An EI ion source and control method for improving the resolution and sensitivity of a mass spectrometer

Abstract

The present invention discloses an EI ion source and a control method for improving the resolution and sensitivity of a mass spectrometer. The present invention relates to the technical field of mass spectrometry resolution, and solves the problem that when different target compounds are processed with the same type of working parameters, the mass spectrometry resolution cannot reach the optimal standard state. The present invention confirms the ion data confirmed for different target compounds in the past, and then re-analyzes and processes the confirmed ion data based on the corresponding processing model. On the premise of knowing the ion mass and ion charge, the magnetic field strength and acceleration voltage are changed, and during the change process, the running trajectories between each ion are analyzed. Then, based on the differences between the running trajectories in the numerical state, the relevant numerical values with the most obvious running trajectory distribution are selected as the optimal numerical values, so as to select the optimal acceleration voltage and the optimal magnetic field parameters. This numerical analysis and processing method makes the numerical processing more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of mass spectrometry resolution, and specifically to an EI ion source and a control method for improving the resolution and sensitivity of a mass spectrometer. Background Art

[0002] Mass spectrometry (also called mass spectrometry method) is a spectroscopic method parallel to spectroscopy. Generally speaking, it is a specialized technique widely used in various disciplinary fields to identify compounds by preparing, separating, and detecting gas-phase ions. Mass spectrometry can provide rich structural information in a single analysis. Combining separation technology with mass spectrometry is a breakthrough in separation science methods.

[0003] The application with the publication number CN106971934B discloses a mass spectrometer, which relates to the technical field of mass spectrometry detection. Among them, the mass spectrometer includes: an ion source, a quadrupole mass analyzer, a reflector assembly, and a detector. The ion source is arranged at the head end of the quadrupole mass analyzer, and is used to ionize the sample into ions and make the ions enter the chamber of the quadrupole mass analyzer. The quadrupole mass analyzer is used to perform the first filtration on the ions entering the chamber to obtain the first target ions. The reflector assembly is installed at the tail end of the quadrupole mass analyzer, and is used to generate an electrostatic field at the tail end of the quadrupole mass analyzer to reflect the first target ions. The quadrupole mass analyzer is also used to perform the second filtration on the reflected first target ions to obtain the second target ions. The detector is arranged at the head end of the quadrupole analyzer and is used to detect the second target ions. The above mass spectrometer can perform secondary filtration on ions to obtain ions with more consistent mass-to-charge ratios, thereby improving the mass resolution of the mass spectrometer.

[0004] When performing mass spectrometry analysis and processing on target compounds, mass spectrometry resolution is carried out on the target compounds based on a preset acceleration voltage and a preset magnetic field intensity. However, the original working parameters are all fixed values. When using the same type of working parameters for relevant processing of different target compounds, its mass spectrometry resolution cannot reach the best standard state, and its mass spectrometry resolution cannot reach the highest accuracy. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides an EI ion source and a control method for improving the resolution and sensitivity of a mass spectrometer, and solves the problem that when using the same type of working parameters for relevant processing of different target compounds, its mass spectrometry resolution cannot reach the best standard state.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: A control method for an EI ion source for improving the resolution and sensitivity of a mass spectrometer includes the following steps:

[0007] S1), based on the mass spectrometry diagram generated during the mass spectrometry analysis of past original target compounds using an EI ion source, determine the separated ions and the ion data of such separated ions from this mass spectrometry diagram. Then, based on a preset processing model, perform relevant analysis on several groups of separated ions confirmed for a single group of original target compounds to identify the optimal magnetic field parameters belonging to this original target compound. The specific sub-steps are as follows:

[0008] S11. Accelerate several groups of separated ions of this single group of original target compounds based on the standard acceleration voltage preset in this processing model, so that the separated ions after acceleration enter the magnetic field region, where the standard acceleration voltage is a preset value;

