Series micro-plasma source and atomic emission spectrum analysis device and method

Abstract

The invention discloses a series micro-plasma source and an atomic emission spectrum analysis device and method. An excitation source is composed of a coaxial dielectric barrier discharge body and a point discharge body which are coaxially arranged in series; point discharge micro-plasma is modulated through dielectric barrier discharge jet, and a point discharge atmosphere is activated to enhance plasma characteristics and excitation capability of an excitation source. According to the atomic emission spectrum analysis device, an excitation source and a steam sampling mode are combined, sample steam is completely introduced into an effective discharge area through a dielectric barrier discharge hollow inner electrode to be fully atomized / excited, characteristic spectrum response of elements to be detected is generated, and a final atomic emission spectrum signal is obtained after the characteristic spectrum response is collected by a small CCD optical fiber spectrometer. The excitation source and the analysis device and method thereof have the characteristics of strong excitation capability, high excitation efficiency, strong anti-interference capability and the like, are combined with the advantages of miniaturization, low power consumption, easiness in operation and the like, and have a good application prospect in field analysis of diversified scenes.

Description

Technical Field

[0001] The present invention belongs to atomic emission spectrometry analysis technology, and in particular relates to a series micro plasma source and an atomic emission spectrometry analysis device and method. Background Art

[0002] As one of the most widely used techniques for elemental analysis, atomic emission spectrometry (OES) plays a vital role in trace element analysis in fields such as environmental monitoring, food safety, and biomedicine due to its advantages, including simultaneous multi-element detection, wide dynamic range, and high sensitivity. However, traditional atomizers / excitation sources (such as acetylene-air flames, arc / spark discharges, and inductively coupled plasmas) mostly rely on high-temperature systems (2000-10000K) to dissociate, atomize, and excite analytes, resulting in high energy consumption. Atomic spectrometers based on these sources are not only bulky and power-hungry, but also typically require associated ancillary equipment (such as air compressors and circulating water cooling systems), severely restricting their application in rapid on-site testing.

[0003] In recent years, microplasma technology has attracted widespread attention from researchers due to its small size (typically on the millimeter scale), low power consumption, and stable operation at atmospheric pressure. It has been introduced as a key excitation source component in atomic emission spectrometers. Among the various microplasmas, dielectric barrier discharge (DBD) and point discharge (PD) microplasmas have attracted considerable attention due to their unique advantages. Dielectric barrier discharge (DBD) microplasmas are stable and controllable microplasmas generated by driving an AC or pulsed high voltage with at least one insulating dielectric layer (such as quartz or ceramic) inserted between two electrodes. The presence of the dielectric layer prevents arc discharge, resulting in a uniform and stable glow discharge. Furthermore, the high concentration of active species (such as high-energy electrons, ions, free radicals, and metastable atoms / molecules) in the DBD plasma atmosphere allows the DBD microplasma and its jet to drive a variety of chemical reactions at low temperatures. However, DBD as an excitation source also has certain limitations. The presence of the dielectric layer results in a relatively dispersed DBD microdischarge channel, resulting in a low energy density and difficulty in meeting the requirements for detecting difficult-to-excite elements. In contrast, tip-discharge microplasma, generated at a high-curvature tip electrode, is a nonequilibrium plasma characterized by a concentrated electric field and high electron density and energy. Its structure is simple and requires no dielectric barrier. The discharge properties can be adjusted by voltage parameters, forming high-energy corona, arc, or spark discharges between the electrodes. However, due to the small discharge area, the overall excitation efficiency of PD is limited. Furthermore, the low power consumption of microplasma makes it susceptible to interference from moisture and matrix in the sample, which can even quench the plasma.

