Ion collecting and focusing system and use method and application thereof

Abstract

The invention discloses an ion collecting and focusing system which comprises a rectangular electrode structure, an electric control device and ion gating devices arranged at the two ends of the rectangular electrode structure, and the ion gating devices are used for controlling ions to be led in or out of the rectangular electrode structure. The rectangular electrode structure comprises at least two electrode groups, each electrode group comprises two PCB electrode plates which are symmetrically arranged along an ion path, the PCB electrode plates between the electrode groups are alternately connected to form the rectangular electrode structure, and each PCB electrode plate is divided into at least five segmented electrodes along the direction of the ion path. The lengths of the segmented electrodes are the same or different, and the rectangular electrode structure is used for collecting and focusing ions; the ion gating device and the PCB electrode plate are respectively connected with the electric control device; the multi-reflection time-of-flight mass spectrometer has an economical and efficient rectangular electrode structure, has a good ion collecting and focusing effect, is suitable for the multi-reflection time-of-flight mass spectrometer, and can realize higher analysis performance.

Description

Technical Field

[0001] The present invention relates to the technical field of mass spectrometry analysis, and in particular to an ion collection and focusing system, a method for using the same, and an application thereof. Background Art

[0002] Mass spectrometry is an analytical method that ionizes a substance to be measured using a mass spectrometer, and then separates and collects data on charged particles in motion according to their respective mass-to-charge ratios (Mass-to-charge ratio, m / z) in an electric field or a magnetic field to obtain a mass spectrum for qualitative or quantitative detection. After more than a hundred years of rapid development, various types of mass spectrometers have emerged one after another and have become a powerful and indispensable analytical tool in the scientific field. The composition of a mass spectrometer generally includes an injection system, an ion source, a transmission and focusing system, a mass analyzer, an ion detector, and a data acquisition system, etc. According to the working principle, mass spectrometers can be classified into several types according to their mass analyzers, such as quadrupole mass analyzers, quadrupole ion trap mass analyzers, time-of-flight mass analyzers, Fourier transform mass analyzers, sector field mass analyzers, etc. The time-of-flight mass analyzer calculates the mass-to-charge ratio of ions by measuring the time it takes for ions accelerated by the same electric field over the same distance or time to reach the detector after flying for a certain distance. As a new generation of time-of-flight mass spectrometry, the multi-reflection time-of-flight (MR-TOF) mass spectrometry realizes ultra-high mass resolution by making ions fly back and forth between two sets of reflectors, extending their flight time and distance, and effectively restricting the divergence of flight time. The factors affecting the realization of ultra-high resolution by the MR-TOF mass analyzer, in addition to the design of its structure and the setting of the internal electrode voltage, also depend to a large extent on the state of ions introduced into the mass analyzer. Generally, the smaller the energy divergence and angular divergence of ions, the higher the mass resolution of the instrument. Therefore, a front end of the MR-TOF mass analyzer needs to be coupled with an ion collection and focusing system for ion collection, cooling and focusing, and uniformly ejecting them to ensure the ion focusing effect and utilization rate, so as to ensure the ultra-high resolution and high sensitivity performance of the instrument.

[0003] Currently, a linear ion trap is generally coupled to the front end of the mass analyzer in the MR-TOF mass spectrometry as an ion collection and focusing system. The linear ion trap is similar in structure to the quadrupole structure and consists of four long rods with a hyperbolic structure. Each rod is axially divided into three parts, namely the front stage, the middle stage, and the rear stage. In fact, the linear ion trap is a two-dimensional ion trap. Its power supply mode is also similar to that of the quadrupole. Adjacent rods are applied with radio frequency voltages with the same amplitude and opposite phases to achieve radial confinement of ions, and the axially divided three stages are applied with DC voltages to achieve axial confinement of ions.

[0004] The High Energy Accelerator Research Organization in Japan, the Institute of Modern Physics of the Chinese Academy of Sciences, and Hexin Instruments Co., Ltd. in Guangzhou have all developed linear ion traps based on PCB technology. Such devices are composed of only two sets of PCB electrode groups placed symmetrically in parallel.

