Ion mobility separation transmission device and ion transmission method

Abstract

The invention discloses an ion mobility separation and transmission device and an ion transmission method. The ion mobility separation and transmission device comprises a focusing guide rod, a guide rod support, a mobility separation electrode plate, a partition plate, a focusing electrode plate, a first circuit board and a second connection circuit board. Ions to be measured enter a mobility separation part of the ion mobility separation transmission device, the mobility separation part is subjected to electric field force and gas collision acting force, the ion separation method is operated according to an assembly line mode, in the first period, the ions enter the device, space arrangement is generated according to the size of a collision cross section, and enrichment of the ions is achieved; reverse voltage is applied to the atmospheric pressure interface air curtain disc to prevent subsequent ions from entering the device. According to the ion mobility separation and transmission device, one-dimensional information of a collision cross section is added, ions can be enriched in the ion mobility separation and transmission device, the ions are always bound by a radio frequency quadrupole field in a channel from entering the ion mobility separation and transmission device, loss is not prone to occurring, and the detection sensitivity can be improved.

Description

Technical Field

[0001] The present invention relates to a mass spectrometry sampling technology, and in particular to an ion mobility separation and transmission device and an ion transmission method. Background Art

[0002] Traditional LC-MS instruments usually introduce samples into the system through an electrospray ion source, an atmospheric pressure interface, and an ion transmission device. The electrospray ion source converts the solvent containing the sample into small droplets and applies a high voltage. During the atomization process, the sample forms a Taylor cone, generating an electrospray phenomenon. During the evaporation of the solvent, charged ions are generated through Coulomb explosion and enter the atmospheric pressure interface. The atmospheric pressure interface is usually composed of an air curtain plate and a sampling cone. The gap between the air curtain plate and the sampling cone is passed through a protective backflush gas to prevent droplets, neutral particles and other contaminants from entering the mass spectrometer. After the sampling cone, the ions enter the vacuum area and are captured by the ion transmission device and transmitted to a triple quadrupole or quadrupole time-of-flight mass analysis system for detection. The ion transmission device is generally composed of a quadrupole, an ion funnel, a capillary, etc. The electrode plates of the ion transmission device and the mobility separation device of the existing ion mobility mass spectrometer are usually processed with stainless steel sheets, gold-plated copper sheets or printed circuit boards, and are soldered together. There are problems such as high difficulty in processing and assembly and difficulty in cleaning after contamination. Moreover, complex airflow channels easily cause ion divergence and loss of detection sensitivity. The present invention proposes a novel ion mobility separation and transmission device for an ion mobility mass spectrometer to solve the above problems. Summary of the invention

[0003] In order to solve the above-mentioned deficiencies in the prior art, an object of the present invention is to provide an ion mobility separation and transmission device and an ion transmission method, which can improve the detection sensitivity when transmitting ions.

[0004] The technical solution adopted by the present invention to solve the technical problem is: an ion mobility separation and transmission device, comprising two first circuit boards and two second circuit boards, a mobility separation electrode sheet is connected between the two first circuit boards, so that the two first circuit boards and the mobility separation electrode sheet together constitute a first module, a focusing electrode sheet is connected between the two second circuit boards, so that the two second circuit boards and the focusing electrode sheet together constitute a second module, one end of the first module is connected to one end of the second module, and the other end of the first module is connected to four focusing guide rods;

[0005] Among the four focusing guide rods, two adjacent ones are the first pair of focusing guide rods, and the other two are the second pair of focusing guide rods, wherein the first pair of focusing guide rods introduces a voltage U0, and the second pair of focusing guide rods introduces a voltage -U0;

