Transmission interface device and mass spectrometer

Abstract

The application relates to a transmission interface device and a mass spectrometer, comprising a cavity, an interface unit and a focusing unit oppositely arranged in the cavity, and a transmission unit arranged in the cavity, wherein the cavity has a pressure difference between inside and outside, a voltage is applied to the interface unit, the transmission unit and the focusing unit, the focusing unit has an outlet hole, and the interface unit, the transmission unit and the focusing unit are coaxially arranged in sequence; the interface unit is used for introducing ions from a previous stage environment into the cavity; the transmission unit is used for cooling and axially converging the ions; and the focusing unit is used for focusing the converged ions on the outlet hole and transmitting the ions to a next stage environment, so that the efficiency and ion utilization rate during ion transmission in the mass spectrometer are improved, and the detection sensitivity of the mass spectrometer is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mass spectrometry instruments, in particular to a transmission interface device and a mass spectrometer. BACKGROUND

[0002] The mass spectrometer is one of the most basic instruments for studying the basic composition, structural characteristics, physical and chemical properties of matter, and is an essential instrument in the fields of life science, material science, food safety, environmental protection, etc., and is the core of modern analytical instruments. The essence of the mass spectrometer is to use electric field and / or magnetic field to separate the moving ions by mass-to-charge ratio in a vacuum environment to realize the detection of the composition of the compound. Among them, the key structure for ion transmission to realize mass-to-charge ratio separation in a vacuum environment is a radio frequency multipole rod, which introduces ions in an atmospheric pressure environment to complete cooling, collision and focusing functions.

[0003] However, at present, the commonly used radio frequency multipole rod is basically parallel, that is, the field inner diameter remains unchanged. When the ions pass through the radio frequency multipole rod to complete cooling and collision, due to the effects of gas expansion, space charge effect and kinetic energy of the ions themselves, the ion beam tends to diverge. When it passes through the through hole into the next vacuum environment, it is difficult to completely focus into a point, resulting in the loss of most ions at this point, and the transmission efficiency is low. SUMMARY

[0004] Therefore, it is necessary to provide a transmission interface device and a mass spectrometer, which can improve the efficiency and ion utilization rate during ion transmission in the mass spectrometer, thereby further improving the detection sensitivity of the mass spectrometer.

[0005] A transmission interface device, comprising a cavity, an interface unit and a focusing unit oppositely arranged in the cavity, and a transmission unit arranged in the cavity, wherein there is a pressure difference between the inside and outside of the cavity, a voltage is applied to the interface unit, the transmission unit and the focusing unit, the focusing unit has an exit hole, and the interface unit, the transmission unit and the focusing unit are arranged in sequence.

[0006] The interface unit is used to introduce ions from the previous environment into the cavity, the transmission unit is used to cool and converge the ions, and the focusing unit is used to focus the converged ions on the exit hole and transmit them to the next environment.

[0007] In one embodiment, the interface unit is a capillary, a skimmer cone or a sampling cone.

[0008] In one embodiment, the transmission unit includes at least one of a multipole rod and an ion funnel.

[0009] In one of the embodiments, the multipole rod comprises at least one of a quadrupole rod, a hexapole rod, an octapole rod, a segmented quadrupole rod, a segmented hexapole rod, and a segmented octapole rod.

[0010] In one of the embodiments, the focusing unit comprises a substrate and focusing electrodes, the substrate is provided with the extraction hole, and the focusing electrodes are provided on the substrate in the center of the extraction hole.

[0011] In one of the embodiments, the focusing electrodes are two or more concentric electrodes arranged at intervals.

[0012] In one of the embodiments, each of the concentric electrodes is applied with a coupling voltage of a direct current voltage and a radio frequency voltage; wherein the direct current voltage applied on each of the concentric electrodes is a direct current voltage that is sequentially increased or decreased, and the radio frequency voltage is a periodic radio frequency voltage with a preset phase difference between adjacent concentric electrodes.