[0005] In the prior art, linear ion traps based on PCB technology have been developed. Such devices are composed of only two sets of symmetrically placed PCB electrode groups, with a simple structure. Compared with the linear ion trap with a conventional four-electrode structure, the radiofrequency voltage applied by this ion trap based on two sets of planar electrode structures cannot form an equivalent quadrupole field effect inside the ion trap, thus limiting its mass range and increasing the risk of electrode discharge.

[0006] Traditional Paul ion traps use four curved electrodes to form an ideal quadrupole field. The ion traps in the prior art use six strip electrodes to form an approximate quadrupole field. Due to the change in its structure, the internal quadrupole field is not ideal and is not suitable for mass analysis, but is very suitable for ion storage and cooling. The four parallel upper and lower electrodes of the ion trap in the prior art simulated by Simion apply radiofrequency electricity to form a non-rational quadrupole field inside. Due to its parallel structure, the magnitude of the radiofrequency electricity applied by the ion trap in the prior art cannot form a quadrupole field with an equivalent voltage inside the ion trap. According to the simulation, the magnitude of the radial voltage of the internal quadrupole field is related to the magnitude of the applied radiofrequency voltage and is approximately equal to 1 / 2 of the radiofrequency voltage. Thus, we can know that the power supply efficiency of the planar ion trap is only 50%. When applying a radiofrequency electricity with a voltage amplitude of A, it is equivalent to applying a quadrupole field of 1 / 2*A radiofrequency electricity.

[0007] Therefore, improving the quadrupole field effect of the parallel placement structure is an urgent problem to be solved in the prior art. Summary of the Invention

[0008] To overcome the problems existing in the related art, the purpose of the present invention is to provide an ion collection and focusing system, its use method, and application.

[0009] In a first aspect, the present application provides an ion collection and focusing system,

[0010] including a rectangular electrode structure, an electric control device, and ion gating devices provided at both ends of the rectangular electrode structure. The ion gating devices are used to control the introduction or extraction of ions into or from the rectangular electrode structure;

[0011] The rectangular electrode structure includes at least two electrode groups. Each electrode group includes two PCB electrode sheets symmetrically arranged along the ion path. The PCB electrode sheets between the electrode groups are alternately connected to form the rectangular electrode structure. The PCB electrode sheets are divided into at least five segmented electrodes along the ion path direction. The lengths of the segmented electrodes are the same or different. The rectangular electrode structure is used for ion collection and focusing;

[0012] The ion gating device and the PCB electrode sheet are respectively connected to the electric control device.

[0013] In one embodiment, the rectangular electrode structure includes a first electrode group and a second electrode group. The first electrode group includes a first PCB electrode sheet and a third PCB electrode sheet symmetrically arranged along the ion path, and the second electrode group includes a second PCB electrode sheet and a fourth PCB electrode sheet symmetrically arranged along the ion path; the first PCB electrode sheet, the second PCB electrode sheet, the third PCB electrode sheet, and the fourth PCB electrode sheet are sequentially connected to form the rectangular electrode structure.

[0014] In one embodiment, the first PCB electrode sheet, the second PCB electrode sheet, the third PCB electrode sheet, and the fourth PCB electrode sheet are respectively divided into seven segmented electrodes along the ion path direction.

[0015] In one embodiment, at least one of the segmented electrodes is provided with a throwing hole for leading out ions from the rectangular electrode structure.

[0016] In one embodiment, the lengths of the segmented electrodes on the same PCB electrode sheet are the same or different.

[0017] In one embodiment, the distances between the segmented electrodes on the same PCB electrode sheet are the same or different.

[0018] In one embodiment, the thickness of the PCB electrode sheet in the ion throwing direction is less than 1 mm.

[0019] In one embodiment, the electric control device applies a controllable radio frequency bias voltage to the PCB electrode sheet, and the electric control device applies a controllable voltage to the ion gating device.

