CN117690778A - Mass spectrometer ion transmission method and device - Google Patents

Abstract

The invention discloses a mass spectrometer ion transmission method and a device, wherein ions are introduced into a vacuum side from an atmospheric pressure side by adopting a sample introduction channel, and the diameter of a sample introduction port of the sample introduction channel positioned on the atmospheric pressure side is smaller than that of a sample outlet positioned on the vacuum side; the transmission channel is funnel-shaped, the axis of the sample introduction channel and the axis of the transmission channel are arranged in an angle or parallel offset manner, the airflow carrying ions entering the vacuum cavity is blocked by the ion funnel assembly, the directional airflow of the gas is fully blocked and diffused, the gas is prevented from flowing into the cavity where the multipole rod assembly is positioned, and the vacuum load pressure of the cavity is relieved; the ion-carrying gas flow contains interfering particles, which are arranged in an angle or offset manner, the ion funnel component blocks the interfering particles, and charged ions to be analyzed are blocked in the funnel-shaped inner space under the pseudopotential well effect of the radio frequency electric field, focused into extremely fine ions and moved towards the outlet side, and cannot leak out of the ion funnel component or collide with the ion funnel component.

Description

Mass spectrometer ion transmission method and device

Technical field

The present invention relates to the field of mass spectrometers, and in particular to mass spectrometer ion transmission methods and devices.

Background technique

Mass spectrometer is an analytical instrument widely used in environmental monitoring, food safety, drug research and development, materials science, life science and petrochemical industry. More than half of all mass spectrometry instruments are atmospheric pressure ionization source mass spectrometers. This type of mass spectrometry faces the problem of transferring charged ions from atmospheric pressure to a vacuum system for mass analysis. At present, typical solutions such as vacuum orifices paired with multipole rods, or capillaries paired with ion funnels are commonly used in mass spectrometry instruments as ion transmission devices at the atmospheric pressure-vacuum interface. The main direction of upgrading mass spectrometry instruments is to improve instrument signal strength and signal-to-noise ratio, and reduce interference noise.

Patent US6107628A discloses a method and equipment for introducing ions and other charged particles generated at near atmospheric pressure into a vacuum area. Capillary sampling is used, and an ion funnel is used to achieve efficient ion focusing under vacuum pressures of 0.1-50 Torr. . Compared with traditional quadrupole solutions, which are mostly used in vacuum pressure environments of mTorr level and below, the ion funnel can achieve ion focusing at higher pressures. Therefore, the injection volume can be increased by increasing the size of the injection hole, and the signal intensity can be improved, which has a higher Good advantage. However, this plan does not consider the high vacuum load produced by the strong directional airflow generated by direct injection of capillary tubes on the next-stage vacuum chamber of the ion funnel vacuum chamber, nor does it consider the impact of neutral particles in the ion flow on the subsequent mass analyzer, Interference problems in detectors and other links.

Patent US9240310B2 discloses a method and device for improving ion entry into a mass spectrometer. The tapered sampling tube has higher ion capture and transmission efficiency and better ion flow concentration than ordinary capillary sampling tubes. It has obvious advantages especially for application scenarios such as nanoelectrospray, which can improve signal strength to a certain extent. However, this solution also does not consider the high vacuum load generated by the strong directional airflow generated by direct injection of the sample tube on subsequent ion transmission or the mass analysis vacuum chamber, nor does it consider the impact of neutral particles in the ion flow on the subsequent mass analyzer. , detectors and other links of interference problems.

Contents of the invention

In order to overcome the shortcomings of the existing technology, one of the purposes of the present invention is to provide a mass spectrometer ion transmission method that can transfer charged ions from atmospheric pressure to a vacuum system and can avoid the directional airflow and neutral particles generated by sample injection to cause subsequent damage. Analytical impact.

In order to overcome the shortcomings of the existing technology, the second object of the present invention is to provide a mass spectrometer ion transmission device that can transfer charged ions from atmospheric pressure to a vacuum system and can avoid the directional airflow and neutral particles generated by sample injection to cause subsequent damage. Analytical impact.

