阅读说明：本技术 一种液体阳极辉光放电微等离子体激发源及激发方法 (Liquid anode glow discharge micro-plasma excitation source and excitation method ) 是由 朱振利 杨春 刘颖 郑洪涛 于 2021-07-28 设计创作，主要内容包括：本发明提供一种液体阳极辉光放电微等离子体激发源,涉及原子发射光谱激发源；激发源包括：直流电源、石英反应池、金属电极、石墨管、陶瓷管和混合气接头；石英反应池为中空腔体结构；石英反应池的内侧壁上设置有石英隔片,石英隔片上设置有通孔；石英反应池上还设置有排气接头和排液接头；排气接头和排液接头均位于石英隔片的下方；混合气接头位于石英隔片的上方；金属电极竖直贯穿设置在石英反应池的顶部；石墨管竖直贯穿设置在石英反应池的底部；陶瓷管穿设在石墨管内；直流电源的正极和负极分别与石墨管和金属电极电性连接；本发明还提出一种液体阳极辉光放电微等离子体激发方法,能够辅助用于重金属元素溶液的直接进样灵敏检测。(The invention provides a liquid anode glow discharge micro-plasma excitation source, relating to an atomic emission spectrum excitation source; the excitation source includes: the device comprises a direct current power supply, a quartz reaction tank, a metal electrode, a graphite tube, a ceramic tube and a mixed gas joint; the quartz reaction tank is of a hollow cavity structure; a quartz spacer is arranged on the inner side wall of the quartz reaction tank, and a through hole is formed in the quartz spacer; the quartz reaction tank is also provided with an exhaust joint and a liquid discharge joint; the exhaust joint and the liquid discharge joint are both positioned below the quartz spacer; the mixed gas joint is positioned above the quartz spacer; the metal electrode vertically penetrates through the top of the quartz reaction tank; the graphite pipe vertically penetrates through the bottom of the quartz reaction tank; the ceramic tube is arranged in the graphite tube in a penetrating way; the positive electrode and the negative electrode of the direct current power supply are respectively and electrically connected with the graphite tube and the metal electrode; the invention also provides a liquid anode glow discharge micro-plasma excitation method which can be used for assisting in the direct sample introduction sensitive detection of the heavy metal element solution.)

1. A liquid anodic glow discharge microplasma excitation source, comprising: the device comprises a direct current power supply, a quartz reaction tank, a metal electrode, a graphite tube, a ceramic tube and a mixed gas joint;

the quartz reaction tank is of a hollow cavity structure; a quartz spacer is arranged on the inner side wall of the quartz reaction tank, and a through hole is formed in the quartz spacer; the quartz reaction tank is also provided with an exhaust joint and a liquid discharge joint; the exhaust joint and the liquid drainage joint are both positioned below the quartz spacer; the mixed gas joint is positioned above the quartz spacer and is used for introducing mixed gas of external reducing gas and inert gas into the quartz reaction tank;

the metal electrode vertically penetrates through the top of the quartz reaction tank and extends to the upper part of the quartz spacer;

the graphite pipe vertically penetrates through the bottom of the quartz reaction tank and is positioned below the quartz spacer; the ceramic tube is arranged in the graphite tube in a penetrating mode and extends to the upper side of the quartz spacer through the through hole;

and the positive electrode and the negative electrode of the direct current power supply are respectively and electrically connected with the graphite tube and the metal electrode.

2. The liquid anode glow discharge microplasma excitation source of claim 1, wherein said metal electrode is a hollow tubular structure open at both ends.

3. The liquid anode glow discharge microplasma excitation source of claim 1, further comprising a current-stabilizing resistor, wherein the resistance value of the current-stabilizing resistor is 10-50 k Ω; the current stabilizing resistor is arranged between the direct current power supply and the metal electrode in series, or the current stabilizing resistor is arranged between the direct current power supply and the graphite tube in series.

4. A liquid anode glow discharge microplasma excitation method of the liquid anode glow discharge microplasma excitation source according to any one of claims 1-3, comprising the steps of:

introducing mixed gas of reducing gas and inert gas into the quartz reaction tank;

injecting element solution to be detected into the ceramic tube, so that the element solution to be detected overflows from the upper end of the ceramic tube to the graphite tube along the outer wall of the ceramic tube to form a liquid anode;

and starting the direct current power supply to form micro plasma between the metal electrode and the liquid anode.

5. The liquid anode glow discharge microplasma excitation method according to claim 4, wherein the operating voltage of the direct current power supply is 500-2000V, and the operating current is 2-45 mA.