[0020] In a second aspect, the present application further provides a method for using the above ion collection and focusing system, the method includes,

[0021] Introduce a cooling gas into the rectangular electrode structure and turn on the ion gating device, and introduce ions into the rectangular electrode structure through the ion gating device;

[0022] Turn off the ion gating device to confine the ions, and apply a controllable radio frequency bias voltage to the PCB electrode sheet through the electric control device to form an equivalent voltage quadrupole field in the rectangular electrode structure, and collect and focus the ions in the rectangular electrode structure;

[0023] Extraction mode one: Turn on the ion gating device and extract the ions from the rectangular electrode structure;

[0024] Ejection mode 2: The ejection electrode with an ejection hole in the middle radially ejects ion clusters from the middle by applying pulses.

[0025] Thirdly, the present application also provides an application of the above ion collection and focusing system in a multi-reflection time-of-flight mass spectrometer.

[0026] The present invention has the following advantages and beneficial effects:

[0027] By setting a rectangular electrode structure to form a quadrupole field with an equivalent voltage inside, and being able to improve its power supply efficiency, the rectangular electrode structure includes at least two electrode groups, and the PCB electrode sheets between the electrode groups are alternately connected to form a rectangular electrode structure. Applying radio frequency electricity to the PCB electrode sheets of the rectangular electrode structure forms a quadrupole field with an equivalent voltage, thus solving the problem that the planar ion trap cannot form a quadrupole field with an equivalent voltage due to its parallel placement structure;

[0028] The present invention can achieve the ion cooling and focusing effect by using the rectangular electrode structure composed of PCB electrode sheets. Since the entire rectangular electrode structure is composed of PCB electrode sheets, this not only significantly reduces the difficulty of processing and assembly, but also greatly reduces the production cost. Therefore, the present invention provides an ion collection and focusing device with an economical and efficient rectangular electrode structure, which is applicable to a multi-reflection time-of-flight mass spectrometer, enabling it to have uniform initial energy and low energy divergence in the mass analyzer, enabling the multi-reflection time-of-flight mass spectrometer to achieve higher analysis performance, reach higher mass resolution, and at the same time solve the problems brought by the two-electrode structure placed in parallel in the prior art.

[0029] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will be obvious from the specification, or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the written specification, claims, and drawings. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0031] Figure 1 It is a schematic diagram of the rectangular electrode structure of the ion collection and focusing system in Embodiment 1 of the present invention;

[0032] Figure 2 It is a schematic top view structure diagram of the ion collection and focusing system in the embodiment of the present invention;

[0033] Figure 3 Schematic side view structure diagram of the ion collection and focusing system in the embodiment of the present invention;

[0034] Figure 4 Working timing diagram of the ion collection and focusing system in the embodiment of the present invention.

[0035] Reference numerals:

[0036] 1. First PCB electrode sheet; 2. Second PCB electrode sheet; 3. Third PCB electrode sheet; 4. Fourth PCB electrode sheet; 5. Segmented electrode; 10. Ion gating device; 11. Ejection hole. Detailed implementation manners

[0037] The optional embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the optional embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "the" and "said" used in the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0039] It should be understood that although the terms "first", "second", "third", etc. may be used in the present invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other.

[0040] The methods and devices adopted in the present invention, unless otherwise specified, are all conventional reagents, methods and devices in the technical field of the present technology.