[0009] S12. The processing model extracts the ion mass m and ion charge z corresponding to the separated ions from the ion data, determines the ratio of the ion mass m to the ion charge z, and labels it as B i , where i represents different separated ions. Then, based on B i =(H 2 ×R 2 )÷2v, where v is the standard acceleration voltage, H is the magnetic field strength of this magnetic field region, and R is the radius value of the movement trajectory. On the premise of knowing the parameters of B i , V, and H, determine the radius R of this separated ion, and generate the movement trajectory of this separated ion in the magnetic field region based on this radius R;

[0010] S13. The processing model changes the magnetic field strength H in real time, records the movement trajectories of several separated ions under different magnetic field strengths H, and the magnetic field strength H changed in real time is within a preset adjustable range. Determine the trajectory center points of the movement trajectories, and confirm the straight-line distance between the trajectory center points of adjacent movement trajectories. Sort the several groups of confirmed straight-line distances from bottom to top to generate different distance sequences associated with different magnetic field strengths H;

[0011] S14. Perform a mean value process on several groups of straight-line distances in different distance sequences to determine the distance mean value J k , where k represents different distance sequences. Then, perform a variance process on several straight-line distances within the distance sequence to determine the undetermined variance F k , and use P k =J k ÷F k to lock the evaluation value P k of the corresponding distance sequence. Select a distance sequence corresponding to the maximum value among the evaluation values P k of several distance sequences as the standard sequence, and use the magnetic field strength H used in this standard sequence as the optimal magnetic field parameter;

[0012] S2), after the best magnetic field parameters of this original target compound are confirmed, adjust the acceleration voltage in the preset processing model, and then perform relevant analysis on several groups of separated ions confirmed for a single group of original target compounds to identify the best acceleration voltage belonging to this original target compound. The specific sub-steps are as follows:

[0013] S21. Keep the best magnetic field parameters of the processing model unchanged, record the running trajectories of several separated ions under the control of the corresponding best magnetic field parameters, and synchronously identify the corresponding evaluation value P k ;

[0014] S22. The processing model changes the acceleration voltage in real time, and the acceleration voltage changed in real time is within the preset adjustable range, and sequentially confirm the evaluation value P corresponding to different acceleration voltages k , and then identify whether there is an evaluation value higher than the evaluation value confirmed in step S14 among the confirmed evaluation values. If there is, mark the relevant evaluation value as a candidate value. If not, mark the standard acceleration voltage as the best acceleration voltage;

[0015] S23. Select the maximum value from several candidate values, and mark the acceleration voltage corresponding to the maximum value as the best acceleration voltage;

[0016] S3). Process different past original target compounds using the preset processing model one by one to identify the best acceleration voltage and best magnetic field parameters of different original target compounds;

[0017] S4. Determine the conductivity of the target compound to be measured, then based on the conductivities of different past original target compounds, lock the acceleration voltage control range and magnetic field strength control range of this target compound to be measured, and based on the determined numerical range, perform mass spectrometry resolution on this target compound to be measured, and based on the numerical change state of the mass spectrometry diagram, lock the voltage to be controlled and the magnetic field to be controlled. The specific sub-steps are as follows:

[0018] S41. The operator determines the conductivity D of the target compound to be measured in advance, and then identifies the two closest conductivities D1 and D2 to this conductivity D from the conductivities of different past original target compounds, where D1 and D2 satisfy: D1 > D and D2 < D. Confirm the best acceleration voltage and best magnetic field parameters of the original target compounds corresponding to the two conductivities D1 and D2. Lock the acceleration voltage control range based on the determined two best acceleration voltages, and then lock the magnetic field strength control range based on the determined two best magnetic field parameters. If the two best acceleration voltages or the two best magnetic field parameters are the same, directly mark them as the voltage to be controlled or the magnetic field to be controlled. If the two best acceleration voltages or the two best magnetic field parameters are different, perform step S42;

