A method and device for calibrating the mass axis of a quadrupole mass spectrometer

Abstract

The present invention provides a mass axis calibration method and device for a quadrupole mass spectrometer. The method comprises: setting calibration conditions, testing different preset standard samples for each calibration condition, and obtaining digital-to-analog conversion values ​​corresponding to the standard samples; fitting a preset high-order curve function based on the standard samples for each calibration condition and the digital-to-analog conversion values ​​corresponding to the standard samples to obtain high-order curve function coefficients for the high-order curve function; and constructing a mapping relationship between the calibration conditions and the high-order curve function coefficients, and storing the mapping relationship. This method can reduce storage costs and improve query response speed.

Description

Technical Field

[0001] The present invention relates to the technical field of mass spectrometers, and in particular to a mass axis correction method and device for a quadrupole mass spectrometer. Background Art

[0002] The mass spectrometer is a widely used instrument in scientific instruments for detecting elements, and the quadrupole mass spectrometer is the most widely used mass spectrometer among them. Mass axis calibration is a calibration step before using the quadrupole mass spectrometer, which is used to calibrate the measured value of the quadrupole mass spectrometer to the theoretical value of the standard sample. The existing calibration method is to fit the actual mass number of multiple spectral peaks of the standard sample with the corresponding digital to analog converter (DAC) value of the quadrupole drive power supply using a high-order curve function to obtain a calibration correspondence table of mass number (Mass) and DAC value, and store the calibration correspondence table so that in subsequent tests, the calibration correspondence table can be queried based on the DAC value obtained by detection to obtain the mass number. However, this method requires setting a corresponding calibration table for each set of quadrupole mass analyzers, each mass resolution, each scanning speed, and positive and negative polarity ions. Taking two sets of quadrupole mass analyzers, three mass resolutions of high, medium and low, five scanning speeds, and positive and negative polarity ions including positive and negative polarity ions as an example, the number of calibration tables that need to be stored is: 2X3X5X2=60. Taking a calibration table with a mass resolution of 1 atomic mass unit (amu), a mass number range of 1300amu, and a DAC bit width of 3 bytes as an example, the data volume of the calibration table is 1300*1*3byte=3600byte. For a higher-end quadrupole mass spectrometer, if the minimum mass resolution is set to 0.001amu, the data volume of a stored calibration table will be 3600000bytes, or approximately 27Mbit. If 60 calibration tables are stored, the corresponding stored data volume will be: 27Mbit*2*3*5*2=1620Mbit, which will greatly increase the storage cost of the quadrupole mass spectrometer. Furthermore, when querying to determine the calibration table to be used, the huge amount of stored data reduces the query response speed. Summary of the Invention

[0003] In view of this, an object of the present invention is to provide a method and apparatus for calibrating the mass axis of a quadrupole mass spectrometer, so as to reduce storage costs and improve query response speed.

[0004] In a first aspect, an embodiment of the present invention provides a mass axis calibration method for a quadrupole mass spectrometer, comprising:

[0005] Set calibration conditions, and for each calibration condition, test different preset standard samples separately to obtain the digital-to-analog conversion value corresponding to the standard sample;

[0006] Fitting a preset high-order curve function based on a standard sample of each calibration condition and a digital-to-analog conversion value corresponding to the standard sample to obtain a high-order curve function coefficient of the high-order curve function;

[0007] Constructing a mapping relationship between the calibration conditions and the coefficients of the high-order curve function, and storing the mapping relationship. In combination with the first aspect, an embodiment of the present invention provides a first possible implementation of the first aspect, wherein the standard sample based on each calibration condition and the digital-to-analog conversion value corresponding to the standard sample are fitted to a preset high-order curve function to obtain the high-order curve function coefficients of the high-order curve function, including:

[0008] Obtaining the mass of each standard sample and the corresponding digital-to-analog conversion value under the first calibration condition;

[0009] The digital-to-analog conversion value corresponding to the standard sample is used as the dependent variable of the high-order curve function, and the mass number corresponding to the standard sample is used as the independent variable of the high-order curve function to construct an equation;

[0010] Constructing an equation system based on the equations corresponding to each standard sample, and fitting the equation system;

[0011] Obtain coefficients of the fitted equation group to obtain the higher-order curve function coefficients of the higher-order curve function under the first correction condition.