One of the purposes of the present invention is achieved by adopting the following technical solutions:

A mass spectrometer ion transmission method includes the following steps:

Ions are made to enter the vacuum side from the atmospheric pressure side by using a sampling channel of a tapered tube. The sampling channel is tapered, and the diameter of the inlet of the sampling channel on the atmospheric pressure side is smaller than that of the outlet on the vacuum side. The diameter of the sample port;

Multiple lens pole pieces are stacked to form an ion funnel assembly. The ion funnel assembly is provided with a transmission channel. The inner diameters of some lens pole pieces close to the sampling channel are the same to form a straight cylindrical ion channel, which facilitates ions to be transported over a wide range. Captured inside the ion funnel assembly, the inner diameter of the part of the lens pole piece away from the sampling channel gradually decreases along the direction of ion movement, forming a funnel-shaped ion channel that facilitates the ions to gradually focus to form a thinner ion beam and pass through the last The lens pole piece with the smallest inner diameter enters the multipole assembly;

The axis of the sampling channel and the axis of the transmission channel are set at an angle or offset in parallel;

A DC voltage V1 is applied to the sampling channel, a DC voltage and a radio frequency voltage are applied to a plurality of the lens pole pieces, wherein a radio frequency voltage with an opposite phase is applied to two adjacent lens pole pieces, and a plurality of the lens pole pieces are applied in the direction of ion movement. The DC voltage on the lens pole piece gradually transitions from V2 to V3, and a DC voltage V4 is applied to the multipole rod assembly. V1, V2, V3, and V4 increase or decrease in one direction to drive ions from the sampling channel through the the transmission channel to the multipole assembly.

Further, when the axis of the sampling channel and the axis of the transmission channel are arranged at an angle, the angle between the axis of the sampling channel and the axis of the transmission channel is 0.1-30°.

Further, when the axis of the sampling channel and the axis of the transmission channel are offset in parallel, the offset distance between the axis of the sampling channel and the axis of the transmission channel is 1-10 mm.

Further, the inner diameter of the injection port of the sampling channel is 0.1-5 mm, and the taper of the sampling channel is 0.3-10°.

Further, the mass spectrometer ion transmission method also includes a heating step. The heating step specifically includes: heating the sampling channel to desolvate and dissociate the solvent-bearing ion clusters entering the sampling channel. Charged ions are formed.

Further, a radio frequency voltage is applied to the multipole rod assembly, wherein the radio frequency voltages applied between two adjacent rods have opposite phases.

The second object of the present invention is achieved by adopting the following technical solutions:

A mass spectrometer ion transmission device used to implement any of the above-mentioned mass spectrometer ion transmission methods. The mass spectrometer ion transmission device includes a vacuum chamber and an ion funnel assembly installed in the vacuum chamber. The mass spectrometer ion transmission device The transmission device also includes a sampling assembly and a multipole rod assembly. The sampling assembly is installed on one side of the vacuum chamber. The multipole rod assembly is installed inside the vacuum chamber. The ion funnel assembly is located on the side of the vacuum chamber. Between the sampling assembly and the multipole assembly, the sampling assembly includes a tapered tube, the tapered tube is provided with a sampling channel, the sampling channel is tapered, and the sampling channel is located The diameter of the sample inlet on the atmospheric pressure side is smaller than the diameter of the sample outlet on the vacuum side. The ion funnel assembly is provided with a transmission channel. The width of the transmission channel close to the sample injection channel is equal to form a straight cylindrical ion channel, the width of the transmission channel near the multipole assembly gradually decreases to form a funnel-shaped ion channel, and the axis of the sampling channel and the axis of the transmission channel are set at an angle or offset in parallel.

Further, the ion funnel assembly includes a plurality of lens pole pieces, the lens pole pieces are stacked, each of the lens pole pieces is provided with an inner hole, and the inner holes of the plurality of lens pole pieces form the transmission channel. , the inner diameter of the lens pole piece close to the sampling channel is the same to form a straight cylindrical ion channel, and the inner diameter of the lens pole piece far away from the sampling channel gradually decreases along the ion movement direction to form a funnel-shaped ion channel. aisle.

Further, when the axis of the sampling channel and the axis of the transmission channel are arranged at an angle, the angle between the axis of the sampling channel and the axis of the transmission channel is 0.1-30°.

