An ion detection system and a detection method

Abstract

The present invention discloses an ion detection system and a detection method. The detection system includes: a quadrupole exit lens, a first deflection lens, a second deflection lens, a first dynode, and a second dynode. Among them, the quadrupole exit lens is configured to focus and output ions generated by a mass spectrometer; the first dynode is accommodated in a first insulating sleeve, and the second dynode is accommodated in a second insulating sleeve. Both the first insulating sleeve and the second insulating sleeve are provided with openings; the first deflection lens and the second deflection lens are symmetrically arranged on both sides of the exit of the quadrupole exit lens. By applying an electric field, the path of the ions output by the quadrupole exit lens is changed, so that positive ions deviate from the second deflection lens and pass through the opening to reach the first dynode, and negative ions deviate from the second deflection lens and pass through the opening to reach the second dynode. The present invention realizes simultaneous detection of positive and negative ions, and solves the problems of low detection efficiency and poor detection accuracy caused by voltage switching delay.

Description

Technical Field

[0001] The present invention relates to the field of mass spectrometry analysis, and in particular to an ion detection system and a detection method. Background Art

[0002] Mass spectrometry is an analytical technique that infers the mass of ions by measuring the operating characteristics of ions in an electric field and / or a magnetic field. The core of mass spectrometry is to ionize the sample, and then separate the ions according to the mass-to-charge ratio (m / z) through the action of an electric field or a magnetic field.

[0003] Traditional ion detection technologies, such as the Chinese patent with the publication number CN103745906A, disclose an ion measurement device that controls an isolation pulse power supply to connect the positive power supply interface or the negative power supply interface as needed, and can realize the switching detection of positive and negative ions.

[0004] Considering that the number of ions reaching the detector after separation according to the mass-to-charge ratio is very limited, a high-energy conversion dynode 200 is usually used, as Figure 1 shown, to receive the ions exiting through the quadrupole exit lens 100. When the analyte ions from the mass spectrometer hit the surface of the dynode 200, a charge exchange process occurs and the ions are converted into electrons, and then these electrons are input into the electron multiplier 300 for further amplification, thereby improving the detection sensitivity. Typically, when it is necessary to detect positive and negative ions, the dynode needs to switch the voltage, that is, switch between a positive high voltage and a negative high voltage, and the voltage value of the high voltage usually reaches more than 8000 volts, even as high as 15000 volts. The high voltage can convert the ions into stronger electrical signals, especially for ions with a very small sample amount, so as to improve the sensitivity. However, for the high-voltage module, the time taken for voltage switching generally requires 20 to 30 ms, and in order to ensure signal stability, a certain delay also needs to be set. Therefore, during the positive and negative ion switching process, usually 50 to 100 ms of ions are lost. These ions lost due to positive and negative ion switching not only reduce the detection efficiency but also significantly affect the detection accuracy of the system.

[0005] The disclosure of the above background art content is only used to assist in understanding the concept and technical solution of the present application. It does not necessarily belong to the prior art of the present application, nor does it necessarily provide technical guidance; in the case where there is no clear evidence indicating that the above content was publicly available before the filing date of the present application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. Summary of the Invention

[0006] The object of the present invention is to provide a system that can simultaneously detect positive and negative ions without switching the positive and negative high voltages of the dynode, and solve the problems of low detection efficiency and poor detection accuracy caused by the voltage switching delay.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] An ion detection system includes a quadrupole exit lens, a first deflection lens, a second deflection lens, a first dynode, and a second dynode. Among them, the quadrupole exit lens is configured to focus and output ions generated by a mass spectrometer;

[0009] The first dynode is accommodated in a first insulating sleeve, and a first opening is provided on the first insulating sleeve; the second dynode is accommodated in a second insulating sleeve, and a second opening is provided on the second insulating sleeve;

[0010] The first deflection lens and the second deflection lens are symmetrically arranged on both sides of the exit port of the quadrupole exit lens. By applying an electric field, the path of the ions output by the quadrupole exit lens is changed, so that positive ions pass through the first opening deviating from the second deflection lens and reach the first dynode, and negative ions pass through the second opening deviating from the first deflection lens and reach the second dynode.