[0012] In combination with the first aspect, an embodiment of the present invention provides a second possible implementation of the first aspect, wherein storing the mapping relationship includes:

[0013] The mapping relationship is stored in a non-volatile storage unit.

[0014] In combination with the first aspect, an embodiment of the present invention provides a third possible implementation of the first aspect, wherein the calibration conditions include: the number of quadrupole mass analyzer sets, mass resolution, scanning speed, and ion polarity.

[0015] In combination with the first aspect and any one of the first to third possible implementations of the first aspect, an embodiment of the present invention provides a fourth possible implementation of the first aspect, wherein the method further includes:

[0016] According to the test conditions set for the sample to be tested, the test conditions include: mass resolution, scanning speed, and ion polarity, querying the stored mapping relationship to obtain a mapping relationship that matches the test conditions;

[0017] Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients;

[0018] The mass number of the sample to be tested is substituted into the constructed high-order test curve function to obtain the DAC value for the sample to be tested.

[0019] In combination with the first aspect and any possible implementation manner of the first aspect to the third possible implementation manner of the first aspect, an embodiment of the present invention provides a fifth possible implementation manner of the first aspect, wherein the method further includes:

[0020] Obtaining a test DAC value under the test conditions set for the sample to be tested, wherein the test conditions include: mass resolution, scan speed, and ion polarity;

[0021] Querying the stored mapping relationships to obtain a mapping relationship that matches the test condition;

[0022] Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients;

[0023] Substitute the test DAC value into the constructed high-order test curve function to obtain the mass number of the sample to be tested.

[0024] In combination with the first aspect and any possible implementation of the first aspect to the third possible implementation of the first aspect, an embodiment of the present invention provides a sixth possible implementation of the first aspect, wherein the high-order curve function is a quartic curve function.

[0025] In a second aspect, an embodiment of the present invention further provides a mass axis correction device for a quadrupole mass spectrometer, comprising:

[0026] The digital-to-analog conversion value acquisition module is used to set the calibration conditions. For each calibration condition, different preset standard samples are tested separately to obtain the digital-to-analog conversion value corresponding to the standard sample.

[0027] A curve function fitting module is used to fit a preset high-order curve function based on a standard sample of each calibration condition and a digital-to-analog conversion value corresponding to the standard sample to obtain a high-order curve function coefficient of the high-order curve function;

[0028] The function coefficient storage module is used to construct a mapping relationship between the correction conditions and the function coefficients of the high-order curve, and store the mapping relationship.

[0029] In a third aspect, an embodiment of the present application provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0030] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are executed.

[0031] The mass axis calibration method and device of a quadrupole mass spectrometer provided in an embodiment of the present invention, by setting calibration conditions, testing different preset standard samples for each calibration condition, and obtaining the digital-to-analog conversion value corresponding to the standard sample; fitting a preset high-order curve function based on the standard sample of each calibration condition and the digital-to-analog conversion value corresponding to the standard sample to obtain the high-order curve function coefficient of the high-order curve function; constructing a mapping relationship between the calibration conditions and the high-order curve function coefficient, and storing the mapping relationship. In this way, by storing the high-order curve function coefficient of the high-order curve function, there is no need to store the corresponding relationship between each mass number and the corresponding DAC value, effectively reducing the storage resources required for storage.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 A schematic flow chart of a method for calibrating the mass axis of a quadrupole mass spectrometer provided by an embodiment of the present invention is shown;