[0041] For the convenience of understanding the embodiments of the present invention, the multi-reflection time-of-flight in the related art will be described first. In the prior art, the multi-reflection time-of-flight (MR-TOF) mass spectrometry is a new generation of time-of-flight mass spectrometry. By making ions fly back and forth between two sets of reflectors, its flight time and distance are extended, and the flight time divergence is effectively restricted, thereby achieving ultra-high mass resolution. The factors affecting the achievement of ultra-high resolution by the MR-TOF mass analyzer, in addition to the design of its structure and the setting of the internal electrode voltage, also depend to a large extent on the ion state introduced into the mass analyzer. Generally, the smaller the energy divergence and angular divergence of ions, the higher the mass resolution of the instrument. Therefore, a front end of the MR-TOF mass analyzer needs to be coupled with an ion collection and focusing system for ion collection, cooling and focusing, and uniformly ejecting them to ensure the ion focusing effect and utilization rate, so as to ensure the ultra-high resolution and high sensitivity performance of the instrument; due to the parallel placement structure of the radio frequency electricity applied by the ion trap in the prior art, a quadrupole field with an equivalent voltage cannot be formed inside the ion trap. According to simulations, the magnitude of the radial voltage of the internal quadrupole field is related to the magnitude of the applied radio frequency electricity voltage, approximately equal to 1 / 2 of the radio frequency voltage. From this, we can know that the power supply efficiency of the planar ion trap is only 50%. When applying a radio frequency electricity with a voltage amplitude of A, an equivalent quadrupole field of 1 / 2*A radio frequency electricity is applied. Therefore, improving the quadrupole field effect of the parallel placement structure is an urgent problem to be solved in the prior art. Based on this, the present application provides an ion collection and focusing system.

[0042] As shown in the attached Figures 1 - 3 figure, an ion collection and focusing system provided by Embodiment 1 of the present application

[0043] includes a rectangular electrode structure, an electronic control device, and ion gating devices 10 provided at both ends of the rectangular electrode structure. The ion gating devices 10 are used to control the introduction or extraction of ions into or from the rectangular electrode structure;

[0044] The rectangular electrode structure includes at least two electrode groups. Each electrode group includes two PCB electrode sheets symmetrically arranged along the ion path. The PCB electrode sheets between the electrode groups are alternately connected to form the rectangular electrode structure. The PCB electrode sheets are divided into at least five segmented electrodes 5 along the ion path direction. The lengths of the segmented electrodes 5 are the same or different. The rectangular electrode structure is used for ion collection and focusing;

[0045] The ion gating devices 10 and the PCB electrode sheets are respectively connected to the electronic control device.

[0046] By setting a rectangular electrode structure to form a quadrupole field with an equivalent voltage inside, and being able to improve its power-on efficiency, the rectangular electrode structure includes at least two electrode groups, and the PCB electrode sheets between the electrode groups are alternately connected to form a rectangular electrode structure. Applying radio frequency electricity to the PCB electrode sheets of the rectangular electrode structure forms a quadrupole field with an equivalent voltage, thus solving the problem that the planar ion trap cannot form a quadrupole field with an equivalent voltage due to its parallel placement structure;

[0047] Through the use of a rectangular electrode structure composed of PCB electrode sheets, the present invention can achieve an ion cooling and focusing effect. Since the entire rectangular electrode structure is composed of PCB electrode sheets, this not only significantly reduces the difficulty of processing and assembly, but also greatly reduces the production cost. Therefore, the present invention provides an ion collection and focusing device with an economical and efficient rectangular electrode structure, which is applicable to a multi-reflection time-of-flight mass spectrometer, enabling it to have uniform initial energy and low energy divergence in the mass analyzer, enabling the multi-reflection time-of-flight mass spectrometer to achieve higher analysis performance and higher mass resolution, while solving the problems brought by the two-electrode structure placed in parallel in the prior art;

[0048] It should be noted that the control of structural parameters such as the ion trap field radius and the size of the segmented electrode 5 of the rectangular electrode structure can be adjusted according to the actual situation. Similarly, the control of electrical parameters in the ion collection and focusing system, the introduction duration, confinement duration, ejection duration, etc. of ions can also be adjusted according to the actual situation. Similarly, the ion collection and focusing system of this embodiment is not limited to functions such as ion collection, cooling, and ejection. The number and direction of ion introduction and ejection are not fixed and can be adjusted according to the actual use situation.