[0004] The discharge structure of DBD easily produces a high-energy plasma jet. If the DBD jet can be combined with PD and the PD discharge can be regulated by the DBD jet, the synergistic effect of the two can be effectively achieved, and their advantages can be complemented, further expanding their application potential in on-site element detection. In addition, the injection method also has a significant impact on the analytical performance of atomic emission spectrometers based on microplasma excitation sources. Traditional liquid injection has low efficiency and is prone to introducing moisture and matrix interference. However, converting the analyte into a gaseous form for introduction can achieve pre-separation of the analyte and the matrix, obtaining a dry and pure gaseous sample vapor, and maximally retaining the excitation energy of the microplasma excitation source for the atomization / excitation of the element to be measured. However, when existing vapor injection methods are used in conjunction with a microplasma excitation source, the gaseous analyte is usually introduced by external diffusion, resulting in the analyte being unable to fully enter the microplasma excitation source for sufficient atomization / excitation, limiting the effective excitation efficiency. In summary, there is an urgent need to design an innovative excitation source that can break through the performance bottleneck of a single microplasma through the synergistic effect of multiple microplasmas, while adapting to an efficient sampling mode to improve the overall excitation ability and efficiency, and ultimately obtain a high-performance miniaturized atomic emission spectrometer device. Summary of the Invention

[0005] In response to the problems and shortcomings of the above-mentioned traditional dielectric barrier discharge and tip discharge microplasmas as excitation sources for atomic emission spectrometers, as well as the problems and shortcomings of existing miniaturized atomic emission spectrometers, the present invention provides a series microplasma source and an atomic emission spectrometer analysis device and method.

[0006] The invention discloses a dielectric barrier discharge jet modulated tip discharge micro plasma excitation source, which comprises a dielectric barrier discharge part and a tip discharge part, wherein the two parts are coaxially connected in series.

[0007] Dielectric barrier discharge (DBD) section: The DBD insulating base is used to fix the DBD hollow inner electrode and the T-shaped quartz tube; the DBD outer electrode is tightly wrapped around the outside of the T-shaped quartz tube; under the action of high voltage, DBD microplasma is generated in the gap between the inner wall of the T-shaped quartz tube and the DBD hollow inner electrode, and is then blown out by the working gas to form a DBD jet; a circle of quartz insulating protrusions is set at the end of the T-shaped quartz tube to avoid direct discharge between the inner and outer electrodes.

[0008] Tip discharge part: Two tip electrodes are symmetrically fixed on the PD insulating base, and an adjustable tip interval is formed to generate PD micro plasma; the tip electrode intercepts and converges the DBD jet, forming an arc between the tip electrode and the DBD hollow inner electrode port.

[0009] Furthermore, the T-shaped quartz tube branch is the DBD discharge gas inlet, one end of the DBD hollow inner electrode is the carrier gas and sample vapor inlet, and the gas outlet is the detection window.

[0010] Furthermore, the DBD insulating base has a diameter of 15 mm and a length of 15 mm. Two holes with diameters of 2 mm and 5 mm, and a length of 7.5 mm, are coaxially arranged in the center of the base. The T-shaped quartz tube has a length of 30 mm, an inner diameter of 3 mm, and an outer diameter of 5 mm. A quartz branch tube with a length of 7 mm, an inner diameter of 3 mm, and an outer diameter of 5 mm is arranged 10 mm away from the port. The DBD hollow inner electrode has a length of 50 mm, an inner diameter of 1.8 mm, and an outer diameter of 2 mm. The DBD outer electrode has a diameter of 0.5 mm. The distance between the DBD hollow inner electrode port and the tip electrode is 10 mm.

[0011] Furthermore, the length × width × height of the PD insulating base is 17 × 17 × 12 mm, with a discharge cavity with a diameter of 5 mm and a length of 17 mm in the middle; the tip electrode has a diameter of 1.5 mm and a length of 15 mm; the spacing between the tips of the tip electrodes is adjustable to 3-5 mm.

[0012] The atomic emission spectrometer of the present invention comprises a peristaltic pump, a working gas system, a steam generation system, the above-mentioned dielectric barrier discharge jet modulated tip discharge micro plasma excitation source, an isolation quartz plate, a collimating lens, and a small CCD fiber optic spectrometer which are arranged in sequence.

[0013] Peristaltic pump: The sample solution containing the element to be measured and the chemical vapor generation reaction reagent enters the vapor generation system through the peristaltic pump.

[0014] Working gas system: The working gas is inert gas argon or helium, which is used as discharge gas to be broken down under high voltage to generate micro plasma, and at the same time acts as carrier gas to bring gaseous analytes into the tip discharge micro plasma excitation source modulated by dielectric barrier discharge jet.

