An integrated full-angle excitation source for atomic fluorescence spectrometer

Abstract

This invention relates to an integrated omnidirectional excitation source for atomic fluorescence spectrometers, belonging to the field of analytical instrument technology. It comprises an excitation source module and a ring atomizer module. The excitation source module includes an outer conductor (1), a microwave input port (2), a microwave antenna (3), and an inner conductor (4), etc. The ring atomizer module includes a flow guide ring (12), a working gas inlet (13), and a sample inlet (14), etc. This invention can be applied to atomic fluorescence spectrometers, and the excitation source has advantages such as high radiation intensity, narrow spectral line width, good spectral selectivity, and the ability to excite the sample at all angles (360 degrees).

Description

Technical Field

[0001] The invention belongs to the technical field of analytical instruments, and in particular relates to an integrated full-angle excitation source for an atomic fluorescence spectrometer. Background Art

[0002] In atomic spectrometers, the excitation source (atomizer and / or excitation light source) is the key and core, which directly determines the structure of the instrument and the quality of the analytical performance. In existing atomic fluorescence spectrometers, the excitation light source and the atomizer are separated in physical space. Usually, the atomizer uses a hydrogen-oxygen flame in a quartz tube furnace, and the excitation light source uses a high-intensity hollow cathode lamp. The quartz tube atomizer is only suitable for elements that can generate gaseous hydrides at room temperature. The hydrogen generated by the hydride generation method is burned with oxygen in the air in an argon environment to achieve sample atomization. Therefore, the types of elements in the sample being tested are subject to certain restrictions.

[0003] The biggest problem with hollow cathode lamps as excitation light sources is that the luminous intensity of the lamp drifts severely, and the instrument needs to calibrate the standard curve regularly, which is inconvenient for users. Secondly, the commonly used hollow cathode lamps are sharp-line light sources. A hollow cathode lamp can only emit light radiation of one element corresponding to it, and can only be used to measure samples of the same type as the element. When different types of elements need to be measured, hollow cathode lamps of different elements need to be replaced. For example, if the zinc element in the sample is measured, a zinc element lamp needs to be configured for analysis. Due to the limitation of the types of hollow cathode lamps, the types of elements to be measured cannot be expanded at will. In addition, for the analysis of samples of multiple elements, lamps of multiple elements must be configured, which requires a larger instrument space.

[0004] In terms of instrument layout, in order to prevent the light radiation emitted by the excitation light source from affecting the measurement of weak atomic fluorescence signals, the direction in which the fluorescence detector receives the light signal must be at right angles or at an acute angle to the direction in which the excitation light irradiates the atomizer. The excitation light beam should at most irradiate the atomizer within a range of 180 degrees, such as Figure 1 As shown. As we all know, the intensity of the fluorescence signal is proportional to the intensity of the excitation light. Since the entire circumference of the quartz tube atomizer can only receive the excitation light within a range of 180 degrees at most, the measurement sensitivity of the instrument will inevitably be affected. Summary of the invention

[0005] In order to overcome the shortcomings of the excitation light source and atomizer itself and the instrument layout in the above-mentioned existing atomic fluorescence spectrometers, the present invention provides an integrated full-angle excitation source, which is based on a microwave coaxial resonant cavity. An easily ionized working gas, a combustible gas and a combustion-supporting gas are introduced into the microwave coaxial resonant cavity. In the same time and space range, a microwave coupled plasma and a high-temperature flame fusion excitation light source are obtained to complete the excitation of the standard sample injected in a pulsed manner and obtain pulsed excitation light. At the same time, a ring-shaped atomizer is arranged inside or outside the outer conductor of the microwave coaxial resonant cavity, and the flame is used to complete the atomization of the sample to be tested. The pulsed excitation light irradiates the atomized sample to be tested in a 360-degree direction to obtain a ring-shaped pulse fluorescence.