[0049] It should be noted that the PCB electrode sheet is divided into at least five segmented electrodes 5 along the ion path direction. When the PCB electrode sheet is divided into five segmented electrodes 5 along the ion path direction, the scheme is to set a pair of electrodes on each side of the ejection hole, which is the minimum unit for forming a gradient voltage. It should also be noted that during the mass scanning process, the system selects the target ion mass number by changing the frequency of the quadrupole field and moderately reduces the high voltage requirement, thereby effectively reducing the discharge risk of the equipment. Since the planar ion trap adopts a symmetric parallel placement structure, the applied radio frequency voltage cannot form an ideal quadrupole field effect inside the ion trap, resulting in a limited mass range and an increased risk of electrode discharge. In contrast, with its four-electrode structure, the approximate quadrupole field formed by this system in the trap can more effectively confine ions in a larger mass range. Compared with the traditional rectangular ion trap, this system uses multi-electrode regulation and the radial ejection method of ions, making the confined ion beam focus into a cluster and enter the time-of-flight mass spectrometer, significantly improving the analysis performance.

[0050] In an alternative embodiment of the present invention, the PCB electrode sheet is divided into at least seven segmented electrodes 5 along the ion path direction; the design of the segmented electrodes 5 allows for more flexible control of the electric field. By dividing the electrode into multiple segments, different voltages can be applied to each segment to form a more complex and precise electric field distribution; the multi-segment design helps to smooth the electric field change in the transition region, enabling the ions to be evenly distributed within the trap. Preferably, the PCB electrode sheet is divided into seven segmented electrodes 5 along the ion path direction; dividing the electrode into 7 segments is a balanced solution that combines processing and cost.

[0051] In an alternative embodiment of the present invention, the rectangular electrode structure includes a first electrode group and a second electrode group. The first electrode group includes a first PCB electrode sheet 1 and a third PCB electrode sheet 3 symmetrically arranged along the ion path, and the second electrode group includes a second PCB electrode sheet 2 and a fourth PCB electrode sheet 4 symmetrically arranged along the ion path; the first PCB electrode sheet 1, the second PCB electrode sheet 2, the third PCB electrode sheet 3, and the fourth PCB electrode sheet 4 are sequentially connected to form the rectangular electrode structure.

[0052] In practical applications, the first PCB electrode sheet 1 and the third PCB electrode sheet 3, and the second PCB electrode sheet 2 and the fourth PCB electrode sheet 4 are arranged parallel to each other and are both connected to an electronic control device. When the electronic control device inputs the same sinusoidal radio frequency to each PCB electrode sheet, a quadrupole electric field can be formed in the rectangular electrode structure, thereby collecting and confining the ions introduced into the rectangular electrode structure.

[0053] In this embodiment, a rectangular electrode structure is provided to form a quadrupole field with an equivalent voltage inside, and its power-on efficiency can be improved. The rectangular electrode structure includes the first PCB electrode sheet 1, the second PCB electrode sheet 2, the third PCB electrode sheet 3, and the fourth PCB electrode sheet 4, which are alternately connected to form the rectangular electrode structure. By applying radio frequency electricity to the PCB electrode sheets of the rectangular electrode structure, a quadrupole field with an equivalent voltage is formed, thereby solving the problem that the planar ion trap cannot form a quadrupole field with an equivalent voltage due to its parallel placement structure.

[0054] In an alternative embodiment of the present invention, the first PCB electrode sheet 1, the second PCB electrode sheet 2, the third PCB electrode sheet 3, and the fourth PCB electrode sheet 4 are respectively divided into seven segmented electrodes 5 along the ion path direction.

[0055] In practical applications, in order to form a quadrupole field with an equivalent voltage inside the rectangular electrode structure, the technical solution of the present application divides the first PCB electrode sheet 1, the second PCB electrode sheet 2, the third PCB electrode sheet 3, and the fourth PCB electrode sheet 4 into seven segmented electrodes 5 along the ion path direction, and the effect of forming a quadrupole field with an equivalent voltage is the most suitable.

