Composite ion source device for coupling atmospheric pressure interface orbitrap mass spectrometry

Abstract

The present invention discloses a composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer, belonging to the field of mass spectrometry detection, and comprising a photoionization / photoinduced association ionization and ion transmission mechanism, a gas sampling mechanism, a high-throughput radio frequency vacuum ultraviolet light source mechanism, and an ion source and mass spectrometer interface mechanism. The present invention adopts the above-mentioned composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer, so that organic components of different polarities, ionization energies, and ion affinities in complex mixtures can be efficiently ionized. Through reasonable structural design, the device is coupled with a high-resolution orbital trap mass spectrometer with an atmospheric pressure interface to achieve a broadened detection range of complex organic components and improve the resolution and detection sensitivity of low-abundance or high-molecular-weight organic components.

Description

Technical Field

[0001] The present invention relates to the field of mass spectrometry detection, in particular to a composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer. Background Art

[0002] The ion source is the core component of a mass spectrometer, converting neutral molecules into ions. It is the primary step in mass spectrometry analysis and is crucial to the sensitivity, analyzable range, stability, and accuracy of the entire mass spectrometer system. Atmospheric pressure ionization (API) is a technique that ionizes sample molecules under atmospheric pressure. Existing ion sources coupled to atmospheric pressure interface mass spectrometers are primarily chemical ionization (CI) sources. However, online CI mass spectrometry typically relies on a specific reagent ion. An ion-molecule reaction between the ion reagent and the analyte creates adduct ions, which charge the analyte. However, the analyte's detectable species are limited by the ion affinity, resulting in strong selectivity and limited measurement of specific compounds. While CI generally works well for polar substances, effectively ionizing and providing complete molecular information, it is less suitable for non-polar or weakly polar substances, resulting in lower ionization efficiency.

[0003] In contrast, another soft ionization technique, photoionization, determines ionization based on whether the photon energy exceeds the ionization energy of the analyte, making it a broad-spectrum ionization method. Photoionization mass spectrometry typically uses vacuum ultraviolet light generated by excited krypton gas to ionize the analyte, with photon energies of approximately 10 eV. With the exception of a few small organic molecules containing three or fewer carbon atoms with ionization energies above 10 eV, it is widely applicable to most polar and non-polar organic compounds. Furthermore, this ionization method offers numerous advantages, including high molecular ion yield, minimal fragmentation, simple mass spectral interpretation, a wide linear dynamic range, and good tolerance to matrix components.

[0004] Photoinduced association ionization (PAI) is a newly discovered ionization pathway. It generates ions through collisions between neutral molecules (excited or unexcited) and involves the formation of new bonds. Essentially, it is neither direct photoionization nor chemical ionization or dopant-assisted photoionization (where reagent ions are used to charge the analyte through ion-molecule reactions). Its ionization efficiency can be tens or even thousands of times higher than direct photoionization. This process utilizes both light energy and the chemical energy of new bond formation to charge the analyte. Therefore, it is not limited by the ionization energy of the analyte and ion affinity (such as proton affinity), and has broad applicability to organic compounds from weak to strong polarity. Furthermore, the resulting mass spectra are concise and clear, achieving both high sensitivity and low detection limits.

[0005] It can be seen that if these two ionization technologies are combined, efficient ionization of organic components with different polarities, ionization energies and ion affinities can be achieved, and the detection range of existing atmospheric pressure ion sources can be broadened. However, there are currently no reports on composite ion sources that combine these two ion sources, nor are there any devices or designs for combining photoinduced association ionization with atmospheric pressure interface mass spectrometry. Summary of the Invention

[0006] The purpose of the present invention is to provide a composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometry, which integrates the two ionization technologies of photoionization and photoinduced association ionization. Based on a high-throughput radio frequency vacuum ultraviolet light source, by adding or not adding gaseous CH2Cl2 in the ionization zone to switch between photoinduced association ionization and photoionization modes, organic components with different polarities, ionization energies and ion affinities in complex mixtures can be efficiently ionized. Through reasonable structural design, it is coupled with a high-resolution orbital trap mass spectrometry with an atmospheric pressure interface to achieve the expansion of the detection range of complex organic components and improve the resolution and detection sensitivity of low-abundance or high-molecular-weight organic components.

