An off-axis linear accelerator collision cell

Abstract

The application discloses an off-axis linear acceleration collision cell for mass spectrometry, comprising a collision cell cavity, an introduction electrode, an introduction segmented quadrupole, an off-axis bending quadrupole, an exit segmented quadrupole, a gas supplement pipeline and an exit electrode. The collision cell is one of the core components of tandem mass spectrometry, and how to reduce the ion residence time in the collision cell and reduce the neutral molecule interference is a difficult problem to be solved in the collision cell technology. Therefore, the application designs an off-axis linear acceleration collision cell, which is combined with the segmented quadrupole and the bending off-axis quadrupole, can realize linear acceleration, reduce the residence time, realize off-axis deflection and reduce the neutral molecule interference. The application can effectively improve the qualitative and quantitative capabilities of the tandem mass spectrometry, and has a good application prospect in high-end tandem mass spectrometry analysis instruments such as triple quadrupole, quadrupole rod-time of flight mass spectrometry and quadrupole rod-orbitrap mass spectrometry.

Description

Technical Field

[0001] This invention relates to the field of mass spectrometry analysis technology, and in particular to an off-axis linear accelerating collision cell technology for tandem mass spectrometry. Background Technology

[0002] The collision cell is a key component of a tandem mass spectrometer. Currently, most collision cells employ multipole structures such as quadrupole, hexapole, and octapole, applying radio frequency and DC voltages to the multipole for ion transport. Current research in collision cell technology focuses on reducing ion residence time within the cell, thereby minimizing crosstalk between molecular ions and increasing instrument throughput. Various instrument manufacturers currently possess patented collision cell designs to minimize crosstalk.

[0003] A search of patents and papers revealed the following relevant patents concerning collision cells: 1. Ionics Mass Spectrometry, on January 11, 2011, disclosed a linear accelerating collision cell (US7,868,289B2). This technology reduces the residence time of ions in the collision cell by adjusting the angle between the quadrupole cylinder and the axis and applying a voltage to the outer shell, ultimately forming an axial electric field. The patent also discloses a rectangular rod; by linearly changing the width of the rectangular rod, combined with the voltage applied to the outer shell, an accelerating electric field is formed axially, effectively reducing the residence time of ions in the collision cell. While this patent does effectively reduce the residence time of ions in the collision cell, it lacks an off-axis design, thus failing to further eliminate the effects of neutral crosstalk. The retrieved SCI papers are as follows: 1. Alexander Loboda from the University of Manitoba, Canada, published an article entitled "Novel Linac II electrode geometry for creating an axial field in a multipoleion guide" in Eur. J. Mass Spectrom in 2000. This article introduces a linear acceleration collision cell technique that generates an axial electric field by adding an auxiliary rod outside the quadrupole and changing the distance between the auxiliary rod and the quadrupole axis. This can effectively reduce the ion residence time in the collision cell, but it does not include off-axis design, and therefore cannot further eliminate the influence of neutral crosstalk. In summary, a reasonable design is needed to combine linear acceleration and off-axis design to reduce residence time while minimizing the crosstalk influence of neutral molecules. Summary of the Invention

[0004] This invention proposes an off-axis linear accelerating collision cell for mass spectrometers to reduce the residence time of the cascade mass spectrometer collision cell and eliminate neutral crosstalk.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] An off-axis linear accelerating collision cell for mass spectrometry includes a collision cell cavity, an introduction electrode, an introduction segmented quadrupole, an off-axis bent quadrupole, an extraction segmented quadrupole, a gas supply line, and an extraction electrode; characterized in that:

[0007] The X direction is defined as to the right, the Y direction as upward, and the Z direction is defined as the direction perpendicular to the XY plane.