Further, when the axis of the sampling channel and the axis of the transmission channel are offset in parallel, the offset distance between the axis of the sampling channel and the axis of the transmission channel is 1-10 mm.

Compared with the prior art, the ion transmission method of the mass spectrometer of the present invention uses a sampling channel of a tapered tube to allow ions to enter the vacuum side from the atmospheric pressure side. The diameter of the sampling port located on the atmospheric pressure side of the sampling channel is smaller than the sample outlet located on the vacuum side. diameter; in the transmission channel of the ion funnel assembly, the inner diameters of some lens pole pieces close to the sampling channel are the same to form a straight cylindrical ion channel, which facilitates ions to be captured into the interior of the ion funnel assembly over a wide range. The inner diameter of the piece gradually decreases along the direction of ion movement, forming a funnel-shaped ion channel, which facilitates ions to gradually focus to form a thinner ion beam, which passes through the last lens pole piece with the smallest inner diameter and enters the multipole assembly; the axis of the injection channel and the transmission The axis of the channel is set at an angle or parallel offset; through the above design, the airflow carrying ions entering the vacuum chamber through the tapered sampling tube in the atmospheric pressure environment will be blocked by the ion funnel assembly, alleviating the strong impact in the airflow. Directional flow can fully block and diffuse the directional flow to avoid flowing into the chamber where the multipole assembly is located, thereby alleviating the vacuum load pressure of the chamber where the multipole assembly is located; the airflow carrying ions also contains some Other interfering particles such as sexual particles, angular or offset layouts can be blocked by the ion funnel assembly, while the charged ions to be analyzed will be blocked under the pseudopotential well effect of the radio frequency electric field of the ion funnel assembly In the internal space of the funnel shape without leaking to the outside of the ion funnel assembly or hitting the ion funnel assembly, it is focused into an extremely fine ion flow and moves along the funnel shape toward the outlet side of the ion funnel assembly.

Description of the drawings

Figure 1 is a flow chart of the ion transmission method of the mass spectrometer of the present invention;

Figure 2 is a perspective view of the first embodiment of the mass spectrometer ion transmission device of the present invention;

Figure 3 is a three-dimensional cross-sectional view of the ion transmission device of the mass spectrometer of Figure 2;

Figure 4 is a cross-sectional view of the conical tube of the mass spectrometer ion transmission device of Figure 2;

Figure 5 is a cross-sectional view of the ion funnel assembly of the mass spectrometer ion transmission device of Figure 2;

Figure 6 is a partial structural cross-sectional view of the ion transmission device of the mass spectrometer of Figure 2;

Figure 7 is a cross-sectional view of a second embodiment of the mass spectrometer ion transmission device of the present invention;

Figure 8 is a simulation diagram of ion focusing and transmission when the axis of the sampling channel and the axis of the transmission channel are offset in the ion transmission device of the mass spectrometer of the present invention.

In the picture: 10. Sampling component; 11. Shell; 12. Conical tube; 120. Installation part; 121. Extension part; 122. Sampling channel; 20. Vacuum chamber; 30. Ion funnel assembly; 31. Lens pole piece; 32. Mounting column; 33. Circuit board; 34. Transmission channel; 40. Multipole assembly.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

It should be noted that when a component is referred to as being "fixed to" another component, it can be directly on the other component or another intermediate component may be present through which it is fixed. When a component is said to be "connected" to another component, it can be directly connected to the other component or there may be another intermediate component present at the same time. When a component is said to be "disposed on" another component, it can be directly located on the other component or another intervening component may be present. The terms "vertical," "horizontal," "left," "right" and similar expressions are used herein for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which the invention belongs. The terminology used herein in the description of the invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to Figures 1 to 7. The mass spectrometer ion transmission method of the present invention includes the following steps:

The sampling channel 122 of the tapered tube 12 is used to allow ions to enter the vacuum side from the atmospheric pressure side. The sampling channel 122 is tapered, and the diameter of the sampling port located on the atmospheric pressure side of the sampling channel 122 is smaller than the diameter of the sample outlet located on the vacuum side. ;

