Pre-rod lens capable of eliminating charge accumulation and mass spectrometer

Abstract

The utility model provides a pre-rod lens capable of clearing charge accumulation and a mass spectrometer, the pre-rod lens capable of clearing charge accumulation comprises a pre-rod seat, a pre-quadrupole rod and an ion lens, the pre-quadrupole rod and the ion lens are respectively arranged on two end surfaces of the pre-rod seat, the pre-rod lens also comprises a shielding field, the shielding field extends towards the pre-quadrupole rod from one end surface, close to the pre-rod seat, of the ion lens, covers an inter-rod gap of the pre-quadrupole rod, and is used for capturing ions escaping from the inter-rod gap of the pre-quadrupole rod; the mass spectrometer comprises the pre-rod lens capable of clearing charge accumulation.

Description

Technical Field

[0001] The utility model relates to the technical field of mass spectrometry analysis instruments, in particular to a pre-rod lens capable of clearing charge accumulation and a mass spectrometer comprising the pre-rod lens capable of clearing charge accumulation. Background Art

[0002] The "pre-pole lens" is a key component in a mass spectrometer, particularly in quadrupole mass spectrometers. In a quadrupole mass spectrometer, the pre-pole lens is located between the ion source and the quadrupole. Its function is to initially focus and shape the ion beam generated by the ion source to facilitate its entry into the quadrupole for subsequent mass spectrometry analysis. It typically contains an electric and / or magnetic field to control and direct the ion beam so that it enters the quadrupole. The pre-pole lens also helps reduce scattering and divergence of the ion beam, thereby improving the resolution and sensitivity of the mass spectrometer. However, in practical applications, ions may escape from the pre-quadrupole as the ion beam passes through the pre-pole lens. Over extended use, the insulating base of the pre-pole lens, also known as the pre-pole seat, accumulates a certain amount of charge, thereby forming an interfering electric field in the ion oscillation path. Therefore, a pre-pole lens and mass spectrometer that can eliminate this charge accumulation are proposed. Utility Model Content

[0003] In order to overcome the problems existing in the related art, the purpose of the present invention is to provide a pre-rod lens that can clear charge accumulation. Through the design of the shielding field, it can capture all-round escaped ions and better prevent the occurrence of charge accumulation.

[0004] In a first aspect, the present application provides a pre-rod lens that can clear charge accumulation, wherein the pre-rod lens includes a pre-rod seat and a pre-quadrupole and an ion lens respectively mounted on both end faces of the pre-rod seat, wherein the pre-rod lens also includes a shielding field, wherein the shielding field extends from an end face of the ion lens close to the pre-rod seat toward the pre-quadrupole, the shielding field covers the inter-rod gap of the pre-quadrupole, and the shielding field is used to capture ions escaping from the inter-rod gap of the pre-quadrupole.

[0005] In one embodiment, the shielding field is formed by four claws of a shielding claw, the shielding claw is fixedly connected to the ion lens, and the four claws are symmetrically arranged in pairs.

[0006] In one embodiment, each claw is located between adjacent rods in the pre-quadrupole.

[0007] In one embodiment, the shielding claw is fixedly welded to an end surface of the ion lens close to the pre-rod seat.

[0008] In one embodiment, the shielding claw and the ion lens are integrally formed.

[0009] In one embodiment, the pre-rod lens further includes a connection terminal provided on any one claw of the shielding claw, and the connection terminal is connected to an external circuit.

[0010] In one embodiment, the pre-rod lens further includes a connection terminal disposed on the ion lens, and the connection terminal is connected to an external circuit.

[0011] In one embodiment, the pre-rod seat includes a cavity extending toward the pre-quadrupole, the cavity being used to accommodate the pre-quadrupole, and an inner side surface of the cavity is provided with a metallized conductive layer forming the shielding field.

[0012] In one embodiment, the metallized conductive layer and the ion lens are each provided with a connection terminal, and the connection terminal is connected to an external circuit.