6. The liquid anode glow discharge microplasma excitation method according to claim 4, wherein the sample injection flow rate of the element solution to be detected is 0.5-10 mL/min.

7. The liquid anode glow discharge microplasma excitation method according to claim 4, wherein the pH value of the element solution to be measured is 2-14.

8. The liquid anode glow discharge microplasma excitation method of claim 4, wherein the distance between the metal electrode and the liquid anode is 3-5 mm.

9. The method of claim 4, wherein the volume of the reducing gas is 0.1-10% of the total volume of the mixed gas.

10. The liquid anode glow discharge microplasma excitation method of claim 4, wherein said reducing gas comprises hydrogen, methane, or syngas; the inert gas comprises helium and/or argon.

Technical Field

The invention relates to the field of atomic emission spectrum excitation sources, in particular to a liquid anode glow discharge microplasma excitation source and an excitation method.

Background

Atomic emission spectrometry is the earliest and used element analysis method so far, and can realize stable, accurate and high-sensitivity detection of elements. An inductively coupled plasma emission spectrometer (ICP-OES) commonly used in a laboratory is widely applied to a plurality of industries such as geology, metallurgy, material science, bioscience, food safety, environmental protection and the like, and is also one of standard methods for analyzing heavy metal elements. However, the ICP excitation source has high power consumption (1000W), high gas consumption, complex structure, high detection cost due to cooling requirement, and the like, and the miniaturized portable emission spectrometer cannot be developed for field and real-time analysis and detection of heavy metals.

In the development process of atomic emission spectroscopy instruments, innovation of an excitation light source is the core of promoting the rapid development of the excitation light source. The microplasma excitation source has the characteristics of low power consumption (<10W), simple structure, small volume, high sensitivity and the like, so that the microplasma excitation source becomes one of ideal light sources for developing miniaturized portable emission spectrometers, and is expected to be used for field and real-time element analysis and detection.

The currently studied microplasma excitation light source mainly includes Dielectric Barrier Discharge (DBD), Atmospheric Pressure Glow Discharge (APGD), and liquid cathode discharge (SCGD). The excitation light source such as the invention patent publication No. CN 101330794B, CN 102445445B, CN 102866224B, CN 103760138B is DBD; the invention patent publication No. CN 103776818B, CN104254188B, application publication No. CN 107991272B and other excitation light sources are APGD; the excitation light sources of patent publication No. CN102288594B, application publication No. CN103969244A, CN105675585A, CN106596515A and the like are SCGD. Innovation and technology development based on microplasma excitation light source is the key to developing miniaturized emission spectroscopy instruments. The micro-plasma excitation light source reported at present is basically difficult to be used for the direct sample injection sensitive detection of heavy metal element solutions such as arsenic, antimony, germanium, tin and the like.

Disclosure of Invention

The invention aims to provide a liquid anode glow discharge micro-plasma excitation source which can be used for assisting in the direct sample introduction sensitive detection of heavy metal element solution.

The invention provides a liquid anode glow discharge micro-plasma excitation source, which comprises: the device comprises a direct current power supply, a quartz reaction tank, a metal electrode, a graphite tube, a ceramic tube and a mixed gas joint;

the quartz reaction tank is of a hollow cavity structure; a quartz spacer is arranged on the inner side wall of the quartz reaction tank, and a through hole is formed in the quartz spacer; the quartz reaction tank is also provided with an exhaust joint and a liquid discharge joint; the exhaust joint and the liquid drainage joint are both positioned below the quartz spacer; the mixed gas joint is positioned above the quartz spacer and is used for introducing mixed gas of external reducing gas and inert gas into the quartz reaction tank;

the metal electrode vertically penetrates through the top of the quartz reaction tank and extends to the upper part of the quartz spacer;

the graphite pipe vertically penetrates through the bottom of the quartz reaction tank and is positioned below the quartz spacer; the ceramic tube is arranged in the graphite tube in a penetrating mode and extends to the upper side of the quartz spacer through the through hole;

and the positive electrode and the negative electrode of the direct current power supply are respectively and electrically connected with the graphite tube and the metal electrode.

Further, the liquid anode glow discharge microplasma excitation source also comprises a sealing plug for sealing the top of the quartz reaction tank; the top of the quartz reaction tank is of an open structure; the metal electrode vertically penetrates through the sealing plug.

Further, the metal electrode is a solid metal rod or a hollow tubular structure with two open ends.

Further, the mixed gas joint is arranged on the quartz reaction tank.