[0015] Vapor generation system: The sample solution containing the element to be measured and the chemical vapor generation reaction reagent react in the vapor generation system, and the volatile form of the element to be measured enters the subsequent dielectric barrier discharge jet modulated tip discharge microplasma excitation source.

[0016] Dielectric barrier discharge jet modulated tip discharge microplasma excitation source: Gaseous analytes are carried by carrier gas from the sample vapor inlet into the dielectric barrier discharge jet modulated tip discharge microplasma excitation source, atomized / excited in the arc and PD microplasma wrapped by the DBD jet, and generate characteristic atomic emission spectrum signals of the elements to be measured.

[0017] Isolation quartz plate: Located between the detection window and the collimating lens of the tip discharge microplasma excitation source modulated by the dielectric barrier discharge jet, it is used to isolate the plasma from the subsequent spectral detection area to prevent contamination of the optical components.

[0018] Collimating lens: Focuses the light of the atomic emission spectrum passing through the isolation quartz plate.

[0019] Small CCD fiber spectrometer: Spectral acquisition of the atomic emission spectrum signal generated by the tip discharge microplasma excitation source modulated by the dielectric barrier discharge jet, to obtain the characteristic atomic emission spectrum of the element to be measured for subsequent data processing.

[0020] An atomic emission spectrometry analysis method of the present invention uses the above-mentioned atomic emission spectrometry analysis device, and the method is specifically as follows:

[0021] The working gas in the working gas system is transported to the vapor generation system, where it acts as a discharge gas to be broken down under high pressure to generate microplasma, and also acts as a carrier gas to carry gaseous analytes into the tip discharge microplasma excitation source modulated by the dielectric barrier discharge jet.

[0022] The sample solution containing the element to be measured and the chemical vapor generation reaction reagent enter the peristaltic pump from the sample inlet and then enter the vapor generation system through the peristaltic pump. The gaseous analyte of the element to be measured is carried by the carrier gas from the sample vapor inlet into the tip discharge microplasma excitation source modulated by the dielectric barrier discharge jet. It is atomized / excited in the arc and PD microplasma wrapped by the DBD jet, and generates the characteristic atomic emission spectrum signal of the element to be measured.

[0023] The collimating lens focuses the light of the atomic emission spectrum after passing through the isolation quartz plate; finally, the small CCD fiber optic spectrometer collects the spectrum of the atomic emission spectrum signal to obtain the characteristic atomic emission spectrum of the element to be measured for subsequent data processing.

[0024] Compared with the prior art, the present invention has the following characteristics and advantages:

[0025] (1) Dielectric barrier discharge jet modulated tip discharge microplasma is used as the excitation source of atomic emission spectrometer. Both of them have small volume and strong excitation ability, and they will also obtain the synergistic effect of the two.

[0026] (2) The tip discharge microplasma is modulated in the dielectric barrier discharge jet to achieve series discharge of the two. The dielectric barrier discharge active jet activates the tip discharge atmosphere, realizes the pre-dissociation, atomization and excitation of the analyte, and improves the overall plasma characteristics and excitation ability. Secondly, the tip electrode intercepts the dielectric barrier discharge microplasma jet, and the formed "three-electrode" discharge makes the energy more focused and the plasma area expanded, achieving the simultaneous improvement of excitation efficiency and excitation ability.

[0027] (3) The analyte vapor is introduced through the hollow inner electrode of the dielectric barrier discharge, which avoids the capture of the analyte by the quartz medium. At the same time, the outlet of the hollow inner electrode is the effective discharge area of the "three-electrode type" microplasma, so that the analyte is completely introduced into the microplasma excitation source, improving the sample introduction efficiency and the final sensitivity.

[0028] (4) The tip discharge excitation source modulated by dielectric barrier discharge jet is combined with the vapor injection method. The analyte is converted into vapor form and efficiently introduced into the excitation source, achieving pre-separation of the analyte and the matrix, reducing the energy consumption and stability of the excitation source caused by moisture and matrix, and thus achieving higher sensitivity, accuracy and stability.

