WO2013107060A1

WO2013107060A1 - Ion guide device

Info

Publication number: WO2013107060A1
Application number: PCT/CN2012/070709
Authority: WO
Inventors: 丁力; 蒋公羽; 孙文剑
Original assignee: 岛津分析技术研发（上海）有限公司
Priority date: 2012-01-21
Filing date: 2012-01-21
Publication date: 2013-07-25

Abstract

An ion guide device consists of multiple layers of filament electrodes (n.1, n.2, n representing the number of layers) straightened and intersecting spatially. The filament electrodes are distributed along a guide shaft z that defines an ion guide direction. Each layer of the filament electrode comprises at least two filaments that are straightened and have a certain distance away from the guide shaft. Each layer of the filament electrode rotates about the guide shaft by a certain angle relative to the adjacent layer of the filament electrode. Therefore, the multiple layers of filament electrodes surround the guide shaft to form a through cage-like ion guide channel (21), and frames (16) for fixing the filaments are arranged at the periphery of the guide channel (21), so that interference of the device on air flows is reduced. A power supply device (19, 20) provides voltage for each layer of the filament electrode, to at least construct an electric field that causes ions to converge to the guide shaft.

Description

Ion guiding device

Technical field

The present invention relates to an ion guiding device, particularly an ion guiding device for introducing ions into a lower pressure environment for mass spectrometry in a higher pressure (or lower vacuum) environment.

Background technique

In mass spectrometers, in order to direct ions from the ion source to the analyzer at higher gas pressures (1~10 ⁴ Pa), high frequency (or RF) guiding devices are usually used, and high frequencies are applied to the electrodes in the device. The effective barrier formed by the voltage causes the ions to accelerate toward the central axis, thereby acting as a convergence. Due to the collision with the neutral gas, the kinetic energy of the ions is lost, and the ions are collected near the central axis, smoothly passing through the differential suction holes, and entering the mass spectrometer in a lower pressure environment. The RF convergence type guiding device is from the multi-pole guiding rod system invented by DJ Douglas (US Pat. No. 5,179,278) to the ion funnel proposed by RD Smith (U.S. Patent No. 6,107,628), to U.S. Patent No. 6,462,338 B1, N. Inatsugu, H. The Q-array introducer invented by Waki; and the traveling wave guiding device proposed by Bateman et al. (US Pat. No. 70,950,013) have undergone various variations. However, as the first-stage guiding lens after the ion source, the strong airflow accompanying the ions entering the low-pressure strong region plays a key role in the ion motion, and even the effect of the airflow on the ions is sometimes greater than the effect of the electric field on the ions. The position of the electrode of the guiding device or its fixing bracket often inevitably interferes with the gas flow. In addition, the influence of the orientation of the pipe on the pumping may cause turbulence, eddy current or airflow jitter in the ion path, which will inevitably affect the ion transmission. .

In U.S. Patent 5,572,035, the inventor Franzen It has been proposed to use a screen electrode to form an ion reflecting surface to align the stroke of the ion, which theoretically has good airflow permeability. However, in general, the texture of the screen is relatively soft, and the inventors have not given a solution for how to securely mount it in a specific position in space without being blown by air. If the bracket is installed, the additional bracket will also affect the direction of the airflow.

Further, in various conventional ion guiding devices, adjacent electrodes to which high-frequency voltages of different phases are applied are not parallel to each other (between lines or between faces), and are concentric arcs with large interelectrode capacitance. For example, US Patent 6107628 The proposed ion funnel uses a sheet electrode with opposite polarity. Due to the multiple stacks, the total capacitance of the electrode structure is large, so that the power consumption of the power supply for which the high frequency voltage is supplied is increased.

In addition, there are many such electrodes arranged in parallel, which are parallel to the high frequency power supply, and the large total capacitance increases the power consumption of the high frequency power supply.

Summary of the invention

One of the objects of the present invention is to design a device capable of effectively guiding ions under low vacuum conditions of higher gas pressure and gas flow, which should minimize the adverse effect of the electrode structure of the ion guide on the gas flow, Neutral gas flow has a small blocking effect, and the interelectrode capacitance should be minimized.

In order to reduce the influence of the electrode structure on the gas flow, it is proposed to use a filament electrode to generate a desired ion guiding electric field. However, the rigidity of the filament is poor and it is difficult to accurately fix it at a specific position in the space, so it is necessary to form the filament electrode in a suitable geometric configuration in space and to effectively fix it. In addition, the proposed geometric configuration of the filament electrode in space not only satisfies the condition of generating an effective guiding electric field, but also satisfies the condition of the minimum interelectrode capacitance as small as possible.

An ion guiding device according to an aspect of the invention comprises a plurality of filament electrodes distributed along a guiding axis defining a direction of ion guiding, each layer of filament electrodes comprising at least two distances from said guiding a straightened filament of a certain distance from the shaft, each layer of filament electrodes being rotated about the guiding axis by a certain angle with respect to the adjacent layer of filament electrodes, so that the multilayer filament electrodes are formed to be transparent around the guiding axis The cage ion guiding channel. The ion guiding device further includes a power supply device that supplies a voltage to each of the layers of filament electrodes to at least configure an electric field that converges ions toward the guiding axis.