[0035] Figure 2 A schematic structural diagram of a mass axis correction device for a quadrupole mass spectrometer provided by an embodiment of the present invention is shown;

[0036] Figure 3 A schematic diagram of the structure of a computer device 300 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0038] Currently, when calibrating the mass axis of a quadrupole mass spectrometer, due to the characteristics of the power supply detector in the quadrupole mass spectrometer, it is necessary to use a higher-order curve function, such as a quartic curve function or higher-order curve function, to fit the mass number and DAC value. For a pre-set quadrupole mass analyzer, a mass resolution, a scan speed, and a positive polarity ion, taking the quartic curve function as an example, its expression is:

[0039] y=ax^4+bx^3+cx^2+dx+e,

[0040] Where y is the DAC value, x is the mass number, and a, b, c, d, and e are the coefficients of the quartic curve function. After calculating the fitted quartic curve function coefficients using a personal computer (PC), a calibration table of mass numbers (Mass) and DAC values ​​for the quadrupole mass analyzer, a mass resolution, a scan speed, and a positive polarity ion was obtained based on the mass range and mass resolution, as shown in Table 1.

[0041] Table 1

[0042]

[0043]

[0044] Since the mass number and the voltage applied to the quadrupole mass spectrometer are not linearly related, the quadrupole mass spectrometer needs to be calibrated. In the prior art, after obtaining the calibration correspondence table, the calibration correspondence table is sent to the control unit of the quadrupole mass spectrometer, and the calibration correspondence table is written to a flash memory or other storage medium through the control unit of the quadrupole mass spectrometer.

[0045] In an embodiment of the present invention, for each stored correction correspondence table, a corresponding high-order curve function is provided. After fitting the high-order curve function, a high-order curve function coefficient is obtained. The correction correspondence table is obtained by drawing the high-order curve function, the high-order curve function coefficient, and the mass number. Therefore, considering storing the high-order curve function coefficient of each correction correspondence table, in subsequent applications, since the mass number is determined for each sample, the count value of the sample characterizes the signal intensity of the corresponding mass number sample. The control unit sets the mass number of the measured sample molecule so that the molecule of the mass number passes through the quadrupole in the quadrupole mass spectrometer and reaches the detector, while the molecules of other mass numbers cannot pass through. In the quadrupole mass spectrometer, the set mass number is converted into a corresponding voltage according to the correction correspondence table and applied to the quadrupole. In actual applications, a plurality of mass numbers are sent to the quadrupole mass spectrometer in the form of a correction correspondence table. The quadrupole mass spectrometer tests the intensity of the corresponding ions one by one according to the mass number in the received correction correspondence table. In the correction correspondence table, each mass number corresponds to a specific scanning speed, ion polarity, and resolution.

[0046] The embodiments of the present invention provide a method and apparatus for calibrating the mass axis of a quadrupole mass spectrometer, which are described below through examples.

[0047] Figure 1 FIG. 1 is a flow chart showing a method for calibrating the mass axis of a quadrupole mass spectrometer according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0048] Step 101: Set calibration conditions. For each calibration condition, test different preset standard samples to obtain the digital-to-analog conversion value corresponding to the standard sample.

[0049] In an embodiment of the present invention, the basic principle of mass axis calibration of a quadrupole mass spectrometer is as follows: a standard sample is ionized to form an ion flow, which enters a vacuum system; in an ion focusing system, neutral ions and photons are intercepted, and positive ions or negative ions pass through and are focused into a quadrupole mass analyzer; the quadrupole mass analyzer separates the ions according to their mass-to-charge ratio and introduces them into a detector; the detector converts the ions into electron pulses, which are amplified and counted by a data collector, and the counts are converted into DAC values; a preset high-order curve function is used to fit the mass number of the standard sample and the corresponding DAC value to obtain the high-order curve function coefficient; and then a high-order curve function with the high-order curve function coefficient is used to construct a correction correspondence table of DAC values ​​corresponding to mass numbers from small to large.