[0006] In the first module, the number of mobility separation electrode sheets is set to be multiple, so that the thickness of the mobility separation electrode sheets after being stacked is adapted to the length of the first circuit board, and every two adjacent mobility separation electrode sheets are separated by a partition, and each mobility separation electrode sheet and the center of the partition are provided with a first center hole; each mobility separation electrode sheet has four electrodes, two opposite ones of which constitute a pair of electrodes, and in the two pairs of electrodes, one pair of electrodes introduces a voltage U1 through one of the first circuit boards, and the other pair of electrodes introduces a voltage -U1 through the other first circuit board; and in the first module, the direction of the electric field is from the direction close to the second module to the direction close to the focusing guide rod;

[0007] In the second module, the number of focusing electrode sheets is set to be multiple, so that the length of the focusing electrode sheets after being stacked is adapted to the length of the second circuit board, each of the focusing electrode sheets is provided with a second central hole, and the aperture of the second central hole of the focusing electrode sheet gradually decreases from one end close to the first module to the end far from the first module, so that the central hole of the focusing electrode sheet in the second module forms a funnel shape; each focusing electrode sheet has four electrodes, and in two adjacent focusing electrode sheets, the four electrodes of the first focusing electrode sheet are introduced into the voltage U2 through one of the second circuit boards, and the four electrodes of the second focusing electrode sheet are introduced into the voltage -U2 through the other second circuit board;

[0008] An airflow is introduced into the first central hole, and the airflow flows from an end close to the focusing guide rod to an end close to the second module.

[0009] Optionally, the mobility separation electrode sheet and the focusing electrode sheet are each provided with two introduction electrodes.

[0010] Optionally, isolation capacitors and voltage-dividing resistors are attached to both the first circuit board and the second circuit board.

[0011] Optionally, the focusing guide rod is made of 316L stainless steel, and the diameter of the focusing guide rod is 4-5 mm, and the electric field radius is 2-3 mm.

[0012] Optionally, the focusing guide rod is connected to the first module via a guide rod bracket.

[0013] Optionally, the guide rod bracket is made of PEEK material or PEI material.

[0014] Based on the above-mentioned ion mobility separation and transmission device, the present invention also provides an ion transmission method, comprising the following steps:

[0015] S1, the sample is ionized to produce ions to be tested;

[0016] S2, the ions to be measured enter the ion mobility separation and transmission device through the sampling cone and the air curtain plate;

[0017] S3, after the ions to be measured enter the first module of the ion mobility separation and transmission device, the ions to be measured collide with the airflow in the first central hole of the first module, and the ions to be measured are spatially arranged according to the size of the collision cross section and reach an equilibrium position;

[0018] S4, after the ions to be measured are spatially arranged in the first central hole, the air curtain disk applies a reverse voltage to prevent subsequent ions from entering the ion mobility separation and transmission device;

[0019] S5, applying a DC voltage to the mobility separation electrode sheet in the first module, and scanning the amplitude of the DC voltage;

[0020] S6. During the process of scanning the amplitude of the DC voltage, the amplitude of the DC voltage gradually decreases. When the collision force of the airflow is greater than the electric field force, the ions to be measured lose balance and move toward the second module of the ion mobility separation and transmission device.

[0021] S7. Under the action of the airflow, the ions to be measured enter the second module in sequence, flow out from the second central hole of the second module, and then enter the mass analysis system.

[0022] Optionally, when the ions to be measured enter the ion mobility separation and transmission device, the movement trajectory of the ions to be measured is constrained by a focusing guide rod, so that the movement trajectory of the ions to be measured converges to the axis of the first central hole.

[0023] Optionally, after a DC voltage is applied to the mobility separation electrode sheet in the first module, the electric field force in the first central hole of the first module is distributed in a gradient.

[0024] Through the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0025] 1. Ions are separated by mobility, which increases the collision cross section information and improves the separation and detection capabilities of complex compounds.

[0026] 2. Ions can be enriched in the ion mobility separation and transmission device to improve detection sensitivity.

[0027] 3. When ions enter the ion mobility separation and transmission device, they are always bound by the radio frequency quadrupole field in the channel and are not easily lost, which can improve the detection sensitivity.

