Point discharge atomic emission spectrum analysis device and method for detecting helium and argon

Abstract

The invention discloses a point discharge atomic emission spectrum analysis device and method for detecting helium and argon, and the device comprises a gas dilution instrument, a flow meter, a point discharge system, a circulating water pump, a high-voltage power supply, a focusing lens and a small CCD spectrum detector, the top is a cooling circulating water storage tank, and two sides are symmetrically provided with a pair of tip electrodes. The method comprises the following steps: helium or argon is conveyed by the gas dilution instrument and the flow meter, passes through the point discharge system and then enters the point discharge chamber to be excited; the generated light is focused by the focusing lens to enter the optical fiber, and is finally detected by the small CCD spectrum detector, so that the intensities of helium and argon emission spectral lines are independently or simultaneously measured, and finally, the corresponding concentrations of helium and argon samples are obtained through calculation. The device has the characteristics of strong excitation capability, high excitation efficiency, strong anti-interference capability, good stability and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of atomic emission spectrometry analysis, and in particular relates to a tip discharge atomic emission spectrometry analysis device and method for detecting helium and argon. Background Art

[0002] At room temperature and pressure, it is difficult for inert gases to react chemically with other substances. Currently known rare gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn, radioactive), and (Og, radioactive, artificial element). Among them, helium and argon are the most common, and they are widely used in leak detection, welding, medical treatment, aerospace and other fields. However, excessive helium and argon pose a risk of asphyxiation, and when argon is used as a protective gas for hazardous environments, if the concentration is reduced, there is a risk of explosion. In addition, the concentration measurement of helium and argon is also very important when exploring gas reserves and predicting geological disasters. Since helium and argon atoms are not easy to lose or gain electrons, it is difficult for them to react chemically with other substances at room temperature and pressure. Therefore, the determination of helium and argon becomes particularly difficult, and they can usually only be detected in the laboratory using a large, complex and expensive gas chromatograph.

[0003] Atomic spectroscopy, as a key component of modern analytical technology, holds a crucial position in the entire analytical field. Over the past few decades, atomic spectroscopy has been widely applied in numerous fields, including environmental, biological, food, and geological materials. Traditional atomic spectroscopy techniques include atomic emission spectroscopy (AES), atomic absorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS), atomic mass spectrometry (AMS), and X-ray fluorescence spectroscopy (XRF). Due to its excellent stability, high sensitivity, and relatively simple structure, atomic spectroscopy is well-suited for instrument miniaturization and holds promise for on-site environmental detection. Currently, atomic emission spectroscopy can measure approximately seventy elements. However, due to the relatively stable electronic energy level structures of helium and argon, their application in helium and argon analysis remains limited, and there are currently no reports on their detection using atomic emission spectroscopy. Over the past few decades, microplasmas, including dielectric barrier discharge (DBD), tip discharge (PD), and atmospheric pressure glow discharge (APGD), have been widely used as excitation sources for atomic emission spectrometers due to their small size, low energy consumption, and ease of operation. Among them, tip discharge is a special type of non-equilibrium microplasma that can generate and maintain microplasma at room temperature and pressure. Previous studies have shown that compared with technologies such as DBD and APGD, tip discharge can provide higher excitation energy, thereby significantly improving the sensitivity of microplasma atomic emission spectrometry devices. However, when air is mixed in, the temperature of the discharge region, especially the electrode, will increase, leading to problems such as signal instability, noise, and reduced lifespan. Therefore, it is of great significance to develop a stable and durable tip discharge atomic emission spectrometry device that can monitor helium and argon in situ. Summary of the Invention

[0004] The purpose of the present invention is to provide a tip discharge atomic emission spectrometry analysis device and method suitable for helium and argon detection, which has the characteristics of strong excitation ability, good stability, good interference resistance, and compact structure.

[0005] The invention discloses a tip discharge atomic emission spectrometer for detecting helium and argon, comprising a gas diluter, a flow meter, a tip discharge system, a circulating water pump, a high voltage power supply, a focusing lens and a small CCD spectrum detector.

[0006] The specific structure of the tip discharge system is as follows: a narrow gas channel is constructed on a polytetrafluoroethylene base, forming a tip discharge chamber from the sample inlet to the outlet, with a cooling circulating water storage tank on top. A pair of tip electrodes of the same size are symmetrically arranged on both sides of the tip discharge chamber, with a discharge gap left between the tips of the electrodes. Microplasma can be formed after applying high voltage.

