Method for detecting linear amplification performance of a mass spectrometer, mass spectrometer and storage medium

Abstract

The application discloses a mass spectrometer linear amplification performance detection method, a mass spectrometer and a storage medium, and relates to the technical field of mass spectrometers. The method comprises the following steps: delivering a standard sample solution with a target concentration to an ion source for ionization; controlling a front-stage ion transmission module to open an ion enrichment function, and controlling the mass spectrometer to work at multiple different resolutions through a multi-stage ion transmission module; for each resolution, controlling a final-stage ion transmission module to open an ion trap function, performing multiple enrichment and release of ions from the front-stage ion transmission module, and the enrichment time length monotonically changes with the number of times; at each time of releasing ions, the signal strength output by an electronic detection module is acquired; and the maximum value of the signal strength linearly increasing with the enrichment time length under all resolutions is taken as an upper limit value of the linear amplification range of the mass spectrometer. Thus, through multi-stage controllable enrichment and release of ions, combined with resolution adjustment, the upper limit of the linear amplification range of the mass spectrometer can be accurately determined under a condition close to a real signal.

Description

Technical Field

[0001] This application relates to the field of mass spectrometry technology, and in particular to a method for detecting the linear amplification performance of a mass spectrometer, a mass spectrometer, and a storage medium. Background Technology

[0002] Mass spectrometers are commonly used testing platforms in the field of analytical detection. Their principle is based on the different flight characteristics (including trajectory deflection, duration, stability, etc.) of ions with different mass-to-charge ratios m / z (m represents the relative molecular mass of the ion, and z represents the amount of charge carried by the ion) in an electric field, thereby enabling the differentiation and detection of different ions.

[0003] The mass spectrometry signal detection system in a mass spectrometer includes an electron detection module, which typically consists of an electron multiplier tube and an amplification and detection circuit. The electron multiplier tube converts the ion signal into electrons, forming a pulsed current signal; the amplification and detection circuit then amplifies and shapes this signal, ultimately converting it into a pulse count value. Since the pulse count value directly corresponds to the number of ions being detected, a good linear correspondence between the two is essential to ensure the accuracy of the standard curve in quantitative analysis using mass spectrometry.

[0004] Currently, the conventional method for detecting the linear amplification performance of mass spectrometers involves generating pulsed current signals of varying frequencies from low to high using an external pulsed current source to simulate the ion conversion signal output by an electron multiplier tube (EMT). This signal is then input into the amplification and detection circuit to monitor the linear relationship between the output pulse count and the frequency of the external pulse source. The advantage of this method is that the pulse frequency is controllable, allowing for the rapid acquisition of a large number of simulated signals. However, the ions actually generated by mass spectrometry have uneven kinetic energy distribution, resulting in pulsed current signals with significant randomness in both intensity and period after EMT conversion. Furthermore, commercially available EMTs have limited gain, and the pulse signals generated by a single ion conversion are typically in the microampere (μA) range. In contrast, the signal intensity from the external pulsed current source is high and clearly periodic, placing lower demands on the bandwidth and signal amplification of the amplification and detection circuit. Therefore, the simulated test results are often overly idealized and fail to accurately reflect the linear performance of the mass spectrometry signal detection system under high-frequency, random signals.

[0005] Another common approach is to generate theoretically linearly varying ion signals using standard samples with linear concentration gradients to verify the linear response of the mass spectrometry signal detection system. However, when the sample concentration is too high, exceeding the upper limit of the ionization capability of the ion source, higher-order ion signals cannot be obtained. Furthermore, the nonlinear distortion of the mass spectrometry signal detection system is prone to occur at high pulse signal input frequencies. Therefore, this method has significant limitations in detecting high-frequency pulse signals and cannot comprehensively evaluate the linear performance of the mass spectrometry signal detection system under actual high-load conditions. Summary of the Invention

[0006] This application aims to at least partially address one of the technical problems in the related art. Therefore, the purpose of this application is to propose a method for detecting the linear amplification performance of a mass spectrometer, a mass spectrometer, and a storage medium, so as to achieve accurate and reliable determination of the upper limit of the linear amplification range of the mass spectrometer under conditions close to the characteristics of actual ion signals.

[0007] In a first aspect, this application proposes a method for detecting the linear amplification performance of a mass spectrometer. The mass spectrometer includes an ion source, a multi-stage ion transport module, and an electron detection module arranged sequentially. The multi-stage ion transport module includes a pre-stage ion transport module and a final-stage ion transport module. The method includes the following steps: delivering a standard sample solution of a target concentration to the ion source for ionization; controlling the pre-stage ion transport module to activate its ion enrichment function and performing multiple enrichment and release operations on ions from the ion source, and controlling the mass spectrometer to operate at multiple different resolutions through the multi-stage ion transport module; for each resolution, controlling the final-stage ion transport module to activate its ion trap function and performing multiple enrichment and release operations on ions from the pre-stage ion transport module, with the enrichment duration monotonically varying with the number of operations, and acquiring the signal intensity output by the electron detection module each time ions are released; and using the maximum value of the signal intensity that linearly increases with the enrichment duration at all resolutions as the upper limit of the linear amplification range of the mass spectrometer.

[0008] In some embodiments, the target concentration is determined as follows: a standard sample solution of a preset concentration is delivered to the ion source; the ion enrichment function of the pre-stage ion transport module is turned off, and the mass spectrometer is controlled to operate at the target resolution through the multi-stage ion transport module; the ion trap function of the final-stage ion transport module is turned on, and ions from the pre-stage ion transport module are enriched and released at least once, with the enrichment time being a preset time, and the signal intensity output by the detection module is acquired when ions are released; if the signal intensity reaches a set intensity threshold, the preset concentration is used as the target concentration; if the signal intensity does not reach the set intensity threshold, the preset concentration is increased to update the preset concentration, and the process proceeds to the step of delivering the standard sample solution of the preset concentration to the ion source.

[0009] In some embodiments, the target resolution is greater than or equal to the minimum of the plurality of different resolutions and less than or equal to the maximum of the plurality of different resolutions; and / or the plurality of different resolutions include a preset high resolution limit and a preset low resolution limit; and / or for each resolution, the enrichment duration of the final-stage ion transport module for the first enrichment of ions is the preset duration.

