Time-of-flight mass spectrometer and working method thereof

Abstract

The invention provides a time-of-flight mass spectrometer and a working method thereof, the time-of-flight mass spectrometer comprises a repulsion electrode, a traction electrode and a power supply, the power supply supplies power to the repulsion electrode and the traction electrode, an ion channel is arranged between a first electrode and a second electrode, and the first electrode and the second electrode extend between the repulsion electrode and the traction electrode; the repulsion electrode, the first electrode, the second electrode and the traction electrode are arranged in sequence; the driving unit is used for driving the first electrode and the second electrode to translate in the direction perpendicular to the repulsion electrode and adjusting the distance between the first electrode and the second electrode; the output end of the power supply is connected with the first electrode and the second electrode; the control unit is connected with the power supply and controls the time when the power supply applies voltage to the first electrode and the second electrode. The method has the advantages of high resolution and the like.

Description

Technical Field

[0001] The present invention relates to mass spectrometry technology, in particular to a time-of-flight mass spectrometer and a working method thereof. Background Art

[0002] The high resolution of a time-of-flight mass spectrometer is often due to the energy dispersion and spatial dispersion of ions at their initial positions. As the technical principles are explored, the spatial dispersion and partial energy dispersion can be compensated to a certain extent by the reflector structure. However, the energy dispersion cannot compensate for the return time caused by the returning ions. Summary of the invention

[0003] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides a time-of-flight mass spectrometer.

[0004] The objective of the present invention is achieved through the following technical solutions: A time-of-flight mass spectrometer comprises a repeller, a pull electrode and a power supply, wherein the power supply supplies power to the repeller and the pull electrode; the time-of-flight mass spectrometer further comprises: A first electrode and a second electrode, wherein an ion channel is formed between the first electrode and the second electrode and extends between the repeller and the pull electrode, and the repeller electrode, the first electrode, the second electrode and the pull electrode are arranged in sequence; a driving unit, the driving unit being used to drive the first electrode and the second electrode to translate along a direction perpendicular to the repelling electrode, so as to adjust the distance between the first electrode and the second electrode; The output end of the power supply is connected to the first electrode and the second electrode; A control unit is connected to the power supply and controls the time for the power supply to apply voltage to the first electrode and the second electrode.

[0005] The present invention also aims to provide a working method of a time-of-flight mass spectrometer, which is achieved by the following technical solutions: According to the working method of the time-of-flight mass spectrometer of the present invention, the working method is: Adjust the distance between the first electrode and the second electrode according to the requirements of resolution and sensitivity. The higher the resolution requirement, the smaller the distance; the higher the sensitivity requirement, the larger the distance; The ions pass through the ion channel between the first electrode and the second electrode and enter the ion repelling zone; The repelling electrode and the pulling electrode apply voltage, and the ions in the repelling zone are pushed out.

[0006] Compared with the prior art, the present invention has the following beneficial effects: 1. Meet the requirements for resolution and sensitivity; The positions of the first electrode and the second electrode between the repelling electrode and the pulling electrode are adjustable. According to the requirements on resolution and sensitivity, the positions of the first electrode and the second electrode are automatically and accurately adjusted to meet different needs.

[0007] 2. High resolution; When a repulsion pulse can be applied to the ions in the repulsion zone, a voltage is applied between the first electrode and the second electrode at the same time, thereby avoiding the appearance of a deformed electric field around the ion channel outlet (between the first electrode and the second electrode), avoiding the increase of the "turnaround time" caused by the longitudinal electric field change, and improving the resolution; By applying a voltage between the first electrode and the second electrode, the ions remaining in the ion channel (between the first electrode and the second electrode) are directly annihilated, thereby obtaining a cleaner mass spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The disclosure of the present invention will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. In the drawings: Figure 1 Schematic diagram of the structure of a time-of-flight mass spectrometer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0009] Figure 1 The following description describes optional specific embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to teach the technical solution of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will understand that variations or replacements derived from these specific embodiments will be within the scope of the present invention. Those skilled in the art will understand that the following features can be combined in various ways to form multiple variations of the present invention. Thus, the present invention is not limited to the following optional specific embodiments, but is only limited by the claims and their equivalents.

[0010] Example 1

[0011] A time-of-flight mass spectrometer according to an embodiment of the present invention, such as Figure 1 As shown, the time-of-flight mass spectrometer comprises: A repeller 11, a pull electrode 12 and a power source, wherein the power source supplies power to the repeller 11 and the pull electrode 12; A first electrode 21 and a second electrode 22, wherein an ion channel is formed between the first electrode 21 and the second electrode 22 and extends between the repeller 11 and the pull electrode 12, and the repeller electrode 11, the first electrode 21, the second electrode 22 and the pull electrode 12 are arranged in sequence; A driving unit, the driving unit is used to drive the first electrode 21 and the second electrode 22 to translate along a direction perpendicular to the repelling electrode 11, so as to adjust the distance between the first electrode 21 and the second electrode 22; The output end of the power supply is connected to the first electrode 21 and the second electrode 22; A control unit is connected to the power supply and controls the time for the power supply to apply voltage to the first electrode 21 and the second electrode 22 .

