Gas jet-magnetic field assistance-solution anode glow discharge atomic emission spectrum device

Abstract

The invention relates to the technical field of atomic emission spectrum analysis, in particular to a gas jet-magnetic field assistance-solution anode glow discharge atomic emission spectrum device, which is characterized in that jet gas in a metal tube is used as a cathode, and a solution overflowing from the top end of a capillary tube surrounded by a platinum wire is used as an anode; the metal element micro-analysis system is established by utilizing the gas jet flow to generate plasma, the constraint effect of an external magnetic field on the plasma, the resistor to stabilize discharge current, the surge flask to eliminate the pulsation of the peristaltic pump and the continuous switching function of the flow injection sample injector. When a certain voltage is applied between the two electrodes, metal ions dissolved in the solution enter a plasma area and are excited, and a spectrograph is used for receiving the characteristic spectrum of the elements, so that the detection of the metal elements is realized. The device is small in size and low in energy consumption, does not need a vacuum and high-temperature environment, does not need sample introduction parts such as an atomizer, is a cheap miniature atomic emission spectrum instrument with relatively high integration, and can be used for field on-site continuous analysis and monitoring.

Description

Technical Field

[0001] The invention relates to the technical field of atomic emission spectrum analysis and testing, in particular to a gas jet-magnetic field auxiliary-solution anode glow discharge atomic emission spectrum device. Background Art

[0002] With the development of industry, agriculture, science and technology, the problem of heavy metal pollution to the environment is becoming increasingly serious. Therefore, it is of great practical significance to monitor the content of heavy metal elements in the environment online in the field. Although atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy, inductively coupled plasma mass spectrometry, X-ray fluorescence spectroscopy, etc. can be used for the detection of metal elements, these instruments are expensive, large in size, high in power consumption, strict in operating conditions, and high in operating costs, which makes them only suitable for analysis and detection in the laboratory. In order to meet the needs of real-time online analysis and detection in the field, the development of convenient and miniaturized analytical instruments has become an important field of analytical chemistry research.

[0003] In recent years, liquid glow discharge technology in microplasma has provided a new idea for the miniaturization of analytical instruments. The basic principle of detecting metal elements is: when a certain voltage is applied between the positive and negative electrodes, the metal ions dissolved in the solution enter the plasma and are atomized, and then the metal atoms are excited to the excited state. The element characteristic spectrum is emitted during the transition from the excited state to the ground state. The composition and concentration of the metal elements in the measured substance can be obtained by receiving and analyzing the spectrum with a spectrometer, thereby realizing the detection of metal elements in the solution. In 1993, the electrolyte cathode glow discharge first proposed by Hungarian scientist Cserfalvi et al. provided a new strategy for solving the miniaturization of atomic emission spectroscopy. After that, researchers developed various miniaturized devices on this basis, including solution cathode glow discharge, liquid injection-atmospheric pressure glow discharge, DC atmospheric pressure glow discharge, liquid anode glow discharge, hydride generation-atmospheric pressure glow discharge, photochemical vapor generation-glow discharge, electrothermal evaporation-glow discharge, etc. The introduction of these discharge technologies has made a major breakthrough in the miniaturization of analytical instruments. However, the stability of the device, the excitation efficiency of the elements, the sensitivity and the detection limit need to be further improved. In addition, most of the excitation sources of these devices use graphite rods, tungsten (titanium, platinum) rods, etc., which can react with OH and H in the plasma under high temperature environment to produce solid particles adsorbed around the metal electrode and capillary, thereby interfering with the spectral determination of the analyte; at the same time, the corrosion of graphite and tungsten (titanium) rods will cause the distance between the metal electrode and the capillary to increase, resulting in poor discharge stability and measurement reproducibility. Summary of the invention

[0004] The patent of this invention is based on the principle of determining metal elements by liquid glow discharge technology and the shortcomings of the above-mentioned discharge device, and constructs a new type of gas jet-magnetic field assisted-solution anode glow discharge device. The jet gas can prevent the metal rod from contacting the solution, which greatly reduces the interference of the corrosion of the positive and negative electrodes on the test; based on the confinement effect of the magnetic field on the plasma, adding magnetic fields on both sides of the plasma helps to improve the excitation efficiency of the elements, thereby improving the sensitivity; the series resistance in the circuit can stabilize the current and improve the stability of the discharge; the buffer bottle eliminates the pulsation of the peristaltic pump in the flow injection injector, further improving the stability of the discharge; the continuous switching function of the flow injection injector can realize integrated and automated injection.