[0019] S42, based on the range values ​​of the acceleration voltage control interval and the magnetic field strength control interval, determine a set of change periods T, where T is a preset value, control the acceleration voltage and magnetic field strength of the EI ion source, so that the acceleration voltage and the magnetic field strength are increased from the lowest value of the acceleration voltage control interval and the magnetic field strength control interval to the maximum value within the change period, and record the mass spectrum generated by this change period T, identify the time period with the fastest value growth change from the mass spectrum, and confirm the acceleration voltage and magnetic field strength increased in this time period;

[0020] S43, selecting the maximum value from the confirmed acceleration voltage and magnetic field strength, and calibrating it as the voltage to be controlled and the magnetic field to be controlled, and subsequently controlling the acceleration voltage and magnetic field strength of the EI ion source based on the voltage to be controlled and the magnetic field to be controlled.

[0021] Preferably, in step S1, the ion data includes ion mass and ion charge.

[0022] Preferably, an EI ion source for improving the resolution and sensitivity of a mass spectrometer comprises a repeller ceramic septum, an ion source heating block, a lens barrel, a repeller, an extraction lens ceramic septum, an extraction lens plate, an extraction lens sleeve, a focusing lens ceramic septum, a focusing lens, an export lens ceramic septum, an export lens, a compression ceramic septum and a locking nut;

[0023] The ion source heating block is made of aluminum alloy, and a heating element and a temperature measuring element are installed on the ion source heating block to provide a constant temperature environment for the ion source. Step holes are processed on the front and rear surfaces of the ion source heating block; the repeller ceramic spacer is installed in the step hole; the repeller passes through the ceramic spacer hole and is locked on the ion source heating block by a nut, and the repeller working surface is a spherical surface and is made of titanium alloy; the lens barrel is made of stainless steel and is connected to the ion source heating block by screws; the extraction lens ceramic spacer, extraction lens plate, extraction lens sleeve, focusing lens ceramic spacer, focusing lens, derivation lens ceramic spacer, derivation lens, and pressing ceramic spacer are sequentially installed in the lens barrel and locked by a locking nut; the extraction lens plate, focusing lens and derivation lens are made of titanium alloy.

[0024] The present invention provides an EI ion source and a control method for improving the resolution and sensitivity of a mass spectrometer. Compared with the prior art, it has the following beneficial effects:

[0025] The present invention confirms the ion data confirmed for different target compounds in the past, and then re-analyzes and processes the confirmed ion data based on the corresponding processing model. On the premise of knowing the ion mass and ion charge, the magnetic field strength and acceleration voltage are changed. During the change process, the trajectories of each ion are analyzed, and based on the differences between the trajectories in the numerical state, the relevant numerical values with the most obvious trajectory distribution are selected as the optimal numerical values, so as to select the optimal acceleration voltage and the optimal magnetic field parameters. This numerical analysis and processing method makes the numerical processing more accurate, facilitating the overall accuracy and control effect in the subsequent ion source control process;

[0026] When performing mass spectrometry resolution processing on subsequent target compounds, relevant compounds are selected from past target compounds based on the conductivity of the corresponding target compounds, and then preliminary resolution processing is carried out. Based on the specific process of the resolution processing, the optimal voltage to be controlled and the magnetic intensity to be controlled are selected, so that the acceleration voltage of the EI ion source and the corresponding magnetic field reach the optimal state. From the relevant data processed by the processing model, the optimal numerical value can be locked, so as to ensure the best resolution effect of the corresponding target compound;

[0027] A spherical repeller is used to focus the generated ions into the lens group, increasing the number of analyzed ions and improving the sensitivity of the instrument. The key parts of the ion source are made of inert titanium alloy, and the EI source constructed by it can generate stable and clear ion signals, which helps to improve the resolution and sensitivity of the mass spectrometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the ion source of the present invention;