A plurality of lens pole pieces 31 are stacked to form an ion funnel assembly 30. The ion funnel assembly 30 is provided with a transmission channel 34. The inner diameters of some of the lens pole pieces 31 close to the sampling channel 122 are the same to form a straight cylindrical ion channel, which facilitates the movement of ions in a wide range. are captured inside the ion funnel assembly 30, and the inner diameter of the part of the lens pole piece 31 away from the sampling channel 122 gradually decreases along the direction of ion movement, forming a funnel-shaped ion channel that facilitates the ions to gradually focus to form a thinner ion beam and pass through the final A lens pole piece 31 with the smallest inner diameter enters the multipole assembly 40;

The axis of the sampling channel 122 and the axis of the transmission channel 34 are set at an angle or are offset in parallel;

A DC voltage V1 is applied to the sampling channel 122, and a DC voltage and a radio frequency voltage are applied to a plurality of lens pole pieces 31, wherein an opposite phase radio frequency voltage is applied to two adjacent lens pole pieces 31, and a plurality of lens pole pieces are applied along the direction of ion movement. The DC voltage on 31 gradually transitions from V2 to V3. A DC voltage V4 and a radio frequency voltage are applied to the multipole rod assembly 40. A radio frequency voltage with opposite phases is applied between two adjacent rods. V1, V2, V3, and V4 are charged according to the charged ions. The positive and negative charge conditions increase or decrease in one direction to drive the ions from the sampling channel 122 to the multipole assembly 40 through the transmission channel 34 .

Specifically, the tapered tube 12 can achieve the equivalent ion capture efficiency using a larger diameter small hole or an ordinary circular cross-section capillary under a smaller inner hole diameter (taking the minimum inner diameter value of the tapered tube 12). Compared with small holes or capillaries with larger pore diameters due to their poor vacuum degree, smaller inner pore diameters bring smaller vacuum load pressures. At the same time, the ion beam divergence of the tapered capillary is relatively small and has relatively good concentration. The sampling channel 122 of the tapered tube 12 has a smaller inner diameter on the ion inlet side and a larger inner diameter on the ion outlet side. Generally, the minimum inner diameter of the tapered tube 12 is between 0.1-5 mm, and the taper of the sampling channel 122 is between 0.3-10°. Preferably, the minimum inner diameter of the tapered tube 12 is between 0.3-1.5 mm, and the taper of the sampling channel 122 is between 0.5-2°. The sampling assembly 10 is provided with a heating function near the sampling channel 122 of the conical tube 12 to achieve efficient desolvation of solvent-bearing ion clusters and dissociation to form charged ions. A DC voltage V1 is applied to the sampling channel 122 of the conical tube 12 .

Specifically, the ion funnel assembly 30 is composed of about 20-100 lens pole pieces 31 stacked together. Direct current voltage and radio frequency voltage are applied to the lens pole piece 31 . The radio frequency voltage amplitude is between 20-400V, the frequency is between 0.1MHz-5MHz, and the preferred frequency is between 0.5-2MHz. Radio frequency voltages with opposite phases are applied between adjacent pole pieces. The 10-50 lens pole pieces 31 on the side near the ion inlet adopt the same inner diameter to form a straight cylindrical ion channel to facilitate ions to be captured into the interior of the ion funnel over a wide range. The 10-50 lens pole pieces 31 near the ion outlet adopt a gradually smaller inner diameter along with the direction of ion movement, so as to form a funnel-shaped ion channel, which facilitates the ions to gradually focus inside the ion funnel to form a thinner ion beam, so as to smoothly Enter the second-stage ion transmission structure through the inner hole of the last lens with the smallest inner diameter in the ion funnel. The DC voltage on the lens pole piece 31 generally transitions gradually from the ion entrance side DC voltage V2 to the ion exit side voltage V3.