[0029] (5) The dielectric barrier discharge jet modulated tip discharge excitation source and its atomic emission spectrometer analysis device have strong excitation capability, compact structure, simple operation, low power consumption and operating cost, which are conducive to the realization of miniaturized high-performance atomic emission spectrometer analysis instruments.

[0030] In summary, the present invention designs a tip discharge excitation source modulated by a dielectric barrier discharge jet. By placing the dielectric barrier discharge part and the tip discharge part coaxially in series, the dielectric barrier discharge active jet modulates the tip discharge microplasma to activate the tip discharge atmosphere, thereby enhancing the plasma characteristics and excitation ability. At the same time, the tip discharge electrode can intercept the dielectric barrier discharge jet to form an energy-concentrated arc. Therefore, the coaxial DBD also acts as a "third electrode", forming a new "three-electrode" discharge, expanding the plasma area, and achieving a simultaneous improvement in excitation efficiency and excitation ability. In addition, the sample vapor is introduced into the microplasma area by the hollow inner electrode of the DBD, realizing efficient sampling and sufficient excitation of the analyte, thereby improving the excitation efficiency. By combining with a vapor generation sampling method, a compact, low-power, easy-to-operate miniaturized atomic emission spectrometer is constructed, which is suitable for on-site analysis applications in multiple scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic cross-sectional view of the structure of a tip discharge excitation source modulated by a dielectric barrier discharge jet according to the present invention.

[0032] Figure 1 Middle: 1. DBD insulating base, 2. DBD hollow inner electrode, 3. Carrier gas and sample vapor inlet, 4. T-shaped quartz tube, 5. DBD discharge gas inlet, 6. DBD outer electrode, 7. DBD microplasma, 8. Quartz insulating protrusion, 9. PD insulating base, 10. Tip electrode, 11. Arc, 12. PD microplasma, 13. DBD jet, 14. Detection window.

[0033] Figure 2 Schematic diagram of the structure and workflow of the analysis device of the present invention.

[0034] Figure 2 Middle: 15. Sample introduction port, 16. Peristaltic pump, 17. Working gas system, 18. Vapor generation system, 19. Dielectric barrier discharge jet-modulated tip discharge excitation source, 20. Atomic emission spectroscopy signal, 21. Isolation quartz plate, 22. Collimating lens, 23. Miniature CCD fiber spectrometer.

[0035] Figure 3 The present invention adopts hydride generation as a sample introduction method for the detection of arsenic (As) element, and obtains the characteristic atomic emission spectrum. Figure 3 Middle: The horizontal axis is wavelength and the vertical axis is spectral intensity.

[0036] Figure 4 The present invention adopts hydride generation as a sample introduction method for the detection of germanium (Ge) element, and obtains the characteristic atomic emission spectrum. Figure 4 Middle: The horizontal axis is wavelength and the vertical axis is spectral intensity.

[0037] Figure 5 The present invention adopts hydride generation as a sample introduction method for the detection of mercury (Hg) element, and obtains a characteristic atomic emission spectrum. Figure 5 Middle: The horizontal axis is wavelength and the vertical axis is spectral intensity.

[0038] Figure 6 The present invention adopts hydride generation as a sample introduction method for the detection of lead (Pb) element, and obtains the characteristic atomic emission spectrum. Figure 6 Middle: The horizontal axis is wavelength and the vertical axis is spectral intensity.

[0039] Figure 7 The present invention adopts hydride generation as a sample introduction method for the detection of antimony (Sb) element, and obtains the characteristic atomic emission spectrum. Figure 7 Middle: The horizontal axis is wavelength and the vertical axis is spectral intensity.

[0040] Figure 8 This is a comparison chart of the atomic emission signal intensity obtained using hydride generation as a sample introduction method for the detection of arsenic (As), germanium (Ge), mercury (Hg), lead (Pb), and antimony (Sb) elements, with that of single dielectric barrier discharge and single tip discharge microplasma excitation sources. Figure 8 Middle: The vertical axis is the relative signal strength. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0042] The present invention is a dielectric barrier discharge jet modulated tip discharge micro plasma excitation source such as Figure 1 As shown, it includes a dielectric barrier discharge section and a tip discharge section, which are coaxially connected in series. The tip discharge is modulated by the dielectric barrier discharge jet, improving the overall excitation capability, excitation efficiency, and anti-interference ability of the constructed new microplasma excitation source.