[0008] The collision pool cavity is a hollow cavity with openings at both ends. Within the cavity, three parts are sequentially arranged: an inlet segmented quadrupole, an off-axis bent quadrupole, and an outlet segmented quadrupole. The off-axis bent quadrupole consists of a pair of curved inner cylindrical rod electrodes with a radius of curvature of R1 on the central axis and a cylindrical radius of R0, and a pair of curved outer cylindrical rod electrodes with a radius of curvature of R2 on the central axis and a cylindrical radius of R0. The two ends of the pair of inner cylindrical rods and the pair of outer cylindrical rods are respectively located at the four vertices of two squares A with the same side length K. Each pair of inner and outer cylindrical rods is arranged vertically, meaning the two outer cylindrical rods are located outside or above the two inner cylindrical rods. The radial cross-sections of the rods and outer cylindrical rods along their axes are four circles with the same radius R0, and the centers of these circles are located at the four vertices of square A; the projections of the left cylindrical end faces of the two inner cylindrical rods and the two outer cylindrical rods onto the plane perpendicular to the Z direction (the plane containing XY) lie on a straight line B; the projections of the right cylindrical end faces of the two inner cylindrical rods and the two outer cylindrical rods onto the plane perpendicular to the Z direction (the plane containing XY) lie on a straight line C; lines B and C intersect at the common center of the arc-shaped central axes of the projection circles of the inner and outer cylindrical rods onto the plane perpendicular to the Z direction (the plane containing XY), and the included angle between lines B and C can be acute, right, obtuse, or straight.

[0009] The introduced segmented quadrupole consists of 4 or more groups of short quadrupoles. Each group of short quadrupoles consists of 4 cylindrical electrodes with the same radius R0 and length. The 4 cylindrical electrodes are symmetrically distributed on the four vertices of a square A with the same side length K as the off-axis curved quadrupole. That is, the two ends of the 4 cylindrical electrodes are respectively set at the four vertices of two squares A with the same side length K. Each group of short quadrupoles is placed sequentially at equal intervals and along the same axis of symmetry. After forming the introduced segmented quadrupole, the projection in the X direction is four circles with the center located at the vertices of square A and the radius R0.

[0010] The structure of the leading segmented quadrupole is the same as that of the introducing segmented quadrupole, both consisting of 4 or more short quadrupole rods, and the number of groups in the leading segmented quadrupole and the introducing segmented quadrupole may be the same or different.

[0011] The introduced segmented quadrupole and the led-out segmented quadrupole are placed on both sides of the off-axis bent quadrupole, that is, at the two ends of the cylindrical rod electrodes of the off-axis bent quadrupole. The circular planes of the four electrodes on the left end face of the off-axis bent quadrupole (closer to the introduced segmented quadrupole) are parallel to and spaced apart from the circular planes of the four electrodes on the right end face of the last group of short quadrupole rods of the introduced segmented quadrupole. The circular planes of the four electrodes on the left end face of the off-axis bent quadrupole and the circular planes of the four electrodes on the right end face of the introduced segmented quadrupole are each placed coaxially and corresponding to each other. The circular planes of the four electrodes on the right end face of the off-axis bent quadrupole (closer to the led-out segmented quadrupole) are parallel to and spaced apart from the circular planes of the four electrodes on the left end face of the first group of short quadrupole rods of the led-out segmented quadrupole. The circular planes of the four electrodes on the left end face of the off-axis bent quadrupole and the circular planes of the four electrodes on the left end face of the led-out segmented quadrupole are each placed coaxially and corresponding to each other.

[0012] Each inner and outer cylindrical rod, with its coaxially aligned lead-in and lead-out segmented quadrupoles, forms four "straight-bent-straight" shaped segmented cylindrical rods. All cylindrical electrodes on each "straight-bent-straight" segmented cylindrical rod are connected to their corresponding adjacent electrodes on the inner or outer cylindrical rod via an equivalent resistance R. That is, the corresponding adjacent electrodes of the lead-in segmented quadrupole, the off-axis bent quadrupole, and the lead-out segmented quadrupole are connected via an equivalent resistance R. Resistor R is connected; all cylindrical electrodes on each "straight-bend-straight" segmented cylindrical pole and the corresponding inner cylindrical pole or corresponding outer cylindrical pole are connected to the radio frequency power supply through an equivalent capacitor C. The radio frequency power supply applied to adjacent "straight-bend-straight" segmented cylindrical poles has the same amplitude and a phase difference of 180°. That is, on the four cylindrical poles introduced into the segmented quadrupole, the off-axis bent quadrupole, and the exited segmented quadrupole, the radio frequency power supply applied to adjacent poles has the same amplitude and a phase difference of 180°.