[0010] In some embodiments, the number of enrichment durations of the final-stage ion transport module is determined as follows: if the signal strength increases linearly with the enrichment duration, then the next enrichment duration is performed for enrichment and release, until the signal strength increases non-linearly with the enrichment duration.

[0011] In some embodiments, for each enrichment duration, the final-stage ion transport module is controlled to enrich and release ions from the preceding-stage ion transport module multiple times, and the average value of the acquired signal intensity is calculated as the signal intensity corresponding to the enrichment duration.

[0012] In some embodiments, the standard sample is reserpine, and the preset concentration is less than 200 ppb.

[0013] In some embodiments, the number of the pre-stage ion transport modules is multiple, and the multiple pre-stage ion transport modules are arranged sequentially; controlling the pre-stage ion transport modules to enable the ion enrichment function includes: controlling the first pre-stage ion transport module to enable the ion enrichment function; controlling the pre-stage ion transport modules to disable the ion enrichment function includes: controlling the first pre-stage ion transport module to disable the ion enrichment function.

[0014] In some embodiments, the number of pre-stage ion transport modules is three, namely a first pre-stage ion transport module, a second pre-stage ion transport module, and a third pre-stage ion transport module arranged sequentially. The first pre-stage ion transport module includes a 0th-stage membrane aperture lens and a 0th-stage transport rod arranged sequentially; the second pre-stage ion transport module includes a 1st-stage membrane aperture lens and a 1st-stage quadrupole arranged sequentially; the third pre-stage ion transport module includes a 2nd-stage transport rod; and the final-stage ion transport module includes a 3rd-stage membrane aperture lens, a 3rd-stage quadrupole, and an exit lens. The ion enrichment function of the pre-stage ion transport module is controlled by adjusting the pulsed DC voltage on the 0th-stage and 1st-stage membrane aperture lenses; the DC voltage on the 1st-stage quadrupole is adjusted accordingly. The voltage is adjusted to control the mass spectrometer to operate at multiple different resolutions. The first-stage quadrupole is also subjected to radio frequency AC voltage and DC voltage. The voltage amplitude and phase of the first-stage quadrupole are the same for each rod, while the voltage amplitude of adjacent rods is the same but the phase is opposite. The DC voltage varies with the radio frequency AC voltage at a preset ratio. By adjusting the radio frequency AC voltage on the third-stage quadrupole and the pulsed DC voltage on the third-stage membrane aperture lens, the final-stage ion transport module enriches ions. By adjusting the auxiliary radio frequency voltage on the third-stage quadrupole and the pulsed DC voltage on the exit lens, the final-stage ion transport module releases ions. The voltage amplitude and phase of the third-stage quadrupole are the same for each rod, while the voltage amplitude of adjacent rods is the same but the phase is opposite.

[0015] Secondly, this application proposes a mass spectrometer, comprising: an ion source, a multi-stage ion transmission module, and an electron detection module arranged sequentially, wherein the multi-stage ion transmission module includes a pre-stage ion transmission module and a final-stage ion transmission module; and a controller for executing the detection method for the linear amplification performance of the mass spectrometer described in the first aspect.

[0016] Thirdly, this application proposes a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the method for detecting the linear amplification performance of a mass spectrometer as described in the first aspect.

[0017] The method, mass spectrometer, and storage medium for detecting the linear amplification performance of a mass spectrometer according to embodiments of this application control the pre-stage ion transport module to perform multiple ion enrichment and release operations. Under different resolution conditions, the final-stage ion transport module is used to capture and release ions multiple times with a monotonically increasing enrichment duration. The signal intensity of the electron detection module is simultaneously collected during each release. Finally, the maximum value where the signal intensity at each resolution increases linearly with the enrichment duration is taken as the upper limit of the linear amplification range. Therefore, the upper limit of the linear amplification range of the mass spectrometer can be accurately and reliably determined under conditions close to the characteristics of actual ion signals.

[0018] The advantages of this application in terms of its additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a mass spectrometry signal detection system according to an embodiment of this application;

[0020] Figure 2 This is a structural block diagram of a mass spectrometer according to an embodiment of this application;

[0021] Figure 3 This is a flowchart of a method for detecting the linear amplification performance of a mass spectrometer according to an embodiment of this application;

[0022] Figure 4 This is a flowchart illustrating the determination of a target concentration according to an embodiment of this application;

[0023] Figure 5 This is a graph showing the relationship between signal strength and enrichment duration, as an example of this application.

[0024] Figure 6 This is a structural block diagram of a mass spectrometer according to another embodiment of this application. Detailed Implementation

[0025] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0026] Example 1: A mass spectrometry signal detection system

[0027] like Figure 1 As shown, the mass spectrometry signal detection system 100 includes: an ion source 1, a multi-stage ion transport module A, and an electron detection module B.

[0028] Ion source 1 is configured to ionize the received sample. A multi-stage ion transport module A is positioned after ion source 1, including a pre-stage ion transport module A1 and a final-stage ion transport module A2. Pre-stage ion transport module A1 has an ion enrichment function to enrich and release ions from ion source 1; final-stage ion transport module A2 has an ion trap function to enrich and release ions from pre-stage ion transport module A1. An electron detection module B is positioned after final-stage ion transport module A2 and is configured to output signal intensity based on the ions released by final-stage ion transport module A2.

[0029] When the mass spectrometry signal detection system 100 is operating, the ion source 1 ionizes sample molecules (such as reserpine at a specific concentration) into charged ions. These ions enter the multi-stage ion transport module A, where they are first selectively enriched and concentrated by the pre-stage ion transport module A1 within a specific time period, achieving initial ion screening and concentration. Subsequently, the final-stage ion transport module A2 performs secondary controllable enrichment of the ions in ion trap mode, and can precisely control the number of ions released each time by adjusting the accumulation time within the trap. Finally, the released ions enter the electron detection module B, where they are efficiently converted into electrical signals and the corresponding signal intensity is output.

[0030] Therefore, through two-stage ion enrichment and controlled release, the detection signal-to-noise ratio and sensitivity can be improved, the linear dynamic range can be effectively extended, and electronic detector saturation can be avoided. At the same time, the system design allows for precise control of ion flux, thereby enhancing the accuracy of quantitative analysis.

[0031] It should be noted that other ion sources 1 with linearly tunable ion generation methods can also be used, such as generating an ion beam with linearly increasing intensity by precisely controlling the electron gun emission current.