[0013] In one of the embodiments, the transmission interface device further comprises a first direct current power supply, a second direct current power supply, a third direct current power supply, a first radio frequency power supply, and a second radio frequency power supply, the first direct current power supply is connected to the interface unit, the second direct current power supply and the first radio frequency power supply are connected to the transmission unit, and the third direct current power supply and the second radio frequency power supply are both connected to the focusing unit.

[0014] In one of the embodiments, a vacuum pump connected to the cavity is further included.

[0015] In one of the embodiments, a mass spectrometer is provided, comprising the above-mentioned transmission interface device.

[0016] The above-mentioned transmission interface device and mass spectrometer, by sequentially arranging the interface unit, the transmission unit, and the focusing unit in the cavity in the axial direction, and then applying different voltages to the interface unit, the transmission unit, and the focusing unit to form electric fields, can promote the ions to enter the cavity from the previous environment under the action of each electric field, to be cooled by the transmission unit, to be transmitted to the focusing unit in the axial direction, to be gathered to the extraction hole and transmitted to the next environment, so as to improve the efficiency and ion utilization rate of ion transmission in the mass spectrometer, and further improve the detection sensitivity of the mass spectrometer. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The system block diagram of the transmission interface device in one of the embodiments;

[0018] Figure 2 The schematic diagram of the focusing unit in one of the embodiments;

[0019] Figure 3 The schematic diagram of the focusing electrodes applying direct current voltage in one of the embodiments;

[0020] Figure 4 A schematic diagram of applying RF voltage on focusing electrodes in one embodiment;

[0021] Figure 5 A schematic diagram of applying RF voltage on focusing electrodes in another embodiment;

[0022] Figure 6 A schematic diagram of the structure of a transmission interface device in one embodiment;

[0023] Figure 7 A schematic diagram of a DC gradient electric field when sin(ωt) = 0 in RF voltage in one embodiment;

[0024] Figure 8 A schematic diagram of a DC gradient electric field when sin(ωt) = -1 in RF voltage in one embodiment;

[0025] Figure 9 A schematic diagram of the structure of a transmission interface device in another embodiment;

[0026] Figure 10 A schematic diagram of a DC gradient electric field when sin(ωt) = -1 in RF voltage in another embodiment;

[0027] Figure 11 A schematic diagram of the structure of a transmission interface device in another embodiment;

[0028] Figure 12 A schematic diagram of a DC gradient electric field in another embodiment. DETAILED DESCRIPTION

[0029] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0031] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It should be understood that the term "comprises / comprising" or "has / having" or the like is specifically intended to indicate the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but does not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0032] In one embodiment, a transmission interface device is provided, which can be applied to a mass spectrometer, in particular to transmission of ions in a mass spectrometer when the ions need to pass through multiple differential vacuum environments. For example, MS (Mass Spectrometry) analysis and IMS (Ion Mobility Spectrometry) analysis are two common ion analysis techniques, and the combination of the two can achieve rapid analysis of complex mixtures. However, IMS analysis needs to work at a higher gas pressure, so that the gas-phase ions are subjected to the combined action of an electric field and background gas molecule collisions to produce differences in ion mobility; while MS analysis needs to use an electric field / magnetic field to control the flight of ions in a high vacuum environment to avoid collisions between ions and background gas molecules. When IMS analysis is combined with MS analysis, ions need to be transmitted from the IMS drift tube at high gas pressure to the MS spectrometer at high vacuum. The transmission interface device of the present application can be applied to the transmission of ions from the IMS to the MS spectrometer, and the ions will not be diverged, but focused on the axial transmission to the next stage environment, ensuring the transmission efficiency of the ions.

[0033] Specifically, referring to Figure 1 , the transmission interface device includes a cavity 110, an interface unit 120 and a focusing unit 140 oppositely arranged in the cavity 110, and a transmission unit 130 arranged in the cavity 110. There is a pressure difference between the cavity 110 and the outside of the cavity 110, and a voltage is applied to the interface unit 120, the transmission unit 130 and the focusing unit 140. The focusing unit 140 has an exit hole, and the interface unit 120, the transmission unit 130 and the focusing unit 140 are arranged in sequence. The interface unit 120 is used to introduce ions from the previous stage environment into the cavity 110, the transmission unit 130 is used to cool and converge the ions, and the focusing unit 140 is used to focus the converged ions on the exit hole and transmit them to the next stage environment.