[0043] Dielectric barrier discharge part such as Figure 1 As shown, the DBD insulating base 1 is used to fix the DBD hollow inner electrode 2 and the T-shaped quartz tube 4; the DBD outer electrode 6 is tightly wrapped around the outside of the T-shaped quartz tube 4; under the action of high voltage, the DBD micro plasma 7 is generated in the gap between the inner wall of the T-shaped quartz tube 4 and the DBD hollow inner electrode 2, and is then blown out by the working gas to form a DBD jet 13; a circle of quartz insulating protrusions 8 is set at the end of the T-shaped quartz tube 4 to avoid direct discharge between the inner and outer electrodes.

[0044] Tip discharge part such as Figure 1 As shown, two tip electrodes 10 are symmetrically fixed on the PD insulating base 9, and an adjustable tip spacing is formed to generate PD micro plasma 12; the tip electrode 10 intercepts and converges the DBD jet 13, and an arc 11 is formed between the tip electrode 10 and the port of the DBD hollow inner electrode 2.

[0045] Further, such as Figure 1 As shown, the four branches of the T-shaped quartz tube are the DBD discharge gas inlet 5, one end of the DBD hollow inner electrode 2 is the carrier gas and sample vapor inlet 3, and the gas outlet is the detection window 14.

[0046] Furthermore, the DBD insulating base 1 has a diameter of 15 mm and a length of 15 mm. Two holes with diameters of 2 mm and 5 mm, and a length of 7.5 mm, are coaxially arranged in the center of the base; the T-shaped quartz tube 4 has a length of 30 mm, an inner diameter of 3 mm, and an outer diameter of 5 mm. A quartz branch tube with a length of 7 mm, an inner diameter of 3 mm, and an outer diameter of 5 mm is arranged 10 mm away from the port; the DBD hollow inner electrode 2 has a length of 50 mm, an inner diameter of 1.8 mm, and an outer diameter of 2 mm; the DBD outer electrode 6 has a diameter of 0.5 mm; and the distance between the port of the DBD hollow inner electrode 2 and the tip electrode 10 is 10 mm.

[0047] Furthermore, the length × width × height of the PD insulating base 9 is 17 × 17 × 12 mm, with a discharge cavity with a diameter of 5 mm and a length of 17 mm in the middle; the tip electrode 10 has a diameter of 1.5 mm and a length of 15 mm; the spacing between the tips of the tip electrodes 10 is adjustable to 3-5 mm.

[0048] The present invention designs a dielectric barrier discharge jet-modulated tip discharge microplasma excitation source. The dielectric barrier discharge portion and the tip discharge portion are coaxially placed in series. Under the action of the working gas, the dielectric barrier discharge jet is swept to the tip discharge area and envelops the tip discharge microplasma, activating the discharge atmosphere of the tip discharge to enhance its plasma characteristics and excitation ability. Secondly, the dielectric barrier discharge jet is intercepted by the tip discharge electrode and converged into a new arc, forming a "three-electrode" discharge, which expands the discharge area and improves the excitation efficiency. At the same time, the analytes are introduced through the hollow inner electrode of the dielectric barrier discharge, all entering the effective discharge area and being fully excited, thereby improving the overall effective excitation rate. The dielectric barrier discharge quartz tube is fixed at one end of the tip discharge insulating cavity, and the other end serves as a spectral detection window. The insulating cavity can be made of transparent material or sealed by covering with a quartz sheet to observe the working state of the dielectric barrier discharge jet-modulated tip discharge microplasma. It can also be constructed entirely of non-transparent materials.

