CN115954260A - Ion extraction method and device and mass spectrometer - Google Patents

Abstract

The application relates to the field of mass spectrometers, and discloses an ion extraction method, an ion extraction device and a mass spectrometer. The method comprises the following steps: controlling the target ions to be input into a collision cell of the vacuum chamber from the introduction electrode; applying a first voltage to the gate electrode to cause target ions to enter the ion storage cell from the collision cell, and applying a second voltage to the extraction electrode to cause target ions to undergo target ion accumulation in the ion storage cell; after a preset time period, the first voltage and/or the second voltage are/is adjusted, so that the target ions are sequentially output from the extraction electrode according to the sequence of the mass-to-charge ratio from large to small. According to the embodiment of the application, the output time of the target ions is correspondingly adjusted by adjusting the applied voltage, so that the time-of-flight mass spectrograms of the target ions with different mass-to-charge ratios can be conveniently acquired by a subsequent time-of-flight mass analysis device at the same moment, and the effective mass-to-charge ratio interval of the mass spectrograms is widened.

Description

Ion extraction method and device and mass spectrometer

Technical Field

The application relates to the field of mass spectrometers, in particular to an ion extraction method and device and a mass spectrometer.

Background

At present, in the application of a time-of-flight mass analyzer of a mass spectrometer, for example, when the time-of-flight mass analyzer is used for enriching ions, in the stage of extracting ions to input into the time-of-flight mass analyzer, the extraction speed and extraction time of ions with different mass-to-charge ratios are different, for example, the extraction speed of ions with small mass-to-charge ratio is fast, and the extraction speed of ions with large mass-to-charge ratio is slow, so that a window where the ions enter an acceleration region of a mass spectrometer focusing device is fixed, and an effective mass-to-charge ratio interval (a ratio interval of proton number/charge number, i.e., an m/z interval) in a time-of-flight mass spectrogram (i.e., TOF spectrogram) of the ions is limited, and further, when ion mass spectrum data is subsequently acquired in the time-of-flight mass analyzer, the ion utilization rate is low and the mass width of the time-of-flight mass spectrogram is narrow.

Disclosure of Invention

In view of the above, in order to solve the deficiencies of the prior art, the present application provides an ion extraction method, an ion extraction apparatus and a mass spectrometer.

In a first aspect, the present application provides an ion extraction method, which is applied to a mass spectrometer, wherein the mass spectrometer comprises a vacuum chamber, and an extraction electrode, an ion transmission channel, a gate electrode, an ion storage unit and an extraction electrode are sequentially arranged in the vacuum chamber; the space between the introduction electrode, the ion transmission channel and the gate electrode forms a collision cell; the method comprises the following steps:

controlling the target ions to be input into the collision cell of the vacuum chamber from the introduction electrode;

applying a first voltage to the gate electrode to cause the target ions to enter the ion storage cell from the collision cell and applying a second voltage to the extraction electrode to cause target ion accumulation of the target ions within the ion storage cell;

after a preset time period, the first voltage and/or the second voltage are/is adjusted, so that the target ions are sequentially output from the extraction electrode according to the sequence of the mass-to-charge ratio from large to small.

In an optional embodiment, when the magnitude of the first voltage is adjusted, the voltage value of the second voltage is controlled to be kept unchanged, and the voltage value of the first voltage is increased so that the voltage value of the first voltage is greater than the voltage value of the second voltage;

and when the magnitude of the second voltage is adjusted, controlling the voltage value of the first voltage to be kept unchanged, and reducing the voltage value of the second voltage so as to enable the voltage value of the first voltage to be larger than the voltage value of the second voltage.

In an optional embodiment, the adjusting the magnitude of the first voltage and/or the second voltage includes:

controlling the output magnitude of the first voltage to increase in an arithmetic progression according to a preset voltage increase amount so that the voltage value of the first voltage is greater than that of the second voltage; and/or the presence of a gas in the atmosphere,

and controlling the output magnitude of the second voltage to be reduced in an arithmetic progression according to a preset voltage reduction amount so that the voltage value of the first voltage is larger than that of the second voltage.

In an alternative embodiment, the vacuum chamber is provided with at least one opening, each opening for introducing a gas, the method further comprising:

and applying a first radio frequency voltage to the ion transmission channel so as to enable the target ions to collide with the gas and generate target ion fragments, and further enabling the target ion fragments to be sequentially output from the extraction electrode according to the sequence of the mass-to-charge ratios from large to small under the action of the voltage applied to the gate electrode or the extraction electrode.

In an alternative embodiment, the mass spectrometer further comprises focusing means and time-of-flight mass analysis means; the method further comprises the following steps:

when the target ions are controlled to be led out from the leading-out electrode and then input into the focusing device, the leading-out time corresponding to the target ions is recorded, and the magnitude of pulse repulsion voltage applied to the focusing device is adjusted according to the leading-out time, so that the target ions with different mass-to-charge ratios are input into the time-of-flight mass analysis device at the same time, and mass spectrum data of the target ions with different mass-to-charge ratios are collected.