[0012] In order to avoid interference caused by the remaining ions in the ion channel, further, when the repelling electrode 11 repels ions, the power supply applies voltage to the repelling electrode 11, the first electrode 21 and the second electrode 22 at the same time; When ions are transferred between the first electrode 21 and the second electrode 22 , the power source no longer applies voltage to the first electrode 21 and the second electrode 22 .

[0013] In order to prevent the formation of a distorted electric field at the exit of the ion channel to improve the resolution, further, during ion repulsion, the voltage on the first electrode 21 is U2=U0-(U0-U1)·D1 / D0, and the voltage on the second electrode 22 is U3=U1+(U0-U1)·D2 / D0, U0 is the voltage on the repulsion electrode 11, U1 is the voltage on the traction electrode 12, D1 is the distance between the first electrode 21 and the repulsion electrode 11, D2 is the distance between the second electrode 22 and the traction electrode 12, and D0 is the distance between the repulsion electrode 11 and the traction electrode 12.

[0014] In order to accurately control the movement of the first electrode 21 and the second electrode 22 , further, the first electrode 21 and the second electrode 22 are respectively arranged on linear guide rails.

[0015] The working method of the time-of-flight mass spectrometer according to an embodiment of the present invention is as follows: Adjust the distance between the first electrode 21 and the second electrode 22 according to the requirements of resolution and sensitivity. The higher the resolution requirement, the smaller the distance; the higher the sensitivity requirement, the larger the distance; The ions pass through the ion channel between the first electrode 21 and the second electrode 22 and enter the ion repulsion zone; The repelling electrode 11 and the pulling electrode 12 apply voltage, and the ions in the repelling zone are pushed out.

[0016] In order to improve the sensitivity, further, the higher the sensitivity requirement, the smaller the distance between the first electrode 21 and the repelling electrode 11 .

[0017] In order to improve the resolution, further, the higher the resolution requirement, the smaller the distance between the first electrode 21 and the repelling electrode 11 .

[0018] Example 2

[0019] An application example of a time-of-flight mass spectrometer and a working method thereof according to Example 1 of the present invention.

[0020] In this application example, Figure 1 As shown, the first electrode 21 and the second electrode 22 are both flat and arranged in parallel, with one end extending into the repeller electrode 11 and the pull electrode 12. An ion channel is formed between the first electrode 21 and the second electrode 22, and ions emitted from the ion collision cell pass through the ion channel and enter the repeller region between the repeller electrode 11 and the pull electrode 12.

[0021] The end of the first electrode 21 is arranged on the first linear guide rail 31, and the end of the second electrode 22 is arranged on the second linear guide rail 32. The motor uses the lead screw to push the electrode on the linear guide rail to precisely translate along the guide rail, that is, the distance between the first electrode 21 and the second electrode 22 is adjusted, and the distance between the first electrode 21 and the repelling electrode 11 is also adjusted, so as to meet the requirements of different resolutions and sensitivities. The power supply applies pulse voltages to the repelling electrode 11, the first electrode 21, the second electrode 22 and the pulling electrode 12 arranged in sequence as required. Specifically, no voltage needs to be applied to the four electrodes between the ions being ejected from the ion collision cell and entering the repelling zone. When the ions reach the repelling zone, the power supply applies pulse voltages to the four electrodes. The voltage U2 on the first electrode 21 = U0-(U0-U1)·D1 / D0, the voltage U3 on the second electrode 22 = U1+(U0-U1)·D2 / D0, U0 is the voltage on the repelling electrode 11, U1 is the voltage on the pulling electrode 12, D1 is the distance between the first electrode 21 and the repelling electrode 11, D2 is the distance between the second electrode 22 and the pulling electrode 12, and D0 is the distance between the repelling electrode 11 and the pulling electrode 12. At this time, the ions remaining in the ion channel are directly annihilated, and a stable electric field is formed at the outlet of the ion channel to avoid the occurrence of a distorted electric field.

[0022] The working method of the time-of-flight mass spectrometer according to an embodiment of the present invention is as follows: The spacing between the first electrode 21 and the second electrode 22 is adjusted according to the requirements of resolution and sensitivity. The higher the resolution requirement, the smaller the spacing is, and the smaller the distance between the first electrode 21 and the repelling electrode 11 is; the higher the sensitivity requirement, the larger the spacing is, and the smaller the distance between the first electrode 21 and the repelling electrode 11 is.

[0023] The ions pass through the ion channel between the first electrode 21 and the second electrode 22 and enter the ion repulsion zone. During this process, the first electrode 21 and the second electrode 22 are grounded, and there is no need to apply voltage to the repulsion electrode 11 and the pulling electrode 12. The power supply applies voltages to the repelling electrode 11, the pulling electrode 12, the first electrode 21 and the second electrode 22, and the voltages on the four electrodes satisfy that the voltage on the first electrode 21 is U2=U0-(U0-U1)·D1 / D0, the voltage on the second electrode 22 is U3=U1+(U0-U1)·D2 / D0, U0 is the voltage on the repelling electrode 11, U1 is the voltage on the pulling electrode 12, D1 is the distance between the first electrode 21 and the repelling electrode 11, D2 is the distance between the second electrode 22 and the pulling electrode 12, and D0 is the distance between the repelling electrode 11 and the pulling electrode 12. At this time, the ions remaining in the ion channel are directly annihilated, and a stable electric field is formed at the exit of the ion channel to avoid the occurrence of a distorted electric field, and the ions in the repelling zone are pushed out.