[0049] An atomic emission spectrometer analysis device of the present invention is as follows Figure 2 As shown, the system includes a peristaltic pump 16, a working gas system 17, a vapor generation system 18, the above-mentioned dielectric barrier discharge jet modulated tip discharge microplasma excitation source 19, an isolation quartz plate 21, a collimating lens 22, and a small CCD fiber spectrometer 23. When the present invention is used to detect samples, the analyte is converted into a gaseous form and introduced. Various vapor introduction methods can be used, such as direct analyte evaporation, electrothermal evaporation, chemical vapor generation (hydride generation, photochemical vapor generation, electrochemical vapor generation, etc.) and the like.

[0050] Peristaltic pump 16 : The sample solution containing the element to be measured and the chemical vapor generation reaction reagent enter the vapor generation system 18 through the peristaltic pump 16 .

[0051] Working gas system 17: The working gas is an inert gas such as argon or helium, which is used as a discharge gas to be broken down under high voltage to generate micro plasma, and at the same time acts as a carrier gas to bring gaseous analytes into the tip discharge micro plasma excitation source 19 modulated by the dielectric barrier discharge jet.

[0052] Vapor generation system 18: The sample solution containing the element to be measured and the chemical vapor generation reaction reagent react in the vapor generation system 18, and the volatile form of the element to be measured is entered into the subsequent dielectric barrier discharge jet modulated tip discharge micro plasma excitation source 19.

[0053] Dielectric barrier discharge jet modulated tip discharge microplasma excitation source 19: Gaseous analytes are carried into the dielectric barrier discharge jet modulated tip discharge microplasma excitation source 19 by the carrier gas from the sample vapor inlet 3, atomized / excited in the arc 11 and PD microplasma 12 wrapped by the DBD jet 13, and generate characteristic atomic emission spectrum signals 20 of the elements to be measured.

[0054] Isolation quartz plate 21: located between the detection window 14 of the dielectric barrier discharge jet modulated tip discharge micro plasma excitation source 19 and the collimating lens 22, used to isolate the plasma from the subsequent spectrum detection area to prevent contamination of optical components.

[0055] Collimating lens 22 focuses the light of the atomic emission spectrum passing through the isolation quartz plate 21 .

[0056] Small CCD fiber spectrometer 23: collects the atomic emission spectrum signal 20 generated by the tip discharge micro-plasma excitation source 19 modulated by the dielectric barrier discharge jet, and obtains the characteristic atomic emission spectrum of the element to be measured for subsequent data processing.

[0057] An atomic emission spectrometry analysis method of the present invention uses the above-mentioned atomic emission spectrometry analysis device, and the method is specifically as follows:

[0058] The working gas in the working gas system 17 is transmitted to the vapor generation system 18, which acts as a discharge gas to be broken down under high pressure to generate microplasma, and also acts as a carrier gas to carry gaseous analytes into the dielectric barrier discharge jet modulated tip discharge microplasma excitation source 19.

[0059] The sample solution containing the element to be measured and the chemical vapor generation reaction reagent enter the peristaltic pump 16 from the sample inlet 15, and then enter the vapor generation system 18 through the peristaltic pump 16. The gaseous analyte of the element to be measured is carried by the carrier gas from the sample vapor inlet 3 into the tip discharge microplasma excitation source 19 modulated by the dielectric barrier discharge jet, atomized / excited in the arc 11 and PD microplasma 12 wrapped by the DBD jet 13, and generates a characteristic atomic emission spectrum signal 20 of the element to be measured.

[0060] The collimating lens 22 focuses the light of the atomic emission spectrum after passing through the isolation quartz plate 21; finally, the small CCD fiber spectrometer 23 collects the spectrum of the atomic emission spectrum signal to obtain the characteristic atomic emission spectrum of the element to be measured for subsequent data processing.

[0061] Example 1:

[0062] Taking hydride generation as an example of the sampling method, the arsenic (As) solution containing dilute hydrochloric acid and the borohydride reagent are synchronously transported to the vapor generation system through a peristaltic pump. After mixing, the reaction produces volatile hydride (or cold vapor). Under the action of the carrier gas, the volatile substance and the reaction solution are brought into the gas-liquid separation device for pre-separation. The separated gaseous analyte is brought into the tip discharge excitation source 19 modulated by the dielectric barrier discharge jet by the working carrier gas, where it is atomized / excited. The atomic emission spectrum signal 20 of the element to be measured is transmitted through the isolation quartz plate 21, focused by the collimating lens 22, and then enters the small CCD fiber spectrometer 23 for detection. Finally, the characteristic emission spectrum of As is obtained, as shown in FIG. Figure 3 shown.

