Time-of-flight mass analysis device and method for improving performance of time-of-flight mass analysis device

Abstract

The invention discloses a time-of-flight mass analysis device, which comprises an ionization acceleration region for generating ions, screening the ions according to the initial energy and initial position of the ions and accelerating the ions to move towards a field-free region; the field-free region is used for providing free motion space with enough distance for ions; the reflection area is located at the tail end of the field-free area and used for reflecting ions to the signal detection area; and the signal detection area is used for detecting ion types. The ionization acceleration area of the device adopts a voltage driving mode of repulsion pulses and introduction of the pulses to reduce the initial space dispersion and initial energy dispersion of ions, meanwhile, the ionization probability of molecules is increased, and the resolution and sensitivity of time-of-flight mass analysis can be improved.

Description

Flight Time Quality Analysis Device and Methods for Improving the Performance of Flight Time Quality Analysis Device Technical Field

[0001] This application belongs to the field of time-of-flight mass spectrometry technology, specifically relating to a time-of-flight mass analysis device and a method for improving the performance of the time-of-flight mass analysis device. Background Technology

[0002] A mass spectrometer typically includes a sample introduction system, an ion source, a modulation and transmission system, a mass analyzer, a detection and recording system, and a vacuum system. It is used to determine the mass-to-nucleus ratio of ions. The mass analyzer is the core component of a mass spectrometer. Based on different types of analyzers, mass spectrometers can be classified as magnetic deflection mass spectrometers, quadrupole mass spectrometers, ion trap mass spectrometers, time-of-flight mass spectrometers, Fourier transform ion cyclotron resonance mass spectrometers, and orbital cyclotron resonance mass spectrometers, among others. Among these, the time-of-flight mass analyzer has become the preferred equipment for researchers due to its high resolution, high precision, high sensitivity, and unlimited mass range. In recent years, with the application of vertical introduction and second-order spatial focusing theory, as well as advancements in electronic technology, the performance of time-of-flight mass analyzers has been significantly improved.

[0003] High-performance time-of-flight quality analyzers (TOF-MMEs) can monitor more complex and diverse products, with key performance indicators including sensitivity and resolution. Further improving the resolution and sensitivity of TOFMEs remains a hot topic in current technological research.

[0004] Based on the above considerations, there is a need for a time-of-flight mass analysis device that can provide higher mass spectral resolution through improvements. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this application is to provide a time-of-flight mass analysis device. By screening and regulating the magnitude and direction of the ion velocity input to the device through an ionization acceleration zone, the ions are allowed to move freely a certain distance in a field-free zone before reaching the reflection zone. In the reflection zone, the ions are further adjusted and reflected to the final signal detection zone. The coordinated control of the ionization acceleration zone, the field-free zone, and the reflection zone ensures that ions with the same mass-to-nucleus ratio arrive at the signal detection zone simultaneously, while ions with different mass-to-nucleus ratios arrive at the signal detection zone sequentially, thereby improving the resolution of the device's detection.

[0006] Specifically, this application relates to the following aspects: According to one aspect of this application, a time-of-flight quality analysis device is provided, comprising: an ionization acceleration region for generating ions and accelerating them toward a field-free region; a field-free region for providing sufficient space for the ions to move freely; a reflection region located at the end of the field-free region for reflecting ions to a signal detection region; and a signal detection region for detecting ion categories; wherein the ionization acceleration region is further used to screen ions based on their initial energy and initial position.

[0007] According to some implementations, the ionization acceleration region includes an EI source, a pulse introduction unit, and an acceleration electrode; the EI source is used to ionize the sample to generate ions; the pulse introduction unit is used to apply a driving pulse with variable polarity to the ions; the acceleration electrode is located at the end of the pulse introduction unit and is used to accelerate the ions to a field-free region.

[0008] According to some implementations, the driving pulse includes a positive driving pulse and a negative driving pulse. The pulse introduction unit for applying a driving pulse with variable polarity to the ions includes: the pulse introduction unit continuously applying a positive driving pulse of a first duration to the ions generated by the EI source, and then continuously applying a negative driving pulse of a second duration to the ions.

[0009] According to some implementations, the peak voltage of the positive drive pulse is 5 V to 70 V, preferably 12 V to 25 V; the peak voltage of the negative drive pulse is not higher than -150 V, preferably -200 V to -320 V.