[0013] In a second aspect, the present application also provides a mass spectrometer comprising a pre-rod lens capable of removing charge accumulation as described in any one of the above items.

[0014] The beneficial effects of the utility model are:

[0015] Compared with the prior art, the utility model adds a shielding field to the periphery of the pre-quadrupole of the pre-rod lens to capture the escaped ions in all directions, and then guides the captured ions directly through the wiring terminals and the external circuit, eliminating the work of frequent disassembly and cleaning required to solve the ion attachment problem in the prior art, ensuring the stability of the mass spectrometer while improving the user experience. The shielding field can be formed by a shielding claw or by a metallized conductive layer on the inner surface of the pre-rod seat, eliminating the occurrence of charge accumulation while maintaining the original assembly structure and assembly process as much as possible. The improvement scheme is easy to implement, and does not increase the installation and maintenance costs when implementing the improvement on the existing mass spectrometer. Instead, it enhances the efficiency and effect of the mass spectrometer based on low improvement difficulty and improvement cost. The improvement scheme has strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the overall structure of the pre-rod lens capable of clearing charge accumulation;

[0017] Figure 2 for Figure 1 Another view of the middle pre-rod lens;

[0018] Figure 3 for Figure 1 Schematic diagram of the structure of the middle pre-rod seat;

[0019] Figure 4 for Figure 3 Another direction view of the middle pre-rod seat;

[0020] Figure 5 Schematic diagram of the structure of the shielding claw combined with the ion lens;

[0021] Figure 6 Schematic diagram of the structure of one of the rods of the pre-quadrupole.

[0022] Reference numerals:

[0023] 1. Pre-rod seat, 11. Connecting rod, 12. Fixing rod, 13. Positioning rod, 14. Cavity, 15. Shielding claw groove, 16. Pre-quadrupole wall, 17. Shielding field wall, 18. Sealing groove, 19. Ion lens groove, 111. Pre-rod seat fixing hole, 110. Connecting hole, 2. Pre-quadrupole, 21. Rod body, 211. Rod body fixing hole, 3. Ion lens, 4. Shielding claw, 5. Terminal block, 6. External circuit wire, 7. Sealing ring. DETAILED DESCRIPTION

[0024] The following describes preferred embodiments of the present invention in more detail with reference to the accompanying drawings. Although preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, 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.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a", "the" and "the" used in the present invention and the appended claims are also intended to include 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 associated listed items.

[0026] It should be understood that although the terms "first", "second", "third", etc. may be used in the present invention to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other.

[0027] Unless otherwise specified, the structures and components used in the present invention are conventional structures and components in the technical field.

[0028] The utility model provides a pre-rod lens capable of clearing charge accumulation, referring to Figure 1 and Figure 2 The pre-rod lens includes a pre-rod seat 1 and a pre-quadrupole 2 and an ion lens 3 respectively mounted on both end surfaces of the pre-rod seat 1, wherein the pre-rod lens also includes a shielding field, which extends from an end surface of the ion lens 3 close to the pre-rod seat 1 toward the pre-quadrupole 2, and the shielding field covers the inter-rod gap of the pre-quadrupole 2. The shielding field is used to capture ions escaping from the inter-rod gap of the pre-quadrupole 2.

[0029] In the first specific embodiment provided by the present utility model, combined with Figure 5 The shielding field is composed of four claws of a shielding claw 4, and the shielding claw 4 is fixedly connected to the ion lens 3. In order to adapt to the distribution of the pre-quadrupole 2, the four claws are symmetrically arranged in pairs, and each claw is located between adjacent rods 21 in the pre-quadrupole 2. The pre-rod lens also includes a terminal 5 arranged on any one of the claws of the shielding claw 4, and the terminal 5 is connected to the external circuit. Of course, since the shielding claw 4 and the ion lens 3 are fixedly connected and can share a circuit, the terminal 5 can also be arranged on the ion lens 3. After power is turned on, the ion lens 3 can focus the ion beam, and the shielding claw 4 can form a shielding field through an electric field to capture ions escaping from between the rods 21 of the pre-quadrupole 2, thereby preventing the escaping ions from adhering to the insulated pre-rod seat 1, and then the charge accumulation is eliminated through the terminal 5 and the external circuit electrically connected through the external circuit wire 6.