The multipole rod assembly 40 is a second-stage ion transmission structure. The multipole rod assembly 40 consists of a set of even numbers of conductive rods arranged in parallel or conical shapes. The conductive rods are made of conductive metal rods, ceramic rods coated with a conductive layer, or quartz rods. Arranged from any one or more of them. Radio frequency voltage and DC voltage are applied to the multipole assembly 40 . The radio frequency voltage amplitude is between 20-4000V, the frequency is between 0.1MHz-5MHz, and the preferred frequency is between 0.5-2MHz. Radio frequency voltages with opposite phases are applied between two adjacent poles. A DC voltage V4 is applied to the metal rod. Preferably, the multipole assembly 40 generally adopts a quadrupole structure, a hexapole structure or an octupole structure.

The DC voltages V1, V2, V3, and V4 on the above-mentioned sampling assembly 10, ion funnel assembly 20, and multipole assembly 40 generally increase or decrease in one direction, mainly depending on the charge properties of the ions being analyzed. For positive ions, generally V1, V2, V3, and V4 are set with one-way decreasing values, so that the positive ions actively move to the rear stage under the action of the electric field force in the gradually decreasing electric potential field. For negative ions, generally V1, V2, V3, and V4 are set with one-way increasing values, so that the negative ions actively move to the rear stage under the action of the electric field force in the gradually increasing electric potential field.

The vacuum chamber 20 is used to isolate the internal vacuum environment from the external atmospheric pressure environment. Generally, the cavity section where the ion funnel assembly 20 is located has a vacuum degree of 1-10Torr, which is achieved by a mechanical pump with a pumping speed range of 10-200 m3 ^/ h; the cavity section where the multipole rod assembly 40 is located, the vacuum degree is 1-10mTorr. , generally implemented by a turbomolecular pump with a pumping speed range of 10-1000 L/s.

In this application, the axis of the sampling channel 122 and the axis of the transmission channel 34 are arranged at an angle or are offset in parallel. When the axis of the sampling channel 122 and the axis of the transmission channel 34 are arranged at an angle, the angle between the axis of the sampling channel 122 and the axis of the transmission channel 34 is 0.1-30°. The preferred range is between 1-5°. When the axis of the sampling channel 122 is offset parallel to the axis of the transmission channel 34, the offset distance between the axis of the sampling channel 122 and the axis of the transmission channel 34 is 1-10 mm. The preferred range is between 2-5mm. When the axis of the sampling channel 122 and the axis of the transmission channel 34 are offset and set parallel to each other, the ion focusing and transmission simulation effects are as shown in Figure 8 . The advantages of this layout are: 1) The airflow carrying ions that enters the vacuum chamber 20 through the conical tube 12 of the sampling assembly 10 in an atmospheric pressure environment will be blocked by the ion funnel assembly 30, alleviating the strong orientation in the airflow. flow, so that the directional flow is fully blocked and diffused to avoid flowing into the chamber where the multipole assembly 40 is located, thereby alleviating the vacuum load pressure of the chamber where the multipole assembly 40 is located; 2) In the air flow carrying ions, also A layout that contains some neutral particles and other interfering particles arranged at an angle or with a parallel offset can block such particles by the ion funnel assembly 30, while the charged ions to be analyzed will be in the pseudopotential well of the radio frequency electric field of the ion funnel assembly 30 Under the effect, the ions are blocked in the internal space of the funnel shape and will not leak out of the ion funnel assembly 30 or hit the ion funnel assembly 30 , and are focused into an extremely fine ion flow, and move toward the outlet side of the ion funnel assembly 30 along the funnel shape.

The present invention also relates to a mass spectrometer ion transmission device for implementing the above mass spectrometer ion transmission method. The mass spectrometer ion transmission device includes a sample introduction assembly 10, a vacuum chamber 20, an ion funnel assembly 30 and a multipole rod assembly 40.