In an alternative embodiment, the mass spectrometer further comprises an ion mass analysis device; the method further comprises the following steps:

applying a second radio frequency voltage to the ion mass analysis device such that target ions of the ions entering the mass spectrometer are input to the vacuum chamber under the second radio frequency voltage.

In a second aspect, the present application provides an ion extraction apparatus comprising a vacuum chamber in which an extraction electrode, an ion transmission channel, a gate electrode, an ion storage unit, and an extraction electrode are sequentially disposed; the space between the introduction electrode, the ion transmission channel and the gate electrode forms a collision cell;

the ion extraction apparatus is for performing the steps of the ion extraction method of any one of the preceding embodiments through the vacuum chamber.

In an alternative embodiment, the entrance electrode, the ion transmission channel, the gate electrode, the ion storage unit and the exit electrode are arranged coaxially.

In alternative embodiments, the ion transport channel is a composite structure of any one or more of a quadrupole rod, a hexapole rod, an octopole rod, a segmented quadrupole rod, a segmented hexapole rod, and a segmented octopole rod;

the extraction electrode comprises a planar substrate and a plurality of conductive circular ring electrodes arranged on the planar substrate, and an ion extraction port is arranged at the center position among the conductive circular ring electrodes.

In a third aspect, the present application provides a mass spectrometer comprising an ion extraction means, a focusing means and a time-of-flight mass analysis means as described in any one of the preceding embodiments; the ion extraction device, the focusing device and the flight time mass analysis device are sequentially connected;

the mass spectrometer is used for leading out target ions from the ion leading-out device, and then inputting the target ions with different mass-to-charge ratios to the time-of-flight mass analysis device at the same moment under the action of pulse repulsion voltage applied to the focusing device, so as to acquire mass spectrum data of the target ions with different mass-to-charge ratios.

The embodiment of the application has the following beneficial effects:

the embodiment of the application controls the target ions to be input into the collision cell of the vacuum chamber from the lead-in electrode; applying a first voltage to the gate electrode to cause target ions to enter the ion storage cell from the collision cell, and applying a second voltage to the extraction electrode to cause target ions to undergo target ion accumulation in the ion storage cell; after a preset time period, the first voltage and/or the second voltage are/is adjusted, so that the target ions are sequentially output from the extraction electrode according to the sequence of the mass-to-charge ratio from high to low. The embodiment of the application adjusts the target correspondingly by adjusting the magnitude of the applied first voltage and/or second voltage

The time of leading out the ions from the leading-out electrode is to lead the target ions with different mass-to-charge ratios into the time-of-flight mass analyzer at approximately the same time 5 so as to facilitate the mass analysis device in the subsequent time-of-flight to be at the same time

And acquiring the flight time mass spectrograms of target ions with different mass-to-charge ratios at all times, and widening the effective mass-to-charge ratio interval of the flight time mass spectrograms.

Drawings

In order to more clearly illustrate the technical solution of the present application, the drawings in which 0 is required to be used in the embodiments will be briefly described below, and it should be understood that the following drawings only show some embodiments of the present application,

and therefore should not be considered as limiting the scope of protection of the present application. Like components are numbered similarly in the various figures.

FIG. 1 shows a first schematic construction of a mass spectrometer in an embodiment of the present application;

FIG. 2 shows a second schematic diagram of a mass spectrometer of an embodiment of the present application;

FIG. 3 shows a third schematic structural diagram of a mass spectrometer in an embodiment of the present application;

fig. 4 shows a schematic structural diagram of an ion extraction device in an embodiment of the present application;

FIG. 5 is a schematic view showing a structure of an extraction electrode in the embodiment of the present application;

FIG. 6 is a schematic diagram showing a planar electric field on an extraction electrode in an embodiment of the present application;

FIG. 7 is a schematic diagram of one embodiment of an ion extraction method in an example of the present application; fig. 8 is a schematic diagram showing a first variation of the respective voltage amplitudes in the ion extraction device in the embodiment of the present application;

fig. 9 is a diagram showing a second variation of the voltage amplitudes in the ion extraction device in the embodiment of the present application;

fig. 10 is a diagram showing a third variation of the voltage amplitudes in the ion extraction device in the embodiment of the present application.

Description of the main element symbols: 100-ion extraction means; 110-an introduction electrode; 120-ion transport channels; 130-gate electrode; 140-an ion storage cell; 150-extraction electrodes; 151-a first conductive ring electrode; 152-a second conductive ring electrode; 153-ion extraction port; 160-opening; 200-a focusing device; 300-time-of-flight mass analysis means; 400-atmospheric pressure interface means; 500-an ion transport device; 600-a quadrupole rod transfer device; 700-quadrupole mass analyser.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.

Hereinafter, the terms "including", "having", and their derivatives, which may be used in various embodiments of the present application, are intended to indicate only specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.

Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the present application belong. The terms (such as terms defined in a commonly used dictionary) will be construed to have the same meaning as the contextual meaning in the related art and will not be construed to have an idealized or overly formal meaning unless expressly so defined in various embodiments of the present application.

Mass spectrometers can be classified into various configurations such as ion traps, quadrupole rods, time of flight, and the like. Different configurations have different advantages. The ion trap can be used for storage and mass analysis, and has the advantage of cascade analysis; carrying out quantitative analysis on the quadrupole rods in a mass filtering mode; the time-of-flight mass analyzer has the technical advantages of high resolution and high mass precision, but has the problems of low ion utilization rate and limited sensitivity.

At present, most commercial instruments realize superposition of advantageous functions in a mode of connecting a plurality of mass analyzers in series, for example, a triple quadrupole rod is added, a collision cell is added on the basis of quantitative advantages, accurate qualitative and quantitative analysis is realized, and the mass spectrometer is also one of the mass spectrometers which are most widely applied in the current market. In addition, a quadrupole-time-of-flight mass spectrometer is a common mass spectrometer, and cascade fragment information and mass spectrum data with high quality precision and high resolution can be obtained by combining a quadrupole and a time-of-flight mass analyzer and combining a collision cell. However, the quadrupole-time-of-flight mass spectrometer also has the problems of low ion utilization rate and low duty ratio of the time-of-flight mass analyzer, and partial instruments are improved by introducing the storage function of the ion trap and adding a storage structure form to a transmission port.

Based on this, an embodiment of the present application provides an ion extraction method, which is used for adjusting output time of a target ion correspondingly by adjusting a voltage applied to an electrode of an ion extraction device disposed in a mass spectrometer, so that each subsequent ion with different mass-to-charge ratios is located in a modulation region (i.e., an acceleration region) of a time-of-flight mass analyzer within a certain time period, thereby facilitating the time-of-flight mass analyzer to acquire time-of-flight mass spectrograms of each ion with different mass-to-charge ratios at the same time, and widening an effective mass-to-charge ratio region of the time-of-flight mass spectrogram, thereby solving technical problems of low ion utilization rate and low duty ratio in the time-of-flight mass analyzer.

Referring to fig. 1, 2 and 3, the present application provides a mass spectrometer comprising an ion extraction device 100, a focusing device 200 and a time-of-flight mass analysis device 300. The ion extraction device 100, the focusing device 200, and the time-of-flight mass spectrometer 300 are connected in this order. Wherein the mass spectrometer is a quadrupole-time-of-flight mass spectrometer.

In this embodiment, after the target ions are extracted from the ion extraction device 100, under the action of the pulse repulsion voltage applied to the focusing device 200, the target ions with different mass-to-charge ratios are input to the time-of-flight mass analysis device 300 at approximately the same time, and the mass spectrometer collects mass spectrum data of the target ions with different mass-to-charge ratios at the current time through the time-of-flight mass analysis device 300.

As an optional implementation, the mass spectrometer further comprises an atmospheric interface 400, an ion transport device 500, a quadrupole transport device 600, and a quadrupole mass analyzer 700.

Exemplarily, the atmospheric pressure interface device 400, the ion transport device 500, the quadrupole rod transport device, the quadrupole rod mass analyzer, the ion extraction device 100, the focusing device 200, and the time-of-flight mass analysis device 300 are sequentially disposed in sequence and coaxially disposed.

In this embodiment, the atmospheric pressure interface device 400 is used to introduce ions to effect a transition from atmospheric pressure to a vacuum environment. The ions then enter the ion transport device 500 through the atmospheric interface device 400, where they are focused within the ion transport device 500 and introduced to the quadrupole rod transport device 600, to which a third rf voltage and bias voltage are applied to direct the ions forward and into the quadrupole mass analyzer 700 by the applied voltages.

The quadrupole mass analyzer 700 is configured to couple the voltages (Vsinwt + U, - (Vsinwt + U)) for mass screening to screen out target ions from all ions by the voltages for mass screening, and to introduce the target ions into the ion extraction device 100, that is, to push the target ions into the ion extraction device 100 by the voltages for mass screening, that is, to push the target ions extracted from the quadrupole mass analyzer 700 to the ion extraction device 100, that is, to apply the fourth rf voltage having the same phase to the pair rods of the quadrupole mass analyzer and to apply the fifth rf voltage having a phase difference of 180 degrees to adjacent rods of the quadrupole mass analyzer.

After being screened by the quadrupole mass analyzer, the target ions enter the ion extraction device 100, and the ion extraction device 100 is configured to adjust extraction times of the target ions with different mass-to-charge ratios according to the magnitude of the applied voltage, so that the target ions with different mass-to-charge ratios are sequentially introduced into the focusing device 200 from large to small according to the order of the mass-to-charge ratios, and are introduced into the time-of-flight mass analysis device 300 under the action of the voltage value applied to the focusing device 200.