[0050] In subsequent applications, under the same test conditions as the standard sample, by obtaining the count of the sample to be tested and converting it into a DAC value, the corresponding mass number of the sample to be tested can be obtained by querying the calibration correspondence table, thereby realizing elemental analysis of the sample to be tested.

[0051] In an embodiment of the present invention, as an optional embodiment, the calibration conditions include, but are not limited to, the number of quadrupole mass analyzer sets, mass resolution, scanning speed, and ion polarity. Taking the example of a quadrupole mass analyzer set of 2 (a first quadrupole mass analyzer and a second quadrupole mass analyzer), two mass resolutions (a high mass resolution and a low mass resolution), two scanning speeds (a first scanning speed and a second scanning speed), and a positive ion polarity, there are eight corresponding calibration conditions. The calibration conditions are specifically set as follows:

[0052] Calibration condition 1: first quadrupole mass analyzer, high mass resolution, first scan speed, positive ion;

[0053] Calibration condition 2: first quadrupole mass analyzer, high mass resolution, second scan speed, positive ion;

[0054] Calibration condition 3: first quadrupole mass analyzer, low mass resolution, first scan speed, positive ions;

[0055] Calibration condition 4: first quadrupole mass analyzer, low mass resolution, second scan speed, positive ion;

[0056] Calibration condition 5: second quadrupole mass analyzer, high mass resolution, first scan speed, positive ion;

[0057] Calibration condition 6: second quadrupole mass analyzer, high mass resolution, second scan speed, positive ion;

[0058] Calibration condition 7: second quadrupole mass analyzer, low mass resolution, first scan speed, positive ion;

[0059] Calibration condition 8: second quadrupole mass analyzer, low mass resolution, second scan speed, positive ions.

[0060] In an embodiment of the present invention, as an optional embodiment, for each calibration condition, the number of masses (molecular weights) in the standard sample that participate in mass axis calibration is 5 to 7, that is, the standard sample can be applied to each calibration condition respectively.

[0061] Step 102: fitting a preset high-order curve function based on the standard sample of each calibration condition and the digital-to-analog conversion value corresponding to the standard sample to obtain the high-order curve function coefficients of the high-order curve function;

[0062] In the embodiment of the present invention, the high-order curve function is a quartic curve function or a higher-order curve function or other curve functions. As an optional embodiment, the high-order curve function is a quartic curve function.

[0063] In this embodiment of the present invention, for each of the eight calibration conditions, a quartic curve function is fitted based on the standard sample and the corresponding DAC value for that calibration condition, resulting in eight sets of quartic curve function coefficients {an, bn, cn, dn, en}, where n∈{1,8}.

[0064] In an embodiment of the present invention, as an optional embodiment, a preset high-order curve function is fitted based on a standard sample of each calibration condition and a digital-to-analog conversion value corresponding to the standard sample to obtain a high-order curve function coefficient of the high-order curve function, including:

[0065] Obtaining the mass of each standard sample and the corresponding digital-to-analog conversion value under the first calibration condition;

[0066] The digital-to-analog conversion value corresponding to the standard sample is used as the dependent variable of the high-order curve function, and the mass number corresponding to the standard sample is used as the independent variable of the high-order curve function to construct an equation;

[0067] Constructing an equation system based on the equations corresponding to each standard sample, and fitting the equation system;

[0068] Obtain coefficients of the fitted equation group to obtain the higher-order curve function coefficients of the higher-order curve function under the first correction condition.

[0069] In the embodiment of the present invention, for each correction condition, the higher-order curve function coefficients of the higher-order curve function under the correction condition can be obtained according to the same process as the first correction condition.

[0070] Step 103: construct a mapping relationship between the correction condition and the coefficient of the high-order curve function, and store the mapping relationship.

[0071] In an embodiment of the present invention, as an optional embodiment, storing the mapping relationship includes:

[0072] The mapping relationship is stored in a non-volatile storage unit.

