Ion guiding device
10515790 ยท 2019-12-24
Assignee
Inventors
Cpc classification
International classification
H01J49/42
ELECTRICITY
Abstract
The disclosure relates to an ion guiding device, including two sets of electrodes extending along a certain space axis, a first power supply device and a second power supply device. The electrodes are expandably arranged along a direction perpendicular to the space axis, at least one surface of each electrode in each set of electrodes is substantially on the same space plane, and the space planes for each set of electrodes are not same and not parallel, thereby forming an ion transmission channel having the cross sectional area gradually reduced in a direction perpendicular to the space axis; the first power supply device is used for applying radio-frequency voltages on at least a part of electrodes in the two sets of electrodes; and the second power supply device is used for applying voltage signals on at least a part of electrodes in the two sets of electrodes.
Claims
1. An ion guiding device, comprising: two sets of electrodes extending along a space axis, a first power supply device and a second power supply device; wherein the two sets of electrodes are expandably arranged along a first direction perpendicular to the space axis, at least one surface of each electrode in each set of electrodes is substantially on a same space plane, and said space planes for the two sets of electrodes are not same and not parallel and nonplanar, thereby forming an ion transmission channel having an ion inlet, an ion outlet, and a cross sectional area gradually reduced in a second direction perpendicular to the space axis and the first direction, and wherein the ion inlet of the ion transmission channel has a larger opening and the ion outlet thereof has a smaller opening; wherein the first power supply device is used for applying radio-frequency voltages on at least a part of electrodes in only the two sets of electrodes to confine ions in the ion transmission channel in at least one direction perpendicular to the space axis; and wherein the second power supply device is used for applying voltage signals on at least a part of electrodes in only the two sets of electrodes to form a voltage distribution in at least one direction perpendicular to the space axis to control ion movement, and form a voltage distribution in a direction of the space axis to realize ion transmission along the space axis.
2. The ion guiding device according to claim 1, characterized in that: the space axis is a linear or curved axis.
3. The ion guiding device according to claim 2, characterized in that: when the space axis is a curved axis, an axial direction at the ion inlet is a first axial direction, an axial direction at the ion outlet is a second axial direction, and an included angle between the first axial direction and the second axial direction is one of less than 10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 90-100, 100-110, 110-120, 120-130, 130-140, 140-150, 150-160, 160-170 and 170-180.
4. The ion guiding device according to claim 1, characterized in that: electrodes in the two sets of plate electrodes are plate or nonplanar electrodes.
5. The ion guiding device according to claim 4, characterized in that: the plate electrodes comprise one or a combination of square-pole electrodes, rectangular plate electrodes, fan-shaped plate electrodes, and thin-layer plate electrodes adhered on an insulating substrate.
6. The ion guiding device according to claim 5, characterized in that: the insulating substrate is one of a printed circuit board, polyimide, ceramics and glass.
7. The ion guiding device according to claim 4, characterized in that: the nonplanar electrodes are electrodes whose surfaces are partially or all nonplanar.
8. The ion guiding device according to claim 1, characterized in that: an area ratio of the ion inlet to the ion outlet is one of 1-10, 10-100, 100-1,000 and more than 1,000.
9. The ion guiding device according to claim 1, characterized in that: the first power supply device sequentially applies radio-frequency voltages with opposite polarity to all electrodes in each set of electrodes.
10. The ion guiding device according to claim 1, characterized in that: voltage signals applied by the second power supply device are selected from one or a combination of DC voltages, square wave voltages, sawtooth wave voltages, triangle wave voltages and AC voltages.
11. The ion guiding device according to claim 10, characterized in that: a duty cycle of the square wave voltages is in the range of one or more of 0-10%, 10% -20%, 20% -40%, 40% -60% and 60% -100%.
12. The ion guiding device according to claim 10, characterized in that: the AC voltage signals have a frequency of 10 Hz -100 MHz.
13. The ion guiding device according to claim 1, characterized in that: the expandable arrangement of the two sets of electrodes in a direction perpendicular to the space axis is parallel and/or non-parallel expanded arrangement.