[0063] Example 2:

[0064] Similar to Example 1, a sample solution containing germanium (Ge) was analyzed by the atomic emission spectrometry analysis device and method of the present invention, and a characteristic atomic emission spectrum was finally obtained, as shown in FIG. Figure 4 shown.

[0065] Example 3:

[0066] Similar to Example 1, a sample solution containing mercury (Hg) is analyzed by the atomic emission spectrometry analysis device and method of the present invention, and a characteristic atomic emission spectrum is finally obtained, as shown in FIG. Figure 5 shown.

[0067] Example 4:

[0068] Similar to Example 1, a sample solution containing lead (Pb) was analyzed by the atomic emission spectrometry analysis device and method of the present invention, and a characteristic atomic emission spectrum was finally obtained, as shown in FIG. Figure 6 shown.

[0069] Example 5:

[0070] Similar to Example 1, the sample solution containing antimony (Sb) was analyzed by the atomic emission spectrometry analysis device and method of the present invention, and finally a characteristic atomic emission spectrum was obtained, as shown in FIG. Figure 7 shown.

[0071] Example 6:

[0072] Similar to Example 1, a sample solution containing arsenic (As), germanium (Ge), mercury (Hg), lead (Pb) and antimony (Sb) was analyzed by the atomic emission spectrometry analysis device and method of the dielectric barrier discharge jet modulated tip discharge excitation source of the present invention. The comparison chart of the atomic emission spectrum signal intensity finally obtained with that of the single dielectric barrier discharge and single tip discharge microplasma excitation sources is as shown in the figure. Figure 8As shown, it can be seen that the signal obtained by the atomic emission spectrometry analysis method of the present invention is enhanced by 5-21 times and 4-6 times compared with the single dielectric barrier discharge and single tip discharge microplasma excitation sources, respectively.

[0073] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A dielectric barrier discharge jet modulated tip discharge microplasma excitation source, characterized in that: It includes a dielectric barrier discharge part and a tip discharge part, and the two parts are coaxially arranged in series; The dielectric barrier discharge part comprises: a DBD insulating base (1) for fixing a DBD hollow inner electrode (2) and a T-shaped quartz tube (4); a DBD outer electrode (6) tightly wound around the outside of the T-shaped quartz tube (4); under the action of high voltage, DBD micro plasma (7) is generated in the gap between the inner wall of the T-shaped quartz tube (4) and the DBD hollow inner electrode (2), and is then blown out by the working gas to form a DBD jet (13); and a circle of quartz insulating protrusions (8) is provided at the end of the T-shaped quartz tube (4); The tip discharge part comprises two tip electrodes (10) symmetrically fixed on a PD insulating base (9) and forming an adjustable tip spacing to generate PD micro plasma (12); the tip electrode (10) intercepts and converges a DBD jet (13), and forms an arc (11) between the tip electrode (10) and a port of a DBD hollow inner electrode (2).

2. The dielectric barrier discharge jet modulated tip discharge microplasma excitation source according to claim 1, characterized in that: The branch pipe of the T-shaped quartz tube (4) is the DBD discharge gas inlet (5), one end of the DBD hollow inner electrode (2) is the carrier gas and sample vapor inlet (3), and the gas outlet is the detection window (14).

3. The dielectric barrier discharge jet modulated tip discharge microplasma excitation source according to claim 1, characterized in that: The DBD insulating base (1) has a diameter of 15 mm and a length of 15 mm. Two holes with diameters of 2 mm and 5 mm, respectively, and a length of 7.5 mm are coaxially arranged at the center of the base. The T-shaped quartz tube (4) has a length of 30 mm, an inner diameter of 3 mm, and an outer diameter of 5 mm. A quartz branch tube with a length of 7 mm, an inner diameter of 3 mm, and an outer diameter of 5 mm is arranged 10 mm away from the port. The DBD hollow inner electrode (2) has a length of 50 mm, an inner diameter of 1.8 mm, and an outer diameter of 2 mm. The DBD outer electrode (6) has a diameter of 0.5 mm. The distance between the port of the DBD hollow inner electrode (2) and the tip electrode (10) is 10 mm.