[0010] According to some embodiments, the pulse introduction unit continuously applies a positive driving pulse of a first duration, including: the pulse introduction unit continuously applies a positive driving pulse of 2 μs to 30 μs, preferably, the pulse introduction unit continuously applies a positive driving pulse of 2 μs to 10 μs; the pulse introduction unit continuously applies a negative driving pulse of a second duration, including: the pulse introduction unit continuously applies a negative driving pulse of 1 μs to 10 μs, preferably, the pulse introduction unit continuously applies a negative driving pulse of 2 μs to 5 μs.

[0011] According to some embodiments, the pulse introduction unit includes a plurality of conductive wires that are parallel to each other and wound around each other, or includes a conductive screen with a specified transmittance.

[0012] According to another aspect of this application, a method for improving the performance of time-of-flight quality analysis is provided, comprising: using the ionization acceleration zone of a time-of-flight quality analysis device, screening ions based on their initial energy and initial position, and accelerating the ions toward the field-free zone of the time-of-flight quality analysis device; allowing the ions to move freely in the field-free zone to the reflection zone of the time-of-flight quality analysis device, and using the reflection zone to adjust the time it takes for the ions to reach the signal detection zone of the time-of-flight quality analysis device; wherein the time-of-flight quality analysis device is the aforementioned time-of-flight quality analysis device.

[0013] According to some implementation methods, ion screening based on the initial energy and initial position of ions includes: continuously applying a positive driving pulse of a first duration to the ions using an ionization acceleration region to filter ions at the initial energy extreme and / or initial position extreme; and continuously applying a negative driving pulse of a second duration to the ions using an ionization acceleration region to accelerate the ions to a field-free region.

[0014] According to some implementation methods, the peak voltage of the positive drive pulse is 5 V to 70 V, and the peak voltage of the negative drive pulse is no higher than -150 V.

[0015] According to some implementation methods, the first duration is 2 μs to 30 μs, and the second duration is 1 μs to 10 μs.

[0016] The time-of-flight mass spectrometry (TOFMS) device provided in this application changes the pulse extraction acceleration configuration and method of existing TOFMS analyzers that extracts ions from the acceleration region. It pre-introduces a repulsion pulse on top of pulse extraction, converting the initial energy dispersion of the ion cluster into initial spatial dispersion, and removing ions with large initial spatial and energy dispersions. This allows ions to redistribute with lower energy within the small space defined by the pulse introduction unit, shortening the time difference for ions of the same mass to finally enter the signal detection region, and improving the resolution of the ion cluster mass spectrometry obtained by the subsequent TOFMS device. Furthermore, by introducing the pre-implemented repulsion pulse, the ionization probability of molecules is increased, thereby also improving the sensitivity of mass spectrometry analysis. Attached Figure Description

[0017] Figure 1 illustrates a schematic diagram of the structure of a flight time quality analysis device according to an embodiment of this application.

[0018] Figure 2 illustrates a schematic diagram of applying a driving pulse to the ionization acceleration region according to an embodiment of this application.

[0019] Figure 3 illustrates a schematic diagram of the trajectories of ions in a device according to an embodiment of this application.

[0020] Figure 4 illustrates the actual ion trajectory diagram of the prior art.

[0021] Figure 5 illustrates an actual ion trajectory diagram according to an embodiment of this application.

[0022] Figure 6 illustrates the ion detection resolution of the prior art.

[0023] Figure 7 illustrates the ion detection resolution according to an embodiment of this application.

[0024] Figure 8 illustrates a flowchart of a method for improving flight time quality analysis performance according to an embodiment of this application. Detailed Implementation

[0025] The present application is further illustrated below with reference to embodiments. It should be understood that the embodiments are only used to further illustrate and explain the present application and are not intended to limit the present application.

[0026] Unless otherwise defined, technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art. While similar or identical methods and materials may be applied in experimental or practical applications, materials and methods are described herein. In case of conflict, the definitions included herein shall prevail. Furthermore, materials, methods, and examples are for illustrative purposes only and are not intended to be limiting. The present application is further described below with reference to specific embodiments, but is not intended to limit the scope of the application.

[0027] Exemplary device Figure 1 illustrates a flight time quality analysis apparatus according to an embodiment of this application.

[0028] Referring to FIG1, the flight time quality analysis apparatus according to various embodiments of the present application includes the following components.