[0034] Specifically, the following explains and describes the interface unit 120 connected to the first stage environment, the cavity 110 as the second stage environment, and the focusing unit 140 connected to the third stage environment. The above-mentioned second stage environment, first stage environment and third stage environment can be a vacuum environment or an atmospheric pressure environment, and the above-mentioned second stage environment has a pressure difference with the first stage environment and the third stage environment, respectively. In this embodiment, the first stage environment, the second stage environment and the third stage environment are all vacuum environments, and the pressure of the second stage environment is less than that of the first stage environment and the third stage environment.

[0035] Further, the cavity 110 constituting the second-stage vacuum environment is a closed structure made of metal material, which is not unique in shape and size, and can be designed according to the specifications of the interface unit 120, the transmission unit 130 and the focusing unit 140 arranged therein, and can be square or cylindrical, without being limited thereto. The metal material making the cavity 110 can be stainless steel or aluminum alloy. In order to form a vacuum environment in the cavity 110, in an embodiment, as shown in Figure 1 the vacuum pump 150 connected to the cavity 110 is further included. Specifically, the vacuum pump 150 can make the working pressure of the second-stage vacuum environment be 80 Pa-300 Pa, for example, in the present embodiment, the working pressure of the second-stage vacuum environment is 90 Pa. In addition, the model of the vacuum pump 150 is not specifically limited in the present embodiment, as long as it can realize the function of vacuumizing the second vacuum environment.

[0036] Further, the interface unit 120 and the focusing unit 140 are respectively arranged on opposite walls of the cavity 110, and the transmission unit 130 is arranged inside the cavity 110. The interface unit 120 is connected between the first-stage vacuum environment and the second-stage vacuum environment, and is used to introduce ions from the first-stage vacuum environment to the second-stage vacuum environment; the focusing unit 140 is connected between the second-stage vacuum environment and the third-stage vacuum environment, and is used to focus ions in the second-stage vacuum environment to the transmission hole to transmit the ions to the third-stage vacuum environment. The interface unit 120 has a through hole, the focusing unit 140 has a transmission hole, and the transmission unit 130 has an axisymmetric transmission channel. When the interface unit 120 and the focusing unit 140 are arranged oppositely, the centers of the through hole and the transmission hole can be arranged oppositely or non-oppositely. Further, the through hole of the interface unit 120, the transmission channel of the transmission unit 130 and the transmission hole of the focusing unit 140 are sequentially communicated, and are used for ion transmission. In particular, the positions of the through hole, the transmission channel and the transmission hole arranged sequentially are not fixed, and can be arranged in the same central axis to achieve the best ion transmission effect and further reduce the loss of ions in the transmission process.

[0037] In this system, voltages are applied to the interface unit 120, transmission unit 130, and focusing unit 140 to create different electric fields that allow ions to sequentially pass through the axial channel formed by the interface unit 120, transmission unit 130, and focusing unit 140 to be transported to the third-level vacuum environment. Specifically, a DC voltage is applied to the interface unit 120 to create an electric field that attracts ions from the first-level vacuum environment into the second-level vacuum environment. A radio frequency (RF) voltage and a DC voltage are applied to the transmission unit 130. First, an RF electric field is created to cause ions to collide and cool with molecules in the gas in the second-level vacuum environment. Then, an axial electric field is created to draw the collided and cooled ions closer to the focusing unit 140. The focusing unit 140 is applied with a coupled RF voltage and a DC voltage, or only a DC voltage, so that the approaching ions, under the influence of the formed DC gradient electric field, gather at the extraction hole and are transported to the third-level vacuum environment.