[0006] The technical solution of the present invention is as follows:

[0007] An integrated full-angle excitation source for an atomic fluorescence spectrometer, consisting of an excitation light source module and a ring atomizer module; characterized in that the excitation light source module is a microwave coaxial resonant cavity, comprising an outer conductor 1, a microwave input port 2, a microwave antenna 3, an inner conductor 4, an outer gas inlet 5, a middle tube 6, a middle gas inlet 7, an inner tube 8, an inner gas inlet 9, a standard sample tube 10, and a standard sample inlet 11; the outer conductor 1, the inner conductor 4, the middle tube 6, the inner tube 8, and the standard sample tube 10 are nested in sequence from outside to inside and are coaxial, the inner conductor 4, the middle tube 6, the inner tube 8 and the sample tube 10 are flush at the outlet end face, and the inner conductor 4, the middle tube 6, the inner tube 8 and the standard sample tube 10 form a standard sample inlet 11 with the outer conductor 1. A microwave resonant cavity with a nested coaxial structure, wherein the characteristic impedance of the resonant cavity ranges from 50 to 80 ohms; the outer conductor 1 is a hollow cylinder with an inner diameter of 35 to 60 mm; the outlet end face of the nested coaxial structure formed by the inner conductor 4, the middle tube 6 and the inner tube 8 also has the function of a high-temperature flame combustion nozzle, and microwave coupled plasma and high-temperature flame are simultaneously generated at the outlet end face; the axis of the microwave input port 2 is 1 / 4 times the wavelength of the microwave used at the bottom of the microwave coaxial resonant cavity, and the microwave antenna 3 introduces microwave energy through the microwave input port 2 and is electrically connected to the inner conductor 4; the upper end face of the outer conductor 1 is (2n+1) / 4 times the wavelength of the microwave used at the bottom of the microwave coaxial resonant cavity, wherein n is 1, 2 or 3;

[0008] The outer gas inlet 5 is located at a radial position at the lower part of the inner conductor 4 near the bottom end of the inner conductor 4, the middle gas inlet 7 is located at a radial position at the lower part of the middle tube 6 near the bottom end of the middle tube 6, and the inner gas inlet 9 is located at a radial position at the lower part of the inner tube 8 near the bottom end of the inner tube 8, all of which adopt a radial air intake method; the easily ionized gas entering from the outer gas inlet 5, the middle gas inlet 7 and the inner gas inlet 9 all flows out at its outlet end face in a laminar state, and is ionized by the microwave electric field energy to form a microwave coupled plasma; the easily ionized gas entering from the outer gas inlet 5, the middle gas inlet 7 and the inner gas inlet 9 The combustible gas and the combustion-supporting gas flow out of the combustion nozzle formed by the outlet end face thereof in a layered state, and burn to form a high-temperature flame; the microwave coupled plasma and the high-temperature flame merge at the same time and space to form a standard sample excitation light source; the standard sample inlet 11 is located at the bottom of the sample tube 10, and the high-concentration standard sample aerosol with the same element type as the sample to be tested enters the standard sample tube 10 through the standard sample inlet 11, and enters the excitation light source at the outlet side end face of the standard sample tube 10, and after excitation, the excitation light required for the fluorescence measurement of the sample to be tested is obtained;

[0009] The annular atomizer module includes a guide ring 12, a working gas inlet 13, a sample inlet 14, a shielding gas inlet 15, an inner layer guide tube 16, a middle layer guide tube 17 and an outer layer guide tube 18. The annular atomizer module is located above the microwave input port 2, on the inner or outer side of the outer conductor 1 of the microwave coaxial resonant cavity.