[0011] Further, based on any one of the above technical solutions or a combination of multiple technical solutions, both the first deflection lens and the second deflection lens are strip-shaped, and the axes in their length directions are parallel to the exit surface of the quadrupole exit lens.

[0012] Further, based on any one of the above technical solutions or a combination of multiple technical solutions, the gap width between the first deflection lens and the exit surface of the quadrupole exit lens ranges from 5 to 10 mm;

[0013] The gap width between the second deflection lens and the exit surface of the quadrupole exit lens ranges from 5 to 10 mm.

[0014] Further, based on any one of the above technical solutions or a combination of multiple technical solutions, the distance between the first deflection lens and the second deflection lens ranges from 10 to 15 mm.

[0015] Further, based on any one of the above technical solutions or a combination of multiple technical solutions, the first dynode and the second dynode are symmetrically arranged on both sides of the exit port of the quadrupole exit lens, and the impacted surfaces of the first dynode and the second dynode are both perpendicular to the exit surface of the quadrupole exit lens.

[0016] Further, based on any one of the above technical solutions or a combination of multiple technical solutions, the distance between the impacted area of the first dynode and the exit surface of the quadrupole exit lens ranges from 18 to 25 mm;

[0017] The distance between the impacted area of the second dynode and the exit surface of the quadrupole exit lens ranges from 18 to 25 mm.

[0018] Further, based on any one of the foregoing technical solutions or a combination of multiple technical solutions, the distance between the impacted area of the first dynode and the impacted area of the second dynode ranges from 40 to 80 mm.

[0019] Further, based on any one of the foregoing technical solutions or a combination of multiple technical solutions, the ion detection system provided by the present invention further includes an electron multiplier, which is configured to receive ions transmitted from the first dynode and the second dynode.

[0020] Further, based on any one of the foregoing technical solutions or a combination of multiple technical solutions, the ion detection system provided by the present invention further includes a first electron multiplier and a second electron multiplier. Among them, the first electron multiplier is disposed within the first insulating sleeve and is configured to receive ions transmitted from the first dynode;

[0021] The second electron multiplier is disposed within the second insulating sleeve and is configured to receive ions transmitted from the second dynode.

[0022] According to another aspect of the present invention, there is provided an ion detection method, including the following steps:

[0023] Focusing and outputting ions generated by a mass spectrometer by using a quadrupole exit lens;

[0024] Applying an electric field to the ions output by the quadrupole exit lens by using two deflection lenses to separate positive ions and negative ions;

[0025] The separated positive ions impact the first dynode, and the separated negative ions impact the second dynode, and the generated electrons are transmitted to the electron multiplier;

[0026] Collecting and processing the electrical signals output by the electron multiplier by using a signal board, and converting the processing result of the signal board into a detection value of ions.

[0027] Further, based on any one of the foregoing technical solutions or a combination of multiple technical solutions, the electric field is applied in the following manner:

[0028] Applying a negative voltage -V to the first deflection lens and a positive voltage V to the second deflection lens;

[0029] Determining the voltage amplitude range V ∈ [Vmin, Vmax], and this range satisfies that the area where ions impact the dynode is within a preset area range;

[0030] Dynamically vary the voltages applied to the first deflection lens and the second deflection lens within the range of the voltage amplitudes.

[0031] The beneficial effects brought by the technical solutions provided by the present invention are as follows:

[0032] a. By constructing a suitable electric field through the ion optical system, separating positive and negative ions and transmitting them to the corresponding dynodes, the switching of the high voltage on the dynodes is avoided. Since the two dynodes are always maintained at their respective fixed high voltage states, theoretically, no ions are lost at all, so the switching of positive and negative ion detection can be carried out more quickly, reducing ion loss and improving the signal-to-noise ratio;

[0033] b. The ion detection system can detect positive and negative ions simultaneously, improving the detection efficiency;