[0013] The gas supply pipe passes through the outside of the collision pool cavity and enters the inside of the collision pool cavity; a total of two gas supply pipes are provided, which are respectively placed near the inlet segment quadrupole and the outlet segment quadrupole; both the inlet electrode and the outlet electrode are flat plate structures with a circular through hole in the middle; the inlet electrode is sealed to the left opening end of the collision pool cavity through an insulating gasket, and is placed parallel to and spaced apart from the left end face of the first group of short quadrupole rods on the left end of the inlet segment quadrupole, and the axis of the through hole in the middle of the inlet electrode coincides with the axis of the inlet segment quadrupole; the outlet electrode is sealed to the opening end of the collision pool cavity near the outlet segment quadrupole through an insulating gasket, and is placed parallel to and spaced apart from the end face of the last group of short quadrupole rods away from the off-axis bent quadrupole of the outlet segment quadrupole, and the axis of the through hole in the middle of the outlet electrode coincides with the axis of the outlet segment quadrupole.

[0014] Furthermore, the gas supply pipeline can be made of one or more of the following materials: metal or non-metal, such as stainless steel, aluminum alloy or copper, or one or more of the following: PEEK, PTFE, plexiglass, etc., with an inner diameter of 0.1 to 6 mm and a sample gas flow rate of 1 to 100 mL / min.

[0015] Furthermore, the diameter of the through hole in the middle of the lead-in electrode and the lead-out electrode is 0.5 to 4 mm; the radius R0 of the inner cylindrical rod, the outer cylindrical rod, and the cylindrical electrode is 2 to 20 mm.

[0016] Furthermore, different voltages (e.g., V1, V2, V3, etc.) are sequentially applied to each electrode of each "straight-bend-straight" segmented cylindrical electrode in descending order of voltage, forming an ion transport electric field with a magnitude of 1 to 100 V / cm; the radio frequency voltage applied to each "straight-bend-straight" segmented cylindrical electrode has an amplitude of 10 to 10000 V and a frequency of 0.5 to 5 MHz.

[0017] Furthermore, the quadrupole (including the short quadrupole introduced into the segmented quadrupole, the quadrupole composed of two inner cylindrical rods and two outer cylindrical rods in the off-axis bending quadrupole, and the short quadrupole led out from the segmented quadrupole) can all be replaced by a six-pole or eight-pole with the same corresponding structure.

[0018] Furthermore, the working pressure of the collision cell is 0.1–5 Pa; the collision cell can be used in cascade mass spectrometry instruments such as triple quadrupole mass spectrometers, quadrupole-time-of-flight mass spectrometers, or quadrupole-orbit trap mass spectrometers.

[0019] This invention cleverly combines a segmented quadrupole with a bent off-axis quadrupole, achieving both linear acceleration and reduced residence time, as well as off-axis deflection and reduced interference from neutral molecules. This design effectively enhances the qualitative and quantitative capabilities of tandem mass spectrometry and shows promising application prospects in high-end tandem mass spectrometry instruments such as triple quadrupole, quadrupole-time-of-flight mass spectrometry, and quadrupole-orbit trap mass spectrometry. Attached Figure Description

[0020] The accompanying drawings further illustrate the present invention, but the content of the drawings does not constitute any limitation on the present invention.

[0021] Figure 1 This is a schematic diagram of the overall structure of an off-axis linear acceleration collision cell according to one embodiment of the present invention; in the figure, 3 is the collision gas, which is generally nitrogen, helium or argon; 8 is a neutral molecule that is not driven by an electric field; 9 is the ion generated after collision dissociation, which can be separated from the neutral molecule under the drive of an electric field to remove neutral interference. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0026] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0027] This embodiment provides an off-axis linear accelerating collision cell for a mass spectrometer, comprising a collision cell cavity 5, an introduction electrode 1, an introduction segmented quadrupole 13, an off-axis bent quadrupole 6, an exit segmented quadrupole 10, a gas supply line 4, and an exit electrode 14; characterized in that:

[0028] The X direction is defined as to the right, the Y direction as upward, and the Z direction is defined as the direction perpendicular to the XY plane.