[0010] Specifically, when the annular atomizer is arranged on the inner side of the outer conductor 1 of the microwave coaxial resonant cavity above the microwave input port 2, the guide ring 12 is located inside the annular space formed by the outer conductor 1 and the inner conductor 4, and the guide ring 12 is made of non-metallic material; the outer conductor 1 has a working gas inlet 13, a sample inlet 14 and a shielding gas inlet 15 on the side; the guide ring 12 has a concave gas guide groove on the outside, and the guide ring 12 is designed with a working gas inlet 13 and a sample inlet 14 on the inside; the height of the gas guide groove is respectively consistent with the height of the working gas inlet 13 and the sample inlet 14 on the side of the outer conductor 1; the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are installed in sequence on the inner side of the guide ring 12, and the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are flush at the upper outlet end face; the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are flush at the upper outlet end face; the inner layer guide tube 16, the middle layer guide tube 1 7 and the outer flow guide tube 18 are made of non-metallic materials that do not affect the electromagnetic field distribution inside the cavity, preferably quartz or ceramics; the inner flow guide tube 16 and the middle flow guide tube 17 constitute an annular atomizer for the sample to be tested, complete the atomization of the sample to be tested, and are excited by the pulsed excitation light source at all angles to generate annular fluorescence; the working gas is introduced into the annular gap formed by the inner flow guide tube 16 and the middle flow guide tube 17; the working gas is introduced in the tangential direction or radial direction of the annular gap formed by the inner flow guide tube 16 and the middle flow guide tube 17, flows to the end face in the form of eddy current or laminar flow, and participates in the flame combustion process; the aerosol of the sample to be tested is introduced into the annular gap formed by the middle flow guide tube 17 and the outer flow guide tube 18; the shielding gas is introduced into the annular gap formed by the outer flow guide tube 18 and the outer conductor 1; the shielding gas is introduced in the tangential or radial direction of the inner diameter of the outer conductor 1 to form an eddy current or laminar shielding layer.

[0011] Specifically, when the annular atomizer is arranged on the outside of the outer conductor 1 of the microwave coaxial resonant cavity above the microwave input port 2, the guide ring 12 is located outside the outer conductor 1 above the microwave input port 2, and the guide ring 12 is made of metal or non-metal material; the side of the guide ring 12 has a working gas inlet 13, a sample inlet 14 and a shielding gas inlet 15; the inner side of the guide ring 12 is successively installed with an inner layer guide tube 16, a middle layer guide tube 17 and an outer layer guide tube 18, and the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are flush at the upper outlet end face; the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 can be non-metallic materials, preferably quartz or ceramics; or they can be metal materials, preferably brass; the outer conductor 1 and the inner flow guide tube 16 form an annular atomizer for the sample to be tested, complete the atomization of the sample to be tested, and are excited by the pulsed excitation light source at all angles to generate annular fluorescence; the working gas is introduced into the annular gap formed by the outer conductor 1 and the inner flow guide tube 16; the working gas is introduced in the tangential or radial direction of the annular gap formed by the outer conductor 1 and the inner flow guide tube 16, flows to the end face in the form of eddy current or laminar flow, and participates in the flame combustion process; the aerosol of the sample to be tested is introduced into the annular gap formed by the inner flow guide tube 16 and the middle flow guide tube 17; the shielding gas is introduced into the annular gap formed by the middle flow guide tube 17 and the outer flow guide tube 18; the shielding gas is introduced in the tangential direction or radial direction of the annular gap formed by the middle flow guide tube 17 and the outer flow guide tube 18, and forms an eddy current or laminar shielding layer.

[0012] Preferably, the standard sample excitation light source is located on the central axis of the microwave coaxial resonant cavity (eg Figure 2 As shown in the figure, the upper end surface of the conductor 4 in the microwave coaxial resonant cavity is 5 to 15 mm lower than the upper end surface of the annular atomizer; the atomizer portion surrounds the standard sample excitation light source at the same height; the excitation light emitted by the standard sample excitation light source irradiates the atomizer surrounding it in a 360-degree (full angle) direction, and the sample to be tested is atomized in the atomizer and excited by the excitation light at all angles to generate annular fluorescence; multiple fluorescence detectors can be arranged outside the fluorescence ring to improve the measurement sensitivity.

[0013] Beneficial effects:

[0014] 1. The light source function of the excitation source of the present invention can replace the hollow cathode lamp used in the existing atomic fluorescence spectrometer, has high stability in time and space, and can obtain good measurement precision. At the same time, the excitation light source has high radiation intensity and narrow spectrum, which is conducive to subsequent fluorescence spectrum measurement. In addition, the spectral selectivity of the excitation light source is good, and the excitation spectrum line is convenient to replace. It only needs to replace the high-concentration standard solution of the same type as the element of the object to be measured, which can be applied to any element in theory.