[0038] The aforementioned transmission interface device, by axially arranging an interface unit, a transmission unit, and a focusing unit sequentially in the cavity, and then applying different voltages to the interface unit, transmission unit, and focusing unit to form an electric field, causes ions to enter the cavity from the previous environment under the action of each electric field. After being cooled by the transmission unit, they are axially transmitted to the focusing unit, focused to the extraction hole, and transmitted to the next environment. This can improve the efficiency of ion transmission and ion utilization in the mass spectrometer, thereby further improving the detection sensitivity of the mass spectrometer.

[0039] In one embodiment, such as Figure 1 As shown, the interface unit 120 can be a capillary, a snipping cone, or a sampling cone. Specifically, the interface unit 120 used to introduce ions from the first-stage vacuum environment to the second-stage vacuum environment is not unique; it can be a capillary, a snipping cone, or a sampling cone. All of the aforementioned capillary, snipping cone, and sampling cone have through holes, the size of which can be between 0.3 mm and 5 mm, and the specific value can be designed according to the pressure difference between the vacuum environments on both sides of the interface.

[0040] In one embodiment, such as Figure 1 As shown, the transmission unit 130 includes at least one of a multipole and an ion funnel.

[0041] Specifically, the structure of the transmission unit 130 for cooling and axial convergence of ions is not unique, which can be a multipole rod or an ion funnel. The ion funnel is composed of ring electrodes arranged in sequence with close spacing, wherein the ring electrodes of the previous section have the same inner diameter, and the inner diameter gradually decreases to a certain region before the extraction hole, and the transmission channel formed in the middle of the electrode is funnel-shaped. It can be understood that the ring electrodes of the previous section with the same inner diameter are used to form a radio frequency electric field after the voltage is applied, so that the ions passing through collide with the molecules in the gas for collision cooling in the second stage vacuum environment. Then, the ions will approach the focusing unit 140 in the region with gradually decreasing inner diameter. However, the ion funnel in this way of reducing the inner diameter of the electrode increases the structural complexity and may also cause ion loss.

[0042] Preferably, in the present embodiment, the transmission unit 130 adopts a multipole rod. The multipole rod is composed of an even number of four or more metal round rods arranged equidistantly and in parallel along the circumference with the extraction hole of the focusing unit 140 as the central axis. Radio frequency voltage and direct current voltage are respectively applied to the above-mentioned metal round rods to form a radio frequency electric field and an axial electric field, so that the ions collide with the molecules in the gas for collision cooling in the second stage vacuum environment, and then approach the focusing unit 140. The parallel arrangement of the metal round rods can ensure that the inner diameter of the entire transmission channel is the same, which can maximize the avoidance of ion loss. In combination with the radio frequency electric field and the direct current gradient electric field formed by the focusing unit 140, the ions can be fully gathered in the extraction hole to be transmitted to the third stage vacuum environment, thereby ensuring the maximum transmission efficiency and utilization rate of the ions. In the present embodiment, the multipole rod structure with simpler structure is adopted as the transmission unit 130, which makes the structure of the transmission interface device simpler, while ensuring the transmission efficiency and utilization rate of the ions.

[0043] In one embodiment, the multipole rod includes at least one of a quadrupole rod, a hexapole rod, an octupole rod, a segmented quadrupole rod, a segmented hexapole rod, and a segmented octupole rod.

[0044] Specifically, according to the number of poles of the multipole rod, it can include a quadrupole rod, a hexapole rod, or an octupole rod. It can be understood that the quadrupole rod is composed of 4 metal round rods arranged equidistantly and in parallel along the circumference with the extraction hole as the central axis; the hexapole rod is composed of 6 metal round rods arranged equidistantly and in parallel along the circumference with the extraction hole as the central axis; and the octupole rod is composed of 8 metal round rods arranged equidistantly and in parallel along the circumference with the extraction hole as the central axis. The number of poles of the multipole rod is not unique, which can be designed according to actual use. In other embodiments, the number of poles can also be 16 or 32, which is not limited. According to the type of the pole of the multipole rod, it can include a non-segmented multipole rod and a segmented multipole rod. The pole of the non-segmented multipole rod is composed of an integral metal round rod; and the segmented multipole rod is composed of two or more metal round rods arranged coaxially with gaps, and the gaps of each section of the metal round rod are also provided with insulating partitions.

