic controller (PLC)) can be used to precisely control the voltage on the ion trap end electrode, adjusting the voltage parameters in real time according to different analytical requirements and ion states to generate the ion trap equipotential line 100. The ion trap 10 is a space enclosed by the intermediate storage region 102, the ion trap field isolation electrode 103, and the ion trap end electrode 101. The ion is confined to the ion confinement region 200 by the ion trap equipotential line 100. It should be noted that the ion trap equipotential line 100 and the ion confinement region 200 in the figure are simulated to illustrate the implementation of the ion trap. Figure 7 This is a schematic diagram of a trap field isolation electrode provided in an embodiment of this application. The trap field isolation electrode 103 can be a square electrode plate with an opening in the middle. By providing this opening, ions in the ion trap end electrode can enter the intermediate storage region 102. The shape of the ion release port opening can be set according to requirements, and can be set as a rectangle, circle, etc.

[0063] In this embodiment, the intermediate storage region includes: multiple ion trap intermediate electrode plates, which form a ring-shaped storage region. An ion release port is located on the ion trap intermediate electrode plate near the orthogonal accelerator. Figure 8 A schematic diagram of the structure of an ion trap intermediate electrode plate near an orthogonal accelerator provided in this application embodiment is shown below. Figure 8As shown, the middle electrode plate of the ion trap can be rectangular, and the ion release port can be a slit.

[0064] See also Figure 2 In some embodiments, the time-of-flight mass spectrometer further includes: a collision cell 6, a second electrostatic lens group 7, and a mass analyzer 8. The collision cell 6 is equipped with an ion focusing and collision fragmentation assembly 9. The second electrostatic lens group 7 is positioned between the collision cell 6 and the mass analyzer 8. The collision cell is the site where collision reactions occur, where charged particles collide with gas molecules or other particles. By analyzing the products after the collisions, information about particle properties and reaction mechanisms can be obtained. The mass analyzer selectively allows ions with specific mass-to-charge ratios to pass through by applying specific radio frequency and DC electric fields, thereby achieving the separation and screening of ions of different masses. The mass analyzer can be a quadrupole. The ion focusing and collision fragmentation assembly can be used to focus and guide ions, helping to control the ion trajectory in the collision cell and improving the efficiency and selectivity of the collision reaction. The ion focusing and collision fragmentation assembly can be a hexapole. The second electrostatic lens group is used to focus and guide ions in the collision cell, ensuring that ions can effectively participate in the collision reaction and guiding the reaction products to the detection area.

[0065] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A time-of-flight mass spectrometer, characterized in that, include: The system includes a flight tube, a detector, and an ion focusing assembly. The detector and the ion focusing assembly are disposed inside the flight tube, with the ion focusing assembly positioned at the front end of the detector. The flight tube is used for flight control of ions, the ion focusing assembly is used for focusing the ions after flight, and the detector is used for detecting the focused ions.

2. The time-of-flight mass spectrometer according to claim 1, characterized in that, The ion focusing assembly includes an ion funnel, which includes multiple first annular electrodes arranged coaxially. The inner diameter of the annular electrode at the inlet end of the ion funnel is larger than the inner diameter of the annular electrode at the outlet end of the ion funnel.

3. The time-of-flight mass spectrometer according to claim 2, characterized in that, The ion focusing assembly also includes an electrostatic lens, each of which includes two second annular electrodes arranged coaxially adjacent to each other, with the distance between the two second annular electrodes being less than a preset distance.

4. The time-of-flight mass spectrometer according to claim 3, characterized in that, The first annular electrode and the second annular electrode are coaxially arranged, and the second annular electrode is disposed between the two first annular electrodes.

5. The time-of-flight mass spectrometer according to claim 1, characterized in that, The time-of-flight mass spectrometer further includes an orthogonal accelerator, an ion trap, and a first electrostatic lens group. The ion trap is disposed between the first electrostatic lens group and the orthogonal accelerator. The ion trap is used to capture, store, and manipulate ions output from the first electrostatic lens group and to send the ions into the orthogonal accelerator.

6. The time-of-flight mass spectrometer according to claim 5, characterized in that, The ion trap includes: two ion trap end electrodes, an intermediate storage region, and two ion trap field isolation electrodes. The intermediate storage region is disposed inside the two ion trap field isolation electrodes. One ion trap field isolation electrode corresponds to one ion trap end electrode, and one of the ion trap field isolation electrodes is disposed inside the corresponding ion trap end electrode.

7. The time-of-flight mass spectrometer according to claim 6, characterized in that, Each ion trap end electrode has a conical space on its inner surface. The small end of the conical space is open for ion entry, and the large end of the conical space is positioned opposite an ion trap field isolation electrode. The ion trap field isolation electrode has an opening that connects the conical space and the intermediate storage region.

8. The time-of-flight mass spectrometer according to claim 6, characterized in that, The intermediate storage region has an ion release port for delivering ions into the orthogonal accelerator.

9. The time-of-flight mass spectrometer according to claim 6, characterized in that, The intermediate storage region includes: multiple ion trap intermediate electrode plates, which form a ring-shaped storage region. The ion trap intermediate electrode plates near the orthogonal accelerator have ion release ports.

10. The time-of-flight mass spectrometer according to claim 1, characterized in that, The time-of-flight mass spectrometer further includes a collision cell, a second electrostatic lens group, and a mass analyzer. The collision cell is equipped with an ion focusing and collision fragmentation assembly, and the second electrostatic lens group is disposed between the collision cell and the mass analyzer.

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