Ion trap for mass spectrometry and mass spectrometer

Abstract

The application discloses a novel ion trap for mass spectrometry and a mass spectrometer, and the novel ion trap is a core component of the mass spectrometer and is used for ionizing, capturing, storing, fragmenting and separating ions. The application is characterized in that two or more electrically unconnected half electrodes are arranged at the inlet of the ion trap body, and an opening for passing gas molecules is arranged between the half electrodes. The half electrodes are further connected with voltage adjusting devices capable of changing voltage. The voltage adjusting devices can adjust the voltage on the half electrodes to form an electric field to ionize the gas molecules passing through the opening. The voltage on the half electrodes can be changed by the voltage adjusting devices to switch the novel ion trap to work in an ionization mode or a mass analysis mode. Compared with the prior art, the application combines the ion trap and the ionization source into an integrated ion trap, simplifies the internal structure of the mass spectrometer, facilitates integrated design, integrated processing, and installation and maintenance, reduces the weight of the mass spectrometer itself, and increases the possibility of the design direction of a small instrument.

Description

Technical Field

[0001] This invention relates to the field of ion trap mass spectrometry analysis technology, and in particular to an ion trap and mass spectrometer for mass spectrometry. Background Technology

[0002] Mass spectrometers are among the most sophisticated modern analytical instruments and represent the future direction of analytical instrument development. Currently, in the field of mass spectrometry, the ion trap and ionization source are designed as two independent structures, which leads to significant limitations in installation, maintenance, production costs, and portability / weight reduction.

[0003] Therefore, designing an ion trap and mass spectrometer for mass spectrometry, integrating the ion trap and ionization source into a single unit, simplifies the structure and improves integration, which has significant practical value and importance. Summary of the Invention

[0004] In view of the limitations of existing technologies, such as the separate design of ion traps and ionization sources, which leads to limitations in the installation, maintenance, production costs, and portability of mass spectrometers, this invention proposes an ion trap and mass spectrometer for mass spectrometry.

[0005] The technical solution of the present invention is to propose an ion trap for mass spectrometry, comprising an ion trap body, a plurality of half electrodes disposed at the entrance of the ion trap body for forming a pre-ion gate, and at least one pair of the half electrodes being electrically disconnected from each other, a voltage regulating device for changing voltage connected to the half electrodes, and an opening for gas molecules to pass through between the pair of non-electrically connected half electrodes, wherein the ion trap switches between ionization mode and mass analysis mode by changing the voltage on the half electrodes.

[0006] Furthermore, the half-electrode includes a first half-electrode and a second half-electrode that are not electrically connected to each other, and the first half-electrode and the second half-electrode are respectively connected to a voltage adjustment device. The opening is located between the first half-electrode and the second half-electrode. The ion trap switches between ionization mode and mass analysis mode by adjusting the voltage difference between the first half-electrode and the second half-electrode.

[0007] Furthermore, when the voltage difference between the first half-electrode and the second half-electrode is greater than the first threshold voltage, the ion trap operates in ionization mode, generating a discharge voltage between the first half-electrode and the second half-electrode, and ionizing the gas molecules passing through the opening.

[0008] Furthermore, when the voltage difference between the first half-electrode and the second half-electrode is less than the second threshold voltage, the ion trap operates in mass analysis mode, and the first half-electrode and the second half-electrode trap sample ions located at the opening.

[0009] Furthermore, it also includes a post-ion gate located at the outlet of the ion trap body, the post-ion gate being used to seal the ion trap body together with the half electrode.

[0010] The present invention also proposes a mass spectrometer having the above-mentioned ion trap.

[0011] Furthermore, the mass spectrometer includes a pulse valve located at the inlet of the ion trap body. The inlet of the pulse valve is used for the introduction of gas molecules, and the outlet is arranged towards the opening between the first half-electrode and the second half-electrode.

[0012] Furthermore, the mass spectrometer includes a detector used in conjunction with the ion trap body, the other end of which is connected to a terminal device for mass spectrometry analysis and generation of mass spectra.

[0013] Furthermore, it also includes a multiplier disposed on the side of the ion trap body, the multiplier being connected to the detector and used to amplify the detection signal transmitted to the detector.