[0045] Furthermore, the transmission unit 130 can be at least one of non-segmented multipole, or at least one of segmented multipole, or a combination of non-segmented and segmented multipole, used to form a transmission channel for cooling and axially converging ions.

[0046] In one embodiment, such as Figure 2 As shown, the focusing unit 140 includes a substrate 141 and a focusing electrode 142. The substrate 141 is provided with an outlet hole 143, and the focusing electrode 142 is disposed on the substrate 141 with the outlet hole 143 as the center.

[0047] Specifically, the substrate 141 serves as a carrier for the focusing electrode 142, fixing the focusing electrode 142 in place. The substrate 141 is made of an insulating material; the specific material used is not limited to one type, such as polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), or ceramic. The method of fixing the focusing electrode 142 to the substrate 141 is also not limited to one type; it can be fixed using insulating adhesive or by plating. Preferably, in this embodiment, a printed circuit board (PCB) is used to fix the focusing electrode 142 to the substrate 141.

[0048] Furthermore, the substrate 141 is provided with an exit hole 143 for allowing the aggregated ions to pass through and be transported to the third-level vacuum environment. The aperture size of the exit hole 143 is not unique and can be designed according to the size of the ions being analyzed and the pressure difference between the vacuum environments before and after. Typically, the aperture size range is between 0.5 mm and 5 mm.

[0049] Furthermore, the focusing electrode 142 is made of a metallic material, such as gold, silver, copper, steel, or carbon. In one embodiment, such as... Figure 2 As shown, the focusing electrode 142 consists of two or more concentric electrodes spaced apart. Specifically, each concentric electrode is sequentially fixed to the substrate 142, with gaps between adjacent concentric electrodes. These gaps can be equal or unequal. Preferably, each concentric electrode has the same width, which can be between 0.01mm and 10mm. The number of concentric electrodes is not limited and can be designed according to the actual design. Furthermore, the shape of each concentric electrode is not unique; it can be a ring-shaped electrode or a square electrode. In this embodiment, the concentric electrodes are ring-shaped.

[0050] In one embodiment, each concentric ring electrode on the substrate 142 is subjected to a coupling voltage of DC voltage and radio frequency voltage; wherein, the DC voltage applied to each concentric electrode is a DC voltage that increases or decreases sequentially, and the radio frequency voltage is a periodic radio frequency voltage with a preset phase difference between adjacent concentric ring electrodes.

[0051] Specifically, as shown in the cross-sectional view of each concentric ring electrode, Figure 3 a DC power supply U1 and a DC power supply U2 are used to provide DC voltages for the innermost electrode and the outermost electrode of each concentric ring electrode, respectively, and the remaining electrodes are connected to the common end of two or more voltage dividing resistors in series to realize a DC gradient electric field, and the two ends of each voltage dividing resistor connected in series are connected to the DC power supply U1 and the DC power supply U2, respectively. The resistance of each voltage dividing resistor can be set to be the same, and the specific specification is not limited, which can be selected according to the actual scheme.

[0052] Further, as shown in the cross-sectional view of each concentric ring electrode, Figure 4 and Figure 5 a periodic radio frequency voltage is also applied to each concentric ring electrode. Among them, the radio frequency voltage applied between adjacent concentric electrodes has a preset phase difference, and the value of the preset phase difference is not unique. It can be as shown in Figure 4 that there is a preset phase difference of 90°, or as shown in Figure 5 that there is a preset phase difference of 180°.

[0053] It can be understood that in actual use, the voltage applied to each concentric ring electrode can be a coupling voltage applied in the manner of Figure 3 and Figure 4 , or a coupling voltage applied in the manner of Figure 3 and Figure 5 .

[0054] In addition, in other embodiments, each concentric ring electrode on the substrate 142 can only apply a DC voltage that increases or decreases sequentially as shown in Figure 3 , without coupling a radio frequency voltage, to achieve the purpose of pushing the nearby ions to the outlet 143 to output to the next stage environment.

