Ion lens device and mass spectrometer

Abstract

The present application relates to an ion lens device and a mass spectrometer, which includes an ion extraction electrode and an even number of ion transport electrodes. Each ion transport electrode is arranged at equal intervals with respect to the ion extraction electrode, enclosing an open cylindrical ion transport channel. An ion extraction hole is provided on the ion extraction electrode; voltages are applied to both the ion extraction electrode and each ion transport electrode, forming an accelerating and deflecting electric field in the cylindrical ion transport channel. The ion beam to be measured is introduced into the cylindrical ion transport channel from the previous-stage environment, and the movement direction of the ion beam to be measured is deflected, enabling the ion beam to be measured to be transmitted from the ion extraction hole to the next-stage environment. Neutral particles and photons that are not affected by the electric field deflection are removed, and the off-axis ion lens structure can also have a higher ion transport efficiency, and the instrument has a higher sensitivity.

Description

Technical Field

[0001] The present application relates to the technical field of mass spectrometry instruments, and particularly to an ion lens device and a mass spectrometer. Background Art

[0002] A mass spectrometer is one of the most basic instruments for studying the basic composition, structural characteristics, physical and chemical properties of substances. It is an essential instrument in fields such as life science, materials science, food safety, and environmental protection, and is the core of modern analytical instruments. The essence of a mass spectrometer is to detect the composition of a compound by separating moving ions according to their mass-to-charge ratio using an electric field and / or a magnetic field in a vacuum environment. Among them, the ion lens device is a key transmission device in the mass spectrometer. It needs to focus and guide the ions to be analyzed from the interface area to the mass spectrometry analysis device, and at the same time prevent background noise such as neutral particles and photons from passing through, which determines the instrument sensitivity, detection limit, and background noise level.

[0003] Currently, common ion lens devices can include an optical baffle type, a 90-degree deflection type, etc. according to the ion deflection method. Among them, although the optical baffle type can well eliminate the interference of neutral particles and photons, it will also cause serious loss of the ions to be measured, resulting in a decrease in the instrument sensitivity. For different mass elements, the focusing point of the 90-degree deflection type is not particularly stable, and even some ions may deflect outside the device during the transmission process, which will also cause the problem of reduced sensitivity. Summary of the Invention

[0004] Based on this, in view of the problem that the existing ion lens device will cause a decrease in ion detection sensitivity, it is necessary to provide an ion lens device and a mass spectrometer.

[0005] An ion lens device includes an ion extraction electrode and an even number of ion transmission electrodes. Each of the ion transmission electrodes is arranged at equal intervals on the ion extraction electrode, enclosing an open cylindrical ion transmission channel. An ion extraction hole is provided on the ion extraction electrode;

[0006] Voltages are applied to both the ion extraction electrode and each of the ion transmission electrodes, forming an accelerating and deflecting electric field in the cylindrical ion transmission channel. The ion beam to be measured is introduced into the cylindrical ion transmission channel from the previous-level environment, and the movement direction of the ion beam to be measured is deflected, so that the ion beam to be measured is transmitted from the ion extraction hole to the next-level environment.

[0007] In one embodiment, the number of the ion transport electrodes is at least four, including a pair of oppositely arranged ion acceleration electrodes and at least a pair of oppositely arranged ion deflection electrodes. The distances between each of the ion acceleration electrodes and the ion extraction hole are the same, and the magnitudes of the voltages applied to each of the ion acceleration electrodes are equal. The distances between two oppositely arranged ion deflection electrodes and the ion extraction hole are different, and the voltage applied to the ion deflection electrode closer to the ion extraction hole is greater than the voltage applied to the ion deflection electrode farther from the ion extraction hole.

[0008] In one embodiment, the polarities of the voltages applied to each of the ion acceleration electrodes and each of the ion deflection electrodes are the same.

[0009] In one embodiment, each of the ion acceleration electrodes and each of the ion deflection electrodes is a stainless steel electrode.