As a preferred embodiment of the present invention, the plane of each layer of filament electrodes is substantially orthogonal to the guide axis, and the angle ranges from 85 ° to 95. °. In other embodiments of the invention, the angle between the plane in which each of the filament electrodes is located and the guide shaft is allowed to expand to between 70 ° and 110 °.

As an embodiment, it is also proposed that each layer of the filament electrode contains a pair of straightened filaments that are equidistant from the axis of the guide. The direction of each layer of filaments is rotated about the guide axis relative to the direction of the next layer of filaments 90 degrees; the phase of the high frequency voltage applied by each layer of filaments is opposite to the phase of the high frequency voltage of the next layer of filaments.

As a preferred embodiment of the present invention, a funnel-type guiding structure in which the distance between the filaments and the guide shaft is gradually reduced is also proposed to facilitate the convergence of ions and the scattering of airflow.

In an embodiment of the present invention, the direction of the rotation of each layer of the filament electrode relative to the direction of the upper layer of the filament electrode can be varied by a plurality of angles, for example, 2 π /N, where N = 4, 5 , 6 , 7 , 8 , 9 , 10 , 11 or 12 . Thereby, a quadrupole field, a hexapole field, an octapole field, or the like can be constructed. In some embodiments, the shape of each layer of filament electrodes may be a polygon such as a triangle, a pentagon, or the like.

In an embodiment of the invention, there are many ways to construct an electric field that converges ions toward the guide axis. For example, a high-frequency voltage having a different phase is supplied to an adjacent layer filament electrode, such as a high-frequency voltage that is opposite to each other, and the high-frequency phase difference is an arc 2 π /M (M is a natural number greater than 1) Gradually changing high frequency voltage, etc. The amplitude of the high frequency voltage can also vary. As another example, a DC voltage is applied to each of the filament electrodes to produce a DC electric field strength that varies along the guide axis within the ion guide channel, the component of which includes an electric field that converges the ions toward the guide axis.

In an embodiment of the invention, the high frequency voltage source includes a plurality of high frequency high voltage switches to generate a rectangular wave high frequency voltage.

In an embodiment of the invention, it is also possible to superimpose different direct current potentials on at least a portion of the layer filament electrodes to form a potential gradient in the direction of the guiding axis.

In an embodiment of the invention, the guide shaft is not limited to a straight line, but may be a curved guide shaft. In this or other embodiments, the DC voltage supply means may be further included to superimpose a DC voltage between the filaments of at least a portion of the layer of the filament electrodes to assist in deflecting the ions along the guide axis.

In an embodiment of the invention, at least a portion of the ion guiding device has a flowing gas, and the direction of the ion migration caused by the potential gradient in the direction of the guiding axis is opposite to the direction of the axial gas flow, so that only specific ion mobility is achieved. A portion of the ions are efficiently transported.

In an embodiment of the invention, the spacing of the filaments in at least a portion of the layer of filament electrodes and the setting of the high frequency voltage allow ions entering the ion guiding device to achieve mass-selective passage in the vicinity of the space in which the filaments are located. , block or destroy.

In another embodiment of the present invention, the setting of the high frequency voltage and the potential gradient setting in the direction of the guiding axis cause the ions entering the ion guiding device to collide with the neutral gas molecules and cause the product ions generated after the collision reaction. , fragment ions, or desolvated ions are efficiently transported.

In an embodiment of the invention, at least a portion of the ion guiding device has a flowing gas, the flowing gas having a gas pressure ranging from 10 to Between 10,000 Pascals. In airflow environments, the diameter of the filament is less than 0.5mm To reduce the impact on the airflow. As an embodiment, in order to effectively fix the filament without allowing the fixing device to interfere with the airflow, the layers of the filament are fixed on the periphery of the cage guiding channel formed by the filament, that is, the fixing bracket or the fixing is provided at the periphery. A frame that wraps, welds, or clamps a filament onto a mounting bracket or a fixed frame. In embodiments where a relatively closed fixed bezel is used, venting holes may be provided in the outer wall of the bezel to reduce obstruction to airflow.

Embodiments of the present invention also provide an ion guiding device assembly comprising a combination of a plurality of the foregoing ion guiding devices, wherein at least a portion of the ion guiding devices are connected in parallel in a first direction to effect convergence of the guiding axes and / or divergent.

Further, in some embodiments, at least a portion of the ion guiding devices are connected in series in a second direction to effect engagement of the guiding shaft.

DRAWINGS

The above described objects, features, and advantages of the present invention will become more apparent from the aspects of the invention.

1 shows a schematic diagram of a straight wire type ion guide according to an embodiment of the present invention.

Fig. 2 shows a structure of a straight wire type ion guide according to an embodiment of the present invention.