[0030] Reference numerals: 1. Repeller ceramic spacer; 2. Ion source heating block; 3. Lens barrel; 4. Repeller; 5. Extraction lens ceramic spacer; 6. Extraction lens plate; 7. Extraction lens sleeve; 8. Focusing lens ceramic spacer; 9. Focusing lens; 10. Export lens ceramic spacer; 11. Export lens; 12. Compression ceramic spacer; 13. Locking nut. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Embodiment 1

[0033] Please refer to Figure 1 and Figure 2 , this application provides an EI ion source for improving the resolution and sensitivity of a mass spectrometer, including:

[0034] The ion source heating block 2 is made of aluminum alloy. A heating element and a temperature measuring element are installed on the ion source heating block 2 to provide a constant temperature environment for the ion source. Step holes are machined on the front and rear surfaces of the ion source heating block 2; the repeller ceramic spacer 1 is installed in the step holes; the repeller 4 passes through the ceramic spacer hole and is locked on the ion source heating block 2 by a nut. The working surface of the repeller 4 is spherical and is made of titanium alloy; the lens barrel 3 is made of stainless steel and is connected to the ion source heating block 2 by screws; the extraction lens ceramic spacer 5, the extraction lens plate 6, the extraction lens sleeve 7, the focusing lens ceramic spacer 8, the focusing lens 9, the extraction lens ceramic spacer 10, the extraction lens 11, and the compression ceramic spacer 12 are sequentially installed in the lens barrel 3 and locked by a locking nut 13; the extraction lens plate 6, the focusing lens 9, and the extraction lens 11 are made of titanium alloy;

[0035] And the EI ion source has two working modes: an extraction mode with higher sensitivity and a standard mode suitable for conventional detection; the extraction mode is that a voltage is applied to the extraction lens, and together with the repeller with voltage applied, it focuses and pulls out the ions in the ion chamber (the area composed of the lens barrel 3, the repeller 4, and the extraction lens plate 6 is called the ion chamber), greatly increasing the number of analyzed ions and improving the sensitivity of the instrument, and is suitable for ultra-trace analysis; the standard mode is that only the repeller 4 is applied with voltage and the extraction lens does not need to be applied with voltage. The sensitivity of this mode is reduced, but it is suitable for analyzing target compounds with higher concentrations;

[0036] A control method for an EI ion source for improving the resolution and sensitivity of a mass spectrometer includes the following steps:

[0037] S1) Based on the mass spectrometry diagram generated during the mass spectrometry analysis of past original target compounds using an EI ion source, determine the separated ions and the ion data of such separated ions from this mass spectrometry diagram. Then, based on a preset processing model, perform relevant analysis on several groups of separated ions confirmed for a single group of original target compounds to identify the optimal magnetic field parameters belonging to this original target compound. Specifically, after each group of different target compounds undergoes mass spectrometry analysis processing, a corresponding mass spectrometry diagram will be generated. Then, from the generated mass spectrometry diagram, the relevant ions of such target compounds and the ion data corresponding to the relevant ions can be confirmed. The ion data includes ion mass and ion charge. The preset processing model performs voltage acceleration and magnetic field trajectory analysis on the separated ions. First, provide an acceleration voltage. Based on standard processing values, accelerate the separated ions. After completion of the acceleration, enter the magnetic field region, and then adjust the relevant parameters of the magnetic field to change the movement trajectory of the separated ions. Based on the movement trajectories of multiple separated ions, identify the optimal magnetic field parameters from them;

[0038] Among them, the specific sub-steps for identification are:

[0039] S11. Accelerate several groups of separated ions of this single group of original target compounds based on the standard acceleration voltage preset in this processing model, so that the separated ions after acceleration enter the magnetic field region. The standard acceleration voltage is a preset value, and its specific value is determined by the operator according to experience;