[0056] In an alternative embodiment of the present invention, at least one of the segmented electrodes 5 is provided with an ejection hole 11, and the ejection hole 11 is used to extract ions from the rectangular electrode structure;

[0057] It should be noted that, in order to finally eject the ions after confinement focusing, ion extraction ports need to be opened on at least one first block electrode 30 and / or at least one second block electrode 60, so as to ensure that after the ions are introduced in the length direction of the strip electrode, they can be extracted in a direction intersecting the length direction to realize the ion ejection operation. It can be understood that the first block electrode 30 or the second block electrode 60 provided with the ion extraction port should be at the bottom (bottom of the peak) position when building the axial potential well. Further, in a more detailed embodiment, in order to ensure that ions can be extracted when building axial potential wells of different numbers and types, ion extraction ports can be opened on the remaining block electrodes except the first block electrode 30 and the second block electrode 60 arranged at both ends; it can be understood that the segmented electrode 5 can apply a gradient voltage;

[0058] It should also be noted that when the ion introduction stage and the ion cooling stage are completed, the ion group is ejected from the ejection hole, and this ejection stage belongs to the ion ejection stage. Under normal working conditions, ions are not extracted from the electrode plate because the extraction direction from the electrode plate does not lead to the mass analyzer. Only when the performance of the rectangular ion trap needs to be tested separately and it is not necessary to be connected in series with the mass analyzer, extraction from the electrode plate is adopted.

[0059] In an alternative embodiment of the present invention, the lengths of the segmented electrodes 5 on the same PCB electrode plate are the same or different.

[0060] It should be noted that in this embodiment, the length of the segmented electrode 5 is not specifically limited, and the lengths of the segmented electrodes 5 can be the same or different, and the lengths of the respective segmented electrodes 5 can be adjusted according to the actual situation; it should also be noted that when the lengths of the segmented electrodes are the same and the spacing is uniform, the entire device will form a symmetric electric field. In this case, the ions will be subjected to a uniform electric field constraint, which is beneficial to the stable capture and storage of ions.

[0061] In an alternative embodiment of the present invention, the spacing between the segmented electrodes 5 on the same PCB electrode plate is the same or different;

[0062] It should be noted that in this embodiment, the spacing between the segmented electrodes 5 is not specifically limited, and the spacing between the segmented electrodes 5 can be the same or different, and the spacing between the respective segmented electrodes 5 can be adjusted according to the actual situation. It should also be noted that the spacing between the electrodes affects the intensity and distribution of the electric field, and the same spacing will generate the same local electric field, which is beneficial to the capture and confinement of ions.

[0063] In an alternative embodiment of the present invention, the thickness of the PCB electrode sheet in the ion ejection direction is less than 1 mm, so that ions can be quickly extracted;

[0064] It should be noted that the smaller the electrode thickness, the faster the ions can be extracted. In practical applications, making the thickness of the PCB electrode sheet in the ion ejection direction less than 1 mm can reduce the interference of the ion flight path; a thinner electrode sheet can reduce the collision and scattering of ions with the electrode material during flight. When ions are ejected, they need to reach the detection area with as little interference as possible. A thicker electrode may increase the probability of interaction between ions and the electrode surface, resulting in deviation of the ion flight direction or energy loss, thus affecting the accuracy and sensitivity of detection; a thinner electrode sheet can make the flight distance of ions shorter after ejection, reducing the diffusion and loss of ions during flight, which helps to improve the ion transmission efficiency, enabling more ions to reach the detection device, thereby increasing the signal intensity of detection;

[0065] In an alternative embodiment of the present invention, the electronic control device applies a controllable radio frequency bias voltage to the PCB electrode sheet, and the electronic control device applies a controllable voltage to the ion gating device 10.

[0066] A method of using any ion collection and focusing system in Embodiment 1 provided in Embodiment 2 of the present application, the method includes,

[0067] Introduce a cooling gas into the rectangular electrode structure and turn on the ion gating device 10, and introduce ions into the rectangular electrode structure through the ion gating device 10;

[0068] Turn off the ion gating device 10 to confine the ions, and apply a controllable radio frequency bias voltage to the PCB electrode sheet through the electronic control device to form an equivalent voltage quadrupole field in the rectangular electrode structure, and collect and focus the ions in the rectangular electrode structure;

[0069] Ejection mode 1: Turn on the ion gating device 10 to eject ions from the rectangular electrode structure;

[0070] Ejection mode 2: The ejection electrode with a ejection hole in the middle ejects the ion cluster radially from the middle by applying a pulse.