[0032] In some embodiments of this application, there are multiple front-stage ion transport modules A1, and the multiple front-stage ion transport modules A1 are arranged sequentially; wherein, at least the first front-stage ion transport module has ion enrichment function.

[0033] In this embodiment, multiple pre-stage ion transport modules A1 can be set with different enrichment durations and release sequences. For example, the first pre-stage ion transport module performs short-term rapid enrichment for preliminary screening and pre-concentration; subsequent pre-stage ion transport modules can perform secondary enrichment with longer durations or higher selectivity, depending on the resolution or mass number range requirements. Effective ion transfer between modules can be achieved by using lenses or radio frequency guiding fields.

[0034] This multi-stage cascaded structure can optimize ion transport efficiency and enrichment effect within different mass-to-charge ratio ranges, further enhancing the system's ability to capture ions in different mass ranges and the overall signal linearity.

[0035] Taking a three-stage ion transport module A1 as an example, Figure 1 As shown, the three pre-stage ion transport modules A1 are the first pre-stage ion transport module A11, the second pre-stage ion transport module A12, and the third pre-stage ion transport module A13, which are arranged sequentially.

[0036] See Figure 1 The first pre-stage ion transmission module A11 includes an air curtain plate 2, a sampling cone 3, an interface focusing rod 4, a zero-stage membrane aperture lens 5, and a zero-stage transmission rod 6 arranged in sequence; the second pre-stage ion transmission module A12 includes a first-stage membrane aperture lens 7, a first-stage pre-prep rod 8, and a first-stage quadrupole 9 arranged in sequence; the third pre-stage ion transmission module A13 includes a second-stage pre-prep rod 10, a second-stage membrane aperture lens 11, a second-stage transmission rod 13 arranged in sequence, and a second-stage focusing electrode 12 arranged parallel to the second-stage transmission rod 13.

[0037] Specifically, the air curtain plate 2 can provide backflushing air to help improve the atomization efficiency of the ion source. Simultaneously, a high-voltage DC is applied to it to create an accelerating electric field between the ion source and the air curtain plate, guiding ions to be captured by the sampling cone 3, which is also subject to the applied DC voltage. The 0th-stage transmission rod 6 can be a quadrupole structure, on which an RF AC voltage can be applied for transmission and focusing of the ion stream. The 0th-stage membrane aperture lens 5, the 1st-stage membrane aperture lens 7, and the 2nd-stage membrane aperture lens 11 are all planar lenses with a central aperture, on which a pulsed DC voltage can be applied. The central aperture is used for ion penetration. The 1st-stage pre-prep rod 8 and the 2nd-stage pre-prep rod 10 can both be short quadrupoles (less than the 1st-stage quadrupole 9), on which an RF AC voltage can be applied for pre-focusing of the ion stream entering the subsequent stage. The 1st-stage quadrupole 9 is a quadrupole structure on which both RF AC and DC voltages can be applied for ion screening.

[0038] In this example, at least the first pre-stage ion transport module A11 has an ion enrichment function. By controlling the potential and timing of the air curtain plate 2, sampling cone 3, level 0 membrane aperture lens 5, and level 1 membrane aperture lens 7, it can selectively enrich and pulse-release ions from the ion source 1, thereby providing a stable and controllable ion flow for subsequent transport and analysis.

[0039] For example, see Figure 1 Both the air curtain plate 2 and the sampling cone 3 adopt a conical structure, and the top of the cone is provided with a small hole for ion penetration.

[0040] This conical structure design enables airflow obstruction and pressure differential transition, and generates an electric field focusing effect on the ion beam, thereby improving ion transmission efficiency and reducing background noise.

[0041] For example, the center of the inner circle of the interface focusing rod 4, the center of the central hole of the 0th-level membrane aperture lens 5, the center of the inner circle of the 0th-level transmission rod 6, the center of the central hole of the 1st-level membrane aperture lens 7, the center of the inner circle of the 1st-level pre-prep rod 8, the center of the inner circle of the 1st-level quadrupole rod 9, the center of the inner circle of the 2nd-level pre-prep rod 10, the center of the central hole of the 2nd-level membrane aperture lens 11, and the center of the inner circle of the 2nd-level transmission rod 13 are coaxial.

[0042] This coaxial design ensures stable ion trajectories during transmission, effectively reducing ion loss and spatial scattering, and improving transmission efficiency and system signal-to-noise ratio.

[0043] For example, see Figure 1 The interface focusing rod 4 includes a first focusing quadrupole 41 and a second focusing quadrupole 42 arranged sequentially, and the lengths of the first focusing quadrupole 41 and the second focusing quadrupole 42 are less than the length of the first-stage quadrupole 9.

[0044] Specifically, the interface focusing rod 4 consists of two short quadrupoles (i.e., the first focusing quadrupole 41 and the second focusing quadrupole 42). Radio frequency AC voltage can be applied to each of the two quadrupoles to focus the ion flow captured by the acquisition cone.

[0045] For example, see Figure 1 The second-stage transmission rod 13 is a bent quadrupole, and the second-stage focusing electrode 12 includes two opposing T-shaped electrodes, which are arranged parallel to the bent quadrupole and located along the first direction of the bent quadrupole (e.g., ...). Figure 1 The two sides of the adjacent rod (in the z-axis direction).

[0046] Specifically, the second-stage transmission rod 13 can be a set of bent quadrupoles, to which an AC radio frequency voltage can be applied for the transmission and focusing of the ion stream; the second-stage focusing electrode 12 can be composed of two T-shaped electrodes, to which a DC voltage can be applied to assist in the efficient transmission of ions in the second-stage transmission rod 13. The center of the inscribed circle of the bent quadrupole can be coaxial with the center of the central hole of the second-stage membrane aperture lens 11 to achieve maximum ion transmission efficiency.

[0047] It should be noted that components such as the interface focusing rod 4, the 0th-stage transmission rod 6, and the 2nd-stage transmission rod 13, which do not perform quality screening functions, can be replaced by multi-electrode rods. Components such as the interface focusing rod 4, the 2nd-stage focusing electrode 12, and the 2nd-stage transmission rod 13, which only perform ion transport guidance functions, can be omitted directly, provided that ion transport efficiency is guaranteed. That is to say, in some embodiments, the first pre-stage ion transport module A11 may not include the interface focusing rod 4, and / or the third pre-stage ion transport module A13 may not include the 2nd-stage focusing electrode 12 and the 2nd-stage transmission rod 13.