[0040] S12. The processing model extracts the ion mass m and ion charge z of the corresponding separated ions from the ion data, determines the ratio of the ion mass m to the ion charge z, and calibrates it as B i , where i represents different separated ions. Then, based on B i = (H 2 × R 2 ) ÷ 2v, where v is the standard acceleration voltage, H is the magnetic field strength of this magnetic field region, and R is the radius value of the movement trajectory. On the premise of knowing the parameters of B i , V, and H, determine the radius R of this separated ion, and generate the movement trajectory of this separated ion in the magnetic field region based on this radius R. Specifically, after the corresponding ion is confirmed, the corresponding ion mass m and the corresponding ion charge z can be locked, and then the movement trajectory that changes in real time corresponding to the ion can be confirmed by adjusting the magnetic field;

[0041] S13. Real - time change the magnetic field strength H through the processing model, record the running trajectories of several separated ions under different magnetic field strengths H, and the real - time changed magnetic field strength H is within the preset adjustable range. Determine the trajectory center points of the running trajectories, confirm the straight - line distances between the trajectory center points of adjacent running trajectories, sort the confirmed groups of straight - line distances from bottom to top, and generate different distance sequences associated with different magnetic field strengths H;

[0042] S14. Perform mean processing on several groups of straight - line distances in different distance sequences to determine the distance mean J k , where k represents different distance sequences. Then perform variance processing on several straight - line distances within the distance sequence to determine the undetermined variance F k , and the specific method of variance processing is: label several straight - line distances of the distance sequence as J1, J2, ……, Jn, and use to determine the undetermined variance F k , use P k = J k ÷F k Lock the evaluation value P of the corresponding distance sequence k , select a distance sequence corresponding to a group of maximum values from the evaluation values P k corresponding to several distance sequences as the standard sequence, and use the magnetic field strength H used in this standard sequence as the optimal magnetic field parameter. Specifically, when its magnetic field strength changes, the corresponding ions will have related changes in their running trajectories during operation. Then the adjacent running trajectories will gradually separate. When the spacing between the running trajectories reaches the maximum during the gradual change of its magnetic field strength, such a magnetic field strength can effectively separate such associated ions sufficiently and achieve a good trajectory separation effect. Such a magnetic field strength belongs to the optimal magnetic field strength;

[0043] S2). After the optimal magnetic field parameter of this original target compound is confirmed, adjust the acceleration voltage in the preset processing model, and then perform relevant analysis on several groups of separated ions confirmed for a single group of original target compounds to identify the optimal acceleration voltage of this original target compound. Specifically, during the adjustment process of the acceleration voltage, it will also cause related changes in the corresponding running trajectories. The acceleration voltage will change the running speed of the corresponding ions, so when the running speed changes, it will also cause related changes in its running trajectory;

[0044] Among them, the specific sub - steps for identifying the optimal acceleration voltage are:

[0045] S21. Keep the optimal magnetic field parameter of the processing model unchanged, record the running trajectories of several separated ions under the control of the corresponding optimal magnetic field parameter, and synchronously identify the corresponding evaluation value P k ;

[0046] S22. Its processing model changes the acceleration voltage in real time, and the acceleration voltage changed in real time is within a preset adjustable range, and the evaluation value P corresponding to different acceleration voltages is confirmed in sequence. k , and then identify whether there is an evaluation value higher than the evaluation value confirmed in step S14 among the confirmed evaluation values. If so, mark the relevant evaluation value as a candidate value. If not, mark the standard acceleration voltage as the optimal acceleration voltage;

[0047] S23. Select the maximum value from several candidate values, and mark the acceleration voltage corresponding to the maximum value as the optimal acceleration voltage;

[0048] Specifically, when the acceleration voltage changes, it will change the running speed of the corresponding ions. After the running speed changes, it will synchronously affect the corresponding running trajectory. Then, through the numerical processing of the processing model, the optimal acceleration voltage is selected from the running trajectory to facilitate subsequent high-standard mass spectrometry resolution.

[0049] S3). Process different past original target compounds one by one using a preset processing model to identify the optimal acceleration voltage and optimal magnetic field parameters of different original target compounds.