Fig. 3 is a view showing a high-frequency electric field distribution diagram formed by an ion guide according to an embodiment of the present invention. 3(a) is an equipotential line distribution on a section passing through the guide axis, and FIG. 3(b) is an equipotential line distribution on a section perpendicular to the guide axis.

Fig. 4 is a view showing an axial potential distribution formed by an ion guide according to an embodiment of the present invention.

Figure 5 shows a simulation of an ion motion trajectory in accordance with an embodiment of the present invention.

Fig. 6 shows an example in which the filament electrode is fixed by a cylindrical stent.

Fig. 7 shows an example in which the filament electrode is fixed by a cylindrical bracket.

Figure 8 shows an embodiment that produces a radial 6-pole field component.

Figure 9 shows an embodiment that produces a radial 8-pole field component.

Figure 10 illustrates an embodiment that produces a rotating multipole field.

Figure 11 shows the manner in which the filaments are tightened by means of elastic pieces.

Figure 12 shows the manner in which the filaments are welded and taut by a spring.

Figure 13 is a view showing a filament ion guiding device for an arcuate guide shaft according to an embodiment of the present invention.

Figure 14 shows a filament ion guiding device for mixing positive and negative ion currents and introducing a collision gas reaction according to an embodiment of the present invention.

Figure 15 is a diagram showing an ion guiding device for forming a focusing ability using a spatial periodic direct current potential according to an embodiment of the present invention, wherein four layers are one cycle.

Figure 16 is a diagram showing an ion guiding device for forming a focusing ability using a spatial periodic direct current potential according to an embodiment of the present invention, wherein six layers are one cycle.

Embodiments of the invention

Under a strong airflow, the use of an alternating electric field to converge and direct the charged particles typically encounters a contradiction between the electrode structure that conforms to the desired electric field and the interference of the airflow under the influence of the electrode structure on the motion of the charged particles. The way to avoid this contradiction is to use filaments that have little effect on the airflow to make the electrodes, but very thin filaments are difficult to place in the desired shape in space.

To this end, the ion guide proposed by the embodiment of the present invention uses a plurality of layers of straightened filaments to form a space structure similar to the 'Oriental Crown' building of the Shanghai World Expo. This structure has good air permeability and does not block the air flow. In the center of the structure, a cage channel is formed, and at the periphery of the structure, the 'wire' constituting the channel is tightly fixed to solve the positional stability of the wire and the insulation problem between the wires. Between each two layers of filaments, the axial direction of the 'filaments' is substantially orthogonal, so the capacitance therebetween can be significantly reduced.

The structure of the straight wire ion guide will now be described by taking the schematic diagram of Fig. 1 as an example. It can be understood that reference is made to Figure 1 below. The ion guides described are for illustrative purposes only and should not be construed as limiting the structure of the ion guide of the present invention.

Along the virtual guide axis z, the filament electrode has 16 The layers, the shapes between the layers are substantially the same. Each layer contains a pair of straightened filaments n.1, n.2 that are equidistant from a guide axis z (n represents the number of layers, in this case 1 to 16) . The second layer of filaments 2.1, 2.2 is perpendicular to the direction of the first layer of filaments 1.1, 1.2. It can also be said that the filament of the second layer is rotated about the guiding axis with respect to the first layer of filaments. Degree. The layers of filaments form a cage guide channel 21 along the guide axis z. All filaments are stretched and secured to the bracket 16. All even layer filaments (ie n.1, n.2 n The even-numbered filaments are connected to the phase Y of the output of the high-frequency power source 20 through the capacitor 17, and all the odd-numbered filaments (i.e., n in the n.1, n.2 are odd-numbered filaments) The other phase X (omitted from the figure) connected to the high-frequency power supply by a capacitor, the X and Y phases are opposite in phase. Bracket 16 It can be made of printed circuit boards, or it can be framed with other materials and attached to printed circuit boards. The filament electrodes can be soldered to the pads of the printed circuit board through small holes in the printed circuit board.

Figure 1 As shown, each layer of filament electrodes essentially uses substantially the same structure, i.e., two parallel filaments. However, alternative embodiments of the present invention allow the structure of the various layers of filament electrodes to be merely similar, such as in this example, the spacing of the two filaments in each layer can vary.

From Figure 1 It can be seen that since the filament electrode is used, and the filaments between adjacent layers are not parallel but rotated by an angle, the interlayer capacitance is greatly reduced, which is advantageous for reducing the power consumption of the high-frequency power source. Considering the possible RF discharge and the diffusion effect of gas molecules in low vacuum, the distance between the filament and the guiding axis is usually not less than 1mm.

The ion guiding device of the present embodiment is particularly suitable for use in an environment where at least a portion of the device or a surrounding gas is present. The pressure range of the flowing gas is typically 10 to 10,000 Between Pascals.

In one embodiment, to reduce the effect of the introducer structure on the airflow, the filaments have a diameter of less than 0.5 mm.

The material which can be used as the filament electrode is typically a metal such as a copper wire, a nickel wire, a stainless steel wire or the like. In order to improve the conductivity of the electrode, gold may be plated on the surface of the filament.