[0034] c. The design of the insulating sleeve can reduce the influence of the electric field generated by the high voltage applied to the dynode on the ion movement trajectory before impact, and accurately control the deflection angle of the ions. Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a schematic structural diagram of a typical device for ion detection by switching the positive and negative high voltages of the dynode;

[0037] Figure 2 It is a schematic structural diagram of a system for simultaneous detection of positive and negative ions provided by an exemplary embodiment of the present invention;

[0038] Figure 3 For Figure 2 the schematic diagram of the ion trajectory inside the insulating sleeve in

[0039] Figure 4 It is a schematic diagram of the ion transmission path of the ion detection system provided by an exemplary embodiment of the present invention;

[0040] Figure 5 It is a schematic structural diagram of a detection system with only one electron multiplier provided by an exemplary embodiment of the present invention;

[0041] Figure 6 It is a side view of the detection system with the deflection lens structure cancelled provided by the first comparative example;

[0042] Figure 7Side view of the ion detection system with the distance parameter changed for the second comparative example;

[0043] Figure 8 Flow schematic diagram of the ion detection method provided for an exemplary embodiment of the present invention.

[0044] Wherein, the reference numerals include: 100 - quadrupole exit lens, 200 - dynode, 210 - first dynode, 220 - second dynode, 300 - electron multiplier, 310 - first electron multiplier, 320 - second electron multiplier, 410 - first deflection lens, 420 - second deflection lens, 510 - first insulating sleeve, 512 - first opening, 520 - second insulating sleeve, 522 - second opening. Detailed implementation manners

[0045] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned accompanying drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, device, product or equipment comprising a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or equipment.

[0047] In an embodiment of the present invention, an ion detection system is provided, as Figure 2 and Figure 4 shown. The detection system includes a quadrupole exit lens 100, a first deflection lens 410, a second deflection lens 420, a first dynode 210 and a second dynode 220. Among them, the quadrupole exit lens 100 is configured to focus and output the ions generated by the mass spectrometer. Specifically, the quadrupole exit lens 100 is located behind the quadrupole. By applying an appropriate voltage, the quadrupole exit lens 100 focuses the ions into a beam and introduces the ions output from the quadrupole (field) into the detection system.

[0048] As Figure 2 shown, the first dynode 210 is accommodated in the first insulating sleeve 510, and a first opening 512 is provided on the first insulating sleeve 510; the second dynode 220 is accommodated in the second insulating sleeve 520, and a second opening 522 is provided on the second insulating sleeve 520; the first dynode 210 and the second dynode 220 are high-energy conversion dynodes, abbreviated as HECD. The first insulating sleeve 510 and the second insulating sleeve 520 are made of insulating materials such as ceramics, polytetrafluoroethylene, etc. The first dynode 210 and the second dynode 220 are made of metal materials such as stainless steel, copper, etc., and their impacted surfaces can be flat surfaces.

[0049] As Figure 2 shown, both the first deflection lens 410 and the second deflection lens 420 are strip-shaped, and the first deflection lens 410 and the second deflection lens 420 are symmetrically arranged on both sides of the exit port of the quadrupole exit lens 100, and the axes in their length directions are all parallel to the exit surface of the quadrupole exit lens 100.

[0050] The first deflection lens 410 and the second deflection lens 420 apply an electric field, so that the ions output from the quadrupole exit lens 100 are affected by the electric field and change their transmission paths, as Figure 4 shown; specifically, the force direction of positive ions in the electric field is the same as the electric field direction, that is, the first deflection lens 410 with a negative voltage applied will attract positive ions, and the second deflection lens 420 with a positive voltage applied will repel positive ions, so that the positive ions pass through the first opening 512 along the first path deviating from the second deflection lens 420 and reach the first dynode 210, and that is, the first deflection lens 410 with a negative voltage applied will repel negative ions, and the second deflection lens 420 with a positive voltage applied will attract positive ions, so that the negative ions pass through the second opening 522 along the second path deviating from the first deflection lens 410 and reach the second dynode 220, as Figure 3 shown.