[0030] Combine Figure 5 In some specific embodiments, the shielding claw 4 is fixedly welded to one end surface of the ion lens 3 close to the pre-rod seat 1, and each claw of the shielding claw 4 is L-shaped, wherein the lower bending section is fixedly connected to the ion lens 3 by welding, and the shielding claw 4 is specifically made of a metal conductive material.

[0031] In some specific embodiments, the shielding claw 4 and the ion lens 3 are integrally formed.

[0032] Combine Figure 3 and Figure 4 In some specific embodiments, in order to adapt to the design of the shielding claw 4 extending to cover the pre-quadrupole 2, four shielding claw grooves 15 opposite each other are opened on the pre-rod seat 1. These shielding claw grooves 15 are used to allow the claw body of the shielding claw 4 to penetrate and extend from one side of the pre-rod seat 1 to the other side of the pre-rod seat 1.

[0033] In a second specific embodiment provided by the present invention, the shielding field is formed by the metallized conductive layer on the inner side of the pre-rod seat 1. Specifically, the pre-rod seat 1 includes a cavity 14 extending toward the pre-quadrupole 2. The cavity 14 is used to accommodate the pre-quadrupole 2. The inner side of the cavity 14 includes a pre-quadrupole wall 16 for fitting and mounting with the rod body 21 of the pre-quadrupole 2. These pre-quadrupole walls 16 are symmetrically arranged in pairs, and a shielding field wall 17 is arranged between each two pre-quadrupole walls 16. These shielding field walls 17 are coated with the metallized conductive layer. The metallized conductive layer can be independently attached to the shielding field wall 17, or it can be extended to be electrically connected to the ion lens 3, that is, the metallized conductive layer extends to the pre-rod seat 1. Ion lens slot 19, when the ion lens 3 is installed, the ion lens 3 is connected to the metallized conductive layer on the ion lens slot 19 to form a whole. Therefore, when these metallized conductive layers are in contact with the ion lens 3, they can share a wiring terminal 5. If these metallized conductive layers and the ion lens 3 are independent of each other and have no contact, they need to be connected to a wiring terminal 5 respectively. Secondly, although these metallized conductive layers are separated by the pre-quadrupole wall 16, they can be connected to form a whole by extending the metallized conductive layer in the pre-quadrupole wall 16. A metallized conductive layer can be completely added to the pre-quadrupole wall 16, or a strip-shaped metallized conductive layer can be used only for connection. The specific connection design will not be repeated here.

[0034] Next reference Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 6 , introduces other structures of the pre-rod lens that can clear charge accumulation:

[0035] In some embodiments, the pre-rod seat 1 also includes a pre-rod seat fixing hole 111 connected to the pre-quadrupole wall 16. When the pre-quadrupole 2 is installed, the rod body 21 of the pre-quadrupole 2 is fitted with the pre-quadrupole wall 16, and the rod body fixing hole 211 of the rod body 21 is aligned with the pre-rod seat fixing hole 111. The rod body 21 is fixed to the pre-quadrupole wall 16 by the fixing rod 12. In a specific implementation, the fixing rod 12 can be a threaded rod, and the holes that cooperate with the fixing rod 12 are all threaded holes.

[0036] In some embodiments, the pre-rod seat 1 also includes a pre-connection hole 110 and a positioning rod 13. The positioning rod 13 is used to position the pre-rod lens when it is connected to the collision unit of the mass spectrometer. After the positioning is completed, the connecting rod 11 is used to reinforce the connection with the collision unit through the connecting hole 110. In a specific implementation, the connecting rod 11 can be a threaded rod.