[0029] The ionization acceleration region is used to generate ions and accelerate them towards the field-free region; the field-free region is used to provide ions with sufficient space for free movement; the reflection region is used to reflect ions to the signal detection region; the signal detection region is used to detect the ion type; the ionization acceleration region, the field-free region, the reflection region, and the signal detection region are connected in sequence to form the entire analytical configuration from giving ions an initial velocity and separating ions with different mass-to-nucleus ratios to performing detection.

[0030] In one example, the ionization acceleration region includes an EI source, a pulse introduction unit, and an accelerating electrode, which are connected sequentially. The pulse introduction unit provides a driving pulse, causing ions distributed within it to be displaced by the pulse force. The pulse introduction unit can be a screen electrode composed of multiple parallel conductive wires wound along a conductor, or a conductive screen with a certain transmittance; preferably, the pulse introduction unit is a conductive screen, which generates a more stable pulse and is easier to install. Applying a voltage of a specific polarity to the pulse introduction unit creates an electric field of a specific strength in the center of the unit. When ions enter the pulse buffer device, they are acted upon by the electric field and move in a specific direction.

[0031] In one example, the EI source is an electron ionization source, which works by generating high-energy electrons to ionize sample molecules, causing them to ionize and fragment, producing ions that can be detected by a mass spectrometer. Since the EI source is located in the pulse introduction unit, for example, before the screen electrode, the movement of ions mainly occurs within the EI source during the application of the electric field sequence. This increases the probability of collisions between ions and molecules, thus improving the sensitivity of the time-of-flight mass analyzer to some extent.

[0032] Existing time-of-flight mass analyzers often employ the aforementioned pulse introduction technique to drive a certain number of ions into the acceleration zone provided by the accelerating electrode when introducing ions for acceleration. After passing through the field-free zone, qualitative / quantitative analysis is performed. For example, referring to the left side of Figure 2, existing time-of-flight mass analyzers apply a short-duration, high-amplitude negative polarity voltage on the left side of the screen electrode to extract ions introduced by the EI source.

[0033] However, ions driven under different conditions will experience kinetic energy and positional issues. For example, the first problem is that because the distribution of molecules in the ionization source region is not completely concentrated, the ionized ion swarm occupies a considerable space when driven into the acceleration region. The greater the spatial dispersion of the particle swarm, the greater the difference in flight time between different types of ions, and even within the same type of ion, from different positions to the detector, thus reducing the detection resolution and sensitivity of the signal detection region. Another problem is that because each ion acquires different kinetic energies during molecular ionization, different ions will have slightly different velocities when subjected to the same electric field in the acceleration region. The dispersion of kinetic energy will cause deviations in flight time, resulting in broadened mass spectrum peaks and affecting resolution and accuracy; the reflector region has limited ability to adjust for this kinetic energy difference.

[0034] In this application, referring to the right side of Figure 2, the pulse introduction unit converts this voltage-driven ion method into a pulse repulsion-drive polarity reversal mode. Before applying the driving negative pulse that drives the ions to move towards the accelerating electrode, the pulse introduction unit introduces a set of pre-compressed repulsion positive pulses with opposite polarities and precise timing. After a certain period of positive pulse application, the pulses are immediately converted to negative pulses. After a certain period of negative pulse application, the voltage is reduced to 0, ending the single drive. Thus, the repulsion pulse applied before the driving pulse repels the ions that are about to enter the accelerating electrode for forward acceleration, causing them to drift away from the accelerating electric field formed by the accelerating electrode. Immediately afterwards, a driving pulse of opposite polarity is applied to guide the ions back.

[0035] In other words, referring to Figure 3, the electric field sequence provided by the pulse introduction unit, which pulls backward and then pushes forward, can eliminate the kinetic energy dispersion caused by the initial energy difference of ions and the distance difference caused by the initial position difference, and redistribute the spatial position of ions. This allows ions with excessively biased initial velocity direction or position to leave the pulse introduction unit directly under the action of the electric field formed by the repulsive pulse. The remaining particles are redistributed at a low speed in the narrow green area under the influence of the backward electric field force. These particles can move more regularly towards the field-free area after being accelerated by the subsequent accelerating electrode. The kinetic energy difference of ions with the same mass-to-charge ratio is effectively reduced, and ions that are difficult to control leave the acceleration area and the freely moving field-free area in advance. This makes ions with the same mass-to-charge ratio more likely to arrive at the signal detection area synchronously, improving the latter's resolution on mass-to-charge ratio.