[0051] The first dynode 210 and the second dynode 220 are symmetrically arranged on both sides of the exit port of the quadrupole exit lens 100, as Figure 4As shown, the impact surfaces of the first dynode 210 and the second dynode 220 are both perpendicular to the exit surface of the quadrupole exit lens 100. The ion detection system further includes an electron multiplier, which is configured to receive ions transferred from the first dynode 210 and / or the second dynode 220. The electrons generated when the ions impact the dynode surface are further amplified by the electron multiplier to form a measurable electrical signal. In a specific embodiment, the electron multiplier includes multiple stages of dynodes, and a certain voltage is applied between each stage of dynodes, such that electrons are generated when the ions impact the dynodes, and these electrons impact the next stage of dynodes to generate more electrons, thereby achieving signal amplification. The output end of the electron multiplier is connected to a signal board, and the signal board is used to collect and process the electrical signal output by the electron multiplier, and convert it into a detection value of the ions according to the processing result of the signal board.

[0052] Take Figure 2 and Figure 4 the direction shown as an example: Ions emitted from left to right enter the electric field between the first deflection lens 410 and the second deflection lens 420 and undergo positive and negative ion deflection separation: Positive ions move upward and forward until they impact the rear surface of the first dynode 210. The ions leaving the first dynode 210 after the impact then enter the electron multiplier backward. It is precisely the upward and forward moving path that causes the impact, without causing interference between the ions before hitting the first dynode 210 and the electrons leaving the first dynode 210 after the impact; Similarly, negative ions move downward and forward until they impact the rear surface of the second dynode 220. The electrons leaving the second dynode 220 after the impact then enter the electron multiplier backward. It is precisely the downward and forward moving path that causes the impact, without causing interference between the ions before hitting the second dynode 220 and the electrons leaving the second dynode 220 after the impact of the device.

[0053] As Figure 2 shown, the number of electron multipliers is two, including a first electron multiplier 310 and a second electron multiplier 320. Among them, the first electron multiplier 310 is arranged in the first insulating sleeve 510 and is configured to receive ions transferred from the first dynode 210. The first electron multiplier 310 is connected to the signal board to process and obtain the detection value of positive ions; the second electron multiplier 320 is arranged in the second insulating sleeve 520 and is configured to receive ions transferred from the second dynode 220. The second electron multiplier 320 is connected to the signal board to process and obtain the detection value of negative ions.

[0054] The present invention does not limit the number of electron multipliers to two. In one embodiment, there is only one electron multiplier 300, as Figure 5As shown in the figure, the angles of the impact surfaces of the first dynode 210 and the second dynode 220 relative to the horizontal plane are adjusted so that the electrons leaving after the impact at the two dynodes converge to the same electron multiplier 300. The electron multiplier 300 is connected to a signal board to process and obtain the detection values of positive ions and negative ions.

[0055] In a specific embodiment, the positional relationship among the quadrupole exit lens 100, the deflection lens, and the dynode is determined as follows: The distance range between the impact area of the first dynode 210 and the exit surface of the quadrupole exit lens 100 is 18 to 25 mm, preferably 20 mm; the distance range between the impact area of the second dynode 220 and the exit surface of the quadrupole exit lens 100 is 18 to 25 mm, preferably 20 mm; the distance range between the impact area of the first dynode 210 and the impact area of the second dynode 220 is 40 to 80 mm, preferably 60 mm. The gap width range between the first deflection lens 410 and the exit surface of the quadrupole exit lens 100 is 5 to 10 mm, preferably 8 mm; the gap width range between the second deflection lens 420 and the exit surface of the quadrupole exit lens 100 is 5 to 10 mm, preferably 8 mm; the distance range between the first deflection lens 410 and the second deflection lens 420 is 10 to 15 mm, preferably 12 mm.