Furthermore, the metal electrode is made of tungsten or titanium.

Further, the sealing plug is made of polytetrafluoroethylene or polyetheretherketone.

Further, the working voltage of the direct current power supply is 500-2000V, and the working current is 2-45 mA.

Further, the liquid anode glow discharge micro-plasma excitation source further comprises a current-stabilizing resistor, and the resistance value of the current-stabilizing resistor is 10-50 k omega; the current stabilizing resistor is arranged between the direct current power supply and the metal electrode in series, or the current stabilizing resistor is arranged between the direct current power supply and the graphite tube in series.

Further, the volume of the reducing gas is 0.1-10% of the total volume of the mixed gas.

Further, the reducing gas comprises hydrogen, methane or syngas; the inert gas comprises helium and/or argon.

The invention also provides a liquid anode glow discharge microplasma excitation method according to the liquid anode glow discharge microplasma excitation source, which comprises the following steps:

introducing mixed gas of reducing gas and inert gas into the quartz reaction tank;

injecting element solution to be detected into the ceramic tube, so that the element solution to be detected overflows from the upper end of the ceramic tube to the graphite tube along the outer wall of the ceramic tube to form a liquid anode;

and starting the direct current power supply to form micro plasma between the metal electrode and the liquid anode.

Further, the working voltage of the direct current power supply is 500-2000V, and the working current is 2-45 mA.

Further, the sample introduction flow rate of the element solution to be detected is 0.5-10 mL/min.

Further, the pH value of the element solution to be detected is 2-14.

Further, the distance between the metal electrode and the liquid anode is 3-5 mm.

The technical scheme provided by the embodiment of the invention has the following beneficial effects: when the liquid anode glow discharge micro-plasma excitation source in the embodiment of the invention is used, mixed gas of reducing gas and inert gas is introduced into the quartz reaction tank, and element solution to be detected is injected into the ceramic tube, so that the element solution to be detected overflows from the upper end of the ceramic tube to the graphite tube along the outer wall of the ceramic tube to form a liquid anode; turning on the direct current power supply to form micro plasma between the metal electrode and the liquid anode; by taking the mixed gas of the reducing gas and the inert gas as the liquid anode glow discharge micro-plasma of the discharge atmosphere, the vapor generation and excitation of heavy metal elements such as arsenic, antimony, germanium, tin and the like can be cooperatively carried out, and the mixed gas is used with an emission spectrometer, so that the qualitative, quantitative and sensitive detection of the element to be detected without using a complex hydride generation system is finally realized; wherein, the detection limit of the antimony element is less than 1ng/mL, which is improved by 3 orders of magnitude compared with the detection limit (2100ng/mL) of the antimony element of the conventional liquid cathode discharge micro-plasma excitation source; in addition, the liquid anode glow discharge micro-plasma excitation source in the embodiment of the invention has steam generation capacity, can generate gaseous species of the element to be detected, can be used as a sample introduction device to convert the element to be detected into the gaseous species, and is introduced into an atomic fluorescence spectrometer, an inductively coupled plasma mass spectrometer and the like to realize the analysis of the element to be detected.

Drawings

FIG. 1 is a schematic structural diagram of a liquid anode glow discharge microplasma excitation source according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a liquid anode glow discharge microplasma excitation source according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of the operation of the liquid anode glow discharge microplasma excitation source of FIG. 1;

FIG. 4 is a graph of atomic emission spectra of a blank background and antimony obtained using helium-hydrogen as a carrier gas (a) and a standard curve (b) plotted for standard solutions of different concentrations of antimony in accordance with an embodiment of the present invention;

FIG. 5 is a graph of atomic emission spectra of arsenic, germanium and tin with helium-hydrogen as a carrier gas for a blank background according to an embodiment of the present invention;

FIG. 6 is a graph of atomic fluorescence spectra of a blank background and antimony obtained with helium-hydrogen as a carrier gas in accordance with an embodiment of the present invention;

wherein, 1, a direct current power supply; 2. a current stabilizing resistor; 3. a spectral detector; 4. a metal electrode; 5. a sealing plug; 6. a quartz reaction tank; 601. a mixed gas joint; 602. a quartz spacer; 603. an exhaust joint; 604. a liquid discharge joint; 7. a graphite tube; 8. a ceramic tube; 9. a microplasma; 10. a reducing gas bottle; 11. an inert gas bottle; 12. a syringe pump.