In order to form an axial electric field in the guiding channel 21, a plurality of voltage dividing resistors 18 may be passed. A direct current potential is applied to each of the filament electrodes. A voltage dividing resistor 18 is connected between each of the filament electrodes. The DC voltage source 19 and the voltage dividing resistor 18 are together in the guiding channel 21 An axial potential gradient of DC is formed to facilitate the transport of ions in the axial direction.

Although in the design of Figure 1, the filaments of each layer are equally spaced from the guide axis z, this distance can be varied as needed. figure 2 A variation structure in which the distance between the filament and the guiding axis is gradually reduced is given. This structure has a large inlet, which is favorable for accepting more dispersed incident ions, and can be obtained more and more as the ions are transmitted forward. The convergence of the role played a funnel role.

Figure 3 shows the internal electric field distribution of the ion guiding device shown in Figure 2. Figure 3 (a) Is the equipotential line distribution on the plane between the first layer and the second layer. As can be seen from the figure, the electric field distribution in the guiding channel is roughly a quadrupole field. This is essentially different from the electric field in the previous 'ion funnel'. The high frequency quadrupole field has a converging effect on ions throughout the field. The rotationally symmetric high-order field in the 'ion funnel' only plays a 'rebound effect' when the ions are close to the funnel wall.

At the same time, the electric field distribution in the bucket ion guiding device is different from the electric field formed by the conventional quadrupole, as shown in Fig. 3(b). The longitudinal profile of the longitudinal profile is visible. In the vicinity of the guide axis, the radial potential distribution is not much different from the potential distribution formed by the quadrupole, but near the filament (potential line 31). Concentric circles) The potential gradient rises abruptly, and ions will be subjected to a large amount of repulsive force in these places, preventing them from escaping from the cage guiding channel.

Figure 4 It shows the potential component line distribution of the DC component along the guiding axis when the DC voltage is evenly distributed by the voltage dividing resistor. This potential gradient helps the ions move in the direction of the guiding axis, avoiding long-term retention of ions in the channel. Until the exit 40 Take out and enter the next low pressure environment.

Figure 5 is a plot of the ion motion trajectory obtained by computer simulation. In the simulation, the high frequency voltage on the filament is ± 150V ( 0- Peak), frequency is 1MHz, and air pressure is 20torr (2660Pa). The distance between the filament and the guide shaft is 5.25mm at the inlet and is gradually reduced to 1.25mm. The diameter of the filament is 0.2mm, the distance between the two layers of filaments is 1mm. The simulation results show that the mass number is 100 to tens of thousands of monovalent ions, and most of them can enter the outlet orifice 51 through the guiding device.

In the above simulation test, the high frequency voltage applied to the filament electrode is a sinusoidal RF voltage. In fact, the high-frequency voltage source can also use a plurality of high-frequency high-voltage switches, and the high-frequency voltage signal generated on the filament electrode is a rectangular wave high-frequency voltage.

In the embodiment of the present invention, the holder for fixing the filaments may be formed not only in a rectangular shape as shown in Fig. 1, but also in a cylindrical shape. Figure 6 As shown, a printed circuit 63 and a perforation 64 can be formed in advance on the wall 61 of a hard insulating material such as ceramic. The filament can be embedded on the wall 61, and a plurality of vent holes are formed in the wall. It is convenient for neutral gas to be discharged.

In addition to the frame-shaped brackets shown in Figures 1 and 6, the column-shaped brackets shown in Figure 7 can also be used.

Columns

71, 72, 73, 74 can be fixed on the cone plate 75, while the

filaments

1 , 2 , 3 ... are wound around the column with a pair of

columns

71 , 73 and 72 , 74 On. The position of the filaments of this structure is not defined by the holes, but by the diameter at different heights of the columns.

In the embodiment of the present invention, the ion guiding device made of the filament can be formed not only in the form of a concentrated high-frequency field mainly for generating a quadrupole field, but also in the form of 6 poles, 8 poles and other multi-pole field-based forms. Figure 8 As shown, the filaments of each layer can be pulled into a triangle with the center of the triangle on the guide shaft. The direction of the next layer of triangular filaments is rotated relative to the direction of the upper layer. Degree. Similarly, all of the even-numbered filaments are connected by capacitance to one phase of the high-frequency power supply, and all of the odd-numbered filaments are connected by capacitance to the other phase of the high-frequency power supply, and the two-phase voltages are opposite in phase. This way, the filaments are seen along the axis to form David 6 The shape of the star. The electric field in the ion guiding channel will be dominated by the 6-pole field except for the vicinity of the filament.

As shown in Figure 9, if there are four filaments on each layer (such as 911, 912, 913, 914) ...) drawn into a square shape (contacting each other at the four corners), the square of the next layer (consisting of

wires

921, 922, 923, 924) is rotated relative to the upper layer about the guide axis 45 The angle of the angle is such that an ion guiding device that produces an 8-pole field is formed. 6, 8 poles and 4 Compared with the polar field, the convergence in the central part is weak, but the convergence at the periphery is stronger. One advantage of the ion guide constructed in accordance with embodiments of the present invention is that it can be rationally selected, blended at the center or periphery for convergence, and combined with ion rebound performance near the filament to accommodate different characteristics of the ion source and gas flow. Guidance requirements under characteristics.