[0071] In practical applications, the working process of the system mainly involves three stages: ion introduction, ion confinement, and ion ejection. 1) In the ion introduction stage, the ion gate voltage is maintained at 0 V to guide ions into the system and capture them under the action of a radio frequency electric field. During this stage, the DC voltage and radio frequency voltage applied to other electrodes remain unchanged. 2) In the ion confinement stage, the ions lose kinetic energy after colliding with the cooling gas, thereby achieving cooling and storage. After a period of collisional cooling, the ions gradually concentrate at the center of the trap under the action of the gradient voltage applied by the DC electrode. During this stage, the DC voltage of the ion gating is adjusted from 0 V to 10 V to prevent the further entry of external ions. 3) In the ion ejection stage, after a cycle of collisional cooling, the ion beam forms an ion cluster. By applying a pulsed voltage to the ejection electrode pair and quickly turning off the square wave radio frequency voltage, the rapid ejection of ions is achieved.

[0072] In practical applications, the introduction, confinement, and ejection of ions are as Figure 4 shown. When introducing ions, when the ion gating device 10 is at a low level, ions are guided into the rectangular electrode structure and captured under the action of a radio frequency electric field. During this stage, the DC voltage and radio frequency voltage applied to other electrodes of the rectangular electrode structure remain unchanged; when confining ions, the ions gradually concentrate at the center of the rectangular electrode structure under the action of the gradient voltage applied by the electrode; during this stage, the ion gating device 10 is adjusted from a low level to a high level to prevent the further entry of external ions; when ejecting ions, after a cycle of collisional cooling, the ion beam forms an ion cluster, and by applying a pulsed voltage to the electrode and quickly turning off the radio frequency voltage, the rapid ejection of ions is achieved.

[0073] In an alternative embodiment of the present invention, referring to the accompanying drawings, the segmented electrode 5 is applied with a controllable pulse, and the ion gating device 10 is applied with a controllable voltage; when one end of the ion gating device 10 is opened, ions can be introduced; when the ion gating device 10 is closed, ions are confined;

[0074] Optionally, when a pulsed current is applied to the segmented electrode 5 with an ejection hole 11, ions can be extracted from the segmented electrode 5 with the ejection hole 11; when the electrode pulse current of the segmented electrode 5 with the ejection hole 11 and the gradient voltage of other segmented electrodes 5 are turned off and the introduction of the cooling gas is closed, ions can be extracted from the ion gating device 10 at the other end.

[0075] In an alternative embodiment of the present invention, referring to the accompanying drawings, the segmented electrode 5 is applied with a controllable pulse superimposed with radio frequency, and the ion gating device 10 is applied with a controllable voltage; when one end of the ion gating device 10 is opened, ions can be introduced; when the ion gating device 10 is closed, ions are confined;

[0076] Optionally, when a pulsed electric current is applied to the segmented electrode 5 with the ejection hole 11, ions can be extracted from the segmented electrode 5 with the ejection hole 11; when the electrode pulsed electric current of the segmented electrode 5 with the ejection hole 11 and the gradient voltages of other segmented electrodes 5 are turned off and the introduction of the cooling gas is turned off, ions can be extracted from the other ion gating device 10.

[0077] An application of any one of the ion collection and focusing systems provided in Embodiment 3 of the present application in a multi-reflection time-of-flight mass spectrometer.

[0078] The ion collection and focusing system is applied in a multi-reflection time-of-flight mass spectrometer. By setting a rectangular electrode structure to form a quadrupole field with an equivalent voltage inside, and its power-on efficiency can be improved. The rectangular electrode structure includes at least two electrode groups. The PCB electrode sheets between the electrode groups are alternately connected to form a rectangular electrode structure. A radio frequency electric current is applied to the electrode sheets of the rectangular electrode structure to form a quadrupole field with an equivalent voltage, thus solving the problem that the planar ion trap cannot form a quadrupole field with an equivalent voltage due to its parallel placement structure.