[0028] 4. In addition to being applied to newly designed instruments, the present invention can also be used to transform traditional LC-MS systems. The ion mobility function can be realized by directly replacing the transmission part with the ion mobility separation and transmission device of the present invention, thereby improving the scalability of the instrument.

[0029] 5. It reduces the complexity of the structure, reduces the difficulty of assembly, and is easy to disassemble and clean after contamination, which is conducive to reducing procurement and use costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of an ion mobility separation transport device;

[0031] Figure 2 is a schematic diagram of a mobility separation electrode sheet;

[0032] Figure 3 It is a specific implementation of the spacer;

[0033] Figure 4 is a schematic diagram of a first circuit board and a second circuit board;

[0034] Figure 5 is a schematic diagram of an ion mobility separation and transport device;

[0035] Figure 6 It is a specific implementation method of the present invention in a triple quadrupole ion mobility mass spectrometer;

[0036] Figure 7 This is another specific implementation of the present invention in a quadrupole time-of-flight ion mobility mass spectrometer. DETAILED DESCRIPTION

[0037] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] The present invention discloses an ion mobility separation and transmission device, such as Figure 1 As shown, the ion mobility separation and transmission device includes: a focusing guide rod 31, a guide rod bracket 46, a mobility separation electrode sheet 41, a partition 42, a focusing electrode sheet 49, a first circuit board 50 and a second circuit board 51.

[0040] In one embodiment of the present invention, the focusing guide rod 31 includes four poles. Optionally, the focusing guide rod 31 is made of 316L material, with a diameter of 4 to 5 mm and a field radius of 2 to 3 mm. The focusing guide rod 31 is connected to the ion mobility separation transmission device through a guide rod bracket 46. Optionally, the guide rod bracket is made of PEEK or PEI material. In another embodiment of the present invention, the number of the focusing guide rod 31 can be, for example, a hexapole, an octopole, etc.

[0041] In the present invention, the number of the mobility separation electrode sheets 41 and the number of the focusing electrode sheets 49 are both set to be multiple, so that the thickness of the multiple mobility separation electrode sheets 41 after being stacked matches the length of the first circuit board 50, and the thickness of the multiple focusing electrode sheets 49 after being stacked matches the length of the second circuit board 51. The mobility separation electrode sheets 41 are separated by partitions 42. In one embodiment of the present invention, the mobility separation electrode sheets 41 are made of a printed circuit board PCB with a thickness of 1.6 mm, and the partitions 42 are also made of a printed circuit board PCB with a thickness of 1.6 mm.

[0042] In the present invention, the first circuit board 50 and the second circuit board 51 are both made of printed circuit boards 418. Figure 4 As shown, the printed circuit board 418 includes a spring contact pin connector 417, and an isolation capacitor 44 and a voltage-dividing resistor 45 are attached to the printed circuit board, and the isolation capacitor 44 and the voltage-dividing resistor 45 together constitute a resistor-capacitor network. There are two first circuit boards 50, and the two first circuit boards 50 are respectively connected to the upper and lower sides of the mobility separation electrode sheet 41 to form a first module. There are also two second circuit boards 51, and the two second circuit boards 51 are respectively connected to the upper and lower sides of the focusing electrode sheet 49 to form a second module. The first circuit board 50 and the second circuit board 51 are both installed in a plug-in manner to achieve rapid combination and replacement of the mobility separation electrode sheet 41 and the focusing electrode sheet 49.

[0043] In the present invention, four electrodes are distributed on the mobility separation electrode sheet 41, such as Figure 2 As shown, after applying radio frequency voltage to the four electrodes, electrode one 410, electrode two 411, electrode three 412, and electrode four 413, a pure radio frequency quadrupole field is formed. Electrode one 410 and electrode three 412 are a pair of electrodes connected to the first introduction electrode 414, and the radio frequency voltage U1 is introduced through the first introduction electrode 414. Electrode two 411 and electrode four 413 are another pair of electrodes connected to the second introduction electrode 415, and the radio frequency voltage -U1 is introduced through the second introduction electrode 415 to form a pure radio frequency quadrupole field. In addition, the four electrodes distributed on the mobility separation electrode sheet 41 are all gold-plated, and the first introduction electrode 414 and the second introduction electrode 415 are both gold-finger-processed to introduce the voltage on the two pairs of electrodes.