[0007] To achieve the above-mentioned objectives, the present invention provides a composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer, comprising a photoionization / photoinduced associated ionization and ion transmission mechanism, a gas injection mechanism, a high-throughput radio frequency vacuum ultraviolet light source mechanism, and an ion source and mass spectrometer interface mechanism. The gas injection mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transmission mechanism, the high-throughput radio frequency vacuum ultraviolet light source mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transmission mechanism, and the ion source and mass spectrometer interface mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transmission mechanism.

[0008] Preferably, the photoionization / photoinduced association ionization and ion transport mechanism includes an ion source cavity housing, a metal grid, an ionizer, an ion focusing introduction electrode, and an ion source exhaust pipe. The ionizer is sealed and connected to the gas injection mechanism, and a metal grid is provided at the connection. The ionizer and the ion focusing introduction electrode are located in the ion source cavity housing, and the ion source exhaust pipes are symmetrically provided on the upper and lower parts of the ion source cavity housing.

[0009] Preferably, the gas injection mechanism includes a sample gas injection tube and a sheath gas injection tube, both of which are stainless steel tubes. Sheath gas is introduced symmetrically on both radial sides of the sheath gas injection tube. The sample gas injection tube is located inside the sheath gas injection tube and is coaxially arranged with the sheath gas injection tube.

[0010] Preferably, the gas introduced into the sheath gas inlet tube is 0.01% to 10% CH2Cl2, and the auxiliary gas is N2 or He.

[0011] Preferably, the high-flux RF vacuum ultraviolet light source mechanism includes a discharge gas flow chamber, a discharge gas inlet pipe, a discharge gas outlet pipe, a RF excitation coil, a RF power supply, a sealing ring, a magnesium fluoride lens, a discharge gas flow chamber sealing cover and a magnesium fluoride lens sealing cover. The discharge gas inlet pipe and the discharge gas outlet pipe are located at the upper end of the discharge gas flow chamber and are distributed in a T shape. A RF excitation coil is wound under the outer wall of the discharge gas flow chamber. One end of the RF excitation coil is connected to the RF power supply and the other end is grounded. The bottom end of the discharge gas flow chamber is sealed with the light outlet of the magnesium fluoride lens through a coaxially installed sealing ring, and a sealing cover is fixed outside the sealing ring.

[0012] Preferably, the discharge gas flow chamber is a cylindrical quartz lamp tube.

[0013] Preferably, the light outlet of the magnesium fluoride lens is sealed and connected to the ionizer, and the light outlet direction is perpendicular to the direction of the sample gas inlet tube.

[0014] Preferably, the ion source and mass spectrometer interface mechanism includes a mass spectrometer sampling cone, an orbital trap mass spectrometer inlet and a circuit interface. The mass spectrometer sampling cone is sealed and connected to the ion source cavity shell. An orbital trap mass spectrometer inlet is provided at the mass spectrometer sampling cone, and a channel is left between the orbital trap mass spectrometer inlet and the mass spectrometer sampling cone. Sampling protective gas passes through the channel. The circuit interface is embedded in the cavity shell above the orbital trap mass spectrometer inlet, which is used to enable the orbital trap mass spectrometer to recognize ion signals and provide the required electrode voltage and sampling protective gas for the mass spectrometer through the orbital trap mass spectrometer.

[0015] Preferably, the ion focusing introduction electrode is a hollow circular stainless steel plate, which is coaxially insulated and installed with the circular hole at the ionizer outlet and the mass spectrometer sampling cone.

[0016] Preferably, the mass spectrometer sampling cone is coaxially installed with the sample gas inlet tube.

[0017] The principle of the present invention is to use PAI technology to generate excited state by absorbing VUV light through gaseous CH2Cl2 , inducing trace H2O molecules in the carrier gas to transfer their protons to the analyte, making the analyte protonated efficiently ( , M represents the analyte molecule).