Optionally, the atmospheric pressure interface apparatus 400 may adopt a structure such as a capillary tube and a taper; the ion transmission device 500 is an ion funnel; the quadrupole mass analyser 700 and the quadrupole transmission device 600 are each arranged correspondingly using a quadrupole. The structural composition and the specific arrangement mode of each device or device in the mass spectrometer are not limited herein, and the device or device can be correspondingly arranged according to actual conditions.

Based on this, referring to fig. 4, an ion extraction apparatus 100 is further provided in the present embodiment, the apparatus includes a vacuum chamber, in which an extraction electrode 110, an ion transmission channel 120, a gate electrode 130, an ion storage unit 140, and an extraction electrode 150 are sequentially disposed; wherein the space between the introduction electrode 110, the ion transport channel 120 and the gate electrode 130 forms a collision cell.

In the present embodiment, the ion extraction apparatus 100 is made to achieve control of the extraction time of target ions by applying voltages to the respective electrodes or cells in the ion extraction apparatus 100.

Specifically, a third direct current voltage (i.e., DC) is applied to the inlet electrode 110 ₀ ) Applying a first radio frequency voltage (i.e., RF) to ion transport channel 120 ₀ ) And a fourth DC voltage, applying a sixth RF voltage (i.e., RF) to the ion storage unit 140 ₂ ) And a seventh radio frequency voltage (i.e., AC) to which the first voltage (i.e., direct current voltage DC) is applied to the gate electrode 130 ₁ ) A second voltage is applied to the extraction electrode 150, wherein the second voltage is a radio frequency voltage (i.e., RF) ₃ ) And/or direct voltage (i.e. DC) ₃ )。

That is, the second voltage applied to the extraction electrode 150 may be a direct current voltage, a radio frequency voltage, or a combination of the direct current voltage and the radio frequency voltage.

Alternatively, the first rf voltage applied to the ion transmission channel 120 and the sixth rf voltage applied to the ion storage unit 140 may be the same amplitude of rf voltage or different amplitudes of rf voltage. The first voltage may vary in an equal gradient, or linearly or non-linearly.

Illustratively, the entrance electrode 110, the ion transmission channel 120, the gate electrode 130, the ion storage unit 140, and the exit electrode 150 are coaxially disposed.

Optionally, the ion transmission channel 120 is a combined structure of any one or more of a quadrupole rod, a hexapole rod, an octopole rod, a segmented quadrupole rod, a segmented hexapole rod, and a segmented octopole rod; in addition, the ion transmission channel 120 may also adopt a lens assembly structure composed of multiple sets of pole pieces; the structure of the ion transmission channel 120 is not limited in this embodiment. Optionally, the ion storage unit 140 is a transfer quadrupole.

Optionally, the extraction electrode 150 includes a plurality of sets of electrodes; preferably, as shown in fig. 5, the extraction electrode 150 includes a planar substrate and a plurality of conductive ring electrodes (a first conductive ring electrode 151 and a second conductive ring electrode 152 shown in fig. 5) disposed on the planar substrate, the plurality of conductive ring electrodes are not connected to each other, and an ion extraction opening 153 is disposed at a central position between the plurality of conductive ring electrodes. The diameter range of the ion leading-out port 153 is 0.5mm-10mm. In addition, the conductive ring electrode can be formed by performing corresponding wiring arrangement on the printed circuit board. Optionally, the width range of the coaxial conductive ring electrodes is 0.01-10mm, and a gap is formed between adjacent conductive ring electrodes. As shown in fig. 6, when a voltage is applied to the extraction electrode 150, a planar electric field is formed.

Further, there is a voltage Difference (DC) between the extraction electrode 150 at the center location (i.e., ion extraction opening 153) and the edge conductive ring electrode ₂ ) So as to form a gradient electric field; while applying a radio frequency voltage to the extraction electrode 150And a phase difference of 180 degrees exists between the adjacent conductive circular ring electrodes.

As an alternative embodiment, the ion extraction apparatus 100 further comprises a power supply unit (not shown) to supply power to each unit or electrode in the ion extraction apparatus 100 through the power supply unit.

Optionally, the ion transport channel 120 and ion storage unit 140 may be in the same vacuum environment or in different vacuum environments. In addition, the ion transmission channel 120 and the ion storage unit 140 may be a connected structure.

Based on this, as shown in fig. 7, an embodiment of the present application further provides an ion extraction method, which is applied to the mass spectrometer of the foregoing embodiment, and is particularly applied to the ion extraction device 100 of the mass spectrometer, and the method includes:

s10, the target ions are controlled to be input into the collision cell of the vacuum chamber from the introduction electrode 110.

Target ions are introduced into the collision cell from the introduction electrode 110 of the vacuum chamber of the ion extraction device 100; wherein the ion extraction apparatus 100 is in a vacuum environment.