The sampling assembly 10 is located on the atmospheric pressure side of the ion transmission device of the mass spectrometer. The sampling assembly 10 includes a housing 11 and a conical tube 12 installed on the housing 11 . The tapered tube 12 is provided with a sampling channel 122, which extends from the atmospheric pressure side to the vacuum side. Specifically, the tapered tube 12 includes a mounting part 120 and an extension part 121 extending from the mounting part 120. The outer surface of the mounting part 120 is tapered, and the extension part 121 is cylindrical. The sampling channel 122 passes through the mounting part 120 and the extension part 121. The sampling channel 122 is tapered as a whole. The diameter of the sampling port on the atmospheric pressure side of the sampling channel 122 is smaller than the diameter of the sampling port on the vacuum side. The minimum inner diameter of the tapered tube 12 is between 0.1-5 mm, and the taper of the sampling channel 122 is between 0.3-10°. Preferably, the minimum inner diameter of the tapered tube 12 is between 0.3-1.5 mm, and the taper of the sampling channel 122 is between 0.5-2°. This design allows the tapered tube 12 to achieve the equivalent ion capture efficiency that can only be achieved by using a larger diameter small hole or an ordinary circular cross-section capillary under a smaller inner hole diameter (taking the minimum inner diameter value of the tapered tube 12). Compared with small holes or capillaries with larger pore diameters due to their poor vacuum degree, smaller inner pore diameters bring smaller vacuum load pressures. At the same time, the ion beam divergence of the tapered capillary is relatively small and has relatively good concentration.

The vacuum chamber 20 is used to isolate the internal vacuum environment from the external atmospheric pressure environment. Specifically, the vacuum chamber 20 has a hollow structure, and one side of the vacuum chamber 20 is sealingly connected to the housing 11 of the sampling assembly 10 . The entire vacuum chamber 20 extends in the direction of ion movement (the extension direction of the sampling channel 122 ). The cavity section where the ion funnel assembly 20 is located has a vacuum degree of 1-10Torr, which is achieved by a mechanical pump with a pumping speed range of 10-200 m3 ^/ h; the cavity section where the multipole assembly 40 is located has a vacuum degree of 1-10mTorr. Generally, a turbomolecular pump with a pumping speed range of 10-1000 L/s is used.

The ion funnel assembly 30 includes a plurality of lens pole pieces 31 , a mounting post 32 and a circuit board 33 . The plurality of lens pole pieces 31 are installed on the mounting post 32 and stacked on each other. The circuit board 33 is mounted on the lens pole piece 31 and applies voltage to the lens pole piece 31 . Specifically, each lens pole piece 31 is provided with an inner hole, and the inner holes of the plurality of lens pole pieces 31 form transmission channels 34 . The inner diameters of the lens pole pieces 31 close to the sampling channel 122 are the same to form a straight cylindrical ion channel, and the inner diameters of the lens pole pieces 31 far away from the sampling channel 122 gradually decrease along the ion movement direction to form a funnel-shaped ion channel. Specifically, the ion funnel assembly 30 is composed of about 20-100 lens pole pieces 31 stacked together. Direct current voltage and radio frequency voltage are applied to the lens pole piece 31 . The radio frequency voltage amplitude is between 20-400V, the frequency is between 0.1MHz-5MHz, and the preferred frequency is between 0.5-2MHz. Radio frequency voltages with opposite phases are applied between adjacent pole pieces. The 10-50 lens pole pieces 31 on the side near the ion inlet adopt the same inner diameter to form a straight cylindrical ion channel to facilitate ions to be captured into the interior of the ion funnel over a wide range. The 10-50 lens pole pieces 31 near the ion outlet adopt a gradually smaller inner diameter along with the direction of ion movement, so as to form a funnel-shaped ion channel, which facilitates the ions to gradually focus inside the ion funnel to form a thinner ion beam, so as to smoothly Enter the second-stage ion transmission structure through the inner hole of the last lens with the smallest inner diameter in the ion funnel. The DC voltage on the lens pole piece 31 generally transitions gradually from the ion entrance side DC voltage V2 to the ion exit side voltage V3.

Please continue to refer to FIG. 6 . In the first embodiment, the axis of the sampling channel 122 is offset parallel to the axis of the transmission channel 34 . The offset distance between the axis of the sampling channel 122 and the axis of the transmission channel 34 is 1-10 mm. . The preferred range is between 2-5mm.

Please continue to refer to FIG. 7 . In the second embodiment, the axis of the sampling channel 122 and the axis of the transmission channel 34 are arranged at an angle. The angle between the axis of the sampling channel 122 and the axis of the transmission channel 34 is 0.1-30. °. The preferred range is between 1-5°.