[0010] In one embodiment, each of the ion acceleration electrodes and each of the ion deflection electrodes is a square frame-shaped electrode with a through hole in the middle.

[0011] In one embodiment, each of the ion acceleration electrodes and each of the ion deflection electrodes is provided with a metal wire.

[0012] In one embodiment, the number of the ion transport electrodes is two. The two ion transport electrodes are oppositely arranged as ion deflection electrodes. The distances between the two ion deflection electrodes and the ion extraction hole are different, and the voltage applied to the ion deflection electrode closer to the ion extraction hole is greater than the voltage applied to the ion deflection electrode farther from the ion extraction hole.

[0013] In one embodiment, the above ion lens device further includes a rotating mechanism connected to the ion extraction electrode. The rotating mechanism is used to drive the ion extraction electrode and each of the ion transport electrodes to rotate along the central axis of the cylindrical ion transport channel, so as to adjust the position of the ion extraction hole on the ion extraction electrode.

[0014] In one embodiment, a mass spectrometer is provided, including an ion generation device, an ion interface device, a collision reaction device, a mass analysis device, and the above ion lens device. The ion generation device is used to generate an ion beam to be measured. After the ion beam to be measured passes through the ion interface device, the ion lens device, and the collision reaction device in sequence, it enters the mass analysis device to complete mass analysis.

[0015] In one embodiment, the ion lens device is provided between the ion interface device and the collision reaction device, and between the collision reaction device and the mass analysis device.

[0016] In the above ion lens device and mass spectrometer, the ion extraction electrode and an even number of ion transmission electrodes enclose a cylindrical ion transmission channel with one end open. By applying voltages to the ion extraction electrode and each ion transmission electrode, an accelerating and deflecting electric field is formed in the cylindrical ion transmission channel. The ion beam to be measured is introduced into the cylindrical ion transmission channel from the previous-stage environment, deflected, and then transmitted to the next-stage environment through the ion extraction hole. Neutral particles and photons that are not affected by the electric field deflection are removed, and the off-axis ion lens structure can also have a higher ion transmission efficiency, and the instrument has a higher sensitivity. Description of the Drawings

[0017] Figure 1 It is a rear view schematic diagram of the ion lens device in an embodiment;

[0018] Figure 2 It is a side view schematic diagram of the ion lens device in an embodiment;

[0019] Figure 3 It is a front view schematic diagram of the ion lens device in an embodiment;

[0020] Figure 4 It is a schematic diagram of the ion transmission electrode being a square electrode in an embodiment;

[0021] Figure 5 It is a schematic diagram of the ion transmission electrode being a square electrode with a metal wire in an embodiment;

[0022] Figure 6 It is a schematic diagram of the movement trajectory of the ion beam to be measured in the ion lens device in an embodiment;

[0023] Figure 7 It is a deflection trajectory diagram when the ion masses of the ion beam to be measured are 9 amu, 115 amu, and 209 amu in an embodiment;

[0024] Figure 8 It is a structural block diagram of a mass spectrometer in an embodiment. Detailed Embodiments

[0025] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] 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 this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0027] It can be understood that the terms "first", "second", etc. used in the present application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of the present application, the first resistor may be referred to as the second resistor, and similarly, the second resistor may be referred to as the first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0028] It can be understood that for the "connection" in the following embodiments, if there is a transfer of electrical signals or data between the connected circuits, modules, units, etc., it should be understood as "electrical connection", "communication connection", etc.

[0029] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising", "including" or "having", etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0030] As described in the background art, the mass spectrometer is the core of modern analytical instruments. In essence, it uses an electric field and / or a magnetic field to separate moving ions by mass-to-charge ratio in a vacuum environment to detect the composition of compounds. Among them, the ion lens device is a key transmission device in the mass spectrometer. It is required to gather and guide the ions to be analyzed from the interface area to the mass spectrometry device, while preventing background noise such as neutral particles and photons from passing through, which determines the instrument sensitivity, detection limit and background noise level. Currently, the commonly used ion lens devices can include optical baffle type and 90-degree deflection type according to the ion deflection method. Among them, although the optical baffle type can well eliminate the interference of neutral particles and photons, it will also cause serious loss of the ions to be measured, resulting in a decrease in the instrument sensitivity. For the 90-degree deflection type, for elements of different masses, the voltage needs to be frequently adjusted, and the ion focusing point is not particularly stable. Even some ions may deflect outside the device during the transmission process, which will also cause the problem of decreased sensitivity.