[0048] See in some examples Figure 1 The final-stage ion transport module A2 includes a three-stage membrane aperture lens 14, a three-stage pre-barrel 15, a three-stage quadrupole 16, an accelerating electrode 17, an exit lens 18, and a shielding lens 19 arranged sequentially.

[0049] Specifically, the third-stage membrane aperture lens 14, the exit lens 18, and the shielding lens 19 are all planar lenses with a central hole, which is used for ion penetration. A pulsed DC voltage can be applied to the third-stage membrane aperture lens 14 and the exit lens 18; a DC voltage can be applied to the shielding lens 19, or it can be directly grounded, to shield the subsequent electric field. The third-stage pre-focusing rod 15 can be a short quadrupole, to which an RF AC voltage can be applied for pre-focusing the ion stream entering the subsequent stage; the third-stage quadrupole 16 is a quadrupole structure, to which both RF AC and DC voltages can be applied for ion screening, and a separate low-frequency, small-amplitude auxiliary RF AC voltage can be applied to one pair of rods of the third-stage quadrupole 16 to achieve a linear ion trap function. The accelerating electrode 17 may include four wedge-shaped electrodes, fixed to an insulating base sleeved on the third-stage quadrupole 16. The same DC voltage is applied to the four wedge electrodes to accelerate ions out of the third-stage quadrupole 16.

[0050] Among them, the center of the central hole of the third-stage membrane aperture lens 14, the center of the inner circle of the third-stage pre-rod 15, the center of the inner circle of the third-stage quadrupole 16, the center of the central hole of the exit lens 18, and the center of the central hole of the shielding lens 19 are coaxial, and are also coaxial with the center of the inner circle of the curved quadrupole, so as to maximize the ion transmission efficiency.

[0051] For example, the central aperture of the exit lens 18 is larger than the central aperture of the shielding lens 19, and the central aperture of the exit lens 18 is covered with a metal grid with an ion transmittance higher than a preset value (e.g., 70%).

[0052] Specifically, the central aperture of the exit lens 18 is larger than that of the subsequent shielding lens 19. This allows ions to undergo initial spatial expansion and trajectory smoothing through the larger aperture of the exit lens 18 after leaving the trap region, before entering the smaller aperture of the shielding lens 19 for collimation. This reduces ion loss caused by the lens edge field and improves beam matching and transmission efficiency. The metal grid is electrically connected to the exit lens 18, and both can be subjected to the same pulsed DC voltage to collaboratively control the ion emission timing and focusing field shape, thereby improving ion extraction efficiency and signal timing resolution.

[0053] In some embodiments of this application, such as Figure 1 As shown, the electronic detection module B includes a high-energy dyno electrode 20, an electron multiplier tube 21, and an amplification and detection circuit 22 arranged sequentially.

[0054] The high-energy dinoflag electrode 20 can adopt a metal bowl-shaped structure and is configured to convert the ions output from the final-stage ion transport module A2 into electrons and output them to the electron multiplier tube 21. The electron multiplier tube 21 is configured to multiply the received electrons to form a pulse current signal; the amplification and detection circuit 22 is configured to amplify and shape the pulse current signal and convert it into a pulse count value as the signal strength.

[0055] Specifically, the high-energy dinoflag electrode 20 is a metal bowl-shaped electrode on which a high negative voltage of -10kV to -20kV can be applied to accelerate the incident positive ions and bombard their inner surface. A large number of electrons are generated through the secondary electron emission effect, realizing the primary amplification and conversion of the signal. The generated electrons then enter the electron multiplier tube 21 for further multiplication, forming a pulse current signal. The amplification and detection circuit 22 is used to amplify and shape the pulse current signal and convert it into a pulse count value as the final signal strength output.

[0056] In other embodiments, the high-energy dinode 20 may be omitted; that is, the electron detection module B includes an electron multiplier tube 21 and an amplification detection circuit 22 arranged sequentially. The electron multiplier tube 21 is configured to directly convert and multiply the ions output from the final-stage ion transport module A2 into electrons.

[0057] In practical operation, if the electron detection module B is equipped with a high-energy danolectrode 20, it works in conjunction with the electron multiplier tube 21 to achieve efficient conversion of positive ions to electrons and signal amplification. If the high-energy danolectrode 20 is not configured, the electron multiplier tube 21 is directly used for negative ion detection or to receive electrons converted by other components. This design allows for flexible adjustment of detection sensitivity and signal dynamic range under different detection requirements.

[0058] It should be noted that the mass spectrometry signal detection system 100 exhibits a significant pressure difference. The gas pressure before sampling cone 3 is close to atmospheric pressure, while the system after sampling cone 3 is a differential vacuum system: the first-stage vacuum chamber is formed by the isolation between sampling cone 3 and the 0th-stage membrane lens 5, with a vacuum pressure around 3.5 torr; the second-stage vacuum chamber is formed by the isolation between the 0th-stage membrane lens 5 and the 1st-stage membrane lens 7, with a vacuum pressure around 8 mtorr; all components after the 1st-stage membrane lens 7 are located in the third-stage vacuum chamber, with an overall vacuum pressure better than 1.5e-5 torr. This differential vacuum system allows for more efficient deceleration, transmission, and focusing of the ion stream, while also protecting components at each stage and extending their service life.

[0059] The mass spectrometry signal detection system 100 of this application embodiment can generate a stable linearly increasing ion current by coordinating and controlling the amplitude and timing of the radio frequency AC voltage and pulsed DC voltage applied to each electrode in the multi-stage ion transport module A, and in conjunction with the corresponding DC voltage electric field, thereby realizing online detection of its linear amplification performance (the specific operating principle is detailed in the following embodiment 3).

[0060] Example 2: A mass spectrometer

[0061] like Figure 2 As shown, the mass spectrometer 1000 includes the mass spectrometry signal detection system 100 of the above embodiment.

[0062] Example 3: A method for detecting the linear amplification performance of a mass spectrometer

[0063] In this embodiment, the method for detecting the linear amplification performance of the mass spectrometer is used in the mass spectrometry signal detection system 100 of the above embodiment. For example... Figure 3 As shown, the method includes the following steps:

[0064] S11 delivers the standard sample solution of the target concentration to the ion source for ionization.

[0065] The standard sample can be reserpine.

[0066] For example, the target concentration is a fixed concentration of less than 200 ppb, such as 50 ppb of reserpine.