[0007] The tip discharge system is connected to a flow meter and a circulating water pump. The gas enters from the sample inlet of the tip discharge system, then passes through the bottom of the cooling circulating water storage tank to reach the tip discharge chamber, and is excited in the discharge microplasma formed between the tips of the two tip electrodes; the light generated in the tip discharge system is focused by a focusing lens, and finally enters a small CCD spectrum detector through an optical fiber for spectrum acquisition, thereby obtaining the atomic emission spectrum intensity of the helium and argon to be measured.

[0008] Furthermore, the top opening of the cooling circulating water storage tank serves as a cooling water inlet, and the bottom opening serves as a cooling water outlet.

[0009] Furthermore, the polytetrafluoroethylene base is 100 mm long, 40 mm wide, and 30 mm high; the sample inlet diameter is 3 mm, and the gas channel length is 100 mm.

[0010] Furthermore, the tip electrode is a tungsten rod electrode with a diameter of 2 mm and a length of 30 mm.

[0011] The present invention provides a tip discharge atomic emission spectrometry method for detecting helium and argon, using the tip discharge atomic emission spectrometry device for detecting helium and argon, and the specific implementation process is as follows:

[0012] Helium or argon is transported by a gas diluter and flowmeter, then passes through a tip discharge system and enters the tip discharge chamber to be excited; the generated light is focused by a focusing lens into an optical fiber, and is finally detected by a small CCD spectrum detector, thereby measuring the intensity of the helium and argon emission lines individually or simultaneously, and finally calculating the corresponding concentrations of the helium and argon samples.

[0013] Compared with the prior art, the present invention has the following characteristics and advantages:

[0014] (1) The innovative use of tip discharge plasma to excite helium and argon reduces the size of the device without reducing the excitation capability.

[0015] (2) The customized cooling circulating water system can provide stable cooling circulating water, so that the tip discharge system can operate at a lower temperature, solving the problem of severe heat release of the tip discharge electrode under high voltage.

[0016] (3) The gas diluter can mix and dilute gases and can be programmed according to different samples to cope with the measurement of multiple gases.

[0017] (4) The tip discharge system can not only generate tip discharge micro plasma, but also transport gas and cooling circulating water.

[0018] (5) The tip discharge system and its analysis device are small in size, compact in structure, low in power consumption, low in cost, and easy to operate, which are conducive to the realization of high-performance miniaturized atomic emission spectrometry analysis instruments.

[0019] The present invention uses a customized tip discharge system, which fully utilizes the advantages of its high excitation ability. Compared with traditional atomic emission spectrometry devices, the series connection of a gas diluter and a cooling circulating water system ensures the stable flow of gas without external interference, and the temperature of the tip discharge chamber can be better controlled. Therefore, after lowering the temperature of the electrode, it can tolerate a larger discharge voltage (increase the working current and power), thereby greatly improving the excitation ability and realizing the excitation and detection of helium and argon. In order to give full play to the performance of the atomic emission spectrometry analysis device, the gas channel is innovatively integrated with the tip discharge area to avoid the discharge area introducing other gases into the tip discharge chamber, thereby further increasing the efficiency of the tip discharge excitation, and ultimately improving the overall performance of the analysis device and method. In addition, the miniaturized volume makes it possible to be used for on-site analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of the tip discharge atomic emission spectrometry analysis device for detecting helium and argon according to the present invention.

[0021] In the figure: 6. Gas diluter; 7. Flow meter; 8. Tip discharge system; 9. Circulating water pump; 10. High-voltage power supply; 11. Focusing lens; 12. Small CCD spectrum detector.

[0022] Figure 2 Schematic diagram of the tip discharge system structure.

[0023] In the figure: 1. Polytetrafluoroethylene base; 2. Sample inlet; 3. Tip discharge chamber; 4. Cooling circulating water storage tank; 5. Tip electrode.

[0024] Figure 3 The present invention adopts tip discharge as the sample excitation mode for detecting helium (He) and obtains a characteristic atomic emission spectrum.

[0025] Figure 4 The present invention adopts tip discharge as the sample excitation mode for the detection of argon (Ar) and obtains a characteristic atomic emission spectrum.