[0031] Based on this, the present application provides an ion lens device for use in a mass spectrometer, specifically for scenarios where it is necessary to focus and guide an ion beam to be measured to achieve a deflection in the direction of motion, while removing background noise such as neutral particles and photons in the ion beam to be measured. For example, it can be applied between an ion interface device and a collision reaction device to remove neutral molecules and photons in the ion beam to be measured. It can also be applied between a collision reaction device and a mass analysis device to remove neutral molecules generated during ion collisions or reactions in the collision reaction device. Specifically, an ion extraction electrode and an even number of ion transport electrodes enclose a cylindrical ion transport channel with one end open. By applying voltages to the ion extraction electrode and each ion transport electrode, an accelerating and deflecting electric field is formed in the cylindrical ion transport channel. The ion beam to be measured is introduced into the cylindrical ion transport channel from the upper-level environment, deflected, and then transmitted through the ion extraction hole to the lower-level environment. Neutral particles and photons that are not affected by the electric field deflection are removed, and the structure of the off-axis ion lens can also have a higher ion transport efficiency, resulting in a higher sensitivity of the instrument for detecting the ion beam to be measured.

[0032] In one embodiment, as Figure 1 shown in Figure 2 Figure [not provided in the original, so it remains Figure 2 ], there is provided an ion lens device, including an ion extraction electrode 110 and an even number of ion transport electrodes 120. Each ion transport electrode 120 is arranged at equal intervals around the ion extraction electrode 110, enclosing an open cylindrical ion transport channel. An ion extraction hole 130 is provided on the ion extraction electrode 110; voltages are applied to both the ion extraction electrode 110 and each ion transport electrode 120, forming an accelerating and deflecting electric field in the cylindrical ion transport channel. The ion beam to be measured is introduced into the cylindrical ion transport channel from the upper-level environment, and the direction of motion of the ion beam to be measured is deflected, so that the ion beam to be measured is transmitted through the ion extraction hole 130 to the lower-level environment.

[0033] Specifically, each ion transport electrode 120 is arranged perpendicular to the ion extraction electrode 110, enclosing an open cylindrical ion transport channel with the ion extraction electrode 110. It can be understood that the central axis direction of the cylindrical ion transport channel is parallel to the direction of motion of the ion beam to be measured, so that the ion beam to be measured is injected from the opening, passes through the cylindrical ion transport channel, and then exits through the ion extraction hole 130 provided on the ion extraction electrode 110 to the lower-level environment, ensuring the ion transport efficiency.

[0034] Among them, the ion transport electrodes 120 are arranged in pairs and are equally spaced on the ion extraction electrode 110 to form a cylindrical ion transport channel. The paired ion transport electrodes 120 are arranged oppositely, which can ensure that when a voltage is applied to form an acceleration and deflection electric field, the ion beam to be measured maintains its original shape without divergence, improving the ion transport efficiency. Correspondingly, in order to keep the overall shape of the device consistent, the ion extraction electrode 110 can be a circular electrode with the same diameter as the cross-section of the cylindrical ion transport channel, and the circular electrode is coaxially arranged with the cylindrical ion transport channel. Further, the number of ion transport electrodes 120 is an even number, which can include a pair of semi-circular ion transport electrodes 120, or can include more than two pairs of arc-shaped ion transport electrodes 120. Among them, the sizes of the ion extraction electrode 110 and the ion transport electrodes 120 and the size of the formed cylindrical ion transport channel are not unique and can be set according to the size of the mass spectrometer. For example, in this embodiment, the thickness of the ion extraction electrode 110 is 1 mm, the thickness of each ion transport electrode 120 is 4 mm, the radius of the enclosed cylindrical ion transport channel is 18.5 mm, and the length is 26 mm.