[0067] It should be noted that although the ion source itself can provide a continuous and stable ion output, experiments have shown that if the number of ions is increased simply by increasing the sample concentration, the ionization efficiency of the sample tends to exhibit nonlinear changes in the high-concentration region, resulting in the actual number of ions not maintaining a linear relationship with the sample concentration. Therefore, this application does not use gradient concentration samples for direct extrapolation, but instead uses a single standard sample with a fixed concentration to obtain a linearly increasing ion signal by controlling the ion transport and enrichment process, thereby achieving reliable detection of subsequent linear amplification performance.

[0068] S12 controls the pre-stage ion transport module to activate the ion enrichment function, and performs multiple enrichment and release of ions from the ion source. It also controls the mass spectrometer to operate at multiple different resolutions through the multi-stage ion transport module.

[0069] For example, the various resolutions include a preset high-resolution limit and a preset low-resolution limit.

[0070] Specifically, resolution refers to the ability to screen ions with a specific mass-to-charge ratio. When the resolution is low, a large number of ions can pass through under a single screening condition (large mass-to-charge ratio range); when the resolution is high, a small number of ions can pass through under a single screening condition (small mass-to-charge ratio range).

[0071] The linear amplification limit of a mass spectrometer's signal processing channel remains essentially the same across different resolutions. Therefore, theoretically, if only this linear amplification limit is needed, measurements can be taken at low resolution to directly find the critical point where the signal intensity and ion quantity lose their linear relationship. However, if only low-resolution measurements (increasing ion quantity) are used to find the linear amplification limit, the signal processing channel may saturate (i.e., lose linearity) too early (at the second point), resulting in too few effective data points and making it impossible to accurately determine the linear interval. Therefore, it is necessary to first adjust the mass spectrometer to a suitable baseline signal intensity to ensure that the initial measurement point is within the linear response region.

[0072] Therefore, this application first conducts tests at a high resolution (greater than or equal to a preset high resolution limit). At this high resolution, the ion flux is relatively low, which helps to systematically increase the enrichment time without premature saturation of the electron detector, thereby verifying the linear relationship between signal intensity and enrichment time under low load conditions. Afterward, the resolution can be gradually reduced, and tests can continue. In other words, the method of this application measures amplification linearity not only at low resolution but also at high resolution.

[0073] For example, multiple resolutions can be preset, and these resolutions can be selected within a range consisting of preset high-resolution limits and preset low-resolution limits. For instance, the resolution range can be divided into several levels uniformly or according to specific rules. The preset high-resolution limits and preset low-resolution limits can both be predetermined based on experimental experience or typical system operating conditions.

[0074] S13, for each resolution, controls the final stage ion transport module to enable the ion trap function, and performs multiple enrichment and release of ions from the previous stage ion transport module, with the enrichment duration monotonically changing with the number of times, and acquires the signal strength output by the electron detection module each time ions are released.

[0075] The enrichment duration varies monotonically with the number of iterations and can be represented by the formula t = t0 + k × n (ms), where t0 is the initial enrichment duration, which can be 0.05 ms; k represents the monotonic variation coefficient, such as 0.025; and n represents the number of iterations, which can take values ​​of 0, 1, 2, ...

[0076] Specifically, the ion trap can control the number of ions captured within it by adjusting the enrichment time. When the system is well-calibrated, a stable linear relationship exists between the total number of ions and the enrichment time, making the enrichment time a reliable parameter for precisely controlling the input ion flux. By gradually changing the enrichment time and simultaneously acquiring the signal intensity output by the electronic detection module, the response curves of the detection system at different ion input levels can be directly obtained, thereby evaluating its input-output characteristics and upper limit of dynamic range within the linear operating range.

[0077] It should be noted that, since the ion trap is affected by the space charge effect when storing ions, an excessively long enrichment time will lead to the loss of ions due to Coulomb repulsion. Therefore, it is necessary to first determine the effective range in which the enrichment time and the number of ions remain linear, so as to provide a reliable basis for the subsequent determination of the linear limit across the entire range.

[0078] S14, the maximum value of the signal intensity that increases linearly with enrichment time at all resolutions is taken as the upper limit of the linear amplification range of the mass spectrometer.

[0079] This method for detecting the linear amplification performance of a mass spectrometer allows for the acquisition of linearly increasing ion signals even against a low-concentration sample background through control of the mass spectrometer. It eliminates the need for an external pulsed current source, enabling verification of the linear amplification performance of the mass spectrometer and achieving reliable online detection.

[0080] In some embodiments of this application, there are multiple front-stage ion transport modules, and the multiple front-stage ion transport modules are arranged sequentially; controlling the front-stage ion transport modules to enable the ion enrichment function includes: controlling the first front-stage ion transport module to enable the ion enrichment function; controlling the front-stage ion transport modules to disable the ion enrichment function includes: controlling the first front-stage ion transport module to disable the ion enrichment function.

[0081] For example, there are three pre-stage ion transmission modules, namely a first pre-stage ion transmission module, a second pre-stage ion transmission module, and a third pre-stage ion transmission module arranged in sequence. The first pre-stage ion transmission module includes a 0th-stage membrane aperture lens and a 0th-stage transmission rod arranged in sequence. The second pre-stage ion transmission module includes a 1st-stage membrane aperture lens and a 1st-stage quadrupole arranged in sequence. The third pre-stage ion transmission module includes a 2nd-stage transmission rod. The final-stage ion transmission module includes a 3rd-stage membrane aperture lens, a 3rd-stage quadrupole, and an exit lens.

[0082] Specifically, by adjusting the pulsed DC voltage on the 0th-stage and 1st-stage membrane aperture lenses, the ion enrichment function of the pre-stage ion transport module can be turned on or off. By adjusting the DC adjustment voltage on the 1st-stage quadrupole, the mass spectrometer can be controlled to operate at multiple different resolutions. The 1st-stage quadrupole is also subject to radio frequency AC voltage and DC voltage, with the amplitude and phase of the voltage between the two poles being the same, and the voltage amplitude of adjacent poles being the same but the phase being opposite. The DC voltage varies with the radio frequency AC voltage at a preset ratio. By adjusting the radio frequency AC voltage on the 3rd-stage quadrupole and the pulsed DC voltage on the 3rd-stage membrane aperture lens, the final-stage ion transport module can enrich ions. By adjusting the auxiliary radio frequency voltage on the 3rd-stage quadrupole and the pulsed DC voltage on the exit lens, the final-stage ion transport module can release ions. The amplitude and phase of the voltage between the two poles on the 3rd-stage quadrupole are the same, and the voltage amplitude of adjacent poles is the same but the phase being opposite.