[0050] Example 2

[0051] In the specific implementation process of this example, when performing mass spectrometry resolution processing on other subsequent target compounds, the mass spectrometry resolution process reaches the best standard to ensure high resolution;

[0052] It also includes the following steps:

[0053] S4). Determine the conductivity of the target compound to be measured. Then, based on the conductivities of different past original target compounds, lock the acceleration voltage control range and magnetic field strength control range of this target compound to be measured. And based on the determined numerical range, perform mass spectrometry resolution on this target compound to be measured, and lock the voltage to be controlled and the magnetic field to be controlled based on the numerical change state of the mass spectrometry diagram. Specifically, if the conductivities of the target compounds are almost the same, then their corresponding ion structures are almost the same. Therefore, the conductivity can be used as a standard for related selection of other values. Among them, the specific sub-steps for locking are:

[0054] S41. The operator determines the conductivity D of the target compound to be measured in advance, and then identifies the two sets of conductivities D1 and D2 that are closest to this conductivity D from the conductivities of different original target compounds in the past. Among them, D1 and D2 satisfy: D1 > D and D2 < D (that is, the two closest values before and after the conductivity D). Confirm the optimal acceleration voltage and the optimal magnetic field parameters of the original target compounds corresponding to the two sets of conductivities D1 and D2. Based on the determined two sets of optimal acceleration voltages, lock the acceleration voltage control range, and then based on the determined two sets of optimal magnetic field parameters, lock the magnetic field strength control range. If the two sets of optimal acceleration voltages or the two sets of optimal magnetic field parameters are the same, directly calibrate them as the voltage or magnetic field to be controlled. If the two sets of optimal acceleration voltages or the two sets of optimal magnetic field parameters are different, execute step S42;

[0055] S42. Based on the range values of the acceleration voltage control range and the magnetic field strength control range, determine a set of change periods T, where T is a preset value, and its specific value is determined by the operator according to experience. Generally, the value is very small. Control the acceleration voltage and the magnetic field strength of the EI ion source so that the acceleration voltage and the magnetic field strength increase from the lowest values of the acceleration voltage control range and the magnetic field strength control range to the maximum values within the change period, and record the mass spectrum generated during this change period T. Identify the time period when the numerical growth changes fastest from the mass spectrum, and confirm the acceleration voltage and the magnetic field strength increased during this time period. Specifically, during the generation of the mass spectrum, the relevant numerical values change. When the numerical values change, there are corresponding change values per unit time. The maximum value of the change values per unit time represents that the corresponding acceleration voltage and magnetic field strength reach the optimal state, so numerical selection and determination are carried out to ensure high resolution during the mass spectrometry resolution process;

[0056] S43. Select the maximum value from the confirmed acceleration voltage and magnetic field strength, and calibrate it as the voltage and magnetic field to be controlled. Subsequently, control the acceleration voltage and the magnetic field strength of the EI ion source based on this voltage and magnetic field to be controlled to complete the entire mass spectrometry analysis process.

[0057] Specifically, in order to ensure that the target compound can achieve the best mass spectrometry resolution processing effect, it is necessary to make the acceleration voltage of the EI ion source and the corresponding magnetic field reach the optimal state. From the relevant data processed by the processing model, the optimal numerical values can be locked, so as to ensure the best resolution effect of the corresponding target compound.

[0058] Example 3

[0059] In the specific implementation process of this example, it includes all the implementation processes of the above two sets of examples.