[0014] Furthermore, it also includes a vacuum chamber for accommodating the ion trap body, and a molecular pump for maintaining the vacuum state of the vacuum chamber is provided at the tail of the vacuum chamber.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] This invention combines an ion trap and an ionization source into a novel integrated ion trap, simplifying the ion trap structure, reducing the weight of the mass spectrometer, and increasing possibilities for miniaturized instrument design. Furthermore, this integrated ion trap reduces post-assembly calibration steps, lowers costs, improves production efficiency, ensures consistency in mass production of the mass spectrometer, and facilitates mass production. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the ion trap structure of the present invention;

[0019] Figure 2 This is a flowchart of the process of the present invention;

[0020] Figure 3 This is a schematic diagram of the ion trap structure of the present invention;

[0021] Figure 4 This is a schematic diagram of the overall structure of the mass spectrometer of the present invention;

[0022] Figure 5 This is an example schematic diagram of the present invention operating in ionization mode;

[0023] Figure 6 This is an example schematic diagram of the present invention operating in quality analysis mode;

[0024] Figure 7 The spectrum of benzene sample is shown.

[0025] In this array, 1 is the first half-electrode, 2 is the second half-electrode, 3 is the ion trap body, 4 is the rear ion gate, 5 is the detector, 6 is the multiplier, 7 is the terminal equipment, 8 is the solenoid valve, 9 is the molecular pump, 10 is the vacuum chamber, and 11 is the electrode. Detailed Implementation

[0026] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention 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 merely illustrative of the present invention and are not intended to limit the present invention.

[0027] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0028] In the description of this invention, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In the current field of mass spectrometry, the ion trap and ionization source are designed as two independent structures, which leads to significant limitations in the installation, maintenance, production costs, and portability of the mass spectrometer. The present invention aims to combine the ion trap and ionization source into a single integrated ion trap, simplifying the ion trap structure and reducing the weight of the mass spectrometer itself.

[0031] Please see Figure 1 and Figure 3 The ion trap proposed in this invention includes an ion trap body 3, a first half-electrode 1 and a second half-electrode 2 disposed at the entrance of the ion trap body 3. The first half-electrode 1 and the second half-electrode 2 together form the front ion gate of the ion trap body 3, which is used to close the ion trap body 3 to bind ions during ion analysis. An opening that allows gas molecules to pass through is provided between the first half-electrode 1 and the second half-electrode 2. At the same time, the first half-electrode 1 and the second half-electrode 2 are respectively connected to a voltage adjustment device for changing the voltage magnitude. Through the action of the voltage adjustment device, the voltage on the first half-electrode 1 and the second half-electrode 2 can be adjusted respectively. By adjusting the voltage difference between the first half-electrode 1 and the second half-electrode 2, the first half-electrode 1 and the second half-electrode 2 can ionize the gas molecules at the opening or bind the sample ions, thereby enabling this invention to work in ionization mode and mass analysis mode respectively.

[0032] It should be pointed out that, Figure 1 As a preferred embodiment of the present invention, in other embodiments of the present invention, multiple half-electrodes may be provided, and their shape is not limited to a semi-circle. The purpose is simply to ensure that there is a pair of half-electrodes that are not electrically connected to each other for ionizing gas molecules or binding sample ions.

[0033] Please see Figure 3The ion trap body 3 proposed in this invention is a hollow cylinder. A front ion gate (composed of at least one pair of half-electrodes) and a rear ion gate 4 respectively form the upper and lower covers of the cylinder. The half-electrodes are not limited to semicircles, and the shape formed by the half-electrodes is not limited to a circle; it only needs to cover the front end of the ion trap body 3. During installation, the half-electrodes form an upper cover fixed to one end face of the ion trap body 3. A through-hole for accommodating gas molecules is opened at the center of the upper cover formed by the half-electrodes, i.e., the opening indicated in this invention. Furthermore, electrodes are connected to the half-electrodes, through which a voltage adjustment device can be connected to change the voltage on the half-electrodes, thereby adjusting the operating mode of this invention. The rear ion gate 4 is installed on the other end face of the ion trap body 3. When the voltage on the half-electrodes is at the binding voltage, the rear ion gate 4 cooperates with the upper cover formed by the half-electrodes to seal the ion trap body 3, binding ions within the ion trap body 3 for detection by the detector 5.

[0034] Specifically, when the voltage difference between the first half-electrode 1 and the second half-electrode 2 is greater than the first threshold voltage (which is the minimum voltage difference that can achieve ionization), the voltage difference between the half-electrodes will cause the ion gate on the high-voltage side to discharge to the ion gate on the low-voltage side, thereby generating an electric field. Since the force on the ion in the electric field is F=qE, different ions experience different forces under the same electric field, thus achieving the effect of ionization.