[0083] Specifically, see Figure 1Based on the optimized linear ion trap scanning method parameters, by adjusting the timing of the pulsed DC voltage on the 0th-order and 1st-order membrane aperture lenses, a short-term ion deceleration and storage function is achieved in the 0th-order transmission rod. Combined with linear ion trap scanning, this results in a linearly increasing ion signal. In the optimized linear ion trap scanning method, the 1st-order quadrupole is mainly used for ion screening. A radio frequency AC amplitude V_RF1, a DC component U_DC1, and a DC adjustment component U_offset are simultaneously applied to the rod. The voltage amplitudes of adjacent rods are in phase, while those of adjacent rods are in opposite phases. The radio frequency AC amplitude V_RF1 determines the mass-to-charge ratio of the ions screened by the quadrupole. The DC component U_DC1 varies with the radio frequency AC amplitude V_RF1 at a fixed ratio. The resolution of the 1st-order quadrupole is controlled by the DC adjustment component U_offset1 applied to it. The three-stage quadrupole primarily functions as a linear ion trap. An RF AC voltage amplitude V_RF3 is applied to each pole, with adjacent poles having the same amplitude but opposite phase. This, combined with the timing control of the high and low levels of the DC voltage on the three-stage aperture lens, enables the temporary storage of ions within the quadrupole. Additionally, a low-frequency, low-amplitude auxiliary RF voltage Aux_RF is applied to one pair of poles. By simultaneously scanning the amplitude of the auxiliary RF voltage Aux_RF and the pulsed DC voltage applied to the exit lens, the ions enriched by the three-stage quadrupole are sequentially ejected and detected by the signal detection system.

[0084] It should be noted that for the aforementioned mass spectrometry signal detection system, a set of key electrical parameters and timing configurations, i.e., "optimized linear ion trap scanning method parameters," can be determined in advance through experiments or simulations. This set of parameters mainly includes:

[0085] 1) Radio frequency parameters: The amplitude and frequency of the main radio frequency voltage applied to the ion trap rod, used to construct the ion trapping electric field;

[0086] 2) Auxiliary radio frequency parameters: the amplitude, frequency, and scanning mode of the auxiliary AC voltage used for resonant excitation of ion ejection;

[0087] 3) DC bias and timing control: including pulsed DC voltage on the exit lens, DC level switching timing of the membrane aperture lens, etc., used to regulate the storage, cooling and ejection process of ions;

[0088] 4) Timing coordination relationship: The synchronization and delay settings between various voltage signals ensure that ions are effectively enriched in the trap and can be stably ejected in order of mass-to-charge ratio.

[0089] The above parameters together constitute the "standard operating mode" for the system to operate stably and achieve linear and controllable ion signal output, and also provide a benchmark state for subsequent pulse modulation and linear performance detection.

[0090] Based on this baseline mode, further selection of appropriate parameters and timing configurations can be made to support different operating functions of the system, such as:

[0091] Parameters that control the first pre-stage ion transport module to enable the ion enrichment function (such as the pulse DC voltage timing on the 0-level membrane aperture lens and the 1-level membrane aperture lens).

[0092] Adjust the parameters of the mass spectrometer resolution (such as the DC adjustment component U_offset1 applied to the first-stage quadrupole 9).

[0093] Parameters that enable the ion trap function of the final-stage ion transport module (such as the RF AC amplitude V_RF3 applied to the 3-stage quadrupole, the auxiliary RF voltage Aux_RF and its scanning settings), etc.

[0094] In some embodiments of this application, such as Figure 4 As shown, the target concentration in step S11 above is determined in the following way:

[0095] S21 delivers a standard sample solution of a preset concentration to the ion source.

[0096] The standard sample can be reserpine, and the preset concentration can be a small concentration, such as 10 ppb.

[0097] S22 controls the pre-stage ion transport module to disable the ion enrichment function and controls the mass spectrometer to operate at the target resolution through the multi-stage ion transport module.

[0098] For example, the target resolution is greater than or equal to the minimum of a plurality of different resolutions, and less than or equal to the maximum of a plurality of different resolutions.

[0099] S23, control the final stage ion transport module to activate the ion trap function, and perform at least one enrichment and release of ions from the previous stage ion transport module, with the enrichment time being a preset time, and acquire the signal strength output by the detection module when releasing ions.

[0100] For example, in step S13 above, for each resolution, the enrichment time of the final stage ion transport module for the first enrichment of ions is a preset time, which can be the minimum enrichment time (e.g., 0.05ms).

[0101] S24, if the signal strength reaches the set strength threshold, the preset concentration is used as the target concentration.

[0102] The intensity threshold can be set as needed, for example, 1e8cps, or 1×10⁻⁶. 8 Count value per second.

[0103] S25, if the signal strength does not reach the set strength threshold, the preset concentration is increased to update the preset concentration, and then the process proceeds to the step of delivering the standard sample solution of the preset concentration to the ion source.

[0104] Specifically, in this embodiment, see Figure 1 First, disable the ion enrichment function of the 0th-stage transmission rod. Determine whether the signal intensity of the 3rd-stage quadrupole reaches the set intensity threshold (e.g., 1e8cps) at the minimum enrichment time (e.g., 0.05ms). If the signal intensity does not reach the set intensity threshold, gradually increase the concentration of the standard sample solution (e.g., from 10ppb to 20ppb, ..., 50ppb, etc.) and repeat steps S21 to S24 until the signal intensity measured at the minimum enrichment time reaches or exceeds the set intensity threshold. The concentration used at this point is determined as the target concentration required for subsequent linear amplification performance detection.

[0105] Subsequently, during the formal amplification and linearity performance testing, the ion enrichment function of the 0th-stage transmission bar is activated, increasing the number of ions in the 3rd-stage quadrupole during the set enrichment time (compared to disabling the ion enrichment function of the 0th-stage transmission bar). It should be noted that the enrichment effect of the 0th-stage transmission bar optimizes ion transport efficiency, allowing more precursor ions to enter the 1st-stage quadrupole, thereby increasing the detection signal intensity of the target compound.