[0035] Further, in order to remove background noises such as neutral particles and photons in the ion beam to be measured, voltages are applied to both the ion extraction electrode 110 and each ion transport electrode 120 to form an acceleration and deflection electric field in the cylindrical ion transport channel. At the same time, the position of the ion extraction hole 130 on the ion extraction electrode 110 deviates from the beam spot position of the ion beam to be measured on the ion extraction electrode 110, so that the ion beam to be measured deflects in the direction of motion under the action of the deflection electric field and is transmitted from the ion extraction hole 130 to the next-level environment. It can be understood that background noises such as neutral particles and photons are not affected by the electric field. If the neutral particles and photons have a certain kinetic energy, they will hit the beam spot position of the ion beam to be measured on the ion extraction electrode 110 along the incident direction and be removed. If the kinetic energy is small, they will be pumped out by the vacuum device and removed. It can be understood that the ion extraction electrode 110 and each ion transport electrode 120 are fixed by insulating materials to ensure that they will not affect each other and maintain the stability of the electric field.

[0036] Among them, the distance of the ion extraction hole 130 from the beam spot position of the ion beam to be measured on the ion extraction electrode 110 along the incident direction is not limited, and can be set according to the actual ion mass and the deflection electric field. However, it is necessary to ensure that the ion extraction hole 130 and the beam spot position of the ion beam to be measured on the ion extraction electrode 110 have no overlapping parts to ensure the removal effect of background noise such as neutral particles and photons. In addition, the size of the ion extraction hole 130 is not unique, and can be set according to the actual diameter of the ion beam to be measured. For example, in this embodiment, the radius of the ion extraction hole 130 can be set to 2mm-4mm. In the embodiment of the present application, in order to facilitate the control of the ion beam transmission path, the ion beam to be measured is injected along the central axis of the cylindrical ion transmission channel, and the ion extraction hole 130 is eccentrically set to the ion extraction electrode 110. Among them, the eccentric distance of the ion extraction hole 130 can be set according to the deflection angle requirement of the ion beam to be measured.

[0037] When an accelerating deflection electric field is formed in the cylindrical ion transmission channel, it can be realized by applying voltages of different polarities or amplitudes to the ion extraction electrode 110 and each ion transmission electrode 120. For example, it can be realized by applying a positive voltage or a negative voltage of the same polarity to each ion transmission electrode 120, and applying a negative polarity voltage to the ion extraction electrode 110, so as to form an accelerating electric field consistent with the moving direction of the ion beam to be measured, so that the ion beam to be measured is accelerated to fly from the cylindrical ion transmission channel into the next level environment. At the same time, it is also possible to form a deflection electric field deflecting toward the ion extraction hole 130 by setting the voltage of the ion transmission electrode 120 close to the ion extraction hole 130 to be greater than the voltage of the ion transmission electrode 120 far from the ion extraction hole 130, so as to realize the deflection of the moving direction of the ion beam to be measured, and fly out from the ion extraction hole 130.

[0038] In addition, the ion lens device also includes a power supply unit for applying voltage to the ion extraction electrode 110 and each ion transmission electrode 120. The power supply unit is connected to an external power supply, and by performing step-up and step-down processing on the power supply voltage of the power supply, a DC voltage that meets the polarity and magnitude of the ion extraction electrode 110 and each ion transmission electrode 120 is obtained, and the DC voltage is output to the ion extraction electrode 110 and each ion transmission electrode 120 accordingly. In addition, the ion lens device also includes a controller, and the controller is used to control the polarity and magnitude of the voltage applied by the power supply unit to the ion extraction electrode 110 and each ion transmission electrode 120 to adjust the deflection angle of the ion beam to be measured and obtain the optimal ion transmission efficiency. It can be understood that the controller and the power supply unit can be realized by using existing devices in the shared mass spectrometer, or can be separately added to the ion lens device at this level.