[0018] Therefore, the present invention adopts the above-mentioned composite ion source device for coupling atmospheric pressure interface orbital trap mass spectrometry, which has the following beneficial effects:

[0019] (1) The composite ion source device provided by the present invention can utilize two ionization modes, namely vacuum ultraviolet photoionization and photoinduced association ionization, and has a wide applicability to polar and non-polar substances. It is not limited by the ionization energy and ion affinity (such as proton affinity) of the analyte. Through reasonable structural design, it is coupled with a high-resolution orbital trap mass spectrometer with an atmospheric pressure interface to achieve a broadened detection range for complex organic components and improve the resolution and detection sensitivity of low-abundance or high-molecular-weight organic components.

[0020] (2) The radio frequency vacuum ultraviolet lamp of the present invention can stably generate high flux photons and can output up to about 10 15 The photon flux of photon / s effectively solves the problem of low light flux of current commercial vacuum ultraviolet lamps (about 10 11 At the same time, due to the high flux of the light source, the amount of CH2Cl2 reaction gas required can be greatly reduced.

[0021] (3) The present invention uses an ingenious structural design to allow vacuum ultraviolet light to irradiate the interior of a field-free ionizer with the same electric potential, thereby preventing the photoelectrons generated by the vacuum ultraviolet light irradiating the metal from being accelerated by the electric field and causing the electron ionization of the reaction gas or background gas. The ionizer as a whole is used as a repelling electrode and an ion focusing introduction electrode to form a focusing electric field to pull ions. This design is significantly different from other ion source designs and is a unique design suitable for the photoinduced association ionization method. In addition, the vacuum ultraviolet light irradiation direction is perpendicular to the ion transmission direction, thereby preventing the vacuum ultraviolet light from irradiating the metal electrode of the ion transmission system through the ionizer outlet, generating photoelectrons, which are accelerated by the electric field and cause the electron ionization of the reaction gas or background gas.

[0022] (4) The entire ion source device is small in size and compact in structure. When used in conjunction with a high-resolution orbital trap mass spectrometer, it can not only broaden the detection range of complex organic components, but also improve the species recognition ability and detection sensitivity of low-abundance or high-molecular-weight organic components. It has broad application prospects in the fields of process monitoring and online monitoring of environmental pollution.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of an embodiment of a composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer according to the present invention.

[0025] Reference numerals

[0026] 1. Ion source chamber housing; 2. Sheath gas inlet tube; 3. Sample gas inlet tube; 4. Metal grid; 5. Ionizer; 6. Ion focusing introduction electrode; 7. Discharge gas flow chamber; 8. Discharge gas inlet pipe; 9. Discharge gas outlet pipe; 10. RF excitation coil; 11. RF power supply; 12. Sealing ring; 13. Magnesium fluoride lens; 14. Discharge gas flow chamber sealing cover; 15. Magnesium fluoride lens sealing cover; 16. Ground state CH2Cl2 molecule; 17. Excited state CH2Cl2 molecule; 18. Sample molecule; 19. Sample ion; 20. Circuit interface; 21. Mass spectrometer sampling cone; 22. Ion source exhaust pipe; 23. Sampling protective gas; 24. Orbitrap mass spectrometer inlet. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0028] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0029] Example 1

[0030] like Figure 1As shown, the present invention provides a composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer, comprising a photoionization / photoinduced associated ionization and ion transmission mechanism, a gas injection mechanism, a high-throughput radio frequency vacuum ultraviolet light source mechanism, and an ion source and mass spectrometer interface mechanism. The gas injection mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transmission mechanism, the high-throughput radio frequency vacuum ultraviolet light source mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transmission mechanism, and the ion source and mass spectrometer interface mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transmission mechanism. The photoionization / photoinduced association ionization and ion transmission mechanism is used to ionize the sample molecules 18 to generate sample ions 19, and to transmit and focus the sample ions 19 to ensure that the sample ions 19 can be efficiently transmitted to the mass spectrometry sampling cone 21 connected to the mass spectrometry end. The gas injection mechanism is used to transport sample gas, reaction gas and auxiliary gas. The high-throughput radio frequency vacuum ultraviolet light source mechanism is used to generate vacuum ultraviolet light. The ion source and mass spectrometry interface mechanism is used to enable the orbital trap mass spectrometer to identify ion signals and provide the required electrode voltage and sampling protection gas 23 for the ion source through the orbital trap mass spectrometer.