[0035] Please see Figure 5 When it is necessary to control the present invention to be in ionization mode, the present invention achieves this by setting the voltage of one half-electrode to zero and setting the other half-electrode to a high discharge voltage, specifically, a discharge voltage of 1000V. Furthermore, in other embodiments of the present invention, multiple half-electrodes can be provided, and the voltages between the multiple half-electrodes form a discharge voltage, which can also achieve the ionization of gas molecules. Figure 5 In each circuit loop composed of half electrodes, a variable resistor is also provided. The variable resistor is directly connected in series with its corresponding half electrode and then connected to the power supply. Due to the voltage division in series, when it is necessary to change the voltage on a certain half electrode in this invention, it can be achieved by adjusting the resistance value of the variable resistor, which is convenient to operate.

[0036] When the voltage difference between the first half-electrode 1 and the second half-electrode 2 is less than the second threshold voltage (the second threshold voltage can be 0), the sample ions (which refer to the ions located in the ion trap body after the gas molecules are ionized) are located at the opening and are subjected to the same force from the first half-electrode 1 and the second half-electrode 2. Under the action of the two forces, the sample ions will be bound at the opening and will not be able to leave the ion trap body 3 through the opening. At the same time, the rear ion gate 4 can bind the ions that have been ionized into the ion trap body 3, thereby enabling the present invention to work in the mass analysis mode.

[0037] Please see Figure 6 In this invention, a voltage regulating device controls the voltage on both the first half-electrode 1 and the second half-electrode 2 to be 220V to achieve a binding voltage. Since the voltage difference between the two electrode plates is zero, the discharge will terminate, binding the sample ions and preventing them from leaving the ion trap body 3. Simultaneously, the voltage on the rear ion gate 4 is also 220V, the same as the voltage on the front ion gate formed by the first half-electrode 1 and the second half-electrode 2, keeping the ion trap body 3 in a bound state. At this time, the first half-electrode 1 and the second half-electrode 2, together with the rear ion gate 4, seal the ion trap body 3, preventing ions from entering or leaving. In this case, a variable resistor is used to ensure that the voltage on the half-electrodes is the same through series voltage division, thereby maintaining the bound state of the ion trap body 3.

[0038] Please see Figure 2 This is a flowchart of the overall workflow of the present invention. The present invention first transmits the gas molecules to be ionized to the opening at the center of the front ion gate of the half-electrode assembly through pulse injection. Then, the voltage on each half-electrode is set to form a discharge electric field on at least one pair of half-electrodes, thereby ionizing the gas molecules to be ionized. After ionization, the gas molecules become ions and pass through the opening into the ion trap body 3 for detection by the detector 5. In this case, the sample molecules have been ionized and no discharge electric field is needed. Instead, the ion trap body 3 needs to be sealed to prevent ions from flowing out. By setting the voltage on the half-electrodes to be the same and acting with the voltage of the rear ion gate 4, the ions are bound within the ion trap body 3. At this time, no discharge occurs after adjusting the voltage. Under the action of the front ion gate (composed of the first half-electrode 1 and the second half-electrode 2) and the rear ion gate 4, the ions are bound within the ion trap body 3. Then, the detector 5 begins to scan the ions within the ion trap body 3, analyzes the detection substance, and finally completes the quality detection.

[0039] As can be seen from the above workflow and principle, this invention, through the design of the half-electrode combination, integrates the functions of both the ion trap body 3 and the ionization source into one, simplifying the structure, reducing the weight of the mass spectrometer, and increasing the possibilities for the design of miniaturized instruments. Furthermore, using this integrated ion trap reduces the need for post-assembly calibration, lowers costs, improves production efficiency, ensures consistency in mass production of the mass spectrometer, and facilitates mass production.

[0040] This invention also proposes a mass spectrometer, which includes a detector 5 used in conjunction with an ion trap body 3. The other end of the detector 5 is connected to a terminal device 7 for mass spectrometry analysis and generation of a mass spectrum. Furthermore, to improve the detection accuracy of the detector 5, a multiplier 6 is provided on the outer side of the ion trap body 3, connected to the detector 5, to amplify the detection signal transmitted to the detector 5, thereby improving the detection accuracy of the detector 5. The terminal device 7 can be a computer, mobile phone, or other similar device, which can be used for data processing and generation of a mass spectrum.