[0039] In the above-mentioned ion lens device, the ion extraction electrode and an even number of ion transmission electrodes together form a cylindrical ion transmission channel with one end open. By applying voltage to the ion extraction electrode and each ion transmission electrode, an accelerating deflection electric field is formed in the cylindrical ion transmission channel, and the ion beam to be measured is introduced from the upper environment into the cylindrical ion transmission channel for deflection and then transmitted from the ion extraction hole to the lower environment. Neutral particles and photons that are not deflected by the electric field are removed. The structure of the off-axis ion lens can also have a higher ion transmission efficiency and a higher instrument sensitivity.

[0040] In one embodiment, Figure 2 and Figure 3 As shown, the number of ion transmission electrodes 120 is at least four, including a pair of oppositely arranged ion acceleration electrodes 122 and at least one pair of oppositely arranged ion deflection electrodes 121, each ion acceleration electrode 122 is at the same distance from the ion extraction hole 130, and the voltage applied by each ion acceleration electrode 122 is equal, the distances between the two oppositely arranged ion deflection electrodes 121 and the ion extraction hole 130 are different, and the voltage applied by the ion deflection electrode 121 close to the ion extraction hole 130 is greater than the voltage applied by the ion deflection electrode 121 far from the ion extraction hole 130.

[0041] Specifically, the distances between the relatively arranged ion acceleration electrodes 122 and the ion extraction hole 130 are the same, which are used to control the kinetic energy of the ion beam to be measured along the central axis direction of the cylindrical ion transmission channel, and to pull the ion beam to be measured to move. And the voltages applied by each ion acceleration electrode 122 are equal, and there is no deflection effect on the ion beam to be measured. Therefore, in other embodiments, the controller can adjust the voltage applied by the power supply unit to the ion acceleration electrode 122 according to the incident kinetic energy of the ion beam to be measured, so as to achieve the purpose of adjusting the movement speed of the ion beam to be measured as needed. In addition, the incident kinetic energy of the ion beam to be measured from the upper environment can also be reduced, so that more neutral particles and photons are vacuum extracted in the current ion lens device, reducing the pollution of the pole piece in the current ion lens device, and then by increasing the voltage applied by each ion acceleration electrode 122, the kinetic energy of the ion beam to be measured is increased.

[0042] Furthermore, the number of ion deflection electrodes 121 may be only one pair, such as Figure 2 and Figure 3As shown, it can also be two pairs or more, without limitation. The distances between the two oppositely arranged ion deflection electrodes 121 and the ion extraction hole 130 are different, and the voltage applied to the ion deflection electrode 121 closer to the ion extraction hole 130 is greater than the voltage applied to the ion deflection electrode 121 farther from the ion extraction hole 130, so that the ion beam to be measured can be deflected towards the ion deflection electrode 121 closer to the ion extraction hole 130. Then, the controller adjusts the magnitudes of the voltages applied by the power supply unit to the ion deflection electrodes 121 on both sides, so that the ion beam to be measured accurately flies out from the ion extraction hole 130, and background noises such as neutral particles and photons are removed because they are not affected by the electric field.

[0043] Among them, the magnitudes of the voltages applied by each ion deflection electrode 121 and each ion acceleration electrode 122 can be determined according to the mass, quantity, and incident kinetic energy of the specific ion beam to be detected. In this embodiment, the voltages applied by each ion deflection electrode 121 and each ion acceleration electrode 122 can be set between -200 V and 200 V. It can be that the voltages of two ion acceleration electrodes 122 are first selected, and then the voltages of each ion deflection electrode 121 are obtained by increasing or decreasing a preset voltage difference based on the voltages of the ion acceleration electrodes 122. The voltage applied to the ion deflection electrode 121 closer to the ion extraction hole 130 is the voltage of the ion acceleration electrode 122 plus the preset voltage difference, and the voltage applied to the ion deflection electrode 121 farther from the ion extraction hole 130 is the voltage of the ion acceleration electrode 122 minus the preset voltage difference. Among them, the preset voltage difference can also be selected according to actual needs. For example, in this embodiment, it is 15 V.