[0031] The photoionization / photoinduced association ionization and ion transmission mechanism includes an ion source cavity shell 1, a metal grid 4, an ionizer 5, an ion focusing introduction electrode 6, and an ion source exhaust pipe 22. The ion source cavity shell 1 is used to support and load the internal components of the ion source and to seal the connection with the mass spectrometer; the ionizer 5 and the ion focusing introduction electrode 6 are located in the ion source cavity shell 1, and the ionizer 5 is used to generate sample ions 19 from sample molecules 18 by photoionization or photoinduced association ionization; the ion focusing introduction electrode 6 is a hollow circular stainless steel plate, which is coaxially insulated with the circular hole at the outlet of the ionizer 5 and the mass spectrometer sampling cone 21, and is used to transmit and focus the sample ions 19 to ensure that the sample ions 19 can be efficiently transmitted to the mass spectrometer. The mass spectrometer sampling cone 21 is connected to the spectrum end; the ionizer 5 is sealed and connected to the gas injection mechanism, and a metal grid 4 is provided at the connection point to make the entire ionization area have the same electric potential, so as to prevent the vacuum ultraviolet light from irradiating the inner surface of the metal ionizer 5 to generate photoelectrons. The photoelectrons are accelerated by the electric field and break up the ground state CH2Cl2 molecules 16 or ionize the background molecules to generate background ions in the form of electron ionization; the ion source exhaust pipe 22 is symmetrically arranged on the upper and lower parts of the ion source cavity shell 1, which is connected to the vacuum pump through a valve to maintain the vacuum environment required by the ion source.

[0032] The gas injection mechanism includes a sample gas injection tube 3 and a sheath gas injection tube 2, both of which are stainless steel tubes. The sheath gas injection tube 2 has a T-shaped structure. The sample gas injection tube 3 is located inside the sheath gas injection tube 2 and is coaxial with the vertical branch tube of the sheath gas injection tube 2. The sample gas injection tube 3 is used for stable injection of the sample gas, and the sheath gas injection tube 2 is used for stable injection of the auxiliary gas N2 or He and the reaction gas CH2Cl2. The auxiliary gas is used to form a laminar flow to allow the sample gas to flow stably through the ionizer 5. At the same time, N2 or He replaces air to reduce the absorption loss of the O2 component in the air to vacuum ultraviolet light. By changing the flow rate of the auxiliary gas, the gas pressure of the ion source can be adjusted to achieve the optimal detection efficiency. The reaction gas CH2Cl2 is used to generate excited CH2Cl2 molecules 17 under vacuum ultraviolet light irradiation to induce light-induced association ionization.

[0033] The high-flux RF vacuum ultraviolet light source mechanism includes a discharge gas flow chamber 7, a discharge gas inlet pipe 8, a discharge gas outlet pipe 9, an RF excitation coil 10, an RF power supply 11, a sealing ring 12, a magnesium fluoride lens 13, a discharge gas flow chamber sealing cover 14, and a magnesium fluoride lens sealing cover 15. The discharge gas inlet pipe 8 and the discharge gas outlet pipe 9 are located at the upper end of the discharge gas flow chamber 7 in a T-shaped arrangement. The RF excitation coil 10 is wound around the lower outer wall of the discharge gas flow chamber 7. One end of the RF excitation coil 10 is connected to the RF power supply 11, and the other end is grounded. The bottom end of the discharge gas flow chamber 7 is sealedly connected to the light outlet of the magnesium fluoride lens 13 via a coaxially mounted sealing ring 12. A sealing cover is fixed to the outer surface of the sealing ring 12. Under the action of RF, the discharge gas generates luminous plasma and releases heat. Due to thermal expansion and contraction, the discharge gas maintains heat exchange and flow between the lower and upper halves of the discharge gas flow chamber 7, thereby maintaining the purity of the discharge gas within the discharge gas flow chamber 7 and achieving stable output of high-flux vacuum ultraviolet light.