In addition to the above angles, the angle of rotation can be radians 2 π /N , N = 5 , 7 , 9 , 10 , 11 or 12 .

Although in the embodiments described above, the angle of rotation between the guide filaments of each layer remains constant, such as 90 °, 60 °, 45 °, etc., but in other embodiments, the angle of rotation of each layer of filaments about the guide axis is not necessarily fixed. For example, in the ion guide scheme shown in Figure 10, the angle of rotation of each layer from the second layer of filaments is: 90, 105, 90, 105... degrees; that is, the layer (12.12, 12.2) turns 90 degrees to the layer (11.11, 11.2), and the layer (13.1, 13.2) Level (12.12, 12.2) to 105 Degree. Here, if all of the even-numbered filaments are still connected to one phase of the high-frequency power source through a capacitor, all of the odd-numbered filaments are connected to another phase of the high-frequency power source through a capacitor, and the voltages of the two phases are opposite in phase. Then, the filaments form a quadrupole field guiding channel that rotates stepwise along the guiding axis. In the ion guide, the shape of the ion cloud also rotates during the ion transport, making the transmission channel more uniform in all directions, and may be more suitable for the presence of the swirling airflow.

As a more singular embodiment, the phase difference of the high frequency voltage between the filaments of each layer may not be 180 degrees. If the phase of the high frequency voltage between the layers is different 120 degrees (or 90 degrees), so that every 3 layers (or 4 layers), the phase of the high-frequency voltage is bypassed for 1 week. This embodiment can be extended to make the high frequency phase difference of adjacent adjacent layers to be arc 2 π /M , sequentially providing the same frequency M phase high frequency voltage to the 1 to M layer filament electrode, and the M layer continues this phase sequence later, where M is greater than 1 Natural number. By using the periodic multi-phase high-frequency electric field between the layers, an axial traveling wave can be generated to facilitate the ion transmission in the guiding direction. Advantageously, in this case it is not necessary to apply an axial direct current potential gradient to push the ions.

The example in which the phase of the high-frequency voltage periodically changes along the respective filament electrode layers is given above. In other embodiments, an electric field can be constructed by providing only high frequency voltages of different phase to the adjacent layer filament electrodes, the electric field comprising a component that converges the ions toward the guiding axis.

Of course, when there is a strong directional airflow in the same direction as the ion guiding direction, even if there is no help of the axial DC potential gradient (the potential gradient in the direction of the guiding axis is negative, the positive ion is positively assisted) A certain concentration of ions of the high-frequency electric field can also be efficiently transmitted. When the velocity of the directional airflow is sufficiently large, the potential gradient in the direction of the guiding axis can prevent the forward transmission of ions, and the direction of the ion migration motion caused by the electric field is opposite to the axial airflow direction. If the ion mobility is large, It cannot be transmitted efficiently, and a part of ions with a small mobility is efficiently transmitted.

From the perspective of the installation process, the stress map straightens and tightens the individual filaments. The filament mounting bracket outside the guiding channel should be processed firmly and accurately. In order to tighten the filament, Figure 11 The steel column retainer 111 with better elasticity is used in the column design to provide tension, and the slot 112 is used to limit the filament 1 , to fix its axial position. For framed brackets and designs that use a printed circuit board to mount the filaments, Figure 12 shows a solution for tightening the filaments with elastic tabs. In the picture,

filaments

1 , 3 Waiting through the small holes 122 on the printed circuit board, soldering into the soldering holes 121 on the elastic soldering piece 120, and the elastic soldering pieces are soldered to the conductive circuits of the printed circuit board 123 On. Also shown is a partial refractory member 124 soldered to the same printed circuit board. It means that the circuit board can be used to install these devices as well as leads, connectors, etc., and it is convenient to implement functions such as high-frequency voltage coupling and DC voltage division.

In a preferred embodiment of the invention, the layers of the filament electrodes of each layer are substantially perpendicular to the guide axis. For example, the angle between the plane of each layer of filament electrodes and the guide axis is set at 85 ° to 95 ° Between. Of course, the orientation of the filaments is not completely perpendicular to the guiding axis and does not have a serious impact on the ability of the ions to converge. Typically, it can be defined that the angle between the plane of the filament and the guide axis is 90 +/- 20 degrees, ie 70 ° -110 °. However, the guide axis defined by the embodiment of the present invention is not necessarily a straight line, and it may include a curve. Figure 13 shows this curved wire electrode ion guide. Guide axis in the figure 132 For an arc, the ion and neutral gas stream 131 enters the guide channel in a tangential direction from one end of the inlet of the guide shaft. The ions are concentrated near the guiding axis by the concentrated electric field and are led to the exit along the arc of the guiding axis. . The neutral gas flow rushes toward the exhaust port 135 in the original direction. In addition to the superimposed axial potential gradients of the straight guide tubes, in this example, two vertical filaments of each odd layer, such as filament 134.1, A DC potential difference can be superimposed between 134.2 to further obtain the deflection force of the ions, preventing the ions from being flushed out of the guiding channel by the strong airflow.