14. The ion guiding device according to claim 1, characterized in that: none of electrodes in the two sets of electrodes is segmented axially.
15. The ion guiding device according to claim 1, characterized by further comprising auxiliary electrodes, wherein the auxiliary electrodes are placed at both sides of the ion guiding device, and the second power supply device applies voltage signals to the auxiliary electrodes to restrict ion movement in a direction perpendicular to the space axis and produce an axial voltage gradient in the ion channel to realize ion transmission.
16. The ion guiding device according to claim 15, characterized in that: the auxiliary electrodes are parallel or not parallel to the space axis.
17. The ion guiding device according to claim 15, characterized in that: the auxiliary electrodes are planar or nonplanar electrodes.
18. The ion guiding device according to claim 1, characterized in that: the operating gas pressure of the ion guiding device is in the range of one or more of 210.sup.5 Pa-210.sup.3 Pa, 210.sup.3 Pa-20 Pa, 20 Pa-2 Pa, 2 Pa-210.sup.1 Pa, 210.sup.1 Pa-210.sup.3 Pa and less than 210.sup.3 Pa.
19. The ion guiding device according to claim 1, characterized in that: an optimal operating gas pressure of the ion guiding device is in the range of 0.1 Pa-100 Pa.
20. The ion guiding device according to claim 1, characterized in that: the two sets of electrodes expand along a direction perpendicular to the space axis to form an array structure.
21. The ion guiding device according to claim 1, characterized in that: the two sets of electrode systems expand along a closed curve to form a closed array structure.
22. The ion guiding device according to claim 1, characterized by comprising a plurality of ion injection ports for injecting ions into the ion inlet.
23. The ion guiding device according to claim 22, characterized in that: the ion injection direction is one or a combination of a direction of the space axis and a direction perpendicular to the space axis.
24. The ion guiding device according to claim 1, characterized in that: the ion guiding device serves as one or a combination of a preceding-stage ion guiding device, an ion mobility analysis device, an ion compression device, an ion storage device, a collision chamber and an ion buncher device of a mass spectrometer or an ion mobility spectrometer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
(25)
DESCRIPTION OF REFERENCE NUMERALS OF ELEMENTS IS AS FOLLOWS
(26) 10 Ion guiding device
(27) 101a Plate electrode
(28) 101b Plate electrode
(29) 102 Space axis
(30) 103 Electrode
(31) 104 Ion inlet
(32) 105 Ion outlet
(33) 106 Slit
(34) 107 Detector
(35) 108 Auxiliary electrode
(36) 400 Array electrode structure
(37) 401 Ion injection port
(38) 402 Ion stream
(39) 403 Ion outlet channel
(40) 404 Ion storage area
(41) 410 Closed electrode structure
DETAILED DESCRIPTION OF THE INVENTION
(42) The embodiments of the present invention will be described hereinafter through specific particular examples, and those skilled in the art can easily understand other advantages and effects of the present invention through the disclosures in the specification. The present invention may also be implemented or applied through other different particular embodiments, and various modifications or changes may also be made to various details in the specification on the basis of different opinions and applications without departing from the spirit of the present invention.
(43) It should be noted that the drawings provided in the embodiment only describe the basic conception of the present invention in an illustrative manner, so the drawings only show the components relevant to the present invention rather than being drawn according to the number, shape and size of the components during actual implementation, the configuration, number and scale of each component may be randomly changed during its actual implementation, and the layout and configuration of the components thereof might also be more complicated.
(44) The ion guiding device of the present invention is an ion guiding device and an ion mobility analysis device for performing operations such as transmission, compression, splitting and collision-induced dissociation of an ion stream, and can be used in ion analyzers such as a mass spectrometer and an ion mobility spectrometer.