[0029] The collision pool cavity 5 is a hollow cavity with openings at both ends. Inside the collision pool cavity 5, three parts are sequentially arranged: an inlet segmented quadrupole 13, an off-axis bent quadrupole 6, and an outlet segmented quadrupole 10. The off-axis bent quadrupole 6 consists of a pair of curved inner cylindrical rods 12 with a radius of curvature of R1 and a cylindrical radius of R0, and a pair of curved outer cylindrical rods 7 with a radius of curvature of R2 and a cylindrical radius of R0. The two ends of the pair of inner cylindrical rods 12 and the pair of outer cylindrical rods 7 are respectively located at the four vertices of two squares A with the same side length K. Each pair of inner cylindrical rods 12 and outer cylindrical rods 7 are arranged vertically, meaning the two outer cylindrical rods 7 are located outside or above the two inner cylindrical rods 12. The inner cylindrical rod 12 and the outer cylindrical rod 7 have radial cross sections of four circles with the same radius R0 along their axes, and the centers of these circles are located at the four vertices of square A. The projections of the left cylindrical end faces of the two inner cylindrical rods 12 and the two outer cylindrical rods 7 onto the plane perpendicular to the Z direction (the plane containing XY) lie on a straight line B. The projections of the right cylindrical end faces of the two inner cylindrical rods 12 and the two outer cylindrical rods 7 onto the plane perpendicular to the Z direction (the plane containing XY) lie on a straight line C. The lines B and C intersect at the common center of the arc-shaped central axis of the projection circles of the inner cylindrical rods 12 and the outer cylindrical rods 7 onto the plane perpendicular to the Z direction (the plane containing XY), and the included angle between the lines B and C can be acute, right, obtuse, or straight.

[0030] The introduced segmented quadrupole 13 consists of four or more groups of short quadrupoles 15. Each group of short quadrupoles 15 consists of four cylindrical electrodes 16 with the same radius R0 and length. The four cylindrical electrodes 16 are symmetrically distributed on the four vertices of a square A with the same side length K as the off-axis curved quadrupole 6. That is, the two ends of the four cylindrical electrodes 16 are respectively set at the four vertices of two squares A with the same side length K. Each group of short quadrupoles 15 is placed sequentially at equal intervals and along the same axis of symmetry. After forming the introduced segmented quadrupole 13, its projection in the X direction is four circles with the center located at the vertices of square A and a radius of R0.

[0031] The leading segmented quadrupole 10 and the introducing segmented quadrupole 13 have the same structure, both consisting of 4 or more short quadrupole rods 15, and the leading segmented quadrupole 10 and the introducing segmented quadrupole 13 may have the same or different number of groups.

[0032] The introduced segmented quadrupole 13 and the led-out segmented quadrupole 10 are placed on both sides of the off-axis bent quadrupole 6, that is, at the two ends of the cylindrical rod electrodes of the off-axis bent quadrupole 6. The circular planes of the four electrode ends on the left end face of the off-axis bent quadrupole 6 (near the introduced segmented quadrupole) are parallel and spaced apart from the circular planes of the four electrode ends on the right end face of the last group of short quadrupole rods 15 of the introduced segmented quadrupole 13. The circular planes of the four electrode ends on the left end face of the off-axis bent quadrupole 6 are coaxially placed with the circular planes of the four electrode ends on the right end face of the introduced segmented quadrupole 13. The circular planes of the four electrode ends on the right end face of the off-axis bent quadrupole 6 (near the led-out segmented quadrupole) are parallel and spaced apart from the circular planes of the four electrode ends on the left end face of the first group of short quadrupole rods 15 of the led-out segmented quadrupole 10. The circular planes of the four electrode ends on the left end face of the off-axis bent quadrupole 6 are coaxially placed with the circular planes of the four electrode ends on the left end face of the led-out segmented quadrupole 10.

[0033] Each inner cylindrical rod 12 and outer cylindrical rod 7, along with the cylindrical electrodes 16 of the inlet segmented quadrupole 13 and outlet segmented quadrupole 10 coaxial with their respective two end faces, form four segmented cylindrical rods in a "straight-bent-straight" shape. All cylindrical electrodes 16 on each "straight-bent-straight" segmented cylindrical rod are connected to their corresponding adjacent electrodes on the inner cylindrical rod 12 or outer cylindrical rod 7 via an equivalent resistance R. That is, the corresponding adjacent electrodes of the inlet segmented quadrupole 13, the off-axis bent quadrupole 6, and the outlet segmented quadrupole 10 are connected... The cylindrical electrodes 16 and the corresponding inner cylindrical rod 12 or the corresponding outer cylindrical rod 7 on each "straight-bend-straight" segmented cylindrical pole are connected to the radio frequency power supply through the equivalent capacitor C. The radio frequency power supply applied to adjacent "straight-bend-straight" segmented cylindrical poles has the same amplitude and a phase difference of 180°. That is, on the four cylindrical poles introduced into the segmented quad pole 13, the off-axis bent quad pole 6 and the exited segmented quad pole 10, the radio frequency power supply applied to adjacent poles has the same amplitude and a phase difference of 180°.