[0073] In an embodiment of the present invention, a PC is used to fit the coefficients of a higher-order curve function. After the coefficients are calculated, the coefficients or mapping relationships are transmitted to the main control unit of the quadrupole mass spectrometer via a communication interface. The main control unit writes the coefficients or mapping relationships to a non-volatile storage unit for retrieval after the quadrupole mass spectrometer is powered on again. As an optional embodiment, the stored mapping relationships are shown in Table 2.

[0074] Table 2

[0075]

[0076]

[0077] In an embodiment of the present invention, as an optional embodiment, the high-order curve function coefficients adopt a double floating point type with a bit width of 4 bytes. In this way, the data volume of a set of quartic curve function coefficients is: 5*4byte=20byte, which is relatively large compared to the data volume of a correction correspondence table with a mass number range of 1300amu and a DAC bit width of 3 bytes in the prior art: 1300*1*3byte=3600byte, greatly reducing the required hardware storage resources. In particular, when a large number of correction correspondence tables need to be stored, compared to the existing correction method, which requires 1620Mbit of hardware storage resources, the method of the embodiment of the present invention only requires 0.005Mbit of hardware storage resources. The advantages of hardware storage resources are obvious, which can greatly reduce hardware costs and simplify hardware design; further, it can also sharply reduce the amount of communication data between the PC and the control unit during the mass axis correction process, thereby improving the response speed during the mass axis correction process.

[0078] In an embodiment of the present invention, as an optional embodiment, the method further includes:

[0079] Obtaining a test DAC value under the test conditions set for the sample to be tested, wherein the test conditions include: mass resolution, scan speed, and ion polarity;

[0080] Querying the stored mapping relationships to obtain a mapping relationship that matches the test condition;

[0081] Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients;

[0082] Substitute the test DAC value into the constructed high-order test curve function to obtain the mass number of the sample to be tested.

[0083] In the embodiment of the present invention, as another optional embodiment, the method further includes:

[0084] According to the test conditions set for the sample to be tested, the test conditions include: mass resolution, scanning speed, and ion polarity, querying the stored mapping relationship to obtain a mapping relationship that matches the test conditions;

[0085] Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients;

[0086] The mass number of the sample to be tested is substituted into the constructed high-order test curve function to obtain the DAC value for the sample to be tested.

[0087] In an embodiment of the present invention, when performing a new scan, the main control unit scans the mapping relationship in sequence, and selects the corresponding high-order curve function coefficient to calculate the DAC value based on the current scanning point information (including mass number, scanning speed, mass resolution, and ion polarity).

[0088] In an embodiment of the present invention, as an optional embodiment, a field programmable gate array (FPGA) is used to realize the fitting of a high-order curve function, and the FPGA is used to realize the operation of a quartic curve function. It is assumed that when performing the fitting operation of the high-order curve function for the first time, the required time is: T=t1+t2+t3+t4+t5, wherein t1, t2, t3, t4, and t5 are the times required for fitting the coefficients of the quartic curve function. In an embodiment of the present invention, after compiling by FPGA, it is actually obtained that T is 43 system clocks and t1 is 21 system clocks. Then, in the subsequent continuous fitting operation of the quartic curve function coefficient under other correction conditions, the required time is shortened to Tc=t1. If the system clock frequency is 100Mhz, T=430ns. This operation speed can far meet the requirements of the quadrupole mass spectrometer for the scan rate.

[0089] In the embodiment of the present invention, it should be noted that the method of the embodiment of the present invention can also be applied to mass axis calibration of other mass spectrometers, including but not limited to time-of-flight, ion trap, and magnetic mass spectrometers.