[0036] That is, the ionization acceleration region is also used to screen ions based on their initial energy and / or initial position; the pulse introduction unit is used to apply a driving pulse with variable polarity to the ions; the driving pulse includes a positive driving pulse and a negative driving pulse, and the pulse introduction unit applies the driving pulse with variable polarity to the ions by continuously applying the positive driving pulse of a first duration to the ions generated by the EI source, and then continuously applying the negative driving pulse of a second duration to the ions.

[0037] Thus, compared to existing technologies in the field that focus on extending the field-free region, such as using multi-level meshless reflection to indirectly extend the field-free region to increase ion movement time, and improving the resolution of the time-of-flight quality analyzer by increasing the performance of the reflective region, the improvement of the ion acceleration region in the device described in this application does not change the overall configuration of the device, does not increase the space occupied by the device, and does not significantly increase the cost and is easy to build. It can achieve the same stable improvement in ion detection resolution by controlling the pulse polarity.

[0038] By adjusting the width of the repulsion pulse, discrete ions with excessively high spatial position or kinetic energy differences can be effectively filtered out. This allows for the selection of ion clusters with more concentrated kinetic energy distributions before they enter the acceleration zone provided by the accelerating electrode, improving the resolution of flight quality analysis in the signal detection area. The amplitude of the repulsion pulse is relatively low compared to the drive pulse to prevent normal ions with non-extreme positions / velocities from being repelled out of the ionization acceleration zone. Adjusting the amplitude of the repulsion pulse can also control the degree to which it repels ions, thus preserving ion clusters with initially concentrated kinetic energy to enter the acceleration zone provided by the accelerating electrode.

[0039] In one example, the peak voltage of the positive pulse is 5 V to 70 V; preferably, the peak voltage of the positive pulse is 12 V to 25 V to provide a balanced repulsion of the ion swarm, causing ions at extreme positions or velocities to leave. The peak voltage of the negative drive pulse is no higher than -150 V; preferably, the peak voltage of the negative pulse is -200 V to -320 V to ensure that the repelled ion swarm can enter the acceleration region.

[0040] In one example, the pulse introduction unit continuously applies a positive pulse of 2 μs to 30 μs; preferably, the pulse introduction unit continuously applies a positive pulse of 2 μs to 10 μs to allow the ion cluster to redistribute within a small space inside the unit for a sufficient time. The pulse introduction unit continuously applies a negative pulse of 1 μs to 10 μs; preferably, the pulse introduction unit continuously applies a negative pulse of 2 μs to 5 μs to allow the redistributed ion cluster to rapidly enter the acceleration region formed by the accelerating electrode, thereby improving the analysis speed of the device.

[0041] Specifically, the repulsion pulse and the driving pulse have opposite polarities, but this example does not restrict the former to be "positive" or the latter to be "negative". Depending on the charged properties of the ions, the direction of the electric field generated by the repulsion pulse causes the ion group to move away from the accelerating electrode, while the direction of the electric field generated by the driving pulse causes the ion group to move towards the accelerating electrode. The positive and negative values ​​of their amplitudes are not absolute, with the former being positive and the latter negative.

[0042] The accelerating electrode is located at the end of the pulse introduction unit, connected before and after it. It receives the ion cluster moving in its direction under the influence of the driving pulse and controls the ion cluster to generate an initial velocity in a specific direction, further accelerating the ion cluster to the field-free region. In one example, the accelerating electrode can be multiple relatively parallel electrode plates that generate a strong electric field. The direction of the electric field is towards or away from the field-free region, causing the positive or negative ion clusters to be accelerated towards the passive region by the electric field force. The direction of the electric field generated by the accelerating electrode forms a certain angle with the outer wall of the passive region, causing the ion cluster to accelerate towards the reflection region with a certain deflection angle.

[0043] The field-free region is located at the end of the accelerating electrode and is connected to the accelerating region formed by the accelerating electrode. No external field source is set in the field-free region and a high vacuum is maintained. The ion group moves at a constant speed in the field-free region at the speed of leaving the accelerating region. Low-mass ions obtain higher speeds in the accelerating region, while high-mass ions obtain relatively lower speeds. Therefore, ions with different mass-to-nucleus ratios can produce displacement differences due to speed differences in the motion space provided by the field-free region, thereby achieving separation.