Parallel offset settings or angled settings have the following advantages: 1) The airflow carrying ions entering the vacuum chamber 20 through the conical tube 12 of the sampling assembly 10 in an atmospheric pressure environment will be blocked by the ion funnel assembly 30, easing the The strong directional flow in the airflow fully blocks and diffuses the directional flow to avoid flowing into the chamber where the multipole assembly 40 is located, thereby alleviating the vacuum load pressure of the chamber where the multipole assembly 40 is located; 2) Carrying The ion flow also contains some neutral particles and other interfering particles. The angular or offset layout can block such particles by the ion funnel assembly 30, while the charged ions to be analyzed will be in the ion funnel assembly 30. Under the pseudopotential well effect of the radio frequency electric field, the ions are blocked in the internal space of the funnel shape and will not leak out of the ion funnel assembly 30 or hit the ion funnel assembly 30, and are focused into an extremely fine ion flow, and flow toward the ion funnel along the funnel shape. The outlet side of assembly 30 moves.

The multipole rod assembly 40 is a second-stage ion transmission structure. The multipole rod assembly 40 is composed of a set of even numbers of conductive rods arranged in parallel or conical shapes. The multipole rod assembly 40 is made of conductive metal rods, ceramic rods or quartz rods plated with a conductive layer, etc. Arranged in any one or more ways. Radio frequency voltage and DC voltage are applied to the multipole assembly 40 . The radio frequency voltage amplitude is between 20-4000V, the frequency is between 0.1MHz-5MHz, and the preferred frequency is between 0.5-2MHz. Radio frequency voltages with opposite phases are applied between two adjacent poles. A DC voltage V4 is applied to the metal rod. Preferably, the multipole assembly 40 generally adopts a quadrupole structure, a hexapole structure or an octupole structure.

The DC voltages V1, V2, V3, and V4 on the above-mentioned sampling assembly 10, ion funnel assembly 20, and multipole assembly 40 generally increase or decrease in one direction, mainly depending on the charge properties of the ions being analyzed. For positive ions, generally V1, V2, V3, and V4 are set with one-way decreasing values, so that the positive ions actively move to the rear stage under the action of the electric field force in the gradually decreasing electric potential field. For negative ions, generally V1, V2, V3, and V4 are set with one-way increasing values, so that the negative ions actively move to the rear stage under the action of the electric field force in the gradually increasing electric potential field.

The ion transmission device of the mass spectrometer of this application is mainly used in the atmospheric pressure ionization source mass spectrometer. The process of transferring charged ions from the atmospheric pressure environment to the mass analyzer in the vacuum environment involves multi-stage differential vacuum and high-efficiency ion transmission links. This solution is significantly different from the solutions used in existing commercial instruments or existing patents. The proposed solution has the characteristics of simple structure, high ion capture efficiency, low vacuum load pressure, and low neutral particle interference. Low vacuum load pressure is conducive to further increasing the opening size of the sampling part to increase the injection volume, thereby improving signal intensity. Therefore, it is expected that the use of this application can significantly improve the signal strength, reduce the noise, and improve the signal-to-noise ratio, which has high practical value and industrialization value.

The above embodiments only express several embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, which are equivalent modifications to the above embodiments based on the essential technology of the present invention. and evolution, these all belong to the protection scope of the present invention.

Claims (10)