[0034] The discharge gas flow chamber 7 is a cylindrical quartz lamp tube, and the light outlet of the magnesium fluoride lens 13 is sealed and connected to the ionizer 5. Its light outlet direction is perpendicular to the direction of the sample gas inlet tube 3, so that the vacuum ultraviolet light irradiation direction is perpendicular to the migration direction of the sample molecules 18 and sample ions 19, avoiding the vacuum ultraviolet light from leaking into the ion migration area. The vacuum ultraviolet light irradiates the metal electrode to generate photoelectrons, and under the action of the ion migration electric field, the ground state CH2Cl2 molecules 16 are broken up by electron ionization or the background molecules are ionized to generate background ions to generate excited state CH2Cl2 molecules 17.

[0035] The ion source and mass spectrometer interface mechanism includes a circuit interface 20, a mass spectrometer sampling cone 21 and an orbital trap mass spectrometer inlet 24. The circuit interface 20 is embedded in the cavity shell 1 above the orbital trap mass spectrometer inlet 24, and is used to enable the orbital trap mass spectrometer to identify ion signals and provide the required electrode voltage and sampling protection gas 23 for the mass spectrometer through the orbital trap mass spectrometer; the mass spectrometer sampling cone 21 is sealed with the ion source cavity shell 1, and an orbital trap mass spectrometer inlet 24 is provided at the mass spectrometer sampling cone 21, and a channel is left between the orbital trap mass spectrometer inlet 24 and the mass spectrometer sampling cone 21, and the sampling protection gas 23 passes through the channel, and the mass spectrometer sampling cone 21 is coaxially installed with the sample gas inlet tube 3.

[0036] When the composite ion source device for coupling atmospheric pressure interface orbital trap mass spectrometry provided by the present invention is used, the following steps are included:

[0037] Step 1: Use the discharge gas inlet pipe 8 and the discharge gas outlet pipe 9 above the discharge gas flow chamber 7 to continuously introduce and discharge krypton gas as the discharge gas. The discharge gas generates high-flux vacuum ultraviolet light and releases heat under the action of the radio frequency excitation coil 10. The generated vacuum ultraviolet light passes through the magnesium fluoride lens 13 and enters the ionizer 5.

[0038] Step 2: Sample molecules 18 are stably introduced into the ion source cavity housing 1 through the sample gas injection tube 3, and the auxiliary gas (N2 or He) and reaction gas (CH2Cl2) are stably introduced through the sheath gas injection tube 2 coaxial with the sample gas injection tube 3 and enter the ionizer 5 through the metal grid 4.

[0039] Step 3: When gaseous CH2Cl2 is not introduced into the ionization region, the sample molecules 18 are directly ionized by single photons under the action of vacuum ultraviolet light to form sample ions 19; when gaseous CH2Cl2 is introduced into the ionization region, the ground state CH2Cl2 molecules 16 generate excited state CH2Cl2 molecules 17 under the irradiation of vacuum ultraviolet light, inducing trace H2O molecules in the carrier gas to transfer their protons to other sample molecules 18, and the sample molecules 18 are efficiently protonated to form sample ions 19.

[0040] Step 4: The generated sample ions 19 flow out of the ionizer 5 under the traction of the flow field. The ionizer 5 itself acts as a repeller electrode and forms an ion focusing transmission electric field with the ion focusing introduction electrode 6 to focus and guide the sample ions 19. The sample ions 19 are efficiently transmitted to the mass spectrometer sampling cone 21 connected to the mass spectrometer end, and then enter the orbital trap mass spectrometer injection port 24 for detection.