[0106] It should be noted that disabling the ion enrichment function of the Class 0 transmission bar is to obtain the baseline signal intensity for subsequent testing. Since the method in this application aims to evaluate the linear amplification capability of the mass spectrometer under high ion flux conditions, specifically focusing on the linear response characteristics of the pulse signal acquisition circuit (i.e., the electronic detection module) under high load, and considering that the system typically maintains a linear relationship naturally at lower ion numbers, this application focuses on performance verification in the high ion intensity range. To achieve an effective test benchmark, when the Class 0 transmission bar is in non-enrichment mode, the concentration of the standard sample solution needs to be adjusted to ensure that the output signal intensity reaches a sufficiently high level, thereby ensuring that the starting point for subsequent linear limit detection is within the high load range that actually needs to be calibrated.

[0107] In some embodiments of this application, the number of enrichment times for the final-stage ion transport module is determined as follows:

[0108] If the signal strength increases linearly with the enrichment duration, then enrichment and de-enrichment are performed for the next enrichment duration until the signal strength increases non-linearly with the enrichment duration.

[0109] See Figure 1In practice, the enrichment duration is controlled by the timing of the DC voltage applied to the third-stage membrane lens: when the DC voltage is low, the ion flow from the second-stage transmission rod is allowed to pass through the membrane lens, enter the third-stage quadrupole, and be enriched therein without being lost from the exit lens; when the DC voltage is switched to high, ions are repelled from entering the third-stage quadrupole 16, and the ion flow delivered by the second-stage transmission rod is guided to the bypass after reaching the third-stage membrane lens and no longer enters the subsequent trap region.

[0110] Therefore, the enrichment duration corresponds to the duration during which the DC voltage on the third-order aperture lens remains at a low level. By gradually extending this low-level period, the number of ions captured in the trap can be systematically increased until the detection signal leaves the linear growth range, thereby determining the maximum enrichment duration (i.e., the linear amplification limit) corresponding to the linear response at this resolution.

[0111] For example, for each enrichment duration, the final-stage ion transport module is controlled to enrich and release ions from the preceding-stage ion transport module multiple times (e.g., 100 times), and the average value of the acquired signal intensity is calculated as the signal intensity corresponding to the enrichment duration.

[0112] Specifically, see Figure 1 For each enrichment duration (e.g., 0.1ms), the three-stage quadrupole is first controlled to enrich ions for that duration. Then, the pulse voltage of the exit lens is turned on, allowing the ions accumulated in the trap to enter the downstream electron detection module all at once. The signal intensity corresponding to this release is recorded. The above "enrichment-release-detection" process is repeated multiple times (e.g., 100 times), and the arithmetic average of all measurement results is taken to obtain the signal intensity corresponding to that enrichment duration.

[0113] The main reason for repeating the measurement multiple times is that the ion current output from the ion source has inherent fluctuations, resulting in an unstable ion flux in the second-stage transmission rod. By repeating the measurement multiple times and taking the average value, the influence of random fluctuations in the ion current on the single measurement result can be effectively suppressed, thereby improving the repeatability of the signal strength and the reliability of the measurement, and more accurately reflecting the intrinsic relationship between enrichment duration and signal response.

[0114] In some embodiments of this application, the number of resolutions is determined in the following manner:

[0115] Based on a preset high-resolution limit, the resolution is gradually reduced until the maximum signal strength at the current resolution, which increases linearly with the enrichment duration, is less than the maximum signal strength at the previous resolution, which also increases linearly with the enrichment duration.

[0116] Specifically, see Figure 1The preset high-resolution limit corresponds to a U_offset1 value less than 0.25, such as 0.2. The resolution is gradually decreased, or U_offset1 is increased in increments of 0.1, 0.2, etc., and the signal strength is tested sequentially at each resolution as a function of enrichment duration. This process continues until the maximum linear increase in signal strength with enrichment duration at the current resolution is lower than the maximum linear increase at the next higher resolution. At this point, all resolutions covered by the test constitute the required set of test resolutions.

[0117] This method allows for the systematic screening of effective resolution ranges that maintain or improve linear signal carrying capacity while reducing resolution, avoiding premature saturation due to excessively low resolution and thus more accurately locating the linear amplification limit of the system across the entire resolution range. To improve detection efficiency and simplify the operation process, linear amplification performance can be tested at each set resolution during the gradual reduction of resolution, and the maximum value of the corresponding signal intensity that linearly increases with enrichment time can be recorded. When the maximum signal intensity first falls below the maximum linear increase at the previous resolution, it indicates that the linear limit has been reached. At this point, the maximum signal intensity measured at the previous resolution (i.e., the penultimate resolution where linear growth is still maintained) is considered the upper limit of the mass spectrometer's linear amplification range.

[0118] Figure 5 The diagram illustrates the relationship between signal strength and enrichment duration for three different values ​​of U_offset1. Details are as follows:

[0119] With U_offset1=0.2, the resolution of the first-stage quadrupole is relatively high (the mass spectrometer resolution is also relatively high at this time). In the range of 0.05 to 0.2 ms, the signal intensity can be considered to increase linearly with the enrichment time, and the signal intensity accumulated over 100 times reaches a maximum of 1.7e9cps.

[0120] With U_offset1=0.4, the resolution of the first-stage quadrupole is relatively low (the mass spectrometer resolution is also low at this time), and ions pass through the first-stage quadrupole more easily. Within the enrichment time of 0.05 to 0.125 ms, the signal intensity increases linearly with the enrichment time. After the enrichment time exceeds 0.125 ms, the rate of increase in signal intensity with enrichment time slows down significantly, and nonlinearity appears. The highest signal intensity accumulated over 100 times reaches 6.4e9 cps.

[0121] With U_offset1=1.5, the resolution of the first-stage quadrupole is lower (the mass spectrometer resolution is also lower at this time), and ions are more likely to pass through the first-stage quadrupole stably. Within the enrichment time of 0.05 to 0.1 ms, the signal intensity increases linearly with the enrichment time. After the enrichment time exceeds 0.1 ms, the rate of increase of the signal intensity with the enrichment time slows down significantly, and nonlinearity appears. The highest signal intensity accumulated over 100 times reaches 6.3e9 cps.

[0122] Therefore, the detection yields a maximum linear amplification range of 6.4e7 cps for a single mass spectrometer.