[0015] 2. The atomizer function of the excitation source of the present invention can replace the hydrogen-oxygen flame used in the existing atomic fluorescence spectrometer. By adjusting the gas flow rate, the ideal atomization efficiency and fluorescence efficiency can be obtained, the measurement sensitivity can be improved, and the detection limit can be reduced. At the same time, the types of measurement objects can be expanded so that they are no longer limited to elements that rely on hydride generation method for sampling.

[0016] 3. The excitation source of the present invention has a compact structure, and the light source is located in the center. It can excite the sample to be tested in a 360-degree direction at all angles to generate annular fluorescence, and can receive fluorescence signals at all angles with high measurement sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a light path diagram of an atomic fluorescence spectrometer in the prior art.

[0018] Figure 2 The optical path diagram of the atomic fluorescence spectrometer constructed by utilizing the integrated full-angle excitation source of the present invention.

[0019] Figure 3 This is a schematic diagram of the integrated full-angle excitation source structure of Example 1.

[0020] Figure 4 This is a schematic diagram of the integrated full-angle excitation source structure of Example 2. DETAILED DESCRIPTION

[0021] Example 1

[0022] Figure 3 This is a structural schematic diagram of the integrated full-angle excitation source of the present invention, which consists of an excitation light source module and a ring atomizer module. The excitation light source module is a microwave coaxial resonant cavity, comprising an outer conductor 1, a microwave input port 2, a microwave antenna 3, an inner conductor 4, an outer gas inlet 5, a middle tube 6, a middle gas inlet 7, an inner tube 8, an inner gas inlet 9, a standard sample tube 10, and a standard sample inlet 11; the outer conductor 1, the inner conductor 4, the middle tube 6, the inner tube 8, and the standard sample tube 10 are nested and coaxial in order from outside to inside, the inner conductor 4, the middle tube 6, the inner tube 8 and the sample tube 10 are flush at the outlet end face, the inner conductor 4, the middle tube 6, the inner tube 8 and the standard sample tube 10 and the outer conductor 1 form a microwave resonant cavity of a nested coaxial structure, and the characteristic impedance range of the resonant cavity is 50 to 80 ohms; the outer conductor 1 is a hollow cylinder with an inner diameter of 35 to 60 mm; the outlet end face of the nested coaxial structure formed by the inner conductor 4, the middle tube 6 and the inner tube 8 also has the function of a high-temperature flame combustion nozzle, and microwave coupled plasma and high-temperature flame can be obtained simultaneously.

[0023] The axis of the microwave input port 2 is 1 / 4 times the wavelength of the microwave used from the bottom surface of the microwave coaxial resonant cavity. The microwave antenna 3 introduces microwave energy through the microwave input port 2 and is electrically connected to the inner conductor 4 .

[0024] Preferably, the depth between the upper end surface of the outer conductor 1 and the bottom surface of the resonance cavity is (2n+1) / 4 times the wavelength of the microwave used, where n is 1, 2 or 3. For example, when n=1, the distance between the upper end surface of the outer conductor and the bottom surface of the resonance cavity is about 90-100 mm. Preferably, the outer diameter of the inner conductor 5 is 10-18 mm, and the inner diameter is 9-16 mm.

[0025] The outer gas inlet 5 is located at a radial position at the lower part of the inner conductor 4 close to the bottom end of the inner conductor 4, the middle gas inlet 7 is located at a radial position at the lower part of the middle tube 6 close to the bottom end of the middle tube 6, and the inner gas inlet 9 is located at a radial position at the lower part of the inner tube 8 close to the bottom end of the inner tube 8, all of which adopt a radial air intake method.

[0026] The easily ionized gas entering from the outer gas inlet 5, the middle gas inlet 7 and the inner gas inlet 9 flows out in a laminar state at its outlet end face, and is ionized by the microwave electric field energy to form a microwave coupled plasma; the combustible gas and the combustion-supporting gas entering from the outer gas inlet 5, the middle gas inlet 7 and the inner gas inlet 9 flow out in a layer state at the combustion nozzle formed at its outlet end face, and burn to form a high-temperature flame; the microwave coupled plasma and the high-temperature flame merge at the same time and space to form a standard sample excitation light source.