[0060] Some of the data in the above formula are numerically calculated after removing their dimensions, and the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0061] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical method of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for controlling an EI ion source for improving the resolution and sensitivity of a mass spectrometer, characterized in that: The following steps are involved: S1), based on the mass spectrum generated by the mass spectrometry analysis of the original target compound in the past by the EI ion source, the separated ions and the ion data of such separated ions are determined from the mass spectrum, and then based on the preset processing model, a correlation analysis is performed on several groups of separated ions confirmed by a single group of original target compounds to identify the optimal magnetic field parameters belonging to the original target compound; S2), after the optimal magnetic field parameters of the original target compound are confirmed, the acceleration voltage in the preset processing model is adjusted, and then a correlation analysis is performed on several groups of separated ions confirmed by a single group of original target compounds to identify the optimal acceleration voltage belonging to the original target compound; S3), using a preset processing model to process different original target compounds one by one, and identifying the optimal acceleration voltage and optimal magnetic field parameters for different original target compounds; S4), determining the conductivity of the target compound to be tested, and then based on the conductivity of different original target compounds in the past, locking the acceleration voltage control interval and the magnetic field strength control interval of the target compound to be tested, and based on the determined numerical interval, performing mass spectrum resolution on the target compound to be tested, and locking the voltage to be controlled and the magnetic field to be controlled based on the numerical change state of the mass spectrum; The ion source uses a spherical repeller to focus the generated ions and push them into the lens group, increasing the number of analyzed ions. The EI ion source has two working modes: extraction mode with higher sensitivity and standard mode suitable for routine detection; In the extraction mode, a voltage is applied to the extraction lens, which works together with the voltage-applied repeller to focus the ions in the ion chamber and pull them out of the ion chamber; In the standard mode, voltage is applied only to the repeller, and no voltage is required to be applied to the extraction lens.

2. The method for controlling an EI ion source for improving the resolution and sensitivity of a mass spectrometer according to claim 1, characterized in that: In step S1, the ion data includes ion mass and ion charge.

3. The method for controlling an EI ion source for improving the resolution and sensitivity of a mass spectrometer according to claim 2, characterized in that: In step S1, the specific sub-steps of identifying the optimal magnetic field parameters of the original target compound are: S11, performing acceleration processing on a plurality of groups of separated ions generated by the single group of original target compounds based on a standard acceleration voltage preset in the processing model, so that the separated ions after the acceleration processing enter the magnetic field region, wherein the standard acceleration voltage is a preset value; S12, the processing model extracts the ion mass m and ion charge z corresponding to the separated ion from the ion data, determines the ratio of the ion mass m to the ion charge z, and calibrates it as B i , where i represents different separated particles, and then based on B i =(H 2 ×R 2 )÷2v, where v is the standard acceleration voltage, H is the magnetic field strength in this magnetic field area, and R is the radius of the motion trajectory. i Under the premise of the parameters of , v and H, the radius R of the separated particle is determined, and the running trajectory of the separated particle is generated in the magnetic field region based on the radius R; S13, changing the magnetic field strength H in real time through the processing model, and recording the running trajectories of several separated particles under different magnetic field strengths H, and the magnetic field strength H changed in real time is within a preset adjustable range, determining the trajectory center point of the running trajectory, and confirming the straight-line distances between the trajectory center points of adjacent running trajectories, sorting the confirmed groups of straight-line distances from bottom to top, and generating different distance sequences associated with different magnetic field strengths H; S14, perform mean processing on several groups of straight-line distances in different distance sequences to determine the distance mean J k , where k represents different distance sequences, and then several straight-line distances within the distance sequence are processed for variance to determine the unknown variance F k , using P k =J k ÷F k Lock the evaluation value P of the corresponding distance sequence k , from the evaluation values ​​P corresponding to several distance sequences k A set of distance sequences corresponding to the maximum values ​​is selected as a standard sequence, and the magnetic field intensity H used by the standard sequence is used as the optimal magnetic field parameter.