[0090] Figure 2 FIG. 1 shows a schematic structural diagram of a mass axis correction device for a quadrupole mass spectrometer provided by an embodiment of the present invention. Figure 2 As shown, the device includes:

[0091] The digital-to-analog conversion value acquisition module 201 is used to set calibration conditions, and for each calibration condition, test different preset standard samples respectively to obtain the digital-to-analog conversion value corresponding to the standard sample;

[0092] In an embodiment of the present invention, as an optional embodiment, the calibration conditions include but are not limited to: the number of quadrupole mass analyzer sets, mass resolution, scanning speed, and ion polarity.

[0093] The curve function fitting module 202 is used to fit a preset high-order curve function based on the standard sample of each calibration condition and the digital-to-analog conversion value corresponding to the standard sample to obtain the high-order curve function coefficients of the high-order curve function;

[0094] In an embodiment of the present invention, as an optional embodiment, the curve function fitting module 202 includes:

[0095] A digital-to-analog conversion value acquisition unit (not shown in the figure) is used to obtain the mass number of each standard sample and the corresponding digital-to-analog conversion value under the first calibration condition;

[0096] An equation construction unit is used to construct an equation using the digital-to-analog conversion value corresponding to the standard sample as the dependent variable of the high-order curve function and the mass number corresponding to the standard sample as the independent variable of the high-order curve function;

[0097] A fitting unit, configured to construct an equation system based on equations corresponding to each standard sample and to fit the equation system;

[0098] The coefficient acquisition unit is used to acquire the coefficients of the fitted equation group and obtain the higher-order curve function coefficients of the higher-order curve function under the first correction condition.

[0099] The function coefficient storage module 203 is used to construct a mapping relationship between the correction conditions and the function coefficients of the high-order curve, and store the mapping relationship.

[0100] In the embodiment of the present invention, as an optional embodiment, the mapping relationship is stored in a non-volatile storage unit.

[0101] In an embodiment of the present invention, as an optional embodiment, the device further includes:

[0102] A DAC value determination module (not shown) is configured to query the stored mapping relationship based on the test conditions set for the sample to be tested, including mass resolution, scan speed, and ion polarity, to obtain a mapping relationship that matches the test conditions;

[0103] Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients;

[0104] The mass number of the sample to be tested is substituted into the constructed high-order test curve function to obtain the DAC value for the sample to be tested.

[0105] In the embodiment of the present invention, as another optional embodiment, the device further includes:

[0106] A mass number determination module is used to obtain a test DAC value under the test conditions set for the sample to be tested, wherein the test conditions include: mass resolution, scan speed, and ion polarity;

[0107] Querying the stored mapping relationships to obtain a mapping relationship that matches the test condition;

[0108] Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients;

[0109] Substitute the test DAC value into the constructed high-order test curve function to obtain the mass number of the sample to be tested.

[0110] like Figure 3 As shown, an embodiment of the present application provides a computer device 300 for executing Figure 1 The mass axis correction method for a quadrupole mass spectrometer in the present invention is provided. The device includes a memory 301, a processor 302 connected to the memory 301 via a bus, and a computer program stored in the memory 301 and executable on the processor 302. When the processor 302 executes the computer program, the steps of the mass axis correction method for a quadrupole mass spectrometer are implemented.

[0111] Specifically, the memory 301 and processor 302 can be general-purpose memories and processors, which are not specifically limited here. When the processor 302 runs the computer program stored in the memory 301, the mass axis correction method of the quadrupole mass spectrometer can be executed.

[0112] Corresponding to Figure 1 The mass axis correction method for a quadrupole mass spectrometer in the embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the mass axis correction method for a quadrupole mass spectrometer are executed.

[0113] Specifically, the storage medium can be a general storage medium, such as a mobile disk, a hard disk, etc. When the computer program on the storage medium is run, the mass axis correction method of the quadrupole mass spectrometer can be executed.

[0114] In the embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. The system embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. There may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interface, indirect coupling or communication connection of the system or unit, which may be electrical, mechanical or other forms.

[0115] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0116] In addition, each functional unit in the embodiments provided in the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0117] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0118] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance.