[0044] The reflective region is located at the end of the field-free region, adjacent to it. In one example, the reflective region consists of a series of ring electrodes or gates to which an increasing voltage is applied, generating a repulsive electrostatic field to reflect ions entering it. Ions with the same mass-to-charge ratio but different kinetic energies due to differences in initial position, etc., enter the reflective region. Ions with higher kinetic energy enter the repulsive electrostatic field deeper and have a longer path, while ions with lower kinetic energy enter the repulsive electrostatic field shallower and have a shorter path. Therefore, after reflection by the reflective region, ions with the same mass-to-charge ratio but different kinetic energies are further regularized to arrive at the signal detection region at closer time points. In the device according to the embodiments of this application, the reflective region, in conjunction with the pulse introduction unit, shortens the mass spectrum peak width of each ion, improving the resolution of ion swarm analysis.

[0045] The signal detection region is used to receive ion clusters arriving sequentially and to detect ion categories. In one example, the signal detection region has a microchannel plate or a danotron electron multiplier. When ion clusters arrive at the microchannel plate or electron multiplier in order of mass, the latter converts the ion signal into an electrical signal and amplifies it. By calibrating the electrical signal against the time-mass relationship of a known standard, the time-of-flight spectra of different ions can be converted into corresponding mass spectra.

[0046] The performance of the apparatus according to an embodiment of this application in establishing a mass spectrometry task will be described below through an example.

[0047] The mass spectra of the toluene peak (m / q = 92) were obtained using the aforementioned time-of-flight mass analyzer.

[0048] Specifically, the EI source consists of a ring-shaped spiral tungsten filament and an electron extraction electrode. Its core function is to generate stable hot electrons and accelerate them, drawing them out to the region where the sample molecules are located to complete bombardment ionization. After the high-energy electrons bombard the sample molecules to achieve ionization, the generated molecular ions and fragment ions are guided by the electrode to the front end of the screen electrode. The screen electrode is made of a conductive screen with a transmittance of 90%, which is fixed to the hollow electrode substrate by spot welding.

[0049] Sample ions are collimated and accelerated by the pulsed voltage applied to the sieve electrodes, then enter the field-free flight region and flow into the reflection region. The reflection region adopts a two-stage reflection structure, composed of multiple stacked electrode plates, with the primary and secondary reflection units separated by a sieve.

[0050] Sample ions reflected by the reflection zone pass through the field-free flight zone again and finally enter the signal detection zone. The signal detection zone converts the ion signal into an electrical signal and amplifies it using a microchannel plate (MCP). By detecting the arrival time of the electrical signal, a corresponding time-of-flight mass spectrum is generated. This spectrum is then calibrated and compared with the time-of-flight mass spectrum of a standard to perform spectral analysis.

[0051] The timing sequence of a single continuous pulse applied to the screen electrode of the ionization acceleration zone device is set as follows: first, a positive pulse is applied with a voltage of 20 V and a duration of 10 μs; immediately after the positive pulse ends, a negative pulse is applied with a voltage of -300 V and a duration of 4 μs. As shown in Figures 4 and 5, ion optics simulations were performed using Simion on the time-of-flight mass analysis device with and without a pulse introduction unit that adjusts the polarity of the positive and negative pulses. The ion swarm starts from the ionization acceleration zone, passes through the field-free region, is reflected by the back reflection region, and finally reaches the signal detection zone. The mass spectrum peaks of the ion swarm are analyzed and obtained in the signal detection zone.

[0052] The simulated mass spectrometry peak results are shown in Figures 6 and 7. Figure 6 shows the mass spectrometry peaks of an existing time-of-flight mass analyzer that does not have an adjustable polarity pulse, and Figure 7 shows the mass spectrometry peaks of the device described in this application. A represents time, and B represents the ion count value. The device reflects its ion resolution through the full width at half maximum (FWHM) value; the smaller the FWHM, the higher the resolution. As can be seen from the parameters in the figures, the mass spectrometry resolution measured by the device is 1.2 times higher than that of existing instruments that only use negative pulses to drive ions. The simulation data demonstrates that the resolution of the time-of-flight mass analyzer can be improved by adopting the newly designed pulse introduction unit.