[0055] In one embodiment, the above transmission interface device further includes a first DC power supply, a second DC power supply, a third DC power supply, a first radio frequency power supply and a second radio frequency power supply, the first DC power supply is connected to the interface unit, the second DC power supply and the first radio frequency power supply are connected to the transmission unit, and the third DC power supply and the second radio frequency power supply are connected to the focusing unit.

[0056] Among them, the DC power supply and the radio frequency power supply are used to apply voltages to the interface unit, the transmission unit and the focusing unit, respectively, to form different electric fields so that the ions pass through the axial channels formed by the interface unit, the transmission unit and the focusing unit in sequence to be transmitted to the third stage vacuum environment.

[0057] Specifically, the first DC power supply interface unit applies a DC voltage to create an electric field that attracts ions from the first-stage vacuum environment into the second-stage vacuum environment. Further, the second DC power supply and the first RF power supply transmission unit apply an RF voltage and a DC voltage to create an RF electric field that causes ions to collide and cool with molecules in the gas in the second-stage vacuum environment. An axial electric field is then created to draw the collided and cooled ions closer to the focusing unit. Even further, the third DC power supply and the second RF power supply focus unit apply an RF voltage and a DC voltage, causing ions approaching the focusing unit to gather at the extraction hole and be transported to the third-stage vacuum environment under the influence of the created RF electric field and DC gradient electric field.

[0058] In one embodiment, such as Figure 6 As shown, the working principle of the transmission interface device is explained by taking the interface unit 120 as a capillary tube, the transmission unit 130 as a non-segmented quadrupole, and the focusing unit 140 including the substrate 141, the concentric ring-shaped focusing electrode 142, and the lead-out hole 143 as an example.

[0059] Specifically, the second-stage vacuum environment inside cavity 110 is at a pressure of 90 Pa under the action of vacuum pump 150. The inner diameter of the capillary is 0.5 mm, and the first DC power supply applies a DC voltage of 100 V to the capillary. The first RF power supply and the second DC power supply apply an RF amplitude of 150 V, a frequency of 1 MHz, and a DC bias of 70 V to the quadrupole, respectively. The focusing electrode 142 includes 12 layers of annular electrodes concentrically fixed on the substrate 141 with the lead-out hole 143 as the center. The width of each annular electrode is 0.5 mm, and the annular electrodes are equally spaced with a spacing of 0.1 mm. Each annular electrode is respectively positioned with... Figure 3 and Figure 4The coupling voltage of radio frequency and direct current voltage is applied in the shown way. The direct current voltage of direct current power supply U1 is set to 43V, the direct current voltage of direct current power supply U2 is set to 10V, and the voltage difference between two adjacent ring electrodes is 3V under the action of each voltage dividing resistor. It can be understood that the direct current voltage applied by the ring electrode close to the lead-out hole 143 is the lowest, and the direct current voltage applied by the ring electrode farther away from the lead-out hole 143 is the highest. The periodic radio frequency voltage amplitude applied on each ring electrode is 100V, and the frequency is 1MHz. There is a phase difference of 90° between two adjacent ring electrodes. That is, in the direction away from the lead-out hole 143, the coupling voltage of radio frequency and direct current voltage applied by every four ring electrodes is respectively: 100sin(ωt)+10+3n, 100sin(ωt+90°)+10+3n, 100sin(ωt+180°)+10+3n, 100sin(ωt+270°)+10+3n, where n is the number of ring electrodes in the direction away from the lead-out hole 143, for example, the ring electrode closest to the lead-out hole 143 is the first ring electrode, and the ring electrode farthest from the lead-out hole 143 is the nth ring electrode.