Specifically, target ions pass through the atmospheric pressure interface device 400, the ion transmission device 500, the quadrupole rod transmission device, and the quadrupole rod mass analyzer, and are introduced into the ion extraction device 100, and then are sequentially extracted from the ion extraction device 100 in the order of decreasing mass-to-charge ratio, and pass through the focusing device 200 to enter the time-of-flight mass analysis device 300, and mass spectrum data of each target ion with different mass-to-charge ratios is collected by the time-of-flight mass analyzer, so as to generate a time-of-flight mass spectrogram.

S20, a first voltage is applied to the gate electrode 130 to cause the target ions to enter the ion storage unit 140 from the collision cell, and a second voltage is applied to the extraction electrode 150 to cause the target ions to undergo target ion accumulation in the ion storage unit 140.

In the present embodiment, the ion storage unit 140 and the ion transmission channel 120 in the ion extraction apparatus 100 are in the same vacuum environment, and are isolated by the gate electrode 130; after the target ions enter the ion storage unit 140, accumulation and cooling of the target ions are realized by the combined action of the voltages applied to the gate electrode 130 and the extraction electrode 150.

Specifically, the target ions enter the collision cell through the gate electrode 130 at a first voltage (i.e., DC voltage DC) applied to the gate electrode 130 ₁ ) Enters the ion storage unit 140 by the action of the voltage difference, and is applied to the extraction electrode 150 at a second voltage (direct current voltage DC) ₃ And/or radio frequency voltage RF ₃ ) So as to be trapped in the ion storage unit 140; that is, the target ions enter the ion storage unit 140 for ion accumulation under the interaction of the first voltage and the second voltage.

And S30, after a preset time period, adjusting the first voltage and/or the second voltage so that the target ions are sequentially output from the extraction electrode 150 according to the sequence of the mass-to-charge ratios from large to small.

In the present embodiment, after a predetermined period of ion accumulation, the gate electrode 130 is closed; the target ions may then be sequentially extracted from the extraction electrode 150 in a predetermined order by adjusting the magnitude of the first voltage applied to the gate electrode 130 and/or adjusting the magnitude of the second voltage applied to the extraction electrode 150. The specific time range value of the preset time period is not limited, and can be set correspondingly according to actual conditions.

In one embodiment, when the magnitude of the first voltage is adjusted, the voltage value of the second voltage is controlled to be kept unchanged, and the voltage value of the first voltage is increased so that the voltage value of the first voltage is larger than the voltage value of the second voltage; when the magnitude of the second voltage is adjusted, the voltage value of the first voltage is controlled to be kept unchanged, and the voltage value of the second voltage is reduced so that the voltage value of the first voltage is larger than the voltage value of the second voltage.

Further, in one embodiment, the output magnitude of the first voltage is controlled to increase in an arithmetic progression by a predetermined voltage increase amount so that the voltage value of the first voltage is larger than the voltage value of the second voltage; or, the output magnitude of the second voltage is controlled to be reduced in an arithmetic progression according to a predetermined voltage reduction amount, so that the voltage value of the first voltage is greater than the voltage value of the second voltage.

Further, when the first voltage is adjusted so that the target ions are sequentially extracted from the extraction electrode 150, the extraction time of each target ion is in a direct proportional relationship with the voltage value of the first voltage, that is, the extraction time of the target ion is shorter and the extraction speed of the target ion is higher as the voltage value of the first voltage is higher.

When the second voltage is adjusted so that the target ions are sequentially extracted from the extraction electrode 150, the extraction time of each target ion and the voltage value of the second voltage are inversely proportional, that is, the extraction time of the target ion is shorter and the extraction speed of the target ion is higher as the voltage value of the second voltage is smaller.

It should be noted that if the second voltage applied to the extraction electrode 150 is a direct current voltage (i.e., DC) ₃ ) When the second voltage is adjusted so that the target ions are extracted, the applied direct current voltage (i.e., DC) is adjusted accordingly ₃ ) The magnitude of the voltage value of (c); if the second voltage applied to the extraction electrode 150 is a radio frequency voltage (i.e., RF) ₃ ) Then, at the stage of extracting target ions, the radio frequency voltage (i.e. RF) is adjusted correspondingly ₃ ) The voltage value of (2); if the second voltage applied to the extraction electrode 150 is a radio frequency voltage (i.e., RF) ₃ ) And direct current voltage (i.e. DC) ₃ ) During the target ion extraction stage, only one of the voltage values can be adjusted, that is, the voltage value of the radio-frequency voltage is kept unchanged, the voltage value of the direct-current voltage is adjusted, or the voltage value of the direct-current voltage is kept unchanged, and the voltage value of the radio-frequency voltage is adjusted.

As an alternative embodiment, the vacuum chamber is provided with at least one opening 160, each opening 160 is used for introducing gas, wherein, the introduced gas can be any gas, and the gas flow rate ranges from 0 to 100mL/min; for example, 0.6mL/min of nitrogen is introduced through opening 160.

By applying a first radio frequency voltage (i.e., RF) to ion transport channel 120 ₀ ) So that the target ions collide with the introduced gas to generate target ion fragments, and thenSo that the target ion fragments are sequentially output from the extraction electrode 150 in the order of the mass-to-charge ratio from large to small under the action of the voltage applied to the gate electrode 130 or the extraction electrode 150.