[0044] In one embodiment, the polarities of the voltages applied by each ion acceleration electrode 122 and each ion deflection electrode 121 are the same. Among them, the polarities of the voltages applied by each ion acceleration electrode 122 and each ion deflection electrode 121 can be the same positive voltage or negative voltage. The voltage applied by the ion extraction electrode 110 can also be a positive-polarity voltage or a negative-polarity voltage.

[0045] In another embodiment, the number of ion transport electrodes 120 can also be two. The two ion transport electrodes are arranged oppositely as ion deflection electrodes 121. The distances between the two ion deflection electrodes 121 and the ion extraction hole 130 are different, and the voltage applied to the ion deflection electrode 121 closer to the ion extraction hole 130 is greater than the voltage applied to the ion deflection electrode 121 farther from the ion extraction hole 130. Similarly, it can achieve the deflection of the ion beam to be measured towards the ion deflection electrode 121 closer to the ion extraction hole 130. Then, the controller adjusts the magnitudes of the voltages applied by the power supply unit to the two ion deflection electrodes 121, so that the ion beam to be measured accurately flies out from the ion extraction hole 130. Further, by setting the magnitudes of the voltages of the two ion deflection electrodes 121 to be less than the voltage applied by the ion extraction electrode 110, the purpose of accelerating the ion beam to be measured can also be achieved.

[0046] In one embodiment, each ion acceleration electrode and each ion deflection electrode are stainless steel electrodes. Making each ion acceleration electrode and each ion deflection electrode from stainless steel material can make each electrode not easily rust, deform or be oxidized, ensuring a longer service life. In addition, the stainless steel electrode has good electrical conductivity and does not affect the electric field distribution of the electrode, and can better achieve the acceleration and deflection of the ion beam to be measured.

[0047] In one embodiment, as Figure 4 shown, each ion acceleration electrode and each ion deflection electrode are box-shaped electrodes with a through hole in the middle. In this embodiment, by digging a through hole in the middle of each ion acceleration electrode and each ion deflection electrode to form a box-shaped electrode, when neutral particles and photons are evacuated in the current-stage ion lens device, they will not adhere to each ion acceleration electrode and each ion deflection electrode, reducing the pollution of the electrodes in the current-stage ion lens device.

[0048] Further, when there are electrodes in the previous stage of the current-stage ion lens device, in order to maintain the vacuum degree of the open cylindrical ion transport channel, in one embodiment, as Figure 5 shown, each ion acceleration electrode and each ion deflection electrode are provided with metal wires. Among them, the metal wires can be arranged on the box-shaped electrode in a winding or fixed manner, so that the through hole in the middle presents a mesh shape. When voltages are applied to each ion acceleration electrode and each ion deflection electrode, the metal wires are also charged synchronously to maintain the vacuum degree of the open cylindrical ion transport channel. At the same time, the mesh-shaped metal wire structure can also reduce the adhesion of neutral particles and photons, achieving the purpose of reducing the pollution of the electrodes in the current-stage ion lens device.

[0049] In one embodiment, the ion lens device further comprises a rotating mechanism connected to the ion extraction electrode, and the rotating mechanism is used to drive the ion extraction electrode and each ion transmission electrode to rotate along the central axis of the cylindrical ion transmission channel, so as to adjust the position of the ion extraction hole on the ion extraction electrode. It can be understood that, since the ion lens device of the present application presents a cylindrical structure, the position of the ion extraction hole on the ion extraction electrode can be arbitrarily adjusted within a range of 360 degrees around the central axis of the ion transmission channel. Under the control of the same set of voltages of the ion extraction electrode and each ion transmission electrode, the ion beam to be measured can be deflected and fly out at multiple angles, which can be easily adapted to the position of the next device.