[0034] The gas supply line 4 passes through the outside of the collision pool cavity 5 and enters the interior of the collision pool cavity 5; a total of 2 gas supply lines 4 are provided, respectively placed near the inlet segment quadrupole 13 and the outlet segment quadrupole 10; the inlet electrode 1 and the outlet electrode 14 are both flat plate structures with a circular through hole in the middle; the inlet electrode 1 is sealed to the left opening end of the collision pool cavity 5 through the insulating gasket seal 2, and is placed parallel and spaced apart from the left end face of the first group of short quadrupole rods 15 at the left end of the inlet segment quadrupole 13, and the axis of the through hole in the middle of the inlet electrode 1 coincides with the axis of the inlet segment quadrupole 13; the outlet electrode 14 is sealed to the opening end of the collision pool cavity 5 near the outlet segment quadrupole 10 through the insulating gasket seal 2, and is placed parallel and spaced apart from the end face of the last group of short quadrupole rods 15 away from the off-axis bent quadrupole 6 of the outlet segment quadrupole 10, and the axis of the through hole in the middle of the outlet electrode 14 coincides with the axis of the outlet segment quadrupole 10.

[0035] Furthermore, the gas supply line 4 can be made of one or more of the following materials: metal or non-metal, such as stainless steel, aluminum alloy or copper, such as PEEK, PTFE, plexiglass or acrylic glass, with an inner diameter of 0.1 to 6 mm and a sample gas flow rate of 1 to 100 mL / min.

[0036] Preferably, in this embodiment, the gas supply line 4 is made of PTFE material, with an inner diameter of 2 mm and a flow rate of 10 mL / min.

[0037] Furthermore, the diameter of the through hole in the middle of the lead-in electrode 1 and the lead-out electrode 14 is 0.5 to 4 mm; the radius R0 of the inner cylindrical rod 12, the outer cylindrical rod 7, and the cylindrical electrode 16 is 2 to 20 mm.

[0038] Preferably, in this embodiment, the diameter of the small hole in the center of the lead-in electrode 1 and the lead-out electrode 14 is 2 mm; the radius R0 of the inner cylindrical rod 12, the outer cylindrical rod 7, and the cylindrical electrode 16 is 6 mm.

[0039] Furthermore, different voltages (e.g., V1, V2, V3, etc.) are sequentially applied to each electrode of each "straight-bend-straight" segmented cylindrical electrode in descending order of voltage, forming an ion transport electric field with a magnitude of 1 to 100 V / cm; the radio frequency voltage applied to each "straight-bend-straight" segmented cylindrical electrode has an amplitude of 10 to 10000 V and a frequency of 0.5 to 5 MHz.

[0040] Furthermore, the quadrupoles (including the short quadrupole introduced into the segmented quadrupole 13, the quadrupole composed of two inner cylindrical rods 12 and two outer cylindrical rods 7 in the off-axis bent quadrupole 6, and the short quadrupole led out into the segmented quadrupole 10) can all be replaced by hexapoles or octapoles of the same corresponding structure.

[0041] Preferably, this embodiment uses a quadrupole.

[0042] Furthermore, the working pressure of the collision cell is 0.1–5 Pa; the collision cell can be used in cascade mass spectrometry instruments such as triple quadrupole mass spectrometers, quadrupole-time-of-flight mass spectrometers, or quadrupole-orbit trap mass spectrometers.

[0043] Preferably, the working pressure of the collision pool is 1 Pa.

[0044] Furthermore, the parent ion enters the collision cell cavity 5 through the introduction electrode 1. Under the combined action of the radio frequency and DC electric fields and the collision gas 3 introduced through the gas supply line 4, the parent ion dissociates to produce daughter ions. The daughter ions are rapidly introduced into the off-axis curved quadrupole 6 under the linear acceleration electric field of the introduced segmented quadrupole 13 and achieve off-axis deflection. At this time, the neutral molecule 8 is not affected by the electric field and cannot be deflected, thereby achieving neutral crosstalk elimination. The ions 9 generated after collision dissociation enter the extraction segmented quadrupole 10 and are rapidly extracted from the extraction electrode 14 under the action of the linear acceleration electric field. Ultimately, the purpose of reducing the residence time and eliminating neutral crosstalk is achieved.

