Ionization enhanced ion mobility spectrometer

Abstract

The invention provides an ionization enhanced ion mobility spectrometer, which relates to the technical field of ion mobility spectrometry analysis, and comprises an ionization source, an insulating ring, a metal electrode ring, an enhanced reflection cavity, an ion gate grid mesh, a shielding grid mesh, a Faraday disc, an insulating tube, an air pump and the like, and the multi-stage reflecting mirror is adopted inside to perform multi-stage reflection on the light source, so that the number of reaction ions in the ionization region is effectively controlled, the signal intensity is improved, and the detection sensitivity of the ion mobility spectrometer is improved.

Description

Technical Field

[0001] This invention relates to the field of ion mobility spectrometry analysis technology, and more particularly to an ionization-enhanced ion mobility spectrometer, and further to a novel ion mobility spectrometer that can improve signal intensity and ultimately improve sensitivity. Background Technology

[0002] Ion mobility spectrometry (IMA) requires higher sensitivity and resolution for on-site detection, especially in critical areas such as the detection of chemical agents, drugs, and explosives. Traditional techniques are no longer sufficient to meet the detection needs of trace substances in complex samples, necessitating a breakthrough in the technical bottleneck of "increasing resolution at the expense of decreasing sensitivity." Insufficient ion source intensity results in low signal strength and high detection limits; furthermore, the ion scavenging effect during use can also reduce sensitivity, leading to severe mobility discrimination at high gate voltage differences (GVDs); and insufficient ion number density affects detection accuracy and reliability. Summary of the Invention

[0003] To address the aforementioned technical problems, an ionization-enhanced ion mobility spectrometer is provided. The technical problem this invention aims to solve is to enhance the optical path of the ultraviolet lamp ionization source through multiple reflections, effectively increasing the number of reacting ions, improving signal intensity, and ultimately enhancing the overall sensitivity of the mobility tube. By setting an enhanced reflection cavity between the inner and outer walls of the ionization and reaction regions, and employing multi-stage mirrors inside to reflect the light source at multiple stages, the number of reacting ions within the ionization region is effectively controlled, increasing signal intensity and thus improving the detection sensitivity of the ion mobility spectrometer.

[0004] The technical means employed in this invention are as follows: An ionization-enhanced ion mobility spectrometer includes: an ionization source, an insulating ring, a metal electrode ring, an enhanced reflection cavity, an ion gate grid, a shielding grid, a Faraday disk, an insulating tube, and a gas pump. One end of the insulating tube is open and connected to a carrier gas inlet, while the other end of the insulating tube is closed. The ionization source and enhanced reflection cavity, the ion gate grid, the metal electrode ring and insulating ring, the shielding grid, and the Faraday disk are sequentially arranged along the inner cavity of the insulating tube from the open end to the closed end. The insulating tube has a first opening on its sidewall near the open end. The ionization source is located at the first opening on the sidewall of the insulating tube and forms an ionization reaction region with the ion gate grid. An inner tube with a diameter smaller than that of the insulating tube is located within the ionization reaction region. The enhanced reflection cavity is located inside the inner tube and consists of mirrors embedded in the inner wall of the inner tube. A second opening is located on the sidewall of the inner tube, and the second opening faces the enhanced reflection cavity. Ultraviolet light shines through the second opening onto the mirrors in the enhanced reflection cavity. The ion gate grid, the insulating ring, the metal electrode ring, and the shielding grid together form an ion migration region. An exhaust gas outlet is provided on the side wall of the insulating tube between the ionization source and the ion gate grid. The exhaust gas outlet is close to the ion gate grid. The Faraday disk is fixedly embedded in the wall of the closed end of the insulating tube. A drift gas inlet is provided on the side wall between the Faraday disk and the closed end of the insulating tube. The carrier gas inlet and the drift gas inlet are connected to the air through a filter tube filled with purifying agent and an air pump.

[0005] Furthermore, at least three reflectors are placed, and the multiple reflectors are arranged in sequence. The angle between each reflector and the light beam is 30° to 60°, and the light beam is reflected multiple times in a loop among the multiple reflectors.

[0006] Furthermore, the reflector is embedded in an annular groove in the inner wall of the inner tube, and is circular or rectangular.

[0007] Furthermore, the metal electrode ring and the insulating ring are coaxially stacked together as a group, with at least three groups stacked and arranged in sequence.

[0008] Furthermore, the ionization source is a vacuum ultraviolet lamp ionization source.

[0009] Furthermore, the purifying agent is molecular sieve particles.

[0010] Compared with the prior art, the present invention has the following advantages: The ionization-enhanced ion mobility spectrometer provided by this invention has an enhanced reflection cavity set between the inner and outer walls of the ionization region and the reaction region. The cavity uses multi-level mirrors to reflect the light source in multiple stages, which effectively controls the number of reacting ions in the ionization region, improves the signal intensity, and thus improves the detection sensitivity of the ion mobility spectrometer. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of an ionization-enhanced ion mobility spectrometer according to the present invention.

[0013] In the diagram: 1. Ionization source; 2. Exhaust gas outlet; 3. Insulating ring; 4. Metal electrode ring; 5. Drift gas inlet; 6. Enhanced reflection cavity; 7. Ion gate grid; 8. Shielding grid; 9. Faraday disk; 10. Insulating tube; 11. Carrier gas inlet. Detailed Implementation

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0020] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0021] like Figure 1 As shown, the present invention provides an ionization-enhanced ion mobility spectrometer, including an insulating tube 10, an enhanced reflection cavity 6, an ionization source 1, a gas pump, a metal electrode ring 4, an ion gate grid 7, an insulating ring 3, a shielding grid 8, a Faraday disk 9, etc.