[0027] The standard sample inlet 11 is located at the bottom of the sample tube 10. The high-concentration standard sample aerosol with the same element type as the sample to be tested enters the standard sample tube 10 through the standard sample inlet 11 and enters the excitation light source at the end face of the outlet side of the standard sample tube 10. After excitation, the excitation light required for fluorescence measurement of the sample to be tested is obtained. When the standard sample enters the excitation light source in a pulsed manner, the pulsed excitation light required for fluorescence excitation of the sample to be tested can be obtained.

[0028] The annular atomizer module includes a guide ring 12 , a working gas inlet 13 , a sample inlet 14 , a shielding gas inlet 15 , an inner layer guide tube 16 , a middle layer guide tube 17 and an outer layer guide tube 18 .

[0029] In this embodiment, the annular atomizer is arranged inside the outer conductor 1 of the microwave coaxial resonant cavity above the microwave input port 2, and the guide ring 12 is located inside the annular space formed by the outer conductor 1 and the inner conductor 4, and the guide ring 12 is made of non-metallic material; the side of the outer conductor 1 is designed with a working gas inlet 13, a sample inlet 14 to be tested and a shielding gas inlet 15; the outer side of the guide ring 12 is designed with a concave gas guide groove, and the inner side of the guide ring 12 is designed with a working gas inlet 13 and a sample inlet 14 to be tested; the height of the gas guide groove is respectively consistent with the height of the working gas inlet 13 and the sample inlet 14 to be tested designed on the side of the outer conductor 1; the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are installed in sequence on the inner side of the guide ring 12, and the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are flush at the upper outlet end face; the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are made of quartz or ceramic, which does not affect the electromagnetic field distribution inside the cavity. The inner layer flow guide tube 16 and the middle layer flow guide tube 17 form an annular atomizer for the sample to be tested, which completes the atomization of the sample to be tested and is excited at all angles by a pulsed excitation light source to generate annular fluorescence.

[0030] The working gas is introduced into the annular gap formed by the inner flow guide tube 16 and the middle flow guide tube 17; the working gas is introduced in the tangential direction of the annular gap formed by the inner flow guide tube 16 and the middle flow guide tube 17, flows to the end face in the form of vortex flow, and participates in the flame combustion process. The working gas can also be introduced in the radial direction of the annular gap formed by the inner flow guide tube 16 and the middle flow guide tube 17, flows to the end face in the form of laminar flow, and participates in the flame combustion process; the working gas can be mixed with combustion-supporting gas and combustible gas, and can also be mixed with inert gas at the same time; the combustion-supporting gas can be air or oxygen, preferably oxygen; the combustible gas can be hydrogen or methane, preferably hydrogen.

[0031] The aerosol of the sample to be tested is introduced into the annular gap formed by the middle flow tube 17 and the outer flow tube 18; the aerosol of the sample to be tested is introduced into the annular gap formed by the middle flow tube 17 and the outer flow tube 18, and the aerosol of the sample to be tested can be mixed with combustible gas or combustion-supporting gas. The mixed combustion-supporting gas or combustible gas participates in the flame combustion process at the same time. The aerosol of the sample to be tested can also be mixed with an inert gas, and preferably, argon is selected as the inert gas. The sample to be tested is atomized in the flame on the end face of the annular atomizer.

[0032] The shielding gas is passed into the annular gap formed by the outer flow guide tube 18 and the outer conductor 1; the shielding gas is introduced in the tangential direction of the outer conductor 1 to form an eddy current shielding layer. The shielding gas can also be introduced in the radial direction of the outer conductor 1 to form a laminar shielding layer. The shielding gas can inhibit the diffusion of the sample to be tested into the free space, and also prevent the atmospheric components from being involved in the flame atomization zone to produce background interference, effectively prevent the quenching of atomic fluorescence, and improve the atomic fluorescence intensity. The shielding gas can be oxygen or argon, preferably, argon.