Detailed Description

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

Referring to fig. 1, the liquid anode glow discharge microplasma excitation source in the present embodiment includes: the device comprises a direct current power supply 1, a quartz reaction tank 6, a metal electrode 4, a graphite tube 7, a ceramic tube 8 and a mixed gas joint 601;

the quartz reaction tank 6 is a hollow cavity structure; a quartz spacer 602 is arranged on the inner side wall of the quartz reaction tank 6, and a through hole (not shown in the figure) is arranged on the quartz spacer 602; the quartz spacer 602 and the quartz reaction tank 6 are bonded into an integral structure through hot melting; the quartz diaphragm 602 divides the quartz reaction tank 6 into an upper space and a lower space, wherein the upper space is a discharge micro-plasma detection area, and the lower space is a waste liquid and waste gas area; the quartz reaction tank 6 is also provided with an exhaust joint 603 and a liquid discharge joint 604; the exhaust joint 603 and the drain joint 604 are both located below the quartz spacer 602; a mixed gas joint 601 is positioned above the quartz spacer 602 and is used for introducing a mixed gas of an external reducing gas and an inert gas into the discharge microplasma detection area in the quartz reaction cell 6;

the metal electrode 4 vertically penetrates through the top of the quartz reaction tank 6 and extends to the upper part of the quartz spacer 602; the upper end of the metal electrode 4 is positioned outside the quartz reaction tank 6; the lower end of the metal electrode 4 is positioned in the discharge micro-plasma detection area;

the graphite tube 7 vertically penetrates the bottom of the quartz reaction tank 6 and is positioned below the quartz spacer 602; the graphite tube 7 is hermetically connected with the bottom of the quartz reaction tank 6; the ceramic tube 8 is arranged in the graphite tube 7 in a penetrating way and extends to the upper part of the quartz spacer 602 through the through hole; the metal electrode 4, the graphite tube 7 and the ceramic tube 8 are coaxially arranged; a gap is reserved between the ceramic tube 8 and the quartz spacer 602, and is used for facilitating the element solution to be detected to overflow from the top of the ceramic tube 8 to the graphite tube 7 along the side wall of the ceramic tube, so that a liquid anode is formed;

the positive electrode and the negative electrode of the direct current power supply 1 are respectively and electrically connected with the graphite tube 7 and the metal electrode 4.

When the liquid anode glow discharge micro-plasma excitation source in the embodiment is used, mixed gas of reducing gas and inert gas is introduced into the quartz reaction tank 6, and element solution to be detected is injected into the ceramic tube 8, so that the element solution to be detected overflows from the upper end of the ceramic tube 8 to the graphite tube 7 along the outer wall of the ceramic tube to form a liquid anode; turning on the direct-current power supply 1, and forming micro plasma 9 between the metal electrode 4 and the liquid anode; the generated waste gas and waste liquid are discharged to the outside of the quartz reaction cell 6 through the exhaust joint 603 and the liquid discharge joint 604, respectively.

Specifically, the top of the quartz reaction tank 6 is of an open structure; the liquid anode glow discharge micro-plasma excitation source also comprises a sealing plug 5; the sealing plug 5 is inserted at the top of the quartz reaction tank 6 and used for sealing the top of the quartz reaction tank 6; the metal electrode 4 is vertically arranged on the sealing plug 5 in a penetrating way.

In this embodiment, the mixture joint 601 is provided on the outer side wall of the quartz reaction cell 6.

In this embodiment, the metal electrode 4 is made of tungsten; as a modification of the present embodiment, the material of the metal electrode 4 may be titanium.

In this embodiment, the material of the sealing plug 5 is teflon; as a modification of this embodiment, the material of the sealing plug 5 may also be polyetheretherketone; the sealing plug 5 can work for a long time at 200 ℃ by setting the material of the sealing plug to be polytetrafluoroethylene or polyetheretherketone.

In the embodiment, in order to better realize the excitation of the liquid anode glow discharge micro-plasma, the working voltage of the direct current power supply 1 is 500-2000V, and the working current is 2-45 mA.

In this embodiment, the liquid anode glow discharge micro-plasma excitation source further comprises a current-stabilizing resistor 2, and the resistance value of the current-stabilizing resistor 2 is 10-50 k Ω; the current stabilizing resistor 2 is arranged between the direct current power supply 1 and the metal electrode 4 in series, or the current stabilizing resistor 2 is arranged between the direct current power supply 1 and the graphite tube 7 in series.