[0022] One end of the insulating tube 10 is open and connected to the carrier gas inlet 11, while the other end is closed. Along the inner cavity of the insulating tube 10 from the open end to the closed end, an ionization source 1, an enhanced reflection cavity 6, an ion gate grid 7, a metal electrode ring 4, an insulating ring 3, a shielding grid 8, and a Faraday disk 9 are sequentially arranged. The side wall of the insulating tube 10 near the open end has a first opening. The ionization source 1, a vacuum ultraviolet lamp ionization source, is tightly fitted to the first opening on the side wall of the insulating tube 10 and forms an ionization reaction zone with the ion gate grid 7. An inner tube with a diameter smaller than that of the insulating tube 10 is located within the ionization reaction zone. The enhanced reflection cavity 6 is located inside the inner tube and consists of mirrors embedded in the inner wall of the inner tube within the ionization reaction zone. A second opening is located on the side wall of the inner tube, directly opposite the enhanced reflection cavity 6. Ultraviolet light enters the mirrors in the enhanced reflection cavity 6 through the second opening. Metal electrode rings 4 and insulating rings 3 are alternately arranged, with insulating rings 3 placed between adjacent metal electrode rings 4. The metal electrode rings 4 and insulating rings 3 are coaxially stacked as a group, with at least three groups stacked sequentially, forming an ion migration zone together with the ion gate grid 7 and the shielding grid 8. A Faraday disk 9 is fixedly embedded in the wall of the closed end of the insulating tube 10. A drift gas inlet 5 is provided on the side wall between the Faraday disk 9 and the closed end of the insulating tube 10. A tail gas outlet 2 is provided on the side wall of the insulating tube between the ionization source 1 and the ion gate grid 7. A carrier gas inlet 11 is located near one end of the ionization source 1, and a tail gas outlet 2 is located near one end of the ion gate grid 7. The carrier gas inlet 11 and the drift gas inlet 5 are connected to the air via a filter tube filled with a purifying agent, which is molecular sieve particles.

[0023] In this invention, a vacuum ultraviolet lamp directs ultraviolet light into the enhanced reflection cavity 6 through an opening in the tube wall. The ultraviolet light illuminates the surface of a reflector in the enhanced reflection cavity 6, with the reflector forming an angle of 30° to 60° with the ultraviolet beam. At least three reflectors are then placed, each with an angle of 30° to 60° with the reflected beam, arranged sequentially until the reflected beam passes through each reflector surface in turn. The beam circulates and reflects multiple times among the reflectors. The reflectors are embedded in an annular groove in the inner wall of the inner tube; the reflectors can be circular or rectangular, and their shape is not unique.

[0024] This invention provides an enhanced reflection cavity between the inner and outer walls of the ionization region and the reaction region. The cavity uses multi-level mirrors to reflect the light source in multiple stages, which effectively controls the number of reacting ions in the ionization region, improves the signal intensity, and thus enhances the detection sensitivity of the ion mobility spectrometer.

[0025] 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 ionization-enhanced ion mobility spectrometer, characterized in that, include: The ionization source (1), insulating ring (3), metal electrode ring (4), enhanced reflection cavity (6), ion gate grid (7), shielding grid (8), Faraday disk (9), insulating tube (10) and gas pump are arranged in sequence. One end of the insulating tube (10) is set as an opening, which is connected to the carrier gas inlet (11), and the other end of the insulating tube (10) is set as a closed end. The ionization source (1), enhanced reflection cavity (6), ion gate grid (7), metal electrode ring (4), insulating ring (3), shielding grid (8) and Faraday disk (9) are arranged in sequence from the open end to the closed end of the inner cavity of the insulating tube (10). The insulating tube (10) has a first opening on its side wall near the open end. The ionization source (1) is located at the first opening on the side wall of the insulating tube (10) and forms an ionization reaction zone with the ion gate grid (7). The ionization reaction zone is provided with an inner tube with a diameter smaller than that of the insulating tube (10). The enhanced reflection cavity (6) is located inside the inner tube and is composed of a reflector embedded in the inner wall of the inner tube. The side wall of the inner tube has a second opening, which faces the enhanced reflection cavity (6). Ultraviolet light shines into the reflector in the enhanced reflection cavity (6) through the second opening. The ion gate grid (7), the insulating ring (3), the metal electrode ring (4), and the shielding grid (8) together form an ion migration zone. An exhaust gas outlet (2) is provided on the side wall of the insulating tube (10) between the ion source (1) and the ion gate grid (7). The exhaust gas outlet (2) is close to the ion gate grid (7). The Faraday disk (9) is fixedly embedded in the wall of the closed end of the insulating tube (10). A drift gas inlet (5) is provided on the side wall between the Faraday disk (9) and the closed end of the insulating tube (10). The carrier gas inlet (11) and the drift gas inlet (5) are connected to the air through a filter tube filled with purifying agent and an air pump.

2. The ionization-enhanced ion mobility spectrometer according to claim 1, characterized in that, At least three reflectors are placed, and multiple reflectors are arranged in sequence. The angle between each reflector and the light beam is 30° to 60°, and the light beam is reflected multiple times in a loop among the multiple reflectors.

3. The ionization-enhanced ion mobility spectrometer according to claim 2, characterized in that, The reflector is embedded in an annular groove in the inner wall of the inner tube, and is circular or rectangular.

4. The ionization-enhanced ion mobility spectrometer according to claim 1, characterized in that, The metal electrode ring (4) and the insulating ring (3) are placed coaxially and stacked together as a group, with at least three groups stacked and arranged in sequence.

5. The ionization-enhanced ion mobility spectrometer according to claim 1, characterized in that, The ionization source (1) is a vacuum ultraviolet lamp ionization source.

6. The ionization-enhanced ion mobility spectrometer according to claim 1, characterized in that, The purifying agent is molecular sieve particles.

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