[0005] In order to achieve the above purpose, the technical solutions provided are as follows:

[0006] A gas jet-magnetic field assisted-solution anode glow discharge atomic emission spectrometer is characterized by comprising a sample injection system, a gas jet system, an excitation source system, a magnetic field confinement system, a detection system and a waste liquid discharge system.

[0007] The injection system includes a sample pool, a flow injection injector and a buffer bottle. The sample pool is connected to the flow injection injector through a silicone tube. The other end of the flow injection injector is connected to the buffer bottle through a silicone tube. Finally, the buffer bottle is connected to the capillary in the excitation source through a silicone tube.

[0008] The gas jet system comprises a metal tube and jet gas, wherein the metal tube is connected in series with a stabilizing resistor and then connected to the negative electrode of a power supply;

[0009] The excitation source system includes a DC stabilized power supply, a capillary tube surrounded by a platinum wire, a cathode jet gas and a metal tube; the platinum wire is wound below the top of the capillary tube and is directly connected to the positive electrode of the DC stabilized power supply, a fountain-like liquid surface is formed at the upper opening of the capillary tube, and the overflowing liquid surface serves as a liquid discharge anode; gas is introduced into the cathode metal tube, a suitable distance is set between the lower port of the cathode metal tube and the overflowing liquid surface, a resistor is connected in series to the upper end of the cathode metal tube, and then connected to the negative electrode of the DC stabilized power supply, and the cathode metal tube is fixed on a translation stage;

[0010] The magnetic field confinement system is composed of the N pole and S pole of two circular magnets, which are fixed on a translation stage (to facilitate the adjustment of the distance between the two magnets) so that the generated plasma is located exactly in the center of the two magnets;

[0011] The analysis and detection system includes a lens, a spectrometer and a data processing system; the lens is arranged at a horizontal position close to the lower end of the cathode metal tube, and a fiber optic probe is placed on the other side of the lens. The lens focuses the glow generated by the interaction between the gas and the convex liquid surface of the overflowing liquid into the fiber optic probe, and the fiber optic probe is connected to the spectrometer. The signal received by the spectrometer is output to the computer data processing system for analysis and detection.

[0012] The waste liquid discharge system comprises a waste liquid tank and a waste liquid discharge outlet, and the waste liquid discharge outlet is arranged at the lower end of the liquid storage tank.

[0013] Preferably, the support platform and the translation stage have an accuracy of micrometer level. In order to make the distance between the cathode metal tube and the overflow liquid surface of the capillary adjustable, the support platform and the translation stage are both adjustable three-dimensional translation stages.

[0014] Preferably, the lens is fixed on an adjustable three-dimensional translation stage with micrometer precision, and the position of the lens is adjusted by adjusting the three-dimensional translation stage, so that the glow generated by the excitation source is converged into the probe of the spectrometer through the lens.

[0015] Preferably, the capillary can be a quartz tube, a ceramic tube, a corundum tube, etc. The inner diameter of the capillary is 0.5-1.5 mm, the diameter of the platinum wire surrounding the capillary is 0.5-1 mm, the distance between the top of the capillary and the surrounding platinum wire is 3-6 mm, and the inner diameter of the cathode metal tube is 0.5-2 mm.

[0016] Preferably, the diameter of the lens is 5-10 mm.

[0017] Preferably, the circular magnet has a diameter of 18 to 30 mm, a thickness of 5 to 15 mm, and a magnetic field strength of 0.1 to 1 T.

[0018] Preferably, the volume of the buffer bottle is 1 to 5 mL.

[0019] Preferably, the shunt resistor is 1-10 kΩ, and the distance between the hollow cathode metal tube and the top of the capillary is 1-4 mm.

[0020] Preferably, the metal tube is made of tungsten, titanium, platinum, silver, nickel, cobalt and other metals, and the jet gas is argon, helium, nitrogen and the like;

[0021] Preferably, the wavelength response range of the spectrometer is 200-1100nm; the resolution is 0.1nm, and the grating is 1800mm -1 , integration time 500ms.