[0033] Example 2

[0034] Figure 4 This is another structural schematic diagram of the integrated full-angle excitation source of the present invention, which is composed of an excitation light source module and a ring atomizer module. The excitation light source module is a microwave coaxial resonant cavity, which is the same as the excitation source embodiment 1 and will not be described in detail here.

[0035] In this embodiment, the annular atomizer is arranged outside the outer conductor 1 of the microwave coaxial resonant cavity above the microwave input port 2, and the guide ring 12 is located outside the outer conductor 1 above the microwave input port 2; the side of the guide ring 12 is designed with a working gas inlet 13, a sample inlet 14 and a shielding gas inlet 15; the inner side of the guide ring 12 is installed with an inner layer guide tube 16, a middle layer guide tube 17 and an outer layer guide tube 18 in sequence, and the inner layer guide tube 16, the middle layer guide tube 17 and the outer layer guide tube 18 are flush at the upper outlet end face.

[0036] The inner layer flow guide tube 16 , the middle layer flow guide tube 17 and the outer layer flow guide tube 18 may be made of non-metallic materials, such as quartz or ceramic, or metallic materials, such as brass.

[0037] The working gas is introduced into the annular gap formed by the outer conductor 1 and the inner flow tube 16; the working gas is introduced in the tangential direction of the annular gap formed by the outer conductor 1 and the inner flow tube 16, flows to the end face in the form of eddy current, and participates in the flame combustion process. The working gas can also be introduced in the radial direction of the annular gap formed by the outer conductor 1 and the inner flow tube 16, flows to the end face in the form of laminar flow, and participates in the flame combustion process. The working gas can be mixed with combustion-supporting gas and combustible gas, and can also be mixed with inert gas at the same time; the combustion-supporting gas can be air or oxygen, preferably oxygen; the combustible gas can be hydrogen or methane, preferably hydrogen.

[0038] The aerosol of the sample to be tested is introduced into the annular gap formed by the inner flow tube 16 and the middle flow tube 17; the aerosol of the sample to be tested is introduced into the annular gap formed by the inner flow tube 16 and the middle flow tube 17, and the aerosol of the sample to be tested can be mixed with combustible gas or combustion-supporting gas. The mixed combustion-supporting gas or combustible gas participates in the flame combustion process at the same time. The aerosol of the sample to be tested can also be mixed with an inert gas, and preferably, argon is selected as the inert gas. The sample to be tested is atomized in the flame on the end face of the annular atomizer.

[0039] The shielding gas is introduced into the annular gap formed by the middle flow tube 17 and the outer flow tube 18; the shielding gas is introduced in the tangential direction of the annular gap formed by the middle flow tube 17 and the outer flow tube 18 to form an eddy current shielding layer. The shielding gas can also be introduced in the radial direction of the annular gap formed by the middle flow tube 17 and the outer flow tube 18 to form a laminar shielding layer. The shielding gas can inhibit the diffusion of the sample to be tested into the free space, and also prevent the atmospheric components from being involved in the flame atomization zone to produce background interference, effectively preventing the quenching of atomic fluorescence and improving the atomic fluorescence intensity. The shielding gas can be oxygen or argon, preferably, argon.

[0040] It is understandable that the excitation source of the present invention has a strong excitation ability because the excitation light source is mainly plasma, and there is no drift problem of hollow cathode lamp, so there is no need to regularly calibrate the working curve of the instrument, and the application is more convenient. At the same time, compared with the existing instruments, since the excitation light source excites the sample to be tested in the annular flame atomizer at all angles, multiple fluorescence detectors can be set around the atomizer, and the distance is close, so that higher measurement sensitivity can be obtained.