[0045] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An off-axis linear accelerating collision cell for mass spectrometry, comprising a collision cell cavity (5), an introduction electrode (1), an introduction segmented quadrupole (13), an off-axis bent quadrupole (6), an exit segmented quadrupole (10), a gas supply line (4), and an exit electrode (14); characterized in that: The X direction is defined as to the right, the Y direction as upward, and the Z direction is defined as the direction perpendicular to the XY plane. The collision pool cavity (5) is a hollow cavity with openings at both ends. The collision pool cavity (5) is provided with three parts in sequence: an inlet segmented quadrupole (13), an off-axis curved quadrupole (6), and an outlet segmented quadrupole (10). The off-axis curved quadrupole (6) consists of a pair of curved inner cylindrical rods (12) electrodes with a radius of curvature of R1 and a cylindrical radius of R0, and a pair of curved outer cylindrical rods (7) electrodes with a radius of curvature of R2 and a cylindrical radius of R0. The two ends of the pair of inner cylindrical rods (12) and the pair of outer cylindrical rods (7) are respectively set at the four vertices of two squares A with the same side length K. Each pair of inner cylindrical rods (12) and outer cylindrical rods (7) are distributed vertically, that is, the two outer cylindrical rods (7) are located at the two inner cylindrical rods (12). Outside or above; the inner cylindrical rod (12) and the outer cylindrical rod (7) have four circular sections with the same radius R0 along the axis radial section, and the center of the circular section is located at the four vertices of the square A; the projection of the left cylindrical end face of the two inner cylindrical rods (12) and the two outer cylindrical rods (7) onto the plane perpendicular to the Z direction (the plane where XY is located) is on a straight line B; the projection of the right cylindrical end face of the two inner cylindrical rods (12) and the two outer cylindrical rods (7) onto the plane perpendicular to the Z direction (the plane where XY is located) is on a straight line C; the straight lines B and C intersect at the common center of the arc-shaped central axis of the projection of the inner cylindrical rod (12) and the outer cylindrical rod (7) onto the plane perpendicular to the Z direction (the plane where XY is located), and the included angle between the straight lines B and C can be an acute angle, a right angle, an obtuse angle or a straight angle; The introduced segmented quadrupole (13) consists of 4 or more short quadrupole rods (15). Each short quadrupole rod (15) consists of 4 cylindrical electrodes (16) with the same radius R0 and length. The 4 cylindrical electrodes (16) are symmetrically distributed on the four vertices of a square A with the same side length K as the off-axis curved quadrupole (6). That is, the two ends of the 4 cylindrical electrodes (16) are respectively set at the four vertices of two squares A with the same side length K. Each group of short quadrupole rods (15) is placed sequentially at equal intervals and along the same axis of symmetry. After forming the introduced segmented quadrupole (13), the projection in the X direction is a circle with four circles centered at the vertices of square A and with a radius of R0. The structure of the leading segmented quadrupole (10) and the introducing segmented quadrupole (13) is the same, both consisting of 4 or more short quadrupole rods (15), and the number of groups of the leading segmented quadrupole (10) and the introducing segmented quadrupole (13) are the same or different. The introduced segmented quadrupole (13) and the led-out segmented quadrupole (10) are placed on both sides of the off-axis bent quadrupole (6), that is, at the two ends of the cylindrical rod electrode of the off-axis bent quadrupole (6); the circular planes of the four electrode ends on the left end face of the off-axis bent quadrupole (6) (closer to the introduced segmented quadrupole) are parallel to and spaced apart from the circular planes of the four electrode ends on the right end face of the last group of short quadrupole rods (15) of the introduced segmented quadrupole (13), and the circular planes of the four electrode ends on the left end face of the off-axis bent quadrupole (6) are parallel to and spaced apart from the circular planes of the four electrode ends on the left end face of the introduced segmented quadrupole (13). The four electrode end circles on the right end face are placed coaxially, corresponding to each other; the four electrode end circles on the right end face of the off-axis bent quadrupole (6) (near the lead-out segment quadrupole) are parallel and spaced apart from the four electrode end circles on the left end face of the first group of short quadrupole rods (15) near the off-axis bent quadrupole (10), and the four electrode end circles on the left end face of the off-axis bent quadrupole (6) are coaxially placed coaxially, corresponding to each other; Each inner cylindrical rod (12) and outer cylindrical rod (7) forms four "straight-bent-straight" segmented cylindrical rods with cylindrical electrodes (16) of the inlet segmented quadrupole (13) and outlet segmented quadrupole (10) coaxial with their respective two end faces. All cylindrical electrodes (16) on each "straight-bent-straight" segmented cylindrical rod are connected to their corresponding adjacent electrodes on the inner cylindrical rod (12) or outer cylindrical rod (7) through an equivalent resistance R. That is, the corresponding adjacent electrodes of the inlet segmented quadrupole (13), the off-axis bent quadrupole (6), and the outlet segmented quadrupole (10) are connected through an equivalent resistance R. All cylindrical electrodes (16) on each "straight-bent-straight" segmented cylindrical rod are connected to the RF power supply through an equivalent capacitance C. The RF power applied to the segmented cylindrical poles has the same amplitude and a phase difference of 180°. That is, on the four cylindrical poles introduced into the segmented quadrupole (13), the off-axis bent quadrupole (6), and the segmented quadrupole (10), the RF power applied to adjacent poles has the same amplitude and a phase difference of 180°. The gas supply line (4) passes through the collision pool cavity (5) from the outside and enters the collision pool cavity (5); a total of 2 gas supply lines (4) are provided, which are respectively placed near the inlet segment quadrupole (13) and the outlet segment quadrupole (10); the inlet electrode (1) and the outlet electrode (14) are both flat plate structures with a circular through hole in the middle; the inlet electrode (1) is sealed to the left opening end of the collision pool cavity (5) through the insulating gasket seal (2), and is connected to the first group of short quadrupole rods (15) at the left end of the inlet segment quadrupole (13). The left end faces are placed parallel and spaced apart, and the axis of the through hole in the middle of the lead electrode (1) coincides with the axis of the lead segment quadrupole (13); the lead electrode (14) is sealed and connected to the opening end of the collision pool cavity (5) near the lead segment quadrupole (10) through the insulating gasket seal (2), and it is placed parallel and spaced apart from the end face of the last set of short quadrupole rods (15) away from the off-axis bent quadrupole (6) of the lead segment quadrupole (10), and the axis of the through hole in the middle of the lead electrode (14) coincides with the axis of the lead segment quadrupole (10).