[0123] Example 4: Another mass spectrometer

[0124] In this embodiment, such as Figure 6 As shown, the mass spectrometer 1000 includes: a controller 200, and an ion source 1, a multi-stage ion transmission module A, and an electron detection module B arranged sequentially.

[0125] The multi-stage ion transport module A includes a pre-stage ion transport module A1 and a final-stage ion transport module A2; the controller 200 is used to execute the method for detecting the linear amplification performance of the mass spectrometer in the above embodiment.

[0126] Example 5: A computer-readable storage medium

[0127] In this embodiment, a computer program is stored on a computer-readable storage medium. When the computer program is executed by a processor, it implements the method for detecting the linear amplification performance of the mass spectrometer described in the above embodiment.

[0128] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0129] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0130] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0131] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0132] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0133] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for detecting the linear amplification performance of a mass spectrometer, characterized in that, The mass spectrometer includes an ion source, a multi-stage ion transport module, and an electron detection module arranged sequentially. The multi-stage ion transport module includes a pre-stage ion transport module and a final-stage ion transport module. The method includes the following steps: A standard sample solution of the target concentration is delivered to the ion source for ionization. The front-stage ion transport module is controlled to activate the ion enrichment function, which enriches and releases ions from the ion source multiple times. The multi-stage ion transport module is used to control the mass spectrometer to operate at multiple different resolutions. For each resolution, the final-stage ion transport module is controlled to activate the ion trap function to enrich and release ions from the preceding ion transport module multiple times, with the enrichment duration changing monotonically with the number of times, and the signal strength output by the electron detection module is acquired each time ions are released. The maximum value of the signal intensity that increases linearly with enrichment duration at all resolutions is taken as the upper limit of the linear amplification range of the mass spectrometer.

2. The method for detecting the linear amplification performance of a mass spectrometer according to claim 1, characterized in that, The target concentration is determined in the following manner: A standard sample solution of a preset concentration is delivered to the ion source; The front-stage ion transport module is controlled to disable the ion enrichment function, and the mass spectrometer is controlled to operate at the target resolution through the multi-stage ion transport module. The final-stage ion transport module is controlled to activate the ion trap function and to enrich and release ions from the preceding ion transport module at least once, with the enrichment time being a preset time. When releasing ions, the signal strength output by the detection module is obtained. If the signal strength reaches a set strength threshold, then the preset concentration is taken as the target concentration; If the signal strength does not reach the set strength threshold, the preset concentration is increased to update the preset concentration, and the process proceeds to the step of delivering the standard sample solution of the preset concentration to the ion source.

3. The method for detecting the linear amplification performance of a mass spectrometer according to claim 1, characterized in that, The number of resolutions is determined as follows: Based on a preset high-resolution limit, the resolution is gradually reduced until the maximum signal strength at the current resolution, which increases linearly with the enrichment duration, is less than the maximum signal strength at the previous resolution, which also increases linearly with the enrichment duration.

4. The method for detecting the linear amplification performance of a mass spectrometer according to claim 1, characterized in that, The number of enrichment times for the final-stage ion transport module is determined as follows: If the signal strength increases linearly with the enrichment duration, then enrichment and release are performed for the next enrichment duration until the signal strength increases non-linearly with the enrichment duration.

5. The method for detecting the linear amplification performance of a mass spectrometer according to claim 4, characterized in that, For each enrichment duration, the final-stage ion transport module is controlled to enrich and release ions from the preceding-stage ion transport module multiple times, and the average value of the acquired signal intensity is calculated as the signal intensity corresponding to the enrichment duration.

6. The method for detecting the linear amplification performance of a mass spectrometer according to claim 2, characterized in that, The standard sample is reserpine, and the preset concentration is less than 200 ppb.

7. The method for detecting the linear amplification performance of a mass spectrometer according to claim 2, characterized in that, The number of the pre-stage ion transport modules is multiple, and the multiple pre-stage ion transport modules are arranged sequentially. The control of the front-stage ion transport module to enable the ion enrichment function includes: controlling the first front-stage ion transport module to enable the ion enrichment function; The control of the front-stage ion transport module to disable the ion enrichment function includes: controlling the first front-stage ion transport module to disable the ion enrichment function.

8. The method for detecting the linear amplification performance of a mass spectrometer according to claim 7, characterized in that, The number of pre-stage ion transmission modules is three, namely a first pre-stage ion transmission module, a second pre-stage ion transmission module, and a third pre-stage ion transmission module arranged in sequence. The first pre-stage ion transmission module includes a 0th-stage membrane aperture lens and a 0th-stage transmission rod arranged in sequence. The second pre-stage ion transmission module includes a 1st-stage membrane aperture lens and a 1st-stage quadrupole arranged in sequence. The third pre-stage ion transmission module includes a 2nd-stage transmission rod. The final-stage ion transmission module includes a 3rd-stage membrane aperture lens, a 3rd-stage quadrupole, and an exit lens. Specifically, by adjusting the pulsed DC voltage on the 0th-level membrane aperture lens and the 1st-level membrane aperture lens, the ion enrichment function of the front-end ion transport module can be controlled to be turned on or off. By adjusting the DC regulating voltage on the first-stage quadrupole, the mass spectrometer can be controlled to operate at multiple different resolutions. The first-stage quadrupole is also subjected to radio frequency AC voltage and DC voltage. The voltage amplitude and phase of the first-stage quadrupole are the same for adjacent rods, and the voltage amplitude of adjacent rods are the same but the phase is opposite. The DC voltage changes with the radio frequency AC voltage at a preset ratio. The final-stage ion transport module enriches ions by regulating the radio frequency AC voltage on the three-stage quadrupole and the pulsed DC voltage on the three-stage membrane lens; the final-stage ion transport module releases ions by regulating the auxiliary radio frequency voltage on the three-stage quadrupole and the pulsed DC voltage on the outlet lens. The voltage amplitude and phase of the three-stage quadrupole are the same for each other, and the voltage amplitude of adjacent quadrupoles is the same but the phase is opposite.

9. A mass spectrometer, characterized in that, include: An ion source, a multi-stage ion transport module, and an electron detection module are arranged sequentially. The multi-stage ion transport module includes a pre-stage ion transport module and a final-stage ion transport module. A controller for performing the method for detecting the linear amplification performance of a mass spectrometer as described in any one of claims 1-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for detecting the linear amplification performance of the mass spectrometer as described in any one of claims 1-8.

Images