(45) Particularly, the ion guiding device of the present invention comprises an ion channel consisting of two sets of electrode systems extending along a certain space axis, wherein the ion channel has a sectional area gradually reduced axially in a direction perpendicular to an axis; and a voltage gradient is applied in a direction perpendicular to the axis to produce an axial voltage gradient to drive axial transmission of ions. In the ion guiding device, electrodes do not need to be segmented axially, which is very favorable for machining and assembling while reducing the complexity of circuit design; and an ion inlet is large and an ion outlet is small, which not only ensures a larger ion acceptance area, but also may realize excellent ion compression effect. Accordingly, the ion guiding device of the present invention can be used in a mass spectrometer, an ion mobility spectrometer and a combination thereof to realize uses such as transmission and collision-induced dissociation of ions as well as compression and splitting of ion stream.
(46) Embodiment 1
(47)
(48) The first power supply device is used for applying radio-frequency voltages on at least a part of electrodes in the two sets of plate electrodes to confine ions in the ion transmission channel in at least one direction perpendicular to the space axis 102.
(49) The second power supply device is used for applying voltage signals on at least a part of electrodes in the two sets of plate electrodes to form a voltage distribution in at least one direction perpendicular to the space axis 102 to control ion movement; and meanwhile, since the ion transmission channel has a cross sectional area gradually reduced along the space axis in a direction perpendicular to the space axis, a voltage distribution in a direction perpendicular to the space axis 102 forms a certain voltage distribution in a direction of the space axis 102, thus ion transmission can be realized along the space axis.
(50) Preferably, the space plane is planar and/or nonplanar.
(51) Preferably, an area ratio of the ion inlet to the ion outlet may be selected from the following: a) 1-10; b) 10-100; c) 100-1,000; and d) >1,000.
(52) Preferably, voltage signals applied by the second power supply device are selected from one or a combination of DC voltages, square wave voltages, sawtooth wave voltages, triangle wave voltages and AC voltages. A duty cycle of the square wave voltages is adjustable and selected from at least one of the following ranges: a) 0-10%; b) 10%-20%; c) 20%-40%; d) 40%-60%; and e) 60%-100%.The AC voltage signals have a frequency of 10 Hz-100 MHz.
(53) Preferably, all electrodes in the two sets of electrodes are not segmented axially.
(54) Preferably, the ion guiding device serves as one or a combination of a preceding-stage ion guiding device, an ion mobility analysis device, an ion compression device, an ion storage device, a collision chamber and an ion buncher device of a mass spectrometer or an ion mobility spectrometer.
(55) Preferably, the operating gas pressure of the ion guiding device is in the range of one or more of 210.sup.5 Pa-210.sup.3 Pa, 210.sup.3 Pa-20 Pa, 20 Pa-2 Pa, 2 Pa-210.sup.1 Pa, 210.sup.1 Pa-210.sup.3 Pa and less than 210.sup.3 Pa. The optimal operating gas pressure of the ion guiding device 10 is in the range of 0.1 Pa-100 Pa. After ions are introduced to the ion inlet 104 via an upstream ion optical device, the ions collide with neutral gas such that a large amount of kinetic energy is lost and the ions are rapidly cooled. To reduce ion loss caused by free diffusion, as shown in
(56) As shown in
(57) In addition, for further flexibly controlling the transmission trajectories of ions, as shown in
(58) In addition, the dwell time of ions can be changed by adjusting the intensity of a DC voltage so as to match the scanning speed of the entire instrument. In another operating mode of the embodiment, a DC power source may also be replaced with a square wave power source having an adjustable duty cycle, which can change the duty cycle to adjust the dwell time of ions on the one hand, and can also realize the bunching operation of an ion stream by using a square wave voltage on the other hand, thereby cutting a continuous ion stream into groups of ion packets and sequentially extracting the ion packets from the ion outlet 105. In addition, the time width of each ion packet can also be adjusted by changing the duty cycle of a square wave voltage so as to match the scanning speed of a subsequent-stage ion analysis device. Accordingly, for pulse-type ion analyzers such as a time-of-flight mass analyzer, an ion trap mass analyzer, an orbitrap mass analyzer and an ion drift tube which are coupled at a subsequent stage, the utilization efficiency of ions can be greatly improved such that these analyzers have a very high ion analyzing duty cycle. Another advantage of using a square wave power source also lies in that the flight path of ions can be prolonged at the same time of using a relatively short device length so as to achieve a higher ion collision-induced dissociation efficiency.