2. The off-axis linear acceleration collision pool according to claim 1, characterized in that: The gas supply pipeline (4) is made of one or more of metal or non-metal materials, with an inner diameter of 0.1 to 6 mm and a sample gas flow rate of 1 to 100 mL / min.

3. The off-axis linear acceleration collision pool according to claim 1, characterized in that: The diameter of the through hole in the middle of the lead-in electrode (1) and the lead-out electrode (14) is 0.5 to 4 mm; the radius R0 of the inner cylindrical rod (12), the outer cylindrical rod (7) and the cylindrical electrode (16) is 2 to 20 mm.

4. The off-axis linear acceleration collision pool according to claim 1, characterized in that: Each of the "straight-bend-straight" segmented cylindrical poles has different voltages applied sequentially on each electrode in descending order of voltage, forming an ion transport electric field with a magnitude of 1 to 100 V / cm; the radio frequency voltage applied to each "straight-bend-straight" segmented cylindrical pole has an amplitude of 10 to 10000 V and a frequency of 0.5 to 5 MHz.

5. The off-axis linear acceleration collision pool according to claim 1, characterized in that: The quadrupoles are all replaced by six-pole or eight-poles of the same corresponding structure. The quadrupoles include the short quadrupole introduced into the segmented quadrupole (13), the quadrupole composed of two inner cylindrical rods (12) and two outer cylindrical rods (7) in the off-axis bending quadrupole (6), and the short quadrupole led out into the segmented quadrupole (10).

6. The off-axis linear acceleration collision pool according to claim 1, characterized in that: The working pressure of the collision cell is 0.1–5 Pa; the collision cell can be used in cascade mass spectrometry instruments such as triple quadrupole mass spectrometers, quadrupole-time-of-flight mass spectrometers, or quadrupole-orbit trap mass spectrometers.

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