[0053] In another example, setting the duration of the positive pulse voltage to 2 μs and the positive pulse voltage to 10 V, and the duration of the negative pulse voltage to 4 μs and the negative pulse voltage to -300 V, the resulting FWHM = 0.01131 represents an improvement of approximately 1.07 times compared to an existing time-of-flight mass analyzer with a negative pulse voltage duration of 4 μs and a negative pulse voltage of -300 V. This demonstrates that introducing a positive pulse voltage does indeed improve the ion resolution of the device, and its duration and amplitude have a further optimized range, potentially improving resolution by up to 20%. Therefore, the optimized range of positive pulse voltage duration and voltage value provided above can further enhance the ion resolution of the device.

[0054] The above embodiments demonstrate that, without altering the existing mechanical structure of the time-of-flight mass analyzer, only the driving method of the pulse on the ion cluster on the pulse introduction unit needs to be changed. This allows the applied pulse voltage sequence to switch from one polarity to another with a specific amplitude and time. This reduces the impact of the initial spatial dispersion and initial energy dispersion of ions on the mass spectrum peak width and increases the molecular ionization probability, thereby improving the resolution and sensitivity of the time-of-flight mass analyzer.

[0055] Exemplary methods Figure 8 illustrates a flowchart of a method for improving flight time quality analysis performance according to an embodiment of this application.

[0056] Referring to Figure 8, the method for improving flight time quality analysis performance according to an embodiment of this application includes the following steps.

[0057] Step S110: Using the ionization acceleration zone of the time-of-flight mass analyzer, ions are screened based on their initial energy and initial position, and the ions are accelerated to move towards the field-free zone of the time-of-flight mass analyzer; Step S120: The ions are allowed to move freely in the field-free zone to the reflection zone of the time-of-flight mass analyzer, and the time it takes for the ions to reach the signal detection zone of the time-of-flight mass analyzer is adjusted using the reflection zone.

[0058] Optionally, the method further includes step S130, acquiring ions using the signal detection region of the time-of-flight mass analyzer to establish a mass spectrometer.

[0059] The time-of-flight mass spectrometry device is the same as the one described in the "Exemplary Device," which includes an ionization acceleration region, a field-free region, a reflection region, and a signal detection region. As can be seen from the above, the mass spectrometry established in step S130 has higher resolution and sensitivity than the mass spectrometry established by the time-of-flight mass spectrometry device that does not have an ionization acceleration region with variable polarity driving pulses, and thus has a stronger ability to analyze ions.

[0060] In one example, ion screening based on the initial energy and initial position of the ions includes: continuously applying a positive driving pulse of a first duration to the ions using an ionization acceleration region to filter ions at the initial energy extreme and / or initial position extreme, and then continuously applying a negative driving pulse of a second duration to the ions using an ionization acceleration region to accelerate the ions to a field-free region.

[0061] In this example, the peak voltage of the positive driving pulse can be set to 5 V ~ 70 V, and the peak voltage of the negative driving pulse can be set to no higher than -150 V. Preferably, the peak voltage of the positive driving pulse can be set to 12 V ~ 25 V to provide balanced repulsion of the ion swarm, causing ions at extreme positions or velocities to leave the ion swarm and reducing their impact on the mass spectrometer. And, preferably, the peak voltage of the negative driving pulse can be set to no higher than -200 V ~ -320 V to ensure that the repelled ion swarm can be accelerated into the acceleration region by the negative pulse in a short time.

[0062] In this example, the first duration is 2 μs to 30 μs, and the second duration is 1 μs to 10 μs. Preferably, the first duration is 8 μs to 15 μs, allowing the ion cluster to redistribute within the small space inside the pulse introduction unit of the ionization acceleration zone for a sufficient first duration. Preferably, the second duration is 2 μs to 5 μs, enabling the redistributed ion cluster to rapidly enter the acceleration zone formed by the accelerating electrode within the second duration, thereby increasing the rate of ion analysis by the method.