4. The method for controlling an EI ion source for improving the resolution and sensitivity of a mass spectrometer according to claim 3, characterized in that: In step S2, the specific sub-steps of identifying the optimal accelerating voltage of the original target compound are: S21, keep the optimal magnetic field parameters of the processing model unchanged, record the running trajectories of several separated particles under the control of the corresponding optimal magnetic field parameters, and simultaneously identify the corresponding evaluation value P k ; S22, the processing model changes the acceleration voltage in real time, and the acceleration voltage changed in real time is within a preset adjustable range, and the evaluation values ​​P corresponding to different acceleration voltages are confirmed in turn. k , and then identify whether the confirmed several evaluation values ​​are higher than the evaluation value confirmed in step S14, if yes, mark the relevant evaluation value as the candidate value, if no, mark the standard acceleration voltage as the optimal acceleration voltage; S23, selecting a maximum value from a plurality of candidate values, and calibrating the acceleration voltage corresponding to the maximum value as the optimal acceleration voltage.

5. The method for controlling an EI ion source for improving the resolution and sensitivity of a mass spectrometer according to claim 1, characterized in that: In step S4, the specific sub-steps of locking the voltage to be controlled and the magnetic field to be controlled are: S41, the operator determines the conductivity D of the target compound to be tested in advance, and then identifies two groups of conductivity D1 and D2 that are closest to the conductivity D from the conductivity of different original target compounds in the past, where D1 and D2 satisfy: D1>D and D2<D, confirms the optimal acceleration voltage and optimal magnetic field parameters of the original target compound corresponding to the two groups of conductivity D1 and D2, locks the acceleration voltage control interval based on the determined two groups of optimal acceleration voltages, and then locks the magnetic field intensity control interval based on the determined two groups of optimal magnetic field parameters. If the two groups of optimal acceleration voltages or the two groups of optimal magnetic field parameters are the same, they are directly calibrated as the voltage to be controlled or the magnetic field to be controlled. If the two groups of optimal acceleration voltages or the two groups of optimal magnetic field parameters are different, execute step S42; S42, based on the range values ​​of the acceleration voltage control interval and the magnetic field strength control interval, determine a set of change periods T, where T is a preset value, control the acceleration voltage and magnetic field strength of the EI ion source, so that the acceleration voltage and the magnetic field strength are increased from the lowest value of the acceleration voltage control interval and the magnetic field strength control interval to the maximum value within the change period, and record the mass spectrum generated by this change period T, identify the time period with the fastest value growth change from the mass spectrum, and confirm the acceleration voltage and magnetic field strength increased in this time period; S43, selecting the maximum value from the confirmed acceleration voltage and magnetic field strength, and calibrating it as the voltage to be controlled and the magnetic field to be controlled, and subsequently controlling the acceleration voltage and magnetic field strength of the EI ion source based on the voltage to be controlled and the magnetic field to be controlled.

6. An EI ion source for improving the resolution and sensitivity of a mass spectrometer, the EI ion source being applied to the control method according to any one of claims 1 to 5, characterized in that: It includes a repeller ceramic septum, an ion source heating block, a lens barrel, a repeller, an extraction lens ceramic septum, an extraction lens plate, an extraction lens sleeve, a focusing lens ceramic septum, a focusing lens, an extraction lens ceramic septum, an extraction lens, a pressing ceramic septum and a locking nut; The ion source heating block is made of aluminum alloy, and a heating element and a temperature measuring element are installed on the ion source heating block to provide a constant temperature environment for the ion source. Step holes are processed on the front and rear surfaces of the ion source heating block; the repeller ceramic spacer is installed in the step hole; the repeller passes through the repeller ceramic spacer hole and is locked on the ion source heating block by a nut, and the repeller working surface is a spherical surface and is made of titanium alloy; the lens barrel is made of stainless steel and is connected to the ion source heating block by screws; the extraction lens ceramic spacer, extraction lens plate, extraction lens sleeve, focusing lens ceramic spacer, focusing lens, derivation lens ceramic spacer, derivation lens, and pressing ceramic spacer are sequentially installed in the lens barrel and locked by a locking nut; the extraction lens plate, focusing lens and derivation lens are made of titanium alloy.

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