[0024] Take the pulse voltage of ±1800V often used in high resolution as an example, that is, U0=1800V, U1=-1800V, D0=6mm, the high-resolution slit (between the first electrode 21 and the second electrode 22) is in the middle position (that is, D1=D2), the distance between the first electrode 21 and the second electrode 22 is 2mm, D1=2mm, D2=2mm. According to the formula U2=U0-(U0-U1)·D1 / D0, U3=U1+(U0-U1)·D2 / D0, the voltage on the first electrode 21 is U2=600V, and the voltage on the second electrode 22 is U3=-600V.

[0025] High sensitivity parameter example, high sensitivity generally sacrifices part of the resolution to improve sensitivity, at this time (the first electrode 21 and the second electrode 22) the position of the slit is still in the middle position, still taking the pulse voltage of ±1800V as an example, that is, U0 is 1800V, U1 is -1800V, D0=6mm, the spacing is 5mm, D1=0.5mm, D2=0.5mm. According to the formula U2=U0-(U0-U1)·D1 / D0, U3=U1+(U0-U1)·D2 / D0, U2=1500V, U3=-1500V.

[0026] The above two simple uses do not require adjustment of other parameters, but only change the initial state of the ion cloud in the repulsion zone, and will not involve changes in the voltage parameters of the deceleration zone and the reflection zone.

[0027] Consider the resolution as much as possible at a suitable sensitivity. Take the pulse voltage of ±1800V as an example, that is, U0 is 1800V, U1 is -1800V, the distance D0 between the repulsion zones is 6mm, the distance between the first electrode 21 and the second electrode 22 is 3mm, D1 is 1mm, and D2 is 2mm. According to the formula U2=U0-(U0-U1)·D1 / D0, U3=U1+(U0-U1)·D2 / D0, the voltage on the first electrode 21 is 1200V, and the voltage on the second electrode 22 is -600V.

Claims

1. A time-of-flight mass spectrometer, comprising a repeller, a pull electrode and a power supply, wherein the power supply supplies power to the repeller and the pull electrode; characterized in that: The time-of-flight mass spectrometer also includes: A first electrode and a second electrode, wherein an ion channel is formed between the first electrode and the second electrode and extends between the repeller and the pull electrode, and the repeller electrode, the first electrode, the second electrode and the pull electrode are arranged in sequence; a driving unit, the driving unit being used to drive the first electrode and the second electrode to translate along a direction perpendicular to the repelling electrode, so as to adjust the distance between the first electrode and the second electrode; The output end of the power supply is connected to the first electrode and the second electrode; A control unit is connected to the power supply and controls the time for the power supply to apply voltage to the first electrode and the second electrode.

2. The time-of-flight mass spectrometer according to claim 1, characterized in that The first electrode and the second electrode are plate-shaped.

3. The time-of-flight mass spectrometer according to claim 2, characterized in that: When the repeller electrode repels ions, the power supply applies voltage to the repeller electrode, the first electrode and the second electrode simultaneously; When ions are transferred between the first electrode and the second electrode, the power supply no longer applies voltage to the first electrode and the second electrode.

4. The time-of-flight mass spectrometer according to claim 3, characterized in that: During ion repulsion, the voltage on the first electrode is U2=U0-(U0-U1)·D1 / D0, and the voltage on the second electrode is U3=U1+(U0-U1)·D2 / D0, where U0 is the voltage on the repeller, U1 is the voltage on the pull electrode, D1 is the distance between the first electrode and the repeller, D2 is the distance between the second electrode and the pull electrode, and D0 is the distance between the repeller and the pull electrode.

5. The time-of-flight mass spectrometer according to claim 1, characterized in that: The first electrode and the second electrode are respectively arranged on the linear guide rail.

6. The time-of-flight mass spectrometer according to claim 1, characterized in that: The time-of-flight mass spectrometer also includes: The ions emitted from the ion collision cell pass through the ion channel and enter the repulsion zone.

7. The working method of a time-of-flight mass spectrometer according to any one of claims 1 to 6, wherein the working method comprises: Adjust the distance between the first electrode and the second electrode according to the requirements of resolution and sensitivity. The higher the resolution requirement, the smaller the distance; the higher the sensitivity requirement, the larger the distance; The ions pass through the ion channel between the first electrode and the second electrode and enter the ion repelling zone; The repeller electrode and the pull electrode apply voltage, and the ions in the repeller zone are pushed out.

8. The working method according to claim 7, characterized in that: The higher the sensitivity requirement, the smaller the distance between the first electrode and the repeller electrode.

9. The sampling method according to claim 7, characterized in that: The higher the resolution requirement, the smaller the distance between the first electrode and the repelling electrode.

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