[0026] Figure 5 The present invention adopts tip discharge as a sample excitation method for detecting helium (He) and obtaining a standard curve.

[0027] Figure 6 The present invention adopts tip discharge as the sample excitation mode for the detection of argon (Ar) and obtains a standard curve. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0029] The present invention is a tip discharge atomic emission spectrometer for detecting helium and argon. Figure 1 As shown, it includes a gas diluter 6, a flow meter 7, a tip discharge system 8, a circulating water pump 9, a high-voltage power supply 10, a focusing lens 11 and a small CCD (Charge Coupled Device) spectrum detector 12.

[0030] Gas diluter 6: It can automatically dilute the sample gas (the diluent gas is air or nitrogen, etc.) in a certain proportion and transport it to the discharge chamber.

[0031] Flow meter 7: capable of adjusting the gas flow rate output by the gas diluter to ensure that the gas flow rate remains within a suitable range.

[0032] Tip discharge system 8: an important component connecting cooling circulating water, gas source and tip discharge electrode.

[0033] Circulating water pump 9: It can pump low-temperature water into the tip discharge system to circulate and cool the electrodes and discharge chamber.

[0034] High voltage power supply 10: provides AC high voltage to the tungsten rod electrodes at both ends of the tip discharge chamber, and the voltage can be adjusted by a transformer.

[0035] Focusing lens 11: focuses the light of the generated atomic emission spectrum.

[0036] Small CCD spectrum detector 12: The light generated by the micro plasma enters the small CCD spectrum detector for spectrum collection. By obtaining and processing the spectrum of the element to be measured, the atomic emission spectrum intensity of the element to be measured is obtained.

[0037] Due to the use of tip discharge combined with a customized cooling circulating water system, the overall sensitivity, stability and anti-interference ability of the constructed atomic emission spectrometry analysis device and method are improved.

[0038] The tip discharge system 8 is connected to the flow meter 7 and the circulating water pump 9. The gas enters from the sample inlet 2 of the tip discharge system 8, then reaches the tip discharge chamber 3 through the bottom of the cooling circulating water storage tank 4, and is excited in the discharge microplasma formed between the tips of the two tip electrodes 5; the light generated in the tip discharge system 8 is focused by the focusing lens 11, and finally enters the small CCD spectrum detector 12 through the optical fiber for spectrum acquisition to obtain the atomic emission spectrum intensity of helium and argon.

[0039] The specific structure of the tip discharge system 8 is as follows: Figure 2 As shown: a narrow gas channel is constructed on a polytetrafluoroethylene base 1, and a tip discharge chamber 3 is formed from the sample inlet 2 to the outlet. On top of the tip discharge chamber 3 is a cooling circulating water storage tank 4. A pair of tip electrodes 5 of the same size are symmetrically arranged on both sides of the tip discharge chamber 3. A discharge gap is left between the tips of the electrodes, and micro plasma can be formed after applying high voltage.

[0040] Furthermore, the top opening of the cooling circulating water storage tank 4 serves as a cooling water inlet, and the bottom opening serves as a cooling water outlet.

[0041] Furthermore, the polytetrafluoroethylene base 1 is 100 mm long, 40 mm wide, and 30 mm high; the sample inlet 2 has a diameter of 3 mm, and the gas channel has a length of 100 mm.

[0042] Furthermore, the tip electrode 5 is a tungsten rod electrode with a diameter of 2 mm and a length of 30 mm.

[0043] The present invention provides a tip discharge atomic emission spectrometry method for detecting helium and argon, using the tip discharge atomic emission spectrometry device for detecting helium and argon, and the specific implementation process is as follows:

[0044] Helium or argon is transported by a gas diluter 6 and a flowmeter 7, then passes through a tip discharge system 8 and enters a tip discharge chamber to be excited; the generated light is focused by a focusing lens 11 into an optical fiber, and is finally detected by a small CCD spectrum detector 12, thereby measuring the intensity of the helium and argon emission lines individually or simultaneously, and finally calculating the corresponding concentrations of the helium and argon samples.