[0060] Further, the ion first enters the second vacuum environment in the cavity 110 under the action of the electric field of the capillary. Then, it collides and cools with the molecules in the gas under the action of the radio frequency electric field of the quadrupole rod, and at the same time, it approaches the focusing electrode 142 under the action of the axial electric field of the quadrupole rod. In the process of approaching the focusing electrode 142, the ion is focused again near the focusing electrode 142 under the action of the radio frequency voltage and the direct current gradient electric field applied by the focusing electrode 142. As shown in Figure 7 With Figure 8 As shown in the direct current gradient electric field schematic diagram when sin(ωt)=0 and sin(ωt)=-1, the ion is gradually pushed to the lead-out hole 143 to gather over time, and finally the ion is introduced from the lead-out hole 143.

[0061] In one embodiment, as shown in Figure 9 The working principle of the transmission interface device is explained and described by taking the interface unit 120 using a sampling cone, the transmission unit 130 using a non-segmented hexapole, and the focusing unit 140 including the substrate 141, the concentric ring-shaped focusing electrode 142, and the lead-out hole 143 as examples.

[0062] Specifically, the aperture of the sampling cone is 0.4 mm, and the first direct current power source applies a direct current voltage of 80 V to the sampling cone. The first radio frequency power source and the second direct current power source respectively apply a radio frequency amplitude of 150 V, a frequency of 1 MHz, and a direct current bias of 40 V to the quadrupole rod. The focusing electrode 142 includes 12 annular electrodes fixed concentrically around the extraction hole 143 on the substrate 141, and the width of each annular electrode is 0.25 mm. The annular electrodes are arranged at equal intervals, and the interval is 0.05 mm. Each annular electrode is applied with a coupling voltage of radio frequency and direct current voltage in the manner shown in FIG. 2. Figure 3 and Figure 5 The direct current voltage of the direct current power source U1 is set to 43 V, and the direct current voltage of the direct current power source U2 is set to 10 V. Under the action of each voltage dividing resistor, the voltage between adjacent two annular electrodes decreases by 3 V. The periodic radio frequency voltage applied to each annular electrode has an amplitude of 50 V and a frequency of 2.5 MHz, and there is a phase difference of 180° between adjacent two annular electrodes. That is, in the direction away from the extraction hole 143, the coupling voltage of radio frequency and direct current voltage applied to each two annular electrodes is 50sin(ωt)+10+3n and 50sin(ωt+180°)+10+3n respectively. Wherein, n is the number of annular electrodes in the direction away from the extraction hole 143. As shown in FIG. 3, it is a schematic diagram of the direct current gradient electric field when sin(ωt)=-1. With the change of time, the ions are gradually pushed to the extraction hole 143 and finally the ions are extracted from the extraction hole 143. Figure 10

[0063] In one embodiment, as shown in FIG. 4, the interface unit 120 adopts a skimmer, the transmission unit 130 adopts a segmented quadrupole rod, and the focusing unit 140 including the substrate 141, the concentric annular focusing electrode 142, and the extraction hole 143 are taken as examples to explain the working principle of the transmission interface device. Figure 11

[0064] Specifically, the aperture of the skimmer is 0.4 mm, and the first direct current power source applies a direct current voltage of 80 V to the skimmer. The first radio frequency power source and the second direct current power source respectively apply a radio frequency amplitude of 450 V, a frequency of 1 MHz, and a direct current bias of 60 V to the quadrupole rod. The focusing electrode 142 includes 12 annular electrodes fixed concentrically around the extraction hole 143 on the substrate 141, and the width of each annular electrode is 0.3 mm. The annular electrodes are arranged at equal intervals, and the interval is 0.1 mm. Each annular electrode is applied with a coupling voltage of radio frequency and direct current voltage in the manner shown in FIG. 6. Figure 3 ​​The DC voltage is applied in the manner shown. Among them, the DC voltage of DC power supply U1 is set to 43V, the DC voltage of DC power supply U2 is set to 10V, and under the action of each voltage dividing resistor, the voltage difference between two adjacent ring electrodes decreases by 3V. It can be understood that the DC voltage applied by the ring electrode close to the lead-out hole 143 is the lowest, and the farther away from the lead-out hole 143, the higher the DC voltage applied by the ring electrode. That is, from the lead-out hole 143 to the direction away from the lead-out hole 143, the DC voltage applied by each ring electrode is 10+3n respectively. Among them, n is the number of ring electrodes from the lead-out hole 143 to the direction away from the lead-out hole 143. After the ion passes through the axial electric field of the segmented quadrupole rod, it approaches the ring electrode, and then gradually pushes the ion to the lead-out hole 143 under the action of the DC gradient electric field shown, and finally realizes the lead-out of the ion from the lead-out hole 143. Figure 12 The DC gradient electric field shown under the action of the DC gradient electric field shown, and finally realizes the lead-out of the ion from the lead-out hole 143.