[0044] A first central hole is provided at the center of the mobility separation electrode sheet 41 . The first central holes of all the mobility separation electrode sheets 41 have the same aperture for passing ions.

[0045] In the present invention, a sealing ring installation groove is provided on the partition plate 42, such as Figure 3 As shown, a FKM sealing ring is installed in the groove to seal the same mobility separation electrode sheet 41. Another implementation of the partition 42 is to place a PTFE sealing gasket between the same mobility separation electrode sheets 41 for sealing.

[0046] In one embodiment of the present invention, the focusing electrode sheet 49 is made of a printed circuit board PCB, and the thickness is preferably 1.0 mm to 3.0 mm.

[0047] Four electrodes are distributed on the focusing electrode sheet 49 of the present invention. A radio frequency voltage U2 is superimposed on the four electrodes of one focusing electrode sheet 49, and a radio frequency voltage -U2 is superimposed on the four electrodes of another adjacent focusing electrode sheet 49. At the same time, a second center hole is opened in the center of the focusing electrode sheet 49, and the aperture of the second center hole gradually decreases from one end close to the mobility separation electrode sheet 41 to the end away from the mobility separation electrode sheet 41, so that the electric field of the focusing electrode sheet 49 can focus ions in the radial direction in the form of a funnel.

[0048] Two lead-in electrodes are also provided on the focusing electrode sheet 49 , and a gold finger process is adopted to introduce voltage to the electrodes of the focusing electrode sheet 49 .

[0049] The focusing guide rod 31 is connected to the mobility separation electrode sheet 41 through the guide rod bracket 46 , the mobility separation electrode sheet 41 is connected through the connecting column 43 and the fastening screw 47 , and the focusing electrode sheet 49 is connected through the focusing electrode sheet mounting bracket 48 .

[0050] The present invention provides an ion transmission method, which comprises the following steps:

[0051] S1. The sample is ionized to produce ions to be tested.

[0052] The sample is sprayed out from the atomizer 101 of the ion source and a high voltage is applied. The sample forms a Taylor cone during the atomization process, generating an electrospray phenomenon, and forming atomized small droplet spray 107. During the evaporation of the solvent, charged ions 108, i.e., the ions to be measured, are generated through Coulomb explosion.

[0053] S2. The ions to be measured pass through the sampling cone and the air curtain plate and enter the ion mobility separation and transmission device.

[0054] Charged ions 108 enter the atmospheric pressure interface composed of the air curtain disk 102 and the sampling cone 103. The gap between the air curtain disk 102 and the sampling cone 103 is passed with protective backflush gas 109 to prevent contamination such as droplets and neutral particles from entering the mass spectrometer.

[0055] S3. After the ions to be measured enter the first module of the ion mobility separation and transmission device, the ions to be measured collide with the airflow in the first central hole of the first module, and the ions to be measured are spatially arranged according to the size of the collision cross section and reach an equilibrium position.

[0056] When the ions to be measured enter the ion mobility separation and transmission device, the moving trajectory is constrained by the focusing guide rod 31, so that the moving trajectory of the ions to be measured converges to the axis of the first central hole.

[0057] Among the four focusing guide rods 31, two opposite poles form a pair, one pair of electrodes is applied with U0 voltage, and the other pair of electrodes is applied with -U0 voltage to form a pure radio frequency quadrupole field, which has a binding effect on the motion trajectory of the ions, and the flight trajectory of the ions converges toward the axis. The U0 amplitude is adjustable from 0 to 200V, and the frequency can be selected from 800kHz to 2000kHz.