[0056] The working principle of the ion detection system in this embodiment is as follows: The ions generated by the mass spectrometer are focused and output through the quadrupole exit lens 100. The output ions include positive ions and negative ions. A negative voltage is applied to the first deflection lens 410, and a positive voltage is applied to the second deflection lens 420. Based on the principle that the positive voltage deflection lens attracts negative ions and repels positive ions, and the negative voltage deflection lens attracts positive ions and repels negative ions, the positive ions and negative ions are separated. The positive ions move along a first path deviating from the second deflection lens 420, pass through the first opening 512 and reach the first dynode 210; the negative ions move along a second path deviating from the first deflection lens 410, pass through the second opening 522 and reach the second dynode 220; the positive ions impact the first dynode 210, the negative ions impact the second dynode 220, and then the electrons after the impact are transferred from the dynode to the electron multiplier. The electron multiplier 300 converts the ions into electrons and outputs an electrical signal. The signal board collects and processes this electrical signal and converts it into the detection value of the ions according to the processing result.

[0057] The ion detection system in this embodiment can detect positive ions and negative ions simultaneously, improving the efficiency of ion detection. By applying an electric field to the ions through the first deflection lens 410 and the second deflection lens 420, the positive ions and negative ions are separated and impact the first dynode 210 and the second dynode 220 respectively, improving the detection sensitivity.

[0058] The First Comparative Example

[0059] The difference from the above embodiments is that in this comparative example, the first deflection lens 410 and the second deflection lens 420 are not provided. As Figure 6 shown, a high voltage is applied to the dynode to generate an electric field. Although the separation of positive and negative ions is achieved, the deflection angle of the ions is too small to reach the effective area of the dynode.

[0060] Second Comparative Example

[0061] The difference from the above embodiments is that in this comparative example, the distance between the first deflection lens 410 / the second deflection lens 420 and the quadrupole exit lens 100 is increased to about 20 mm. As Figure 7 shown, the ions are deflected and move towards the dynode. However, since the first deflection lens 410 / the second deflection lens 420 is too far from the exit lens 100, the ions cannot reach the effective area of the dynode.

[0062] An embodiment of the present invention also provides an ion detection method. Refer to Figure 8 , and the detection method includes the following steps:

[0063] Focus and output the ions generated by the mass spectrometer using the quadrupole exit lens;

[0064] Apply an electric field to the ions output by the quadrupole exit lens using two deflection lenses to separate positive ions and negative ions;

[0065] The separated positive ions strike the first dynode, and the separated negative ions strike the second dynode, and the generated electrons are transmitted to the electron multiplier;

[0066] Collect and process the electrical signal output by the electron multiplier using the signal board, and convert it into the detection value of the ions according to the processing result of the signal board.

[0067] Specifically, the electric field is applied in the following manner: Apply a negative voltage -V to the first deflection lens and a positive voltage V to the second deflection lens; Determine the voltage amplitude range V ∈ [Vmin, Vmax], and this range satisfies that the area where the ions strike the dynode is within the preset area range; Dynamically change the voltages applied to the first deflection lens and the second deflection lens within the voltage amplitude range. In a specific embodiment, taking Vmin as 1000 V and Vmax as 1200 V as an example, the voltage amplitude V starts from 1000 V, increases by 10 V every 0.1 second until it reaches 1200 V, and then decreases by 10 V every 0.1 second until it returns to 1000 V, and so on in a cycle. This can make the position where the ions strike the dynode change dynamically within the preset area range, avoiding fatigue at the fixed impact position of the dynode or reducing the response efficiency.

[0068] It should be noted that the ion detection method provided in this embodiment and the ion detection system provided in the above embodiment belong to the same inventive concept, that is, the ion detection method in this embodiment can be applied to the ion detection system. Herein, the entire content of the ion detection system embodiment is incorporated into this ion detection method embodiment by reference.