[0050] like Figure 6 The figure shows a motion trajectory diagram of an ion beam 10 to be measured with an ion mass of 115amu and an ion number of 100 through the ion lens device of the present application in one embodiment. Specifically, after the ions in the ion beam 10 to be measured enter the ion lens device, the controller controls the power supply unit to adjust the voltage of the ion acceleration electrode 122 to 100V according to the incident kinetic energy of the ions, so that the ion acceleration electrode 122 controls the transverse kinetic energy of the ions and pulls the ion beam 10 to be measured to move axially in the cylindrical ion channel. The controller then controls the power supply unit to control the voltage of the relatively arranged ion deflection electrodes 121 to 110V and 95V, so as to realize the trajectory deflection of the ion beam 10 to be measured, and smoothly fly out of the ion lens device under the traction of the ion extraction electrode 110, and enter the next stage of transmission. At this time, the deflection angle of the ion beam 10 to be measured can be achieved to be about 14°, and the transmission efficiency is the highest.

[0051] like Figure 7 As shown in (a), (b) and (c), it is the deflection trajectory diagram under the condition that the voltage of the two ion acceleration electrodes 122 is selected to be 100V, the voltage of the ion deflection electrode 121 arranged oppositely is 110V and 95V, and the voltage of the ion extraction electrode 110 is -10V, and the ion masses of the ion beam to be measured correspond to 9amu, 115amu and 209amu. Through comparative analysis, it can be known that the ion lens device of the present application has good transmission efficiency for ions of different mass numbers. When a set of suitable voltages is selected, ions of the full mass range can pass through the lens smoothly and enter the next stage of transmission without frequent adjustment of the pole piece voltage.

[0052] In one embodiment, Figure 8 As shown, a mass spectrometer is provided, including an ion generating device 21, an ion interface device 22, a collision reaction device 24, a mass analysis device 25 and the above-mentioned ion lens device 23. The ion generating device 21 is used to generate an ion beam to be measured. The ion beam to be measured passes through the ion interface device 22, the ion lens device 23 and the collision reaction device 24 in sequence, and then enters the mass analysis device 25 to complete mass analysis.

[0053] Specifically, the sample is ionized by the ion generation device 21 to obtain an ion beam to be measured. The ion beam to be measured enters the mass spectrometry cavity 26 through the ion interface device 22. After the neutral particles and photons enter the mass spectrometry cavity 26, they are removed by the ion lens device 23. The ion extraction electrode of the ion lens device 23 can serve as the inlet pole piece of the collision reaction device 24. The ion beam to be measured is further collided or reacted by the collision reaction device 24 to remove polyatomic interference and mass spectrometry interference, and then enters the mass analysis device 25 to complete the quantitative or qualitative analysis of the sample.

[0054] Among them, the ion interface device 22 includes a sampling cone 32, an intercepting cone 33 and an extraction lens 34, which belongs to the interface part of the mass spectrometer and realizes the transition of the vacuum environment and the extraction of the ion beam to be measured. The vacuum environment of the interface part is obtained by pumping through the pumping port 35 by the mechanical pump 31, and the required vacuum degree is less than 200 Pa. The ion lens device 23 and the collision reaction device 24 belong to the ion transmission part of the mass spectrometer. The vacuum environment of the ion transmission part is evacuated through the molecular pump 29 connected to the pumping port 27, and the vacuum degree is controlled at 10 -2 -10 -3 Pa. The mass analysis device 25 is evacuated through the molecular pump 30 connected to the pumping port 28, and the vacuum degree is controlled at 10 -5 -10 -6 Pa.

[0055] In addition, the mass spectrometer mentioned in the embodiments of the present application is an inductively coupled plasma mass spectrometer (ICP-MS). Its ion generation device 21 is a device that forms a plasma by applying high-frequency power to a coil coupled to a plasma torch tube. The mass analysis device 25 can be implemented by using a quadrupole mass spectrometer, a magnetic field mass spectrometer, a time-of-flight mass spectrometer, etc.

[0056] In one embodiment, an ion lens device is provided between the ion interface device and the collision reaction device, and between the collision reaction device and the mass analysis device.