The above various embodiments are only intended to illustrate a possible construction method of the multilayer filament ion guiding device, and a part of the technical details to show the implementability of the guiding device. However, the invention is not limited to the several wire-forming forms and electric field structures given above. For example, each layer of filaments can also be formed into a similar pentagon, pentagram or rectangle, or even six or seven sides and above. It will be appreciated that in these embodiments, it is preferred that the layers of filament electrodes remain substantially identical. However, the polygons of the respective filament electrodes are allowed to have similarities in size difference, or slight deformation between the polygons of the respective filament electrodes is allowed.

and, The voltage signals attached to the filaments may also be square waves, sawtooth waves, pulse trains, and may also be a combination of sine waves, square waves and pulse sequences. The alternating voltage signal generating the radially bound electric field does not have to be equally distributed on the layers of filaments, but can be in the same guiding device The spacing of the filaments in at least a portion of the layer of filament electrodes is combined to select ions. Figure 3a For example, the guidance device with a quadrupole RF electric field distribution is described. The influence of the quadrupole electric field on the stability of ion trajectories with different mass-to-charge ratios can be used. Parameter description, the value is roughly inversely proportional to the square of the filament spacing and the mass-to-charge ratio of the ions, and is proportional to the amplitude of the RF voltage attached to the filament. In the specific design, according to the mass-to-charge ratio of the ions, the spacing of the filaments in the bonding structure, through the values of the

RC networks

17 and 18 in Fig. 1, static or The RF voltage is dynamically changed, and ions of a selected range of mass-to-charge ratios have q parameters corresponding to stable ion trajectories. Thereby achieving the passage or elimination of the quality of the passing ions. At the same time, when the amplitude of the RF voltage between the filament layers changes, similar to the radial selection described above, an equivalent barrier can also be generated in the axial direction of the guiding device, and the barrier is also in accordance with the ion mass-to-charge ratio. The change can be used to achieve temporary interception of certain ions. Using these features and the device can also be used as an ion desolvator to achieve the best ion transport effect through the window through the mass-to-charge ratio dynamic change of the ion mass-to-charge ratio during desolvation.

Further, the direct current potential that generates the axial electric field does not have to be equally distributed on the respective layers of filaments. Alternatively, the distribution of the resistor 18 network can be set as needed to change its distribution and change its distribution as needed. For example, a relatively negative DC voltage can be temporarily applied to certain layers to allow ions to be trapped in the areas of these layers during this time. Then, change to a normal gradient distribution to release the trapped ions. Another example is the use of an axial electric field to accelerate ions, or even an alternating axial or transverse electric field to induce high-speed vibration of ions in space, increasing the collision probability and intensity of ions with neutral molecules to achieve ions at high pressure. Under the conditions, it collides with the neutral gas, and then the reaction product ions, ion fragments or desolvated products are effectively guided for analysis.

Without limiting the scope, it is not an exemplification of the embodiments in which the various changes described above are combined, and a combination of the various variations described above to constitute a practically usable example is a basic ability of one of ordinary skill in the art.

For example, some or all of the straight wire electrodes in the guiding device can be made of a resistance heating material. By adding a heating current source device between the two ends of the electric resistance wire, a heating function can be added to the device, and infrared rays can be radiated to generate a pair. The heat-assisted desolvation, thermal dissociation, and infrared radiation dissociation of the target ions in the guiding device. In addition, as a variant of the resistance wire, when the device is operated with a high-frequency alternating current power source, a straight wire electrode can be made of a material having a high magnetic permeability, and the magnetic wire is heated by a magnetic induction eddy current like an induction cooker to achieve the same purpose. Additional heating current source devices can be eliminated.

For example, by multiplexing a plurality of the guiding device structures (such as 141.1 and 141.2 in Fig. 14), a part of the filaments are shared (as shown in Fig. 14). 14 The combination of 143.1 and 143.2) or the formed guide device can further enhance the ion conduction capability of the device. As further shown in FIG. 14, a plurality of filament ion guiding structures are connected in series, as shown in the figure. 141, 142, 143 As shown, the dispersion or convergence and overlap of the plurality of virtual guide axes in the array can be realized, so that a plurality of ion sources and lower ion analysis devices disposed upstream and downstream of the ion guiding structure can realize one-to-many and more For one, many to many ion sources - Analyzer coordination, ie the role of ion current shunts, multiplexers and exchangers.