In one embodiment, target ions enter the collision cell through the gate electrode 130, are bound by the first rf voltage applied to the ion transport channel 120, and collide with the introduced gas to produce target ion fragments; the target ion fragments are then subjected to a first voltage (i.e., a DC voltage DC) applied to the gate electrode 130 ₁ ) Is applied to the ion storage unit 140 and is applied with a second voltage (DC voltage DC) applied to the extraction electrode 150 ₃ And/or radio frequency voltage RF ₃ ) Active trapping within the ion storage cell 140; over a period of ion accumulation, the gate electrode 130 closes; then, the voltage value of the first voltage is gradually increased, so that the target ion fragments are extracted from the ion storage unit 140 in a certain sequence and enter the focusing device 200 connected to the ion extraction device 100 in the mass spectrometer.

In one embodiment, target ions enter the collision cell through the introduction electrode 110, are bound by a first rf voltage applied to the ion transport channel 120, and collide with the introduced gas to produce target ion fragments; then, when passing through the gate electrode 130, the target ion fragments enter the ion storage unit 140 under the action of the first voltage, and are trapped in the ion storage unit 140 under the action of the second voltage applied to the extraction electrode 150; over a period of ion accumulation, the gate electrode 130 closes; then, the second voltage (DC voltage DC) is gradually decreased ₃ Or radio frequency voltage RF ₃ ) Such that the target ion fragments are drawn out of the ion storage unit 140 into the focusing assembly 200 of the mass spectrometer in a sequence.

It should be noted that the extraction electrode 150 is an ion blanket device, and applying the rf voltage to the extraction electrode 150 forms a pseudo-potential well. For ions or ion fragments with different mass-to-charge ratios, under the same radio frequency amplitude, the larger the mass-to-charge ratio is, the smaller the charge amount is, and the larger the mass-to-charge ratio is, the smaller the depth of the pseudo-potential well is; further, ions or ion fragments with a large mass-to-charge ratio are preferentially and unstably extracted during the fall in the amplitude of the radio frequency voltage.

It is worth mentioning that the target ions or target ion fragments can be extracted by adjusting the magnitude of the voltage value of the first voltage and/or the second voltage. The method specifically comprises the following adjusting modes: 1. increasing the first voltage (i.e. the direct voltage DC) ₁ ) Voltage value of (d); 2. reducing applied radio frequency voltage (i.e. RF) ₃ ) Or a direct voltage (i.e. DC) ₃ ) Voltage value of (d); 3. reducing applied radio frequency voltage (i.e., RF) ₃ ) And direct current voltage (i.e. DC) ₃ ) Voltage value of (d); 4. increasing the first voltage (i.e. the direct voltage DC) ₁ ) And reducing the radio frequency voltage (i.e., RF) ₃ ) And/or direct voltage (i.e. DC) ₃ ) The voltage value of (2).

As an alternative embodiment, FIG. 8 illustrates the operation of the electrode assembly by adjusting the RF voltage (i.e., RF) applied to the extraction electrode 150 ₃ ) Is so large that the first voltage (i.e., direct current voltage DC) applied to the gate electrode 130 when the target ions or target ion fragments are extracted from the extraction electrode 150 ₁ ) And a radio frequency voltage (i.e., RF) applied to the extraction electrode 150 ₃ ) And direct current voltage (DC) ₃ ) Is detected.

It will be appreciated that a radio frequency voltage (i.e., RF) is applied to extraction electrode 150 ₃ ) And direct current voltage (DC) ₃ ) In the stage of extracting the target ions or target ion fragments, the target ions or target ion fragments are gradually extracted by changing the amplitude of the radio frequency voltage loaded on the extraction electrode 150; that is, by reducing the voltage value of the applied radio frequency voltage, the target ions or target ion fragments are caused to be extracted from the extraction electrode 150.

Alternatively, as shown in FIG. 9, FIG. 9 shows the first voltage (i.e. DC voltage DC) applied to the gate electrode 130 by adjusting the voltage ₁ ) Such that a first voltage (i.e., a DC voltage DC) is applied to the gate electrode 130 when the target ions or target ion fragments are extracted from the extraction electrode 150 ₁ ) And a radio frequency voltage (i.e., RF) applied to the extraction electrode 150 ₃ ) And direct current voltage (DC) ₃ ) Is detected.

Here, as shown in fig. 9, in a stage where the target ions are introduced from the introduction electrode 110, the voltage value of the first voltage is small, and then the voltage value is gradually increased, so that the target ions or target ion fragments trapped in the ion storage unit 140 are extracted. Wherein a radio frequency voltage (i.e., RF) is applied to the extraction electrode 150 ₃ ) And direct current voltage (DC) ₃ ). Radio frequency voltage (i.e., RF) when the target ions or target ion fragments are extracted by adjusting the voltage value of the first voltage ₃ ) May be constant, or the radio frequency voltage may be gradually reduced (i.e., RF) during the period in which the target ions or target ions are extracted from the extraction electrode 150 ₃ ) The amplitude value. Direct voltage (i.e. DC) ₃ ) The amplitude of (c) remains unchanged.