[0069] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0070] The above are only specific embodiments of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. An ion detection system, characterized in that: The invention comprises a quadrupole output lens (100), a first deflection lens (410), a second deflection lens (420), a first dynode (210) and a second dynode (220), wherein the quadrupole output lens (100) is configured to focus and output ions generated by a mass spectrometer; The first dynode (210) and the second dynode (220) are both high-energy conversion dynodes. The first dynode (210) is accommodated in a first insulating sleeve (510), and the first insulating sleeve (510) is provided with a first opening (512); the second dynode (220) is accommodated in a second insulating sleeve (520), and the second insulating sleeve (520) is provided with a second opening (522); the impacted surfaces of the first dynode (210) and the second dynode (220) are both perpendicular to the exit surface of the quadrupole exit lens (100); the distance between the impacted area of ​​the first dynode (210) and the exit surface of the quadrupole exit lens (100) is in the range of 18 to 25 mm, and the distance between the impacted area of ​​the second dynode (220) and the exit surface of the quadrupole exit lens (100) is in the range of 18 to 25 mm; The first deflection lens (410) and the second deflection lens (420) are symmetrically arranged on both sides of the exit port of the quadrupole exit lens (100); the gap width between the first deflection lens (410) and the exit surface of the quadrupole exit lens (100) is in the range of 5 to 10 mm, and the gap width between the second deflection lens (420) and the exit surface of the quadrupole exit lens (100) is in the range of 5 to 10 mm; an electric field is applied in the following manner to change the path of ions output by the quadrupole exit lens (100), so that positive ions pass through the first opening (512) along a first path deviating from the second deflection lens (420) and reach the first dynode (210), and negative ions pass through the second opening (522) along a second path deviating from the first deflection lens (410) and reach the second dynode (220): A negative voltage -V is applied to the first deflection lens, and a positive voltage V is applied to the second deflection lens; a voltage amplitude range V∈[Vmin,Vmax] is determined, and the range satisfies that the area where ions impact the dynode is within a preset area range; and the voltages applied to the first deflection lens and the second deflection lens are dynamically changed within the voltage amplitude range.

2. The ion detection system according to claim 1, characterized in that: The first deflection lens (410) and the second deflection lens (420) are both strip-shaped, and their axes in the length direction are both parallel to the exit surface of the quadrupole exit lens (100).

3. The ion detection system according to claim 2, characterized in that: The distance between the first deflecting lens (410) and the second deflecting lens (420) ranges from 10 to 15 mm.

4. The ion detection system according to claim 1, characterized in that: The first dynode (210) and the second dynode (220) are symmetrically arranged on both sides of an exit port of the quadrupole exit lens (100).

5. The ion detection system according to claim 1, characterized in that: The distance between the struck area of ​​the first dynode (210) and the struck area of ​​the second dynode (220) ranges from 40 to 80 mm.

6. The ion detection system according to any one of claims 1 to 5, characterized in that: Also included is an electron multiplier (300) configured to receive ions transferred from the first dynode (210) and the second dynode (220).

7. The ion detection system according to any one of claims 1 to 5, characterized in that: It also includes a first electron multiplier (310) and a second electron multiplier (320), wherein the first electron multiplier (310) is disposed in the first insulating sleeve (510) and is configured to receive ions transferred from the first dynode (210); The second electron multiplier (320) is disposed in the second insulating sleeve (520) and is configured to receive ions transferred from the second dynode (220).

8. An ion detection method based on the ion detection system according to any one of claims 1 to 7, characterized in that: The following steps are involved: The ions generated by the mass spectrometer are focused and output using the quadrupole exit lens; Using two deflection lenses to apply an electric field to the ions output by the quadrupole output lens to separate positive ions from negative ions; The separated positive ions hit the first dynode, and the separated negative ions hit the second dynode, and the generated electrons are transferred to the electron multiplier; The signal board is used to collect and process the electrical signal output by the electron multiplier, and the signal is converted into the detection value of the ion according to the processing result of the signal board.

9. The ion detection method according to claim 8, characterized in that: The electric field is applied by: Applying a negative voltage -V to the first deflection lens and applying a positive voltage V to the second deflection lens; Determine a voltage amplitude range V∈[Vmin,Vmax], which satisfies that the region where the ions impact the dynode is within a preset region; The voltage applied to the first deflecting lens and the second deflecting lens is dynamically changed within the voltage amplitude range.

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