The combination of guides shown in Figure 14 also allows positive ion currents 144, negative ion currents 145, and neutral molecular flows of different polarities. 146 The polymerization, mixing and separation are carried out to initiate molecular ion reaction and charge transfer reaction to fragment the target ions, and a separated product ion stream is obtained for subsequent cascade mass spectrometry. For example, in the system shown, the peripheral circuit system can add a DC potential offset that is successively decreasing from left to right between the layers of the guiding system to make the positive ion current 144 is subjected to a guided axial potential distribution 147 that decreases stepwise along the flow direction, while causing the reverse negative ion current 145 to receive a pilot axial potential distribution that rises stepwise along the flow direction. The effect of the inflow into the guiding structure middle section 142 is mixed with each other. Both the positive and negative ion currents in the mid-section of the series guiding structure 142 are directed toward the guiding structure 142 due to the internal alternating quadrupole field. The central axis converges and reacts to obtain the ion fragmentation effect of the so-called charge transfer dissociation (EDD) method. The new positive and negative ion currents obtained after the reaction can pass through the filament groups 142.1 on both sides of the guiding structure The DC deflection potential is further superimposed between 142.2 to deflect and separate to the respective exit channels. Furthermore, the permeability of the filament ion guiding structure can be utilized to guide the structure to the middle section 142 A suitable collision gas 146 such as argon, isobutane or the like is introduced to increase the residence time of the positive ion stream 144 and the negative ion stream 145, and can pass the collision gas 146. Catalysts increase the charge transfer efficiency to increase the dissociation effect.

Finally, it is pointed out that the convergence of the ions as they pass through the ion guide of the invention can also be achieved by applying only a special DC voltage across the filaments. When different DC voltages are applied to the respective filament electrodes, A DC electric field strength that varies along the guiding axis is generated within the ion guiding channel. These DC voltages are configured such that the component of the DC electric field strength includes an electric field that converges ions toward the steering axis. Now take Figure 15 Take an example to illustrate its working principle. Each layer here contains a pair of parallel straight filaments n.1, n.2 (n represents the number of layers, and n is a natural number). The second layer of filament 2.1, 2.2 Direction with the first layer of filaments 1.1, 1, 2 The direction is perpendicular, the filament direction of the third layer is perpendicular to the direction of the second layer of filaments, the filament direction of the third layer is parallel to the direction of the first layer of filaments, and so on. The potentials on the filaments of each layer are shown in the figure, and the relationship is also shown by the U Show it out. It can be seen that the voltage of each layer of filaments is superimposed with +/- ΔV on each even layer in addition to a gradually decreasing amount of direct current. For example, when Δ V=10V, the potential of each layer is 130V. , 110V (120-10), 110V, 110V (100+10), 90V, 70V (80-10), 70V, 70V (60+10), 50V, 30V (40-10), 30V, 30V (20+10), 10V. The resulting DC electric field strength is along the guiding axis. The periodic variation of a layer. This feature is close to a series of DC quadrupole lenses that reverse the potential and cause periodic focusing and focusing of ions as they move along the guiding axis. Defocused. The ion can reach a speed of several tens to several hundred meters per second in the axial direction of the ion guide under the action of the airflow and the direct current electric field gradient, at such a speed within a distance of a few millimeters as a refocusing and defocusing unit. Movement is equivalent to the action of a quadrupole field generated by an ion undergoing an alternating voltage of several thousand to several hundreds of thousands of hertz at the same position, thereby achieving focusing of the ions in the radial direction. Again 16 For example, an equal DC voltage is applied to three adjacent pairs of layers, and the three layers are a group. The voltage between the groups is decremented. The DC electric field generated at this time also causes the ions to move along the axial direction of the guide. Sexual ( 6 Layer-by-cycle) focusing and defocusing, focusing defocusing combined with ion collision cooling to achieve convergence of ions in the radial direction.

The above description of the preferred embodiments and various modifications of the present invention can be made by those skilled in the art in various combinations and substitutions on the basis of the above preferred embodiments and variations. However, such variations are intended to be included within the scope of the invention as defined by the appended claims.

Claims

An ion guiding device comprising:

a plurality of filament electrodes distributed along a guiding axis defining a direction of ion guiding, each layer of filament electrodes comprising at least two straight filaments at a distance from the guiding axis, each layer of filament electrodes Rotating a certain angle with respect to the adjacent layer filament electrode about the guiding axis, so that the multilayer filament electrode forms a transparent cage ion guiding channel around the guiding axis;