4. The dielectric barrier discharge jet modulated tip discharge microplasma excitation source according to claim 1, characterized in that: The PD insulating base (9) has a length×width×height of 17×17×12 mm, and a discharge cavity with a diameter of 5 mm and a length of 17 mm is provided in the middle; the tip electrode (10) has a diameter of 1.5 mm and a length of 15 mm; and the spacing between the tips of the tip electrodes (10) is adjustable to 3-5 mm.

5. An atomic emission spectrometry analyzer, characterized in that: The device comprises a peristaltic pump (16), a working gas system (17), a steam generation system (18), a dielectric barrier discharge jet modulated tip discharge micro plasma excitation source (19) as claimed in any one of claims 1 to 4, an isolation quartz plate (21), a collimating lens (22), and a small CCD fiber optic spectrometer (23) arranged in sequence; Peristaltic pump (16): The sample solution containing the element to be measured and the chemical vapor generation reaction reagent enter the vapor generation system (18) through the peristaltic pump (16); Working gas system (17): The working gas is an inert gas, argon or helium, which is used as a discharge gas to be broken down under high pressure to generate micro plasma, and at the same time acts as a carrier gas to carry gaseous analytes into the tip discharge micro plasma excitation source (19) modulated by the dielectric barrier discharge jet; Vapor generation system (18): a sample solution containing the element to be measured and a chemical vapor generation reaction reagent react in the vapor generation system (18), and the generated volatile form of the element to be measured enters a subsequent dielectric barrier discharge jet modulated tip discharge micro plasma excitation source (19); Dielectric barrier discharge jet modulated tip discharge microplasma excitation source (19): Gaseous analytes are carried by carrier gas from the sample vapor inlet (3) into the dielectric barrier discharge jet modulated tip discharge microplasma excitation source (19), atomized / excited in the arc (11) and PD microplasma (12) wrapped by the DBD jet (13), and generate characteristic atomic emission spectrum signals (20) of the elements to be measured; An isolation quartz plate (21) is located between a detection window (14) of a tip discharge microplasma excitation source (19) modulated by a dielectric barrier discharge jet and a collimating lens (22), and is used to isolate the plasma from a subsequent spectrum detection region to prevent contamination of optical components. Collimating lens (22): focusing the light of the atomic emission spectrum passing through the isolation quartz plate (21); A small CCD fiber spectrometer (23) collects the atomic emission spectrum signal (20) generated by the tip discharge micro-plasma excitation source (19) modulated by the dielectric barrier discharge jet, and obtains the characteristic atomic emission spectrum of the element to be measured for subsequent data processing.

6. An atomic emission spectrometry analysis method, characterized in that: Using the atomic emission spectrometer as claimed in claim 5, the method is specifically as follows: The working gas in the working gas system (17) is transmitted to the vapor generation system (18), which acts as a discharge gas to be broken down under high pressure to generate micro plasma, and also acts as a carrier gas to carry gaseous analytes into the tip discharge micro plasma excitation source (19) modulated by the dielectric barrier discharge jet; A sample solution containing the element to be measured and a chemical vapor generation reaction reagent enters a peristaltic pump (16) from a sample inlet (15), and enters a vapor generation system (18) through the peristaltic pump (16). The generated gaseous analyte of the element to be measured is carried by a carrier gas from a sample vapor inlet (3) into a tip discharge microplasma excitation source (19) modulated by a dielectric barrier discharge jet, and is atomized / excited in an arc (11) and a PD microplasma (12) wrapped by a DBD jet (13), and generates a characteristic atomic emission spectrum signal (20) of the element to be measured. The collimating lens (22) focuses the light of the atomic emission spectrum after passing through the isolation quartz plate (21); finally, the small CCD fiber optic spectrometer (23) collects the spectrum of the atomic emission spectrum signal to obtain the characteristic atomic emission spectrum of the element to be measured for subsequent data processing.

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