[0119] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. However, these modifications, changes, or replacements do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application. They should all be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. A method for calibrating the mass axis of a quadrupole mass spectrometer, characterized in that: include: Set calibration conditions, and for each calibration condition, test different preset standard samples separately to obtain the digital-to-analog conversion value corresponding to the standard sample; Based on the standard sample of each calibration condition and the digital-to-analog conversion value corresponding to the standard sample, a preset high-order curve function is fitted to obtain the high-order curve function coefficients of the high-order curve function; wherein, the mass number of each standard sample and the corresponding digital-to-analog conversion value under the first calibration condition are obtained; the digital-to-analog conversion value corresponding to the standard sample is used as the dependent variable of the high-order curve function, and the mass number corresponding to the standard sample is used as the independent variable of the high-order curve function to construct an equation; based on the equation corresponding to each standard sample, an equation group is constructed and the equation group is fitted; the coefficients of the fitted equation group are obtained to obtain the high-order curve function coefficients of the high-order curve function under the first calibration condition; A mapping relationship between the correction condition and the coefficient of the high-order curve function is constructed, and the mapping relationship is stored.

2. The method according to claim 1, characterized in that The storing of the mapping relationship includes: The mapping relationship is stored in a non-volatile storage unit.

3. The method according to claim 1, characterized in that The calibration conditions include: the number of quadrupole mass analyzer sets, mass resolution, scanning speed and ion polarity.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: According to the test conditions set for the sample to be tested, the test conditions include: mass resolution, scanning speed, and ion polarity, querying the stored mapping relationship to obtain a mapping relationship that matches the test conditions; Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients; The mass number of the sample to be tested is substituted into the constructed high-order test curve function to obtain the DAC value for the sample to be tested.

5. The method according to any one of claims 1 to 3, characterized in that The method further comprises: Obtaining a test DAC value under the test conditions set for the sample to be tested, wherein the test conditions include: mass resolution, scan speed, and ion polarity; Querying the stored mapping relationships to obtain a mapping relationship that matches the test condition; Extracting high-order curve function coefficients from the acquired mapping relationship, and constructing a high-order test curve function based on the extracted high-order curve function coefficients; Substitute the test DAC value into the constructed high-order test curve function to obtain the mass number of the sample to be tested.

6. The method according to any one of claims 1 to 3, characterized in that The high-order curve function is a quartic curve function.

7. A mass axis calibration device for a quadrupole mass spectrometer, characterized in that: include: The digital-to-analog conversion value acquisition module is used to set the calibration conditions. For each calibration condition, different preset standard samples are tested separately to obtain the digital-to-analog conversion value corresponding to the standard sample. A curve function fitting module is used to fit a preset high-order curve function based on the standard sample of each calibration condition and the digital-to-analog conversion value corresponding to the standard sample to obtain the high-order curve function coefficients of the high-order curve function; wherein, the mass number of each standard sample and the corresponding digital-to-analog conversion value under the first calibration condition are obtained; the digital-to-analog conversion value corresponding to the standard sample is used as the dependent variable of the high-order curve function, and the mass number corresponding to the standard sample is used as the independent variable of the high-order curve function to construct an equation; an equation group is constructed based on the equation corresponding to each standard sample, and the equation group is fitted; the coefficients of the fitted equation group are obtained to obtain the high-order curve function coefficients of the high-order curve function under the first calibration condition; The function coefficient storage module is used to construct a mapping relationship between the correction conditions and the function coefficients of the high-order curve, and store the mapping relationship.

8. A computer device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the computer device is running, the processor and the memory communicate via the bus. When the machine-readable instructions are executed by the processor, the steps of the mass axis correction method for a quadrupole mass spectrometer as described in any one of claims 1 to 6 are performed.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, executes the steps of the mass axis calibration method for a quadrupole mass spectrometer according to any one of claims 1 to 6.

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