Alternatively, as shown in FIG. 10, FIG. 10 illustrates the voltage applied to the extraction electrode 150 by adjusting the DC voltage (i.e., DC) ₃ ) Such that a first voltage (i.e., a DC voltage DC) is applied to the gate electrode 130 when the target ions or target ion fragments are extracted from the extraction electrode 150 ₁ ) A sixth radio frequency voltage (i.e., RF) applied to the ion storage unit 140 ₂ ) And the amplitude variation of the seventh radio frequency voltage (i.e., AC), and a direct current voltage (i.e., DC) applied to the ion extraction electrode 150 ₃ ) Is detected.

It will be appreciated that by stepping down the direct voltage (i.e. DC) over time ₃ ) To a sixth radio frequency voltage (i.e., RF) when the target ions or target ion fragments are extracted ₂ ) And the magnitude of the seventh radio frequency voltage (i.e., AC) may remain constant.

In summary, in the present embodiment, no matter whether the target ions in the ion extraction apparatus 100 collide with the gas, the target ions can be extracted in the order of decreasing mass-to-charge ratio by changing the timing of the power voltage applied to the gate electrode 130 or the extraction electrode 150 in the ion extraction apparatus 100; in the process, the extraction speed and the extraction time of the target ions can be correspondingly adjusted through the adjustment of the first voltage and/or the second voltage, so that the wide-range extraction of the target ions is realized.

In one embodiment, the second rf voltage is applied to the ion mass spectrometer, so that the target ions in the ions entering the mass spectrometer are input into the vacuum chamber under the action of the second rf voltage, i.e. in the ion mass spectrometer, the target ions are introduced from the ion mass spectrometer to the ion extraction device 100 under the action of the second rf voltage, and the screening of the ions is realized.

In one embodiment, when the target ions are controlled to be extracted from the extraction electrode 150 and then input to the focusing device 200, the extraction time corresponding to the target ions is recorded, and the magnitude of the pulse repulsion voltage applied to the focusing device 200 is adjusted according to the extraction time, so that the target ions with different mass-to-charge ratios are input to the time-of-flight mass analysis device 300 at the same time, and mass spectrum data of the target ions with different mass-to-charge ratios are collected.

Specifically, after the ion storage unit 140 accumulates for a certain period of time, the target ions are extracted from the extraction electrode 150 in the order of the mass-to-charge ratio from large to small by changing the scanning timing of the eighth rf voltage and the second voltage applied to the extraction electrode 150 in combination with the combined action of the first voltage applied to the gate electrode 130. In addition, the extraction time of the target ions with different mass-to-charge ratios can be adjusted by adjusting the scanning timing of the eighth rf voltage and the second voltage applied to the extraction electrode 150.

After being extracted by the extraction electrode 150, the target ions enter the time-of-flight mass analysis device 300 through the focusing device 200, and when the target ions with different mass-to-charge ratios pass through the focusing device 200, the target ions approximately reach an acceleration region in the focusing device 200 at the same time point, and are introduced into the time-of-flight mass analysis device 300 under the action of pulse repulsion voltage applied to the focusing device 200.

Further, each target ion with different mass-to-charge ratios is input to the time-of-flight mass analysis device 300 approximately at the same time, and the mass spectrometer acquires mass spectrum data of each target ion with different mass-to-charge ratios at the current time through the time-of-flight mass analysis device 300, that is, mass spectrum data of each target ion with different mass-to-charge ratios can be acquired simultaneously.

It can be understood that the output time of each target ion with different mass-to-charge ratios is controlled by the ion extraction device 100, so that each target ion is input to the time-of-flight mass analysis device 300 approximately in the same time, mass spectrum data of each target ion with different mass-to-charge ratios at the same time can be correspondingly acquired, the acquisition efficiency of the mass spectrum data is improved, the target ions with different mass-to-charge ratios are conveniently analyzed through the acquired mass spectrum data, and the ion utilization rate in the time-of-flight mass analysis device 300 is improved and the mass width of the ions when the mass spectrum data is generated is increased.

In this embodiment, the extraction time of the target ions with different mass-to-charge ratios from the extraction electrode is correspondingly adjusted by adjusting the magnitude of the first voltage applied to the gate electrode and/or the magnitude of the second voltage applied to the extraction electrode, so that the target ions with different mass-to-charge ratios are controlled to be introduced into the time-of-flight mass analyzer at approximately the same time, thereby facilitating the subsequent time-of-flight mass analysis device to acquire time-of-flight mass spectrograms of the target ions with different mass-to-charge ratios at the same time, and widening the effective mass-to-charge ratio interval of the time-of-flight mass spectrogram.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The apparatus embodiments described above are merely illustrative and, for example, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, each functional module or unit in each embodiment of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

The functions may be stored in a computer-readable storage medium if they are implemented in the form of software functional modules and sold or used as separate products. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a smart phone, a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application.