[0057] Specifically, the ion lens device of the present application can be applied between the ion interface device and the collision reaction device to remove neutral molecules and photons in the ion beam to be measured. It can also be applied between the collision reaction device and the mass analysis device to remove the neutral molecules generated during the ion collision or reaction process in the collision reaction device.

[0058] Among them, when applied between the ion interface device and the collision reaction device, it is installed behind the ion extraction lens 34. The transmission hole is relatively small, and the vacuum degree inside the ion lens device can be better guaranteed. Each ion acceleration electrode and each ion deflection electrode therein can adopt a square electrode with a through hole in the middle. When applied between the collision reaction device and the mass analysis device, since the previous-stage collision reaction device is the output pole piece, it is impossible to better guarantee the vacuum degree inside the ion lens device, and metal wires need to be provided in the through holes of each ion acceleration electrode and each ion deflection electrode.

[0059] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0060] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An ion lens device, characterized in that, It includes an ion extraction electrode and an even number of ion transport electrodes. Each of the ion transport electrodes is arranged at equal intervals on the ion extraction electrode, enclosing an open cylindrical ion transport channel. An ion extraction hole is provided on the ion extraction electrode; the number of the ion transport electrodes is at least four, including a pair of oppositely arranged ion acceleration electrodes and at least a pair of oppositely arranged ion deflection electrodes. The distances from each of the ion acceleration electrodes to the ion extraction hole are the same, and the magnitudes of the voltages applied to each of the ion acceleration electrodes are equal. The distances from the two oppositely arranged ion deflection electrodes to the ion extraction hole are different, and the voltage applied to the ion deflection electrode closer to the ion extraction hole is greater than the voltage applied to the ion deflection electrode farther from the ion extraction hole; Voltages are applied to both the ion extraction electrode and each of the ion transport electrodes to form an acceleration and deflection electric field in the cylindrical ion transport channel. The ion beam to be measured is introduced into the cylindrical ion transport channel from the previous-stage environment, and the movement direction of the ion beam to be measured is deflected so that the ion beam to be measured is transmitted from the ion extraction hole to the next-stage environment.

2. The ion lens device according to claim 1, wherein, The polarities of the voltages applied to each of the ion acceleration electrodes and each of the ion deflection electrodes are the same.

3. The ion lens device according to claim 1, characterized in that, Each of the ion acceleration electrodes and each of the ion deflection electrodes is a stainless-steel electrode.

4. The ion lens device according to claim 1, characterized in that, Each of the ion acceleration electrodes and each of the ion deflection electrodes is a box-shaped electrode with a through-hole in the middle.

5. The ion lens device according to claim 4, characterized in that, Metal wires are provided on each of the ion acceleration electrodes and each of the ion deflection electrodes.

6. The ion lens device according to any one of claims 1 to 5, characterized in that, It further includes a rotating mechanism connected to the ion extraction electrode. The rotating mechanism is used to drive the ion extraction electrode and each of the ion transport electrodes to rotate along the central axis of the cylindrical ion transport channel so as to adjust the position of the ion extraction hole on the ion extraction electrode.

7. A mass spectrometer, characterized in that, It includes an ion generation device, an ion interface device, a collision reaction device, a mass analysis device, and the ion lens device according to any one of claims 1 to 6. The ion generation device is used to generate an ion beam to be measured. After the ion beam to be measured passes through the ion interface device, the ion lens device, and the collision reaction device in sequence, it enters the mass analysis device to complete mass analysis.

8. The mass spectrometer according to claim 7, characterized in that, The ion lens device is provided between the ion interface device and the collision reaction device, and between the collision reaction device and the mass analysis device.

9. The mass spectrometer according to claim 7, characterized in that, The ion interface device includes a sampling cone, an intercepting cone, and an extraction lens.

10. The mass spectrometer according to claim 7, characterized in that, The mass analysis device is a quadrupole mass spectrometer, a magnetic field mass spectrometer, or a time-of-flight mass spectrometer.

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