[0065] In an embodiment, a mass spectrometer is provided, comprising the transmission interface device described above.

[0066] Specifically, the mass spectrometer can be a time-of-flight mass spectrometer, a quadrupole mass spectrometer, an ion trap mass spectrometer, or a magnetic mass spectrometer, etc. The transmission interface device can connect the ion source in the upper level vacuum environment to obtain ions, and transmit them to the lower level vacuum environment for IMS analysis. The transmission interface device can also be connected to the upper level vacuum environment to obtain ions after IMS analysis, and transmit them to the lower level vacuum environment for subsequent MS analysis, etc. The transmission interface device can also be applied to other ion transmission scenarios of the mass spectrometer, which is not limited in the present embodiment.

[0067] The solution provided by the mass spectrometer includes the implementation scheme described in the transmission interface device, so the specific limitations in one or more mass spectrometer embodiments provided above can refer to the limitations of the transmission interface device described above, which will not be repeated here.

[0068] In the present embodiment, the mass spectrometer introduces ions from the upper level environment into its cavity through the transmission interface device for cooling and focusing, and then transmits them to the lower level environment through the lead-out hole, which can improve the efficiency and ion utilization rate of ion transmission in the mass spectrometer, thereby further improving the detection sensitivity of the mass spectrometer.

[0069] The technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0070] The above-described embodiments are merely illustrative of several embodiments of the present application, which are described in more detail and in a specific and detailed manner, but should not be construed as limiting the scope of the patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A transmission interface device, characterized in that, The transmission interface device comprises a cavity, an interface unit and a focusing unit oppositely arranged in the cavity, and a transmission unit arranged in the cavity, wherein the cavity has a pressure difference between inside and outside, the interface unit, the transmission unit and the focusing unit are sequentially arranged and each is applied with a voltage. The interface unit is used to introduce ions from a previous environment into the cavity, the transmission unit is used to cool and converge the ions, and the focusing unit is used to focus the converged ions on the exit hole and transmit them to a next environment.

2. The transport interface device of claim 1, wherein, The interface unit is a capillary, a skimmer or a sampling cone.

3. The transport interface device of claim 1, wherein, The transmission unit comprises at least one of a multipole rod and an ion funnel.

4. The transport interface device of claim 3, wherein, The multipole rod comprises at least one of a quadrupole rod, a hexapole rod, an octapole rod, a segmented quadrupole rod, a segmented hexapole rod and a segmented octapole rod.

5. The transport interface device of claim 1, wherein, The focusing electrode is made of a metal material.

6. The transport interface device of claim 5, wherein, The widths of the concentric electrodes are the same, and the widths range from 0.01 mm to 10 mm.

7. The transport interface device of claim 6, wherein, The substrate is a PCB, and the focusing electrode is fixed to the substrate in the form of a printed circuit board.

8. The transport interface device of any of claims 1-7, wherein, The device further comprises a first DC power supply, a second DC power supply, a third DC power supply, a first RF power supply and a second RF power supply, wherein the first DC power supply is connected to the interface unit, the second DC power supply and the first RF power supply are connected to the transmission unit, and the third DC power supply and the second RF power supply are connected to the focusing unit.

9. The transport interface device of any of claims 1-7, wherein, The device further comprises a vacuum pump connected to the cavity.

10. A mass spectrometer, characterized by, The device comprises any one of the transmission interface devices in claims 1-9.

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