Referring to fig. 2, as a modification of the present embodiment, the metal electrode 4 is a hollow tubular structure with both ends open; in this embodiment, the metal electrode 4 can serve as the mixed gas joint 601, and the mixed gas joint 601 does not need to be additionally arranged, so that the structure is simplified, and the mixed gas can be effectively introduced between the metal electrode 4 and the liquid anode; illustratively, in this embodiment, the metal electrode 4 has an inner diameter of 2 to 5mm and an outer diameter of 3 to 8 mm.

Referring to fig. 3, the liquid anode glow discharge microplasma excitation method using the liquid anode glow discharge microplasma excitation source in the present embodiment includes the following steps:

introducing mixed gas of reducing gas and inert gas into the quartz reaction tank 6 through a mixed gas joint 601;

injecting element solution to be detected into the ceramic tube 8 through an injection pump 12, so that the element solution to be detected overflows from the upper end of the ceramic tube 8 to the graphite tube 7 along the outer wall of the ceramic tube to form a liquid anode;

the direct current power supply 1 is turned on, and microplasma 9 is formed between the metal electrode 4 and the liquid anode.

In the present embodiment, the reducing gas and the inert gas are supplied through a reducing gas bottle 10 and an inert gas bottle 11, respectively; the gas outlets of the reducing gas bottle 10 and the inert gas bottle 11 are mixed through a pipeline and then are introduced into the quartz reaction tank 6.

Specifically, the working voltage of the direct current power supply 1 is 500-2000V, and the working current is 2-45 mA; the sample introduction flow rate of the element solution to be detected is 0.5-10 mL/min; the pH value of the element solution to be detected is 2-14; the distance between the metal electrode 4 and the liquid anode is 3-5 mm.

The following illustrates that the liquid anode glow discharge microplasma excitation source in this embodiment can be applied to the detection of various heavy metal elements by selecting different heavy metal element sample solutions. Wherein, the cathode of the liquid anode glow discharge micro-plasma excitation source in all the following embodiments is a metal electrode 4, the metal electrode 4 is a 2mm tungsten rod, and the tip of the metal electrode is polished to a sharp angle of 30-60 degrees; the inner diameter of the quartz reaction tank 6 is 25mm, and the length is 75 mm; the aperture of the through hole on the quartz spacer 602 is 8 mm; the sealing plug 5 is made of polytetrafluoroethylene with the diameter of 25 mm; the anode consists of a ceramic tube 8 and a graphite tube 7, the inner diameter of the ceramic tube 8 is 0.8mm, the length of the ceramic tube is 70mm, and the outer diameter of the graphite tube 7 is 6mm, and the length of the graphite tube is 30 mm; the element solution to be detected is led into the lower end of the ceramic tube 8 by the injection pump 12 and overflows from the upper end of the ceramic tube 8 to flow down and be connected with the graphite tube 7 to form a conductive path; helium and helium-hydrogen mixed gas are selected as discharge gas, and the hydrogen accounts for 3 percent; the sample introduction flow rate of the element solution to be detected is 4-10mL/min, and the pH value of the element solution to be detected is 2-14; the distance between the metal electrode 4 and the solution anode is 5mm, the direct current voltage for maintaining the micro-plasma discharge work is 500-2000V, and the current is 2-25 mA; the spectrum detector 3 is a micro spectrometer with a wavelength range of 180 and 324 nm.

Example 1

In the embodiment, an analysis method for detecting trace antimony element in a solution is established based on the combination of a liquid anode glow discharge excitation source and an emission spectrometer; in the present embodiment, the operating voltage of the dc power supply 1 is 2000V, and the operating current is 10 mA; the resistance value of the current stabilizing resistor 2 is 20k omega; the flow rate of sample injection of the injection pump 12 is 4 mL/min; the pH value of the element solution to be detected is 14; mixing helium as inert gas and hydrogen as reducing gas to obtain helium-hydrogen mixed gas; wherein the flow rate of the helium gas is 1000mL/min, and the flow rate of the hydrogen gas is 30 mL/min.

The specific detection steps are as follows: 1) introducing helium-hydrogen mixed gas, starting an injection pump 12 to introduce a blank solution or an antimony-containing solution into the lower end of the ceramic tube 8, and uniformly overflowing from the upper end of the ceramic tube 8 and flowing down to the graphite tube 7; 2) setting the working voltage of the direct current power supply 1 to be 2000V and the working current to be 10mA, then starting the direct current power supply 1, and automatically performing breakdown discharge to form stable micro plasma 9 between the metal electrode 4 and the solution anode; 3) the liquid anode glow discharge excitation source reacts with the blank solution or the antimony element solution to generate an analyte gaseous species and excites the analyte gaseous species to obtain characteristic emission light of the blank or the antimony, and the emission spectrogram of the blank solution or the antimony element solution (see figure 4(a)) obtained by the detection of a micro spectrometer realizes the detection of trace antimony elements.