[0063] As can be seen from the above, steps S110-S120 and optionally S130 of the method for improving the performance of time-of-flight mass spectrometry have been described in detail in the "Exemplary Device". The functions of the ionization acceleration region, the field-free region, the reflection region, and the signal detection region will not be repeated here. By implementing this method, especially step S110, the resolution and sensitivity of time-of-flight mass spectrometry can be effectively improved. It should be noted that the method for improving the performance of time-of-flight mass spectrometry according to various embodiments of this application is not limited to the time-of-flight mass spectrometry device in the "Exemplary Device". Those skilled in the art can set the polarity of the driving pulse of the ion acceleration region of any time-of-flight mass spectrometer according to the actual situation, so as to screen ions with suitable initial energy and position by using a low-amplitude, long-duration first polar pulse (e.g., a positive pulse), and then rapidly accelerate the ion group formed by the indicated ions to the ion acceleration region by using a high-amplitude, short-duration second polar pulse (e.g., a negative pulse) to achieve performance improvement for subsequent mass spectrometry analysis.

[0064] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0065] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0066] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0067] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0068] The above description has been given for illustrative and descriptive purposes. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A time-of-flight quality analysis device, characterized in that, include: The ionization acceleration region generates ions and accelerates them toward the field-free region. Field-free region, used to provide ions with enough space to move freely; The reflective region, located at the end of the field-free region, is used to reflect ions to the signal detection region; the signal detection region is used to detect the ion type; wherein, the ionization acceleration region is also used to screen ions based on their initial energy and initial position.

2. The flight time-mass analysis device according to claim 1, wherein, The ionization acceleration region includes an EI source, a pulse introduction unit, and an acceleration electrode; the EI source is used to ionize the sample to generate ions. The pulse introduction unit is used to apply a driving pulse with variable polarity to the ions; the accelerating electrode is located at the end of the pulse introduction unit and is used to accelerate the ions to the field-free region.

3. The flight time-mass analysis device according to claim 2, wherein, The driving pulse includes a positive driving pulse and a negative driving pulse. The pulse introduction unit is used to apply a driving pulse with variable polarity to the ions by: continuously applying the positive driving pulse of a first duration to the ions generated by the EI source, and then continuously applying the negative driving pulse of a second duration to the ions.

4. The flight time-quality analysis device according to claim 3, wherein, The peak voltage of the positive driving pulse is 5 V ~ 70 V, preferably 12 V ~ 25 V; the peak voltage of the negative driving pulse is not higher than -150 V, preferably -200 V ~ -320 V.

5. The flight time-mass analysis device according to claim 3, wherein, The pulse introduction unit continuously applies a positive driving pulse for a first duration, which includes: the pulse introduction unit continuously applies a positive driving pulse for 2 μs to 30 μs, preferably, the pulse introduction unit continuously applies a positive driving pulse for 2 μs to 10 μs; the pulse introduction unit continuously applies a negative driving pulse for a second duration, which includes: the pulse introduction unit continuously applies a negative driving pulse for 1 μs to 10 μs, preferably, the pulse introduction unit continuously applies a negative driving pulse for 2 μs to 5 μs.

6. The time-of-flight quality analysis device according to claim 2, wherein, The pulse introduction unit includes multiple parallel conductive wires wound around each other, or includes a conductive screen with a specified transmittance.

7. A method for improving the performance of flight time-quality analysis, characterized in that, include: Using the ionization acceleration zone of the time-of-flight quality analyzer, ions are screened based on their initial energy and initial position, and the ions are accelerated to move towards the field-free zone of the time-of-flight quality analyzer; the ions are then allowed to move freely in the field-free zone to the reflection zone of the time-of-flight quality analyzer, and the time it takes for the ions to reach the signal detection zone of the time-of-flight quality analyzer is adjusted using the reflection zone; wherein, the time-of-flight quality analyzer is the time-of-flight quality analyzer according to any one of claims 1-6.

8. The method for improving flight time quality analysis performance according to claim 7, wherein, Ions are screened based on their initial energy and initial position by: continuously applying a positive driving pulse of a first duration to the ions in the ionization acceleration region to filter ions at the extremes of their initial energy and / or initial position; and continuously applying a negative driving pulse of a second duration to the ions in the ionization acceleration region to accelerate the ions to the field-free region.

9. The method for improving flight time quality analysis performance according to claim 8, wherein, The peak voltage of the positive drive pulse is 5 V ~ 70 V, and the peak voltage of the negative drive pulse is no higher than -150 V.

10. The method for improving flight time quality analysis performance according to claim 8, wherein, The first duration is 2 μs to 30 μs, and the second duration is 1 μs to 10 μs.

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