[0058] S4. After the ions to be measured are spatially arranged in the first central hole, the air curtain disk applies a reverse voltage to prevent subsequent ions from entering the ion mobility separation and transmission device.

[0059] The bound ions to be measured enter the mobility separation part of the ion mobility separation and transmission device, which includes a mobility separation electrode sheet 41, a partition 42, a focusing electrode sheet 49, a first circuit board 50, and a second circuit board 51. The ions to be measured are subjected to electric field force and gas collision force in this part.

[0060] S5. Apply a DC voltage to the mobility separation electrode sheet in the first module, and scan the amplitude of the DC voltage.

[0061] In the first module, the electric field force is generated as follows:

[0062] The DC voltage U1 is distributed to the mobility separation electrode sheets 41 through the resistor and capacitor elements on the first circuit board. The first mobility separation electrode sheet 41 near the inlet is grounded or connected to a bias voltage. The mobility separation electrode sheet 41 near the outlet is applied with voltage U1. According to the difference in voltage on each electrode sheet, a spatial gradient electric field distribution along the axial direction is generated, forming an axial electric field force from the outlet to the inlet required for mobility separation. The formed electric field distribution is as follows: Figure 5As shown in the figure, the coordinate system represents the potential distribution along the axial direction, the origin O represents the position at the entrance of the mobility separation part as the origin of the coordinate, the abscissa X represents the axial displacement, and the ordinate E represents the electric field intensity. The OA segment indicates that there is a linearly increasing gradient electric field intensity in this section, and the AB segment indicates that there is an equal electric field intensity in this section.

[0063] The magnitude of the axial electric force on the ions is related to the position of the ions on the axis. For ions of the same charge, the electric force they experience is smaller near the entrance and larger near the exit.

[0064] In addition, an airflow in the same direction as the flight direction of the ions to be measured is introduced into the ion mobility separation and transmission device, and the flow direction is from the inlet to the outlet. The gas collision force on the ions to be measured is related to the collision cross section. The ions to be measured with a large collision cross section are subject to a large force, and the ions to be measured with a small collision cross section are subject to a small force. After the forces on the ions to be measured are balanced, the ions to be measured with a large collision cross section are close to the outlet, and the ions to be measured with a small collision cross section are close to the inlet. The distribution of the ions to be measured produces spatial separation according to the size of the collision cross section.

[0065] A pair of RF voltages U1 and -U1 are distributed to the mobility separation electrode sheet 41 through the resistor and capacitor elements on the first circuit board 50. The mobility separation electrode sheet 41 is provided with four electrodes, and the electrodes facing each other form a pair. One pair of electrodes is applied with voltage U1, and the other pair of electrodes is applied with voltage -U1, forming a pure RF quadrupole field, which binds ions in the radial direction and distributes them to a space close to the axis. The amplitude of U1 is adjustable from 0 to 500V, and the frequency can be selected from 800kHz to 2000kHz.

[0066] S6. During the scanning of the amplitude of the DC voltage, the amplitude of the DC voltage gradually decreases. When the collision force of the airflow is greater than the electric field force, the ions to be measured lose balance and move toward the second module of the ion mobility separation and transmission device.

[0067] S7. Under the action of the airflow, the ions to be measured enter the second module in sequence, flow out from the second central hole of the second module, and then enter the mass analysis system.

[0068] In the second module, the four electrodes of two adjacent focusing electrode sheets 49 are superimposed with radio frequency voltage, and the four electrodes of the first of the two adjacent focusing electrode sheets are superimposed with voltage U2 at the same time, and the four electrodes of the second are superimposed with voltage -U2 at the same time, so as to realize ion focusing in the radial direction in the form of a funnel. The amplitude of U2 is adjustable from 0 to 500V, and the frequency can be selected from 800kHz to 2000kHz, which can be selected to be equal to U1.

[0069] The method of transporting the ions to be measured in the device operates in a periodic assembly line manner.