[0041] Please see Figure 4 A pulse valve 8 is provided at the front end of the vacuum chamber 10. A channel for sample molecules to pass through is provided within the pulse valve 8. Gas molecules enter through the inlet of this channel to acquire the gas molecules to be tested. The outlet faces the opening formed by the top cover of the first half-electrode 1 and the second half-electrode 2, used to transfer the gas molecules to be ionized into the opening for ionization. Furthermore, the pulse valve 8 can be used to control the opening and closing of this channel. When the ion trap body 3 needs to receive gas molecules for detection, the channel is opened by the pulse valve 8, allowing the gas molecules to enter the opening for ionization. The resulting ions then enter the ion trap body 3. In this invention, the opening time of the pulse valve 8 is approximately 15.3 ms. The pulse valve 8 allows for easier control of the number of ions within the ion trap body 3.

[0042] In other embodiments of the present invention, other control devices may be used to replace the pulse valve 8, which can be used to control the opening or closing of the channel, thereby controlling the input of sample molecules. Any device that adopts the above control method should be within the protection scope of the present invention.

[0043] Please see Figure 4 A molecular pump 9 is also provided at the tail end of the vacuum chamber 10. One end of the molecular pump 9 is located inside the vacuum chamber 10, and the other end is set to the outside. It is used to extract air from the vacuum chamber 10 to maintain the vacuum state inside the vacuum chamber 10, so as to ensure the working environment of the ion trap body 3.

[0044] Please see Figure 7 This is the test spectrum of the benzene sample. The present invention can obtain a more accurate mass spectrum.

[0045] Compared with existing technologies, this invention combines the ion trap and ionization source into a novel integrated ion trap, simplifying the ion trap structure, reducing the weight of the mass spectrometer, and increasing possibilities for the design of miniaturized instruments. Furthermore, using this integrated ion trap reduces post-assembly calibration steps, lowers costs, improves production efficiency, ensures consistency in mass production of the mass spectrometer, and facilitates mass production.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An ion trap for mass spectrometry, characterized in that, The ion trap includes an ion trap body, a plurality of half electrodes disposed at the entrance of the ion trap body for forming a front ion gate, and at least one pair of the half electrodes are not electrically connected to each other. A voltage regulating device that can change the voltage is connected to the half electrodes. An opening for gas molecules to pass through is provided between the pair of half electrodes that are not electrically connected. The ion trap switches between ionization mode and mass analysis mode by changing the voltage on the half electrodes. The half-electrode includes a first half-electrode and a second half-electrode that are not electrically connected to each other, and the first half-electrode and the second half-electrode are respectively connected to a voltage adjustment device. The opening is located between the first half-electrode and the second half-electrode. The ion trap switches between ionization mode and mass analysis mode by adjusting the voltage difference between the first half-electrode and the second half-electrode. When the voltage difference between the first half-electrode and the second half-electrode is greater than the first threshold voltage, the ion trap operates in ionization mode, a discharge voltage is generated between the first half-electrode and the second half-electrode, and gas molecules passing through the opening are ionized. When the voltage difference between the first half-electrode and the second half-electrode is less than the second threshold voltage, the ion trap operates in mass analysis mode, and the first half-electrode and the second half-electrode trap sample ions located at the opening.

2. The ion trap according to claim 1, characterized in that, It also includes a post-ion gate located at the outlet of the ion trap body, which is used to seal the ion trap body together with the half electrode.

3. A mass spectrometer, characterized in that, The mass spectrometer has an ion trap as described in any one of claims 1 to 2.

4. The mass spectrometer according to claim 3, characterized in that, The mass spectrometer includes a pulse valve located at the inlet of the ion trap body. The inlet of the pulse valve is used for the introduction of gas molecules, and the outlet faces the... The opening between the first half-electrode and the second half-electrode is described.

5. The mass spectrometer according to claim 3, characterized in that, The mass spectrometer includes components related to the ions. The detector is used in conjunction with the trap body, and the other end of the detector is connected to a terminal device for mass spectrometry analysis and generation of mass spectra.

6. The mass spectrometer according to claim 5, characterized in that, It also includes a multiplier disposed on the side of the ion trap body, the multiplier being connected to the detector and used to amplify the detection signal transmitted to the detector.

7. The mass spectrometer according to claim 3, characterized in that, It also includes a vacuum chamber for accommodating the ion trap body, and a molecular pump for maintaining the vacuum state of the vacuum chamber is provided at the tail of the vacuum chamber.

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