[0037] In some embodiments, the pre-rod seat 1 further includes a sealing groove 18 for accommodating a sealing ring 7 , and the sealing ring 7 is used to seal the ion lens 3 .

[0038] The utility model also provides a mass spectrometer, which comprises an ion source, a pre-rod lens capable of clearing charge accumulation, a collision unit, a mass spectrometer and a detector.

[0039] The utility model adds a shielding field to the periphery of the pre-quadrupole of the pre-rod lens to capture the escaped ions in all directions, and then directly guides the captured ions out through the wiring terminals and external circuits, eliminating the work of frequent disassembly and cleaning to solve the ion attachment problem in the prior art, and the voltage value of the shielding field is only within tens of volts, and an electric field is only formed in the vicinity, which is located outside the lens hole. Since the electric field of the pre-rod is much larger than the shielding electric field, the addition of the shielding field only solves the problem of ion escape and does not affect the performance of other modules of the mass spectrometer, ensuring the stability of the mass spectrometer while improving the user experience. The shielding field can be formed by a shielding claw or by a metallized conductive layer on the inner surface of the pre-rod seat, eliminating the occurrence of charge accumulation while maintaining the original assembly structure and assembly process as much as possible. The improvement scheme is easy to implement, and does not increase the installation and maintenance costs when implementing the improvement on the existing mass spectrometer, while enhancing the efficiency and effect of the mass spectrometer based on low improvement difficulty and improvement cost. The improvement scheme has strong versatility.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A pre-rod lens capable of removing charge accumulation, the pre-rod lens comprising a pre-rod seat and a pre-quadrupole and an ion lens respectively mounted on both end surfaces of the pre-rod seat, characterized in that: The pre-rod lens also includes a shielding field, which extends from an end surface of the ion lens close to the pre-rod seat toward the pre-quadrupole, covers the inter-rod gaps of the pre-quadrupole, and is used to capture ions escaping from the inter-rod gaps of the pre-quadrupole.

2. The pre-rod lens capable of clearing charge accumulation according to claim 1, characterized in that: The shielding field is formed by four claw bodies of a shielding claw, the shielding claw is fixedly connected to the ion lens, and the four claw bodies are symmetrically arranged in pairs.

3. The pre-rod lens capable of clearing charge accumulation according to claim 2, characterized in that: Each claw body is respectively located between adjacent rod bodies in the pre-quadrupole.

4. The pre-rod lens capable of clearing charge accumulation according to claim 2, characterized in that: The shielding claw is fixedly welded on an end surface of the ion lens close to the pre-rod seat.

5. The pre-rod lens capable of clearing charge accumulation according to claim 2, characterized in that: The shielding claw is integrally formed with the ion lens.

6. The pre-rod lens capable of clearing charge accumulation according to claim 2, characterized in that: The pre-rod lens also includes a connection terminal arranged on any one claw body of the shielding claw, and the connection terminal is connected to an external circuit.

7. The pre-rod lens capable of clearing charge accumulation according to claim 2, characterized in that: The pre-rod lens also includes a connection terminal arranged on the ion lens, and the connection terminal is connected to an external circuit.

8. The pre-rod lens capable of clearing charge accumulation according to claim 1, characterized in that: The pre-rod seat comprises a cavity extending towards the pre-quadrupole, the cavity is used to accommodate the pre-quadrupole, and the inner side of the cavity is provided with a metallized conductive layer forming the shielding field.

9. The pre-rod lens capable of clearing charge accumulation according to claim 8, characterized in that: The metallized conductive layer and the ion lens are both provided with a connection terminal, and the connection terminal is connected to an external circuit.

10. A mass spectrometer, characterized in that: It comprises a pre-rod lens capable of clearing charge accumulation as described in any one of claims 1 to 9.

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