1. A mass spectrometer ion transmission method, characterized in that it includes the following steps: Ions are made to enter the vacuum side from the atmospheric pressure side by using a sampling channel of a tapered tube. The sampling channel is tapered, and the diameter of the inlet of the sampling channel on the atmospheric pressure side is smaller than that of the outlet on the vacuum side. The diameter of the sample port; Multiple lens pole pieces are stacked to form an ion funnel assembly. The ion funnel assembly is provided with a transmission channel. The inner diameters of some lens pole pieces close to the sampling channel are the same to form a straight cylindrical ion channel, which facilitates ions to be transported over a wide range. Captured inside the ion funnel assembly, the inner diameter of the part of the lens pole piece away from the sampling channel gradually decreases along the direction of ion movement, forming a funnel-shaped ion channel that facilitates the ions to gradually focus to form a thinner ion beam and pass through the last The lens pole piece with the smallest inner diameter enters the multipole assembly; The axis of the sampling channel and the axis of the transmission channel are set at an angle or offset in parallel; A DC voltage V1 is applied to the sampling channel, a DC voltage and a radio frequency voltage are applied to a plurality of the lens pole pieces, wherein a radio frequency voltage with an opposite phase is applied to two adjacent lens pole pieces, and a plurality of the lens pole pieces are applied in the direction of ion movement. The DC voltage on the lens pole piece gradually transitions from V2 to V3, and a DC voltage V4 is applied to the multipole rod assembly. V1, V2, V3, and V4 increase or decrease in one direction to drive ions from the sampling channel through the the transmission channel to the multipole assembly. 2. The mass spectrometer ion transmission method according to claim 1, characterized in that: when the axis of the sampling channel and the axis of the transmission channel are arranged at an angle, the axis of the sampling channel and the axis of the transmission channel are arranged at an angle. The angle between the axes of the channels is 0.1-30°. 3. The mass spectrometer ion transmission method according to claim 1, characterized in that: when the axis of the sampling channel and the axis of the transmission channel are offset in parallel, the axis of the sampling channel is parallel to the axis of the transmission channel. The offset distance of the axis of the transmission channel is 1-10mm. 4. The mass spectrometer ion transmission method according to claim 1, characterized in that: the inner diameter of the injection port of the sampling channel is 0.1-5 mm, and the taper of the sampling channel is 0.3-10°. 5. The mass spectrometer ion transmission method according to claim 1, characterized in that: the mass spectrometer ion transmission method further includes a heating step, and the heating step specifically includes: heating the sampling channel to allow the ions to enter the mass spectrometer. The solvent-bearing ion clusters in the injection channel are desolvated and dissociated to form charged ions. 6. The mass spectrometer ion transmission method according to claim 1, characterized in that: a radio frequency voltage is applied to the multipole rod assembly, and the radio frequency voltage applied between two adjacent rods has opposite phases. 7. A mass spectrometer ion transmission device, used to implement the mass spectrometer ion transmission method according to any one of claims 1-6, the mass spectrometer ion transmission device includes a vacuum chamber and is installed in the vacuum chamber The ion funnel assembly is characterized in that: the mass spectrometer ion transmission device also includes a sampling assembly and a multipole rod assembly, the sampling assembly is installed on one side of the vacuum chamber, and the multipole rod assembly is installed on Inside the vacuum chamber, the ion funnel assembly is located between the sampling assembly and the multipole assembly. The sampling assembly includes a tapered tube, and the tapered tube is provided with a sampling channel. The sampling channel is tapered, and the diameter of the sampling port located on the atmospheric pressure side of the sampling channel is smaller than the diameter of the sample outlet located on the vacuum side. The ion funnel assembly is provided with a transmission channel, and the transmission channel The width of the side close to the sampling channel is equal to form a straight cylindrical ion channel, and the width of the transmission channel close to the multipole assembly gradually decreases to form a funnel-shaped ion channel. The axis of the sampling channel is in line with the transmission channel. The axis is set at an angle or parallel offset. 8. The mass spectrometer ion transmission device according to claim 7, wherein the ion funnel assembly includes a plurality of lens pole pieces, the lens pole pieces are stacked, and each lens pole piece is provided with an inner hole. , the inner holes of a plurality of the lens pole pieces form the transmission channel, the inner diameters of the part of the lens pole pieces close to the sampling channel are the same to form a straight cylindrical ion channel, and the part of the lens far away from the sampling channel The inner diameter of the pole piece gradually decreases along the direction of ion movement, forming a funnel-shaped ion channel. 9. The mass spectrometer ion transmission device according to claim 7, characterized in that: when the axis of the sampling channel and the axis of the transmission channel are arranged at an angle, the axis of the sampling channel and the axis of the transmission channel are arranged at an angle. The angle between the axes of the channels is 0.1-30°. 10. The mass spectrometer ion transmission device according to claim 7, characterized in that: when the axis of the sampling channel and the axis of the transmission channel are offset parallel to each other, the axis of the sampling channel is parallel to the axis of the transmission channel. The offset distance of the axis of the transmission channel is 1-10mm.