Claims (10)

1. The ion extraction method is characterized by being applied to a mass spectrometer, wherein the mass spectrometer comprises a vacuum chamber, and an introduction electrode, an ion transmission channel, a gate electrode, an ion storage unit and an extraction electrode are sequentially arranged in the vacuum chamber; the space between the introduction electrode, the ion transmission channel and the gate electrode forms a collision cell; the method comprises the following steps:

controlling target ions to be input into a collision cell of the vacuum chamber from the introduction electrode;

applying a first voltage to the gate electrode to cause the target ions to enter the ion storage cell from the collision cell, and applying a second voltage to the extraction electrode to cause target ion accumulation of the target ions in the ion storage cell;

after a preset time period, the first voltage and/or the second voltage are/is adjusted, so that the target ions are sequentially output from the extraction electrode according to the sequence of the mass-to-charge ratio from high to low.

2. The ion extraction method according to claim 1, wherein when the first voltage is adjusted in magnitude, the voltage value of the second voltage is controlled to be kept constant, and the voltage value of the first voltage is increased so that the voltage value of the first voltage is larger than the voltage value of the second voltage;

when the magnitude of the second voltage is adjusted, the voltage value of the first voltage is controlled to be kept unchanged, and the voltage value of the second voltage is reduced, so that the voltage value of the first voltage is larger than the voltage value of the second voltage.

3. The ion extraction method according to claim 1 or 2, wherein the adjusting the magnitude of the first voltage and/or the second voltage comprises:

controlling the output magnitude of the first voltage to increase in an arithmetic progression according to a preset voltage increase amount so that the voltage value of the first voltage is greater than that of the second voltage; and/or the presence of a gas in the gas,

and controlling the output magnitude of the second voltage to be reduced in an arithmetic progression according to a preset voltage reduction amount so that the voltage value of the first voltage is larger than that of the second voltage.

4. The ion extraction method of claim 1, wherein the vacuum chamber is provided with at least one opening, each opening for introducing a gas, the method further comprising:

and applying a first radio frequency voltage to the ion transmission channel so as to enable the target ions to collide with the gas and generate target ion fragments, and further enabling the target ion fragments to be sequentially output from the extraction electrode according to the sequence of the mass-to-charge ratios from large to small under the action of the voltage applied to the gate electrode or the extraction electrode.

5. The ion extraction method of claim 1, wherein the mass spectrometer further comprises a focusing device and a time-of-flight mass analysis device; the method further comprises the following steps:

when the target ions are controlled to be led out from the leading-out electrode and then input into the focusing device, the leading-out time corresponding to the target ions is recorded, and the magnitude of pulse repulsion voltage applied to the focusing device is adjusted according to the leading-out time, so that the target ions with different mass-to-charge ratios are input into the time-of-flight mass analysis device at the same time, and mass spectrum data of the target ions with different mass-to-charge ratios are collected.

6. The ion extraction method of claim 1, wherein the mass spectrometer further comprises an ion mass analysis device; the method further comprises the following steps:

applying a second radio frequency voltage to the ion mass analysis device such that target ions of the ions entering the mass spectrometer are input to the vacuum chamber under the action of the second radio frequency voltage.

7. The ion extraction device is characterized by comprising a vacuum chamber, wherein an introduction electrode, an ion transmission channel, a gate electrode, an ion storage unit and an extraction electrode are sequentially arranged in the vacuum chamber; the space between the introduction electrode, the ion transmission channel and the gate electrode forms a collision cell;

the ion extraction device is used for performing the steps of the ion extraction method of any one of claims 1-6 through the vacuum chamber.

8. The ion extraction apparatus of claim 7, wherein the extraction electrode, the ion transmission channel, the gate electrode, the ion storage unit and the extraction electrode are coaxially arranged.

9. The ion extraction device according to claim 7, wherein the ion transport channel is a combined structure of any one or more of a quadrupole rod, a hexapole rod, an octopole rod, a segmented quadrupole rod, a segmented hexapole rod, and a segmented octopole rod;

the extraction electrode comprises a planar substrate and a plurality of conductive circular ring electrodes arranged on the planar substrate, and an ion extraction port is arranged at the center position among the conductive circular ring electrodes.

10. A mass spectrometer comprising an ion extraction means, a focusing means and a time-of-flight mass analysis means as claimed in any one of claims 7 to 9; the ion extraction device, the focusing device and the flight time mass analysis device are sequentially connected;

the mass spectrometer is used for leading out target ions from the ion leading-out device, and then inputting the target ions with different mass-to-charge ratios to the time-of-flight mass analysis device at the same moment under the action of pulse repulsion voltage applied to the focusing device, so as to acquire mass spectrum data of the target ions with different mass-to-charge ratios.

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