A power supply device provides a voltage to each of the layers of filament electrodes to at least configure an electric field that converges ions toward the guide axis.
The ion guiding device according to claim 1, further comprising a suspension holder located outside said ion guiding channel formed by said plurality of filament electrodes, said filament of said multilayer filament electrode being fixed to said Said suspension bracket.
The ion guiding device according to claim 1, wherein an angle between a plane in which each of the filament electrodes is located and the guiding shaft is between 70° and 110°.
The ion guiding device according to claim 1, wherein an angle between a plane in which each of the filament electrodes is located and the guiding shaft ranges from 85 to 95.
The ion guiding device according to claim 1, wherein each of the filaments of each of the filament electrodes has the same distance from the guide shaft.
The ion guiding device according to claim 5, wherein at least two of the filament electrodes of each layer are parallel to each other.
The ion guiding device according to claim 1, wherein the direction of each of the filament electrodes is rotated by 2π/N around the guiding axis with respect to the direction of the upper layer of the filament electrodes, wherein N = 4,5,6,7,8,9,10,11 or 12.
The ion guiding device according to claim 1, 3 or 4, wherein each of the filament electrodes comprises a pair of filaments, and the pair of filaments are substantially equal in distance from the guide axis and substantially parallel to each other.
The ion guiding device according to claim 8, wherein the direction of each of the filament electrodes is rotated by an angle of π/2 around the guiding axis with respect to the direction of the upper layer of the filament electrodes.
The ion guiding device according to claim 1 or 9, wherein said power supply device comprises a high-frequency voltage source for supplying a high-frequency voltage to each of the filament electrodes to at least configure an electric field for converging ions toward said guiding axis .
The ion guiding device according to claim 10, wherein said high frequency voltage source supplies a high frequency voltage to each of the plurality of filament electrodes, and comprises supplying a high frequency voltage of a different phase to the adjacent layer filament electrodes.
The ion guiding device according to claim 10, wherein said high frequency voltage source supplies a high frequency voltage to each of the plurality of filament electrodes, comprising: providing mutually inverted high frequency voltages to adjacent layer filament electrodes .
The ion guiding device according to claim 11 or 12, wherein a distance between the set of filament electrodes to which at least the in-phase high-frequency voltage is applied to the respective layers of the filament electrodes and the guide shaft is gradually reduced along the guiding axis.
The ion guiding apparatus according to claim 10, wherein said power supply means comprises a direct current voltage source such that at least a portion of the layer filament electrodes are superimposed with different direct current potentials to form a potential gradient in the direction of said guiding axis.
The ion guiding device according to claim 11, wherein said high frequency voltage source supplies a high frequency voltage to each layer of the filament electrodes, and comprises sequentially supplying the same frequency M phase high frequency voltage to the 1 to M layer filaments. The high frequency phase difference of the electrodes and adjacent layers is 2π/M, and the M layer continues this phase sequence later, and M is a natural number greater than 1.
The ion guiding device according to claim 10, wherein said high frequency voltage source supplies a high frequency voltage to each of the plurality of filament electrodes including providing different high frequency voltage amplitudes to the respective layer of filament electrodes.
The ion guiding device according to claim 1 or 2, wherein said power supply means comprises a direct current voltage source for supplying a direct current voltage to each layer of the filament electrodes, and generating in said ion guiding channel along the guiding axis a varying DC electric field strength whose component contains an electric field that converges ions toward the guiding axis
The ion guiding device according to claim 17, wherein the electric field intensity in said ion guiding channel changes periodically along the guiding axis.
The ion guiding device according to claim 2, wherein each of the filaments is fixed to the suspension holder by welding, winding or clamping.
The ion guiding device according to claim 2, wherein said suspension bracket has a threading hole and a printed circuit.
The ion guiding device according to claim 2, further comprising a tensioning mechanism made of an elastic material attached to said suspension bracket.
The ion guiding device according to claim 2, wherein at least a portion of the filaments of the suspension stent constitute an outer wall of the ion guiding device.
The ion guiding device according to claim 22, wherein said ion guiding means has an exhaust hole on an outer wall thereof.
The ion guiding device according to claim 1, wherein said guiding shaft is a curved guiding shaft.
The ion guiding device according to claim 24, further comprising DC voltage supply means for superimposing a direct current voltage between the filaments of at least a portion of the layer of the filament electrodes to assist in deflecting the ions along the curved guiding axis .
The ion guiding apparatus according to claim 10, wherein said high frequency voltage source comprises a plurality of high frequency high voltage switches to generate a rectangular wave high frequency voltage.
The ion guiding device according to claim 14, wherein the direction of the ion migration caused by the potential gradient in the direction of the guiding axis is opposite to the direction of the axial gas flow, so that a part of ions having only a specific ion mobility are efficiently transmitted. .
The ion guiding device according to claim 10, wherein the spacing of the filaments in at least a portion of the layer of filament electrodes and the setting of the high frequency voltage enable ions entering the ion guiding device to be realized in the vicinity of the space in which the filaments are located Passivity, pass or eliminate.
The ion guiding device according to claim 14, wherein said setting of said high frequency voltage and said potential gradient setting of said guiding axis direction cause an ion entering the ion guiding device to collide with a neutral gas molecule, and The product ions, fragment ions, or desolvated ions generated after the collision reaction are efficiently transported.
The ion guiding device according to claim 1 or 2, wherein at least a portion of said ion guiding means has a flowing gas, and said flowing gas has a gas pressure ranging between 10 and 10,000 Pascals.
The ion guiding device according to claim 1 or 2, wherein the filament has a diameter of less than 0.5 mm.
The ion guiding device of claim 1 wherein at least a portion of the filament electrode of said ion guiding device also functions as a heater.
An ion guiding device assembly comprising a plurality of combinations of ion guiding devices according to claim 1 wherein said plurality of ion guiding devices share at least a portion of the filaments.
An ion guiding device assembly comprising a plurality of combinations of ion guiding devices according to claim 1 wherein there is convergence, divergence or coincidence of the guiding axes of the ion guiding devices.