[0070] In the first cycle, the ions to be measured enter the ion mobility separation and transmission device, and a spatial arrangement is generated according to the size of the collision cross section to achieve enrichment of the ions to be measured.

[0071] In the second cycle, a reverse voltage is applied to the atmospheric pressure interface air curtain disk to prevent subsequent ions to be measured from entering the device.

[0072] A specific implementation of the present invention in a triple quadrupole ion mobility mass spectrometer is as follows Figure 6 As shown, the sample is ejected from the nebulizer 101 of the ion source and a high voltage is applied. The sample forms a Taylor cone during the atomization process, generates an electrospray phenomenon, and forms atomized small droplet spray 107. During the evaporation of the solvent, charged ions 108 are generated through Coulomb explosion and enter the atmospheric pressure interface composed of the air curtain plate 102 and the sampling cone 103. The gap between the air curtain plate 102 and the sampling cone 103 is connected with a protective backflush gas 109 to prevent contamination such as droplets and neutral particles from entering the mass spectrometer. After passing through the ion mobility separation and transmission device 105 of the present invention, the ions to be measured are enriched in the first cycle, and mobility separation is generated in the second cycle, and they enter the next vacuum region in turn, and are transmitted into the high vacuum region through the ion transmission quadrupole 111. The parent ion is screened by the first quadrupole 112, and is fragmented in the collision cell composed of the second quadrupole 113 and lens one 117, lens two 118, lens three 119, lens four 120 and the shell, and enters the third quadrupole 114 for daughter ion screening, and deflected or secondary electrons are generated by the dynode 115, which are detected by the electron multiplier one 116. The system can obtain ion mobility information as well as mass spectrometry information.

[0073] Another specific implementation of the present invention in a quadrupole time-of-flight ion mobility mass spectrometer is as follows Figure 7As shown. The sample is sprayed out from the atomizer 101 of the ion source and a high voltage is applied. The sample forms a Taylor cone during the atomization process, generating an electrospray phenomenon, forming atomized small droplet spray 107. During the evaporation of the solvent, charged ions 108 are generated through Coulomb explosion and enter the air curtain plate 102. The atmospheric pressure interface composed of the sampling cone 103, the gap between the air curtain plate 102 and the sampling cone 103 is passed through a protective backflush gas 109 to prevent contamination such as droplets and neutral particles from entering the mass spectrometer. After passing through the ion mobility separation and transmission device 105 of the present invention, the ions to be measured are enriched in the first cycle and generate mobility separation in the second cycle. The ions are separated and sequentially enter the next vacuum region, and are transmitted into the high vacuum region through the ion transmission quadrupole 111. The parent ions are screened by the first quadrupole 112, and are fragmented in the collision pool composed of the second quadrupole 113, lens 1 117, lens 2 118, lens 3 119, lens 4 120 and the housing. After being focused by lens 5 121, the ions are accelerated by the vertical introduction device 122 into the flight time tube, and are reflected by the reflector 123 to produce a V-shaped reflection flight trajectory, which is detected by the channel electron multiplier 2 124. The system can obtain ion mobility information and high-resolution mass spectrum information.

[0074] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

[0075] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described here in detail.