Preparing a series of antimony standard solutions with concentrations of 5ng/mL, 10ng/mL, 20ng/mL, 50ng/mL, 100ng/mL, 200ng/mL, 500ng/mL, 1000ng/mL, 2000ng/mL, 5000ng/mL and the like, respectively detecting according to the detection steps, and drawing a standard curve (see the attached figure 4(b)), wherein the equation of the standard curve is as follows: y is 17.1x +224.8, correlation coefficient R²0.999; the detection limit of the antimony element obtained by the standard curve is 0.85ng/mL, which is improved by 3 orders of magnitude compared with the detection limit (2100ng/mL) of the antimony element of the conventional liquid cathode discharge micro-plasma excitation source.

Example 2

In the embodiment, an analysis method for detecting arsenic, germanium and tin elements in a solution is established based on the combination of a liquid anode glow discharge excitation source and an emission spectrometer; in the present embodiment, the operating voltage of the dc power supply 1 is 2000V, and the operating current is 10 mA; the resistance value of the current stabilizing resistor 2 is 20k omega; the flow rate of sample injection of the injection pump 12 is 10 mL/min; the pH value of the element solution to be detected is 3; mixing helium as inert gas and hydrogen as reducing gas to obtain helium-hydrogen mixed gas; wherein the flow rate of the helium gas is 1000mL/min, and the flow rate of the hydrogen gas is 50 mL/min.

The specific detection steps are as follows: 1) introducing helium-hydrogen mixed gas, starting an injection pump 12 to introduce a blank solution or solutions respectively containing arsenic, germanium and tin with the concentration of 10mg/L into the lower end of the ceramic tube 8, and uniformly overflowing from the upper end of the ceramic tube 8 and flowing down to the graphite tube 7; 2) setting the working voltage of the direct current power supply 1 to be 2000V and the working current to be 10mA, then starting the direct current power supply 1, and automatically performing breakdown discharge to form stable micro plasma 9 between the metal electrode 4 and the solution anode; 3) the liquid anode glow discharge excitation source reacts with the blank solution or the antimony element solution to generate an analyte gaseous species, the analyte gaseous species is excited to obtain characteristic emission light of the blank solution or the solutions respectively containing arsenic, germanium and tin elements, and the emission spectrogram (shown in figure 5) of the blank solution or the solution containing arsenic, germanium and tin elements is obtained by the detection of a micro spectrometer to realize the detection of the arsenic, germanium and tin elements.

Example 3

In the embodiment, an analysis method for detecting trace antimony element in a solution is established based on the combination of a liquid anode glow discharge excitation source and an emission spectrometer; in the present embodiment, the operating voltage of the dc power supply 1 is 2000V, and the operating current is 10 mA; the resistance value of the current stabilizing resistor 2 is 20k omega; the flow rate of sample injection of the injection pump 12 is 4 mL/min; the pH value of the element solution to be detected is 14; mixing helium as inert gas and hydrogen as reducing gas to obtain helium-hydrogen mixed gas; wherein the flow rate of the helium gas is 1000mL/min, and the flow rate of the hydrogen gas is 30 mL/min.

The specific detection steps are as follows: 1) introducing helium-hydrogen mixed gas, starting an injection pump 12 to introduce a blank solution or an antimony-containing solution into the lower end of the ceramic tube 8, and uniformly overflowing from the upper end of the ceramic tube 8 and flowing down to the graphite tube 7; 2) setting the working voltage of the direct current power supply 1 to be 2000V and the working current to be 10mA, then starting the direct current power supply 1, and automatically performing breakdown discharge to form stable micro plasma 9 between the metal electrode 4 and the solution anode; 3) the liquid anode glow discharge excitation source reacts with the blank solution or the antimony element solution to generate analyte gaseous species, the analyte gaseous species is introduced into the atomic fluorescence spectrometer through the exhaust joint 603, and the atomic fluorescence spectrometer detects the analyte gaseous species to obtain an atomic fluorescence signal spectrogram (shown in figure 6) of the blank solution or the antimony element solution so as to realize the detection of the antimony element.

The above is not relevant and is applicable to the prior art.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

The features of the embodiments and embodiments described herein above may be combined with each other without conflict.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.