(59) Furthermore, in another operating mode of the implementation structure, another group of radio-frequency voltages RF2 may be used instead of the above DC voltages, and then are applied on the electrodes 103 at both sides to restrict the movement of ions towards the both sides. Meanwhile, according to the pseudopotential theory, the radio-frequency voltages RF2 will penetrate in the ion guiding device to form an equivalent axial pseudopotential voltage distribution for driving axial transmission of ions. This operating mode is superior to the use of DC voltages in that, the radio-frequency voltages RF2 can form a radio-frequency focusing field in a radial direction of the ion channel, thus allowing ions to keep away from an electrode surface and converge towards the center. This can reduce the risk of striking on an electrode surface of ions to a certain extent. As is well known, an electric field formed by a DC voltage merely converges in a direction of both sides and diverges in a direction substantially perpendicular to an electrode surface, and the movement of ions towards an electrode surface is therefore intensified, which increases the risk of striking on an electrode surface of ions and therefore is adverse to lossless transmission of ions.
(60) In other embodiments of the ion guiding device 10, the two sets of plate electrodes 101a and 101b may also be the forms as shown in
(61) It should be noted that not only plate electrodes but also nonplanar electrodes can be used for the two sets of electrodes 101a and 101b to realize their functions. The nonplanar electrodes may be electrodes whose surfaces are partially and/or all nonplanar.
(62) Embodiment 2
(63)
(64) Embodiment 3
(65) Different from the case that two sets of electrodes are in parallel expandable arrangement in a transverse direction as shown in
(66) Embodiment 4
(67) Different from the embodiment in which the space axis is a linear axis as shown in
(68) It should be noted that, when the space axis is a curved axis, an axial direction at the ion inlet is the first axial direction, an axial direction at the ion outlet is the second axial direction, and an included angle between the first axial direction and the second axial direction is one of less than 10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 90-100, 100-110, 110-120, 120-130, 130-140, 140-150, 150-160, 160-170 and 170-180.
(69) Embodiment 5
(70) In other embodiments of the ion guiding device of the present invention, an electrode structure can also expand in a transverse direction to form an array-distributed electrode structure 400, as shown in
(71) As shown in
(72) Additionally, in other operating modes of the embodiment, a transverse voltage distribution can also be dynamically adjusted such that the array-distributed electrode structure has multiple ion manipulation functions, e.g. ion storage, ion mobility separation and measurement, etc. As shown in
(73) Further, as shown in
(74) In summary, the ion guiding device of the present invention has the following advantages: the electrode shape and the device structure are simple, thereby facilitating machining, assembling and function expansion; efficient transmission and effective compression of ions can be realized; the device can be applied to relevant technical fields such as mass spectrometry and ion mobility spectrometry; the device can be applied to ion beam compression in an orthogonal-injection ion time-of-flight mass spectrometer, wherein ions are efficiently compressed to reduce the initial spatial distribution of the ions, thereby improving the resolution of the instrument; and in triple quadrupole mass spectrometers and other mass spectrometers, the device can conveniently realize off-axision optical design, which not only can effectively reduce the interference from neutral gas molecules and greatly improve the signal-to-noise ratio of the instrument, but also can reduce the volume of the instrument. Accordingly, the present invention effectively overcomes various disadvantages in the prior art and has a high industrial application value.
(75) The above embodiments are only used for illustratively describing the principles and effects of the present invention, but are not intended to limit the present invention. Any persons skilled in the art can make modifications or changes to the above embodiments without departing from the spirit and scope of the present invention. Accordingly, all equivalent modifications or changes made by the persons having ordinary skill in the art without departing from the spirit and technical thought disclosed in the present invention still shall be covered by the claims of the present invention