Claims

1. An ion mobility separation and transmission device, It is characterized in that It comprises two first circuit boards and two second circuit boards, a mobility separation electrode sheet is connected between the two first circuit boards, so that the two first circuit boards and the mobility separation electrode sheet together constitute a first module, a focusing electrode sheet is connected between the two second circuit boards, so that the two second circuit boards and the focusing electrode sheet together constitute a second module, one end of the first module is connected to one end of the second module, and the other end of the first module is connected to four focusing guide rods; Among the four focusing guide rods, two adjacent ones are the first pair of focusing guide rods, and the other two are the second pair of focusing guide rods, wherein the first pair of focusing guide rods introduces a voltage U 0 , the second pair of focusing guide rods introduces voltage -U 0 ; In the first module, the number of mobility separation electrode sheets is set to be multiple, so that the thickness of the mobility separation electrode sheets after stacking is adapted to the length of the first circuit board, and each adjacent two mobility separation electrode sheets are separated by a partition, and each mobility separation electrode sheet and the center of the partition are provided with a first center hole; each mobility separation electrode sheet has four electrodes, two of which are opposite to each other and constitute a pair of electrodes, and in the two pairs of electrodes, one pair of electrodes is introduced with a voltage U through one of the first circuit boards 1 , another pair of electrodes is introduced into the voltage U through another first circuit board 1 ; and in the first module, the direction of the electric field is from a direction close to the second module to a direction close to the focusing guide rod; In the second module, the number of focusing electrode sheets is set to be multiple, so that the length of the focusing electrode sheets after being stacked is adapted to the length of the second circuit board, each of the focusing electrode sheets is provided with a second central hole, and the aperture of the second central hole of the focusing electrode sheet gradually decreases from one end close to the first module to the end far from the first module, so that the central hole of the focusing electrode sheet in the second module forms a funnel shape; each focusing electrode sheet has four electrodes, and in two adjacent focusing electrode sheets, the four electrodes of the first focusing electrode sheet are introduced into the voltage U through one of the second circuit boards 2 The four electrodes of the second focusing electrode sheet are connected to a voltage U through another second circuit board. 2 ; An airflow is introduced into the first central hole, and the airflow flows from an end close to the focusing guide rod to an end close to the second module.

2. The ion mobility separation and transmission device according to claim 1, It is characterized in that The mobility separation electrode sheet and the focusing electrode sheet are both provided with two introduction electrodes.

3. The ion mobility separation and transmission device according to claim 2, It is characterized in that Isolation capacitors and voltage-dividing resistors are attached to both the first circuit board and the second circuit board.

4. The ion mobility separation and transmission device according to claim 3, It is characterized in that The focusing guide rod is made of 316L stainless steel, and the diameter of the focusing guide rod is 4-5 mm, and the electric field radius is 2-3 mm.

5. The ion mobility separation and transmission device according to claim 4, It is characterized in that The focusing guide rod is connected to the first module via a guide rod bracket.

6. The ion mobility separation and transmission device according to claim 5, It is characterized in that The guide rod bracket is made of PEEK material or PEI material.

7. A method for ion transport, It is characterized in that The following steps are included: S1, the sample is ionized to produce ions to be tested; S2, the ions to be measured enter the ion mobility separation and transmission device through the sampling cone and the air curtain plate; S3, after the ions to be measured enter the first module of the ion mobility separation and transmission device, the ions to be measured collide with the airflow in the first central hole of the first module, and the ions to be measured are spatially arranged according to the size of the collision cross section and reach an equilibrium position; S4, after the ions to be measured are spatially arranged in the first central hole, the air curtain disk applies a reverse voltage to prevent subsequent ions from entering the ion mobility separation and transmission device; S5, applying a DC voltage to the mobility separation electrode sheet in the first module, and scanning the amplitude of the DC voltage; S6. During the process of scanning the amplitude of the DC voltage, the amplitude of the DC voltage gradually decreases. When the collision force of the airflow is greater than the electric field force, the ions to be measured lose balance and move toward the second module of the ion mobility separation and transmission device. S7. Under the action of the airflow, the ions to be measured enter the second module in sequence, flow out from the second central hole of the second module, and then enter the mass analysis system.

8. The ion transport method according to claim 7, It is characterized in that When the ions to be measured enter the ion mobility separation and transmission device, the moving trajectories are constrained by the focusing guide rods, so that the moving trajectories of the ions to be measured converge toward the axis of the first central hole.

9. The ion transport method according to claim 7, It is characterized in that After a DC voltage is applied to the mobility separation electrode sheet in the first module, the electric field force in the first central hole of the first module is distributed in a gradient.

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