[0079] The ion collection and focusing system can achieve the effect of ion cooling and focusing by using a rectangular electrode structure composed of PCB electrode sheets. Since the entire rectangular electrode structure is composed of PCB electrode sheets, this not only significantly reduces the difficulty of processing and assembly, but also greatly reduces the production cost. Therefore, the ion collection and focusing device has an economical and efficient rectangular electrode structure, is suitable for a multi-reflection time-of-flight mass spectrometer, enables it to have uniform initial energy and low energy divergence in the mass analyzer, enables the multi-reflection time-of-flight mass spectrometer to achieve higher analysis performance and higher mass resolution, and at the same time solves the problems brought by the two-electrode structure placed in parallel in the prior art.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ion collection and focusing system, characterized in that: It comprises a rectangular electrode structure, an electric control device and an ion gating device arranged at both ends of the rectangular electrode structure, wherein the ion gating device is used to control the introduction or extraction of ions into or out of the rectangular electrode structure; The rectangular electrode structure includes at least two electrode groups, and the electrode group includes two PCB electrode sheets symmetrically arranged along the ion path. The PCB electrode sheets between the electrode groups are alternately connected to form the rectangular electrode structure. The PCB electrode sheet is divided into at least five segmented electrodes along the ion path direction. The lengths of the segmented electrodes are the same or different. The rectangular electrode structure is used for ion collection and focusing. The ion gating device and the PCB electrode sheet are respectively connected to the electric control device.

2. The ion collection and focusing system according to claim 1, characterized in that: The rectangular electrode structure includes a first electrode group and a second electrode group, the first electrode group includes a first PCB electrode sheet and a third PCB electrode sheet symmetrically arranged along the ion path, and the second electrode group includes a second PCB electrode sheet and a fourth PCB electrode sheet symmetrically arranged along the ion path; the first PCB electrode sheet, the second PCB electrode sheet, the third PCB electrode sheet and the fourth PCB electrode sheet are connected in sequence to form the rectangular electrode structure.

3. The ion collection and focusing system according to claim 2, characterized in that: The first PCB electrode sheet, the second PCB electrode sheet, the third PCB electrode sheet and the fourth PCB electrode sheet are respectively divided into seven segmented electrodes along the ion path direction.

4. The ion collection and focusing system according to claim 3, characterized in that: At least one of the segmented electrodes is provided with an ejection hole, and the ejection hole is used to extract ions from the rectangular electrode structure.

5. The ion collection and focusing system according to claim 3, characterized in that: The lengths of the segmented electrodes on the same PCB electrode sheet are the same or different.

6. The ion collection and focusing system according to claim 3, characterized in that: The intervals between the segmented electrodes on the same PCB electrode sheet are the same or different.

7. The ion collection and focusing system according to claim 1, characterized in that: The thickness of the PCB electrode sheet in the ion ejection direction is less than 1 mm.

8. The ion collection and focusing system according to claim 1, characterized in that: The electric control device applies a controllable radio frequency bias voltage to the PCB electrode sheet, and the electric control device applies a controllable voltage to the ion gating device.

9. A method for using the ion collection and focusing system according to any one of claims 1 to 8, characterized in that: The method comprises, Introducing cooling gas into the rectangular electrode structure and turning on the ion gating device, and introducing ions into the rectangular electrode structure through the ion gating device; The ion gating device is closed to confine the ions, and a controllable radio frequency bias is applied to the PCB electrode sheet through the electric control device to form an equivalent voltage quadrupole field in the rectangular electrode structure, so as to collect and focus the ions in the rectangular electrode structure; Extraction mode 1: Turn on the ion gating device to extract ions from the rectangular electrode structure; Extraction mode 2: The ejection electrode with an ejection hole in the middle ejects ion clusters radially from the middle by applying pulses.

10. Use of the ion collection and focusing system according to any one of claims 1 to 8 in a multiple reflection time-of-flight mass spectrometer.

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