Claims

1. An integrated full-angle excitation source for an atomic fluorescence spectrometer, consisting of an excitation light source module and a ring atomizer module; characterized in that: The excitation light source module is a microwave coaxial resonant cavity, comprising an outer conductor (1), a microwave input port (2), a microwave antenna (3), an inner conductor (4), an outer gas inlet (5), a middle tube (6), a middle gas inlet (7), an inner tube (8), an inner gas inlet (9), a standard sample tube (10), and a standard sample inlet (11); the outer conductor (1), the inner conductor (4), the middle tube (6), the inner tube (8), and the standard sample tube (10) are nested in sequence from outside to inside and are coaxial; the inner conductor (4), the middle tube (6), the inner tube (8), and the sample tube (10) are flush at the outlet end surface; the inner conductor (4), the middle tube (6), the inner tube (8), and the standard sample tube (10) form a nested coaxial structure with the outer conductor (1). A microwave resonant cavity, wherein the characteristic impedance of the resonant cavity ranges from 50 to 80 ohms; the outer conductor (1) is a hollow cylinder with an inner diameter of 35 to 60 mm; the outlet end face of the nested coaxial structure formed by the inner conductor (4), the middle tube (6) and the inner tube (8) also has the function of a high-temperature flame combustion nozzle, and microwave coupled plasma and high-temperature flame are simultaneously generated at the outlet end face; the axis of the microwave input port (2) is 1 / 4 times the wavelength of the microwave used at the bottom of the microwave coaxial resonant cavity, and the microwave antenna (3) introduces microwave energy through the microwave input port (2) and is electrically connected to the inner conductor (4); the upper end face of the outer conductor (1) is (2n+1) / 4 times the wavelength of the microwave used at the bottom of the microwave coaxial resonant cavity, wherein n is 1, 2 or 3; The outer gas inlet (5) is located at a radial position at the lower part of the inner conductor (4) close to the bottom end of the inner conductor (4), the middle gas inlet (7) is located at a radial position at the lower part of the middle tube (6) close to the bottom end of the middle tube (6), and the inner gas inlet (9) is located at a radial position at the lower part of the inner tube (8) close to the bottom end of the inner tube (8), all of which adopt a radial gas intake method; the easily ionized gas entering from the outer gas inlet (5), the middle gas inlet (7) and the inner gas inlet (9) all flows out at their outlet end faces in a laminar flow state, and is ionized by microwave electric field energy to form microwave coupled plasma; the easily ionized gas entering from the outer gas inlet (5), the middle gas inlet (7) and the inner gas inlet (9) flows out in a laminar flow state at their outlet end faces, and is ionized by microwave electric field energy to form microwave coupled plasma; The combustible gas and the combustion-supporting gas entering the layer gas inlet (9) flow out in a layer state from the combustion nozzle formed at the outlet end face thereof, and burn to form a high-temperature flame; the microwave-coupled plasma and the high-temperature flame merge at the same time and space to form a standard sample excitation light source; the standard sample inlet (11) is located at the bottom of the sample tube (10); a high-concentration standard sample aerosol having the same element type as the sample to be tested enters the standard sample tube (10) through the standard sample inlet (11), and enters the excitation light source at the outlet end face of the standard sample tube (10); after excitation, the excitation light required for fluorescence measurement of the sample to be tested is obtained; The annular atomizer module comprises a flow guide ring (12), a working gas inlet (13), a sample inlet (14), a shielding gas inlet (15), an inner flow guide tube (16), a middle flow guide tube (17) and an outer flow guide tube (18); the annular atomizer module is located above a microwave input port (2) and on the inner or outer side of an outer conductor (1) of a microwave coaxial resonant cavity.