[0045] Example 1:

[0046] The present invention's tip discharge atomic emission spectrometer for detecting helium and argon uses tip discharge as the sample excitation source: a gas sample containing helium (He) and a diluent gas (air: 80% nitrogen and 20% oxygen) are regulated by a gas diluter 6 and a flowmeter 7 before entering a tip discharge system 8. A microplasma is generated between the tip electrode 5 connected to a high-voltage power supply 10, exciting the gas sample to produce an emission spectrum. After being focused by a focusing lens 11, the spectrum is detected by a small CCD spectrum detector 12. The resulting characteristic emission spectrum of helium and a standard curve (linear range: 50-1000 ppm) are shown in Figure 1. Figure 3 and 5 As shown. During the reaction, circulating water pump 9 drives low-temperature deionized water into the tip discharge system 8 to remove heat generated by the tip discharge excitation. It can be seen that the tip discharge atomic emission spectrometry device and method for detecting helium and argon of the present invention have the advantages of good stability, high excitation efficiency, low detection limit, and wide detection range when measuring helium.

[0047] Example 2:

[0048] Similar to Example 1, a gas sample containing argon (Ar) is regulated by a gas diluter 6 and a flowmeter 7 before entering a tip discharge system 8. A microplasma is generated between the tip electrodes 5 connected to a high-voltage power supply 10, exciting the gas sample to produce an emission spectrum. The emission spectrum is then focused by a focusing lens 11 and then detected by a small CCD spectrum detector 12. The characteristic emission spectrum of helium gas and the standard curve (linear range 20-500 ppm) are finally obtained, as shown in FIG. Figure 4 and 6 As shown. During the reaction, circulating water pump 9 drives low-temperature deionized water into the tip discharge system 8 to remove heat generated by the tip discharge excitation. It can be seen that the tip discharge atomic emission spectrometry device and method for detecting helium and argon of the present invention have the advantages of good stability, high excitation efficiency, low detection limit, and wide detection range when measuring argon.

[0049] 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 tip discharge atomic emission spectrometer for detecting helium and argon, characterized in that: It includes a gas diluter (6), a flow meter (7), a tip discharge system (8), a circulating water pump (9), a high-voltage power supply (10), a focusing lens (11) and a small CCD spectrum detector (12); The specific structure of the tip discharge system (8) is as follows: a narrow and long gas channel is constructed on a polytetrafluoroethylene base (1), and a tip discharge chamber (3) is formed from the sample inlet (2) to the outlet. A cooling circulating water storage tank (4) is located on the top of the tip discharge chamber (3). A pair of tip electrodes (5) of the same size are symmetrically arranged on both sides of the tip discharge chamber (3). A discharge gap is left between the tips of the electrodes, and micro plasma can be formed after high voltage is applied; The tip discharge system (8) is connected to a flow meter (7) and a circulating water pump (9); gas enters from a sample inlet (2) of the tip discharge system (8), then passes through the bottom of a cooling circulating water storage tank (4) to reach a tip discharge chamber (3), and is excited in a discharge microplasma formed between the tips of two tip electrodes (5); light generated in the tip discharge system (8) is focused by a focusing lens (11), and finally enters a small CCD spectrum detector (12) through an optical fiber for spectrum acquisition, thereby obtaining the atomic emission spectrum intensity of the helium and argon to be measured.

2. The tip discharge atomic emission spectrometer for detecting helium and argon according to claim 1, characterized in that: The top opening of the cooling circulating water storage tank (4) serves as a cooling water inlet, and the bottom opening serves as a cooling water outlet.

3. The tip discharge atomic emission spectrometer for detecting helium and argon according to claim 1, characterized in that: The polytetrafluoroethylene base (1) is 100 mm long, 40 mm wide and 30 mm high; the sample inlet (2) has a diameter of 3 mm and the gas channel has a length of 100 mm.

4. The tip discharge atomic emission spectrometer for detecting helium and argon according to claim 1, characterized in that: The tip electrode (5) is a tungsten rod electrode with a diameter of 2 mm and a length of 30 mm.

5. A tip discharge atomic emission spectrometry method for detecting helium and argon, characterized in that: The tip discharge atomic emission spectrometer for detecting helium and argon according to any one of claims 1 to 4 is used, and the specific implementation process is as follows: Helium or argon is transported by a gas diluter (6) and a flow meter (7), then passes through a tip discharge system (8) and enters a tip discharge chamber to be excited; the generated light is focused by a focusing lens (11) into an optical fiber, and is finally detected by a small CCD spectrum detector (12), thereby measuring the intensity of the helium and argon emission lines individually or simultaneously, and finally calculating the corresponding concentrations of the helium and argon samples.

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