[0041] Therefore, the present invention adopts the above-mentioned composite ion source device for coupling with atmospheric pressure interface orbital trap mass spectrometry, so that organic components with different polarities, ionization energies and ion affinities in complex mixtures can be efficiently ionized, and through reasonable structural design, coupled with a high-resolution orbital trap mass spectrometry with an atmospheric pressure interface, the detection range of complex organic components can be broadened, and the resolution and detection sensitivity of low-abundance or high-molecular-weight organic components can be improved.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A composite ion source device for coupling an atmospheric pressure interface orbital trap mass spectrometer, characterized in that: It includes a photoionization / photoinduced associated ionization and ion transport mechanism, a gas injection mechanism, a high-throughput radio frequency vacuum ultraviolet light source mechanism, and an ion source and mass spectrometry interface mechanism. The gas injection mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transport mechanism, the high-throughput radio frequency vacuum ultraviolet light source mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transport mechanism, and the ion source and mass spectrometry interface mechanism is fixedly connected to the photoionization / photoinduced associated ionization and ion transport mechanism. The photoionization / photoinduced association ionization and ion transport mechanism includes an ion source cavity housing, a metal grid, an ionizer, an ion focusing introduction electrode, and an ion source exhaust pipe. The ionizer is sealed and connected to the gas injection mechanism, and a metal grid is provided at the connection. The ionizer and the ion focusing introduction electrode are located in the ion source cavity housing. The ion source exhaust pipes are symmetrically provided on the upper and lower parts of the ion source cavity housing. The gas injection mechanism includes a sample gas injection tube and a sheath gas injection tube. Both the sample gas injection tube and the sheath gas injection tube are stainless steel tubes. Sheath gas is introduced symmetrically on both radial sides of the sheath gas injection tube. The sample gas injection tube is located inside the sheath gas injection tube and is coaxially arranged with the sheath gas injection tube. The high-throughput RF vacuum ultraviolet light source mechanism includes a discharge gas flow chamber, a discharge gas inlet pipe, a discharge gas outlet pipe, a RF excitation coil, a RF power supply, a sealing ring, a magnesium fluoride lens, a discharge gas flow chamber sealing cover, and a magnesium fluoride lens sealing cover. The discharge gas inlet pipe and the discharge gas outlet pipe are located at the upper end of the discharge gas flow chamber and are distributed in a T-shape. A RF excitation coil is wound under the outer wall of the discharge gas flow chamber. One end of the RF excitation coil is connected to the RF power supply, and the other end is grounded. The bottom end of the discharge gas flow chamber is sealed and connected to the light outlet of the magnesium fluoride lens through a coaxially installed sealing ring, and a sealing cover is fixed to the outside of the sealing ring. The light outlet of the magnesium fluoride lens is sealed and connected to the ionizer, and the light outlet direction is perpendicular to the direction of the sample gas inlet tube.

2. The composite ion source device for coupling atmospheric pressure interface orbital trap mass spectrometry according to claim 1, characterized in that: The gas introduced into the sheath gas inlet tube is 0.01%~10% CH2Cl2, and the auxiliary gas is N2 or He.

3. The composite ion source device for coupling atmospheric pressure interface orbital trap mass spectrometry according to claim 1, characterized in that: The discharge gas flow cavity is a cylindrical quartz lamp tube.

4. The composite ion source device for coupling atmospheric pressure interface orbital trap mass spectrometry according to claim 1, characterized in that: The ion source and mass spectrometer interface mechanism includes a mass spectrometer sampling cone, an orbital trap mass spectrometer inlet and a circuit interface. The mass spectrometer sampling cone is sealed and connected to the ion source cavity shell. An orbital trap mass spectrometer inlet is provided at the mass spectrometer sampling cone, and a channel is left between the orbital trap mass spectrometer inlet and the mass spectrometer sampling cone. Sampling protection gas passes through the channel. The circuit interface is embedded in the cavity shell above the orbital trap mass spectrometer inlet.

5. The composite ion source device for coupling atmospheric pressure interface orbital trap mass spectrometry according to claim 4, characterized in that: The ion focusing introduction electrode is a hollow circular stainless steel plate, which is coaxially insulated with the circular hole at the ionizer outlet and the mass spectrometer sampling cone.

6. The composite ion source device for coupling atmospheric pressure interface orbital trap mass spectrometry according to claim 4, characterized in that: The mass spectrometer sampling cone is installed coaxially with the sample gas inlet tube.

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