2. The integrated full-angle excitation source for atomic fluorescence spectrometer according to claim 1, characterized in that: When the annular atomizer is arranged on the inner side of the outer conductor (1) of the microwave coaxial resonant cavity above the microwave input port (2), the guide ring (12) is located inside the annular space formed by the outer conductor (1) and the inner conductor (4), and the guide ring (12) is made of non-metallic material; the side of the outer conductor (1) is provided with a working gas inlet (13), a sample inlet (14) to be tested, and a shielding gas inlet (15); the outer side of the guide ring (12) is provided with a concave gas guide groove, and the inner side of the guide ring (12) is provided with a The invention comprises a working gas inlet (13) and a sample inlet (14); the height of the gas guide groove is respectively consistent with the height of the working gas inlet (13) and the sample inlet (14) on the side of the outer conductor (1); an inner layer guide tube (16), a middle layer guide tube (17) and an outer layer guide tube (18) are sequentially installed on the inner side of the guide ring (12), and the inner layer guide tube (16), the middle layer guide tube (17) and the outer layer guide tube (18) are flush at the upper outlet end surface; the inner layer guide tube (16), the middle layer guide tube (17) and the outer layer guide tube (18) are flush at the upper outlet end surface; the inner layer guide tube (16) and the middle layer guide tube (17 ... The flow guide tube (16), the middle flow guide tube (17) and the outer flow guide tube (18) are made of non-metallic materials that do not affect the electromagnetic field distribution inside the cavity; the inner flow guide tube (16) and the middle flow guide tube (17) form an annular atomizer for the sample to be tested, complete the atomization of the sample to be tested, and are excited at all angles by a pulsed excitation light source to generate annular fluorescence; the working gas is introduced into the annular gap formed by the inner flow guide tube (16) and the middle flow guide tube (17); the working gas is discharged through the inner flow guide tube The gas is introduced in the tangential direction or radial direction of the annular gap formed by the middle flow tube (16) and the middle flow tube (17), flows to the end face in the form of eddy current or laminar flow, and participates in the flame combustion process; the sample aerosol to be tested is passed into the annular gap formed by the middle flow tube (17) and the outer flow tube (18); the shielding gas is passed into the annular gap formed by the outer flow tube (18) and the outer conductor (1); the shielding gas is introduced in the tangential direction or radial direction of the inner diameter of the outer conductor (1), forming an eddy current or laminar shielding layer.

3. The integrated full-angle excitation source for atomic fluorescence spectrometer according to claim 1, characterized in that: When the annular atomizer is arranged on the outer side of the microwave coaxial resonant cavity outer conductor (1) above the microwave input port (2), the guide ring (12) is located outside the outer conductor (1) above the microwave input port (2), and the guide ring (12) is made of metal or non-metal material; the side of the guide ring (12) is provided with a working gas inlet (13), a sample inlet (14) to be tested, and a shielding gas inlet (15); an inner layer guide tube (16), a middle layer guide tube (17), and an outer layer guide tube (18) are sequentially installed on the inner side of the guide ring (12), and the inner layer guide tube (16), the middle layer guide tube (17), and the outer layer guide tube (18) are flush at the upper outlet end surface; ... The layer flow guide tube (18) is made of non-metallic material or metallic material; the outer conductor (1) and the inner layer flow guide tube (16) form an annular atomizer for the sample to be tested, complete the atomization of the sample to be tested, and are excited by a pulsed excitation light source at all angles to generate annular fluorescence; the working gas is introduced into the annular gap formed by the outer conductor (1) and the inner flow guide tube (16); the working gas is introduced from the tangent or radial direction of the annular gap formed by the outer conductor (1) and the inner flow guide tube (16), flows to the end face in the form of eddy current or laminar flow, and participates in the flame combustion process; the aerosol of the sample to be tested is introduced into the annular gap formed by the inner flow guide tube (16) and the middle flow guide tube (17); the shielding gas is introduced into the annular gap formed by the middle flow guide tube (17) and the outer flow guide tube (18); The shielding gas is introduced in the tangential direction or radial direction of the annular gap formed by the middle flow guide tube (17) and the outer flow guide tube (18), and forms an eddy flow or laminar flow shielding layer.

4. An integrated full-angle excitation source for an atomic fluorescence spectrometer according to any one of claims 1 to 3, characterized in that: The standard sample excitation light source is located on the central axis of the microwave coaxial resonant cavity, and the upper end surface of the conductor (4) in the microwave coaxial resonant cavity is 5 to 15 mm lower than the upper end surface of the annular atomizer; the atomizer part surrounds the standard sample excitation light source at the same height; the excitation light emitted by the standard sample excitation light source irradiates the atomizer surrounding it in a 360-degree direction, and the sample to be tested is excited at all angles by the excitation light after being atomized in the atomizer, thereby generating annular fluorescence.

Images