[0022] The beneficial effects of the present invention are:

[0023] 1. The design of the instrument in the present invention ensures integration and automation; the application of the flow injection injector and the buffer bottle in the injection system avoids the influence of the pulse phenomenon of the overflow liquid at the top of the quartz tube on the discharge stability; the design of the waste liquid discharge port on the liquid storage tank does not require the use of a dual-channel peristaltic pump, which reduces the cost and increases miniaturization.

[0024] 2. In the present invention, gas discharge is used instead of traditional metal electrode discharge, which effectively prevents the contact between the metal electrode and the solution, and greatly reduces the interference of the corrosion of the positive and negative electrodes on the test; at the same time, the jet gas discharge can increase the volume of the discharge plasma, enhance the excitation efficiency of the elements, and expand the linear concentration range of the detected elements; in addition, the continuous jet gas makes the generated plasma more stable.

[0025] 3. The plasma generated in the present invention is located at the center of the magnetic field, so that the magnetic field can effectively confine the plasma, thereby increasing the collision probability between the metal element and the plasma, improving the excitation efficiency of the element, thereby improving the sensitivity and reducing the detection limit.

[0026] 4. The stabilizing resistor in the present invention prevents the transformation of the glow discharge microplasma into arc discharge, and at the same time stabilizes the discharge current, further improving the stability of the glow discharge microplasma. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of a gas jet-magnetic field assisted-solution anode glow discharge atomic emission spectrometer provided in Example 1 of the present invention. In the figure: 1-sample pool, 2-silicone tube, 3-flow injection injector, 4-buffer bottle, 5-liquid storage tank, 6-capillary, 7-platinum wire, 8-liquid discharge port, 9-cathode metal tube, 10-circular magnet N pole, 11-circular magnet S pole, 12-glow discharge plasma, 13-resistance, 14-power supply, 15-waste liquid pool, 16-jet gas, 17-lens, 18-optical fiber probe, 19-spectrometer, 20-data processing system.

[0028] Figure 2 The glow discharge atomic emission spectrum provided in Example 2 of the present invention is Figure 1 ,in, Figure 2 (a) is the In solution without magnetic field, Figure 2 (b) is In solution under 0.46T magnetic field, discharge gap 2.0mm, gas flow rate 300mL / min, solution flow rate 3mL / min, discharge voltage 660V.

[0029] Figure 3 The glow discharge atomic emission spectrum provided in Example 2 of the present invention is Figure 2 ,in, Figure 3(a) is the Bi solution in the absence of magnetic field, Figure 3 (b) is Bi solution under 0.46T magnetic field, discharge gap 2.5mm, gas flow rate 300mL / min, solution flow rate 3mL / min, discharge voltage 640V.

[0030] Figure 4 The glow discharge atomic emission spectrum provided in Example 2 of the present invention is Figure 3 ,in, Figure 4 (a) is Hg solution without magnetic field, Figure 4 (b) is Hg solution under 0.46T magnetic field, discharge gap 2.5mm, gas flow rate 300mL / min, solution flow rate 2.5mL / min, discharge voltage 650V.

[0031] Figure 5 The ICCD camera provided in Example 1 of the present invention takes discharge images of glow plasma in the absence of a magnetic field (a) and in a magnetic field of 0.46 T (b).

[0032] Figure 6 This is the relationship between the signal intensity of In (451.1 nm), Bi (306.7 nm) and Hg (253.7 nm) provided in Example 2 of the present invention and the change with time in the absence of a magnetic field (a) and in the presence of a 0.46 T magnetic field (b).

[0033] Figure 7 3 is a graph showing the relationship between the signal intensity and the concentrations of In (a), Bi (b) and Hg (c) under different magnetic field strengths provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] A gas jet-magnetic field-assisted-solution anode glow discharge emission spectrometer, such as Figure 1 As shown, it includes a sample injection system, a gas jet system, an excitation source system, a magnetic field confinement system, a detection system and a waste liquid discharge system;

[0036] The injection system includes a sample pool 1, a silicone tube 2, a flow injection injector 3 and a buffer bottle 4. The sample pool 1 is connected to the flow injection injector 3 through the silicone tube 2, and the other end of the flow injection injector 3 is connected to the buffer bottle 4 through the silicone tube, and then connected to the capillary 6 of the excitation source system through the silicone tube.

[0037] The gas jet system is composed of a metal tube 9 and a jet gas 16 , and the jet gas is jetted to the glow discharge region 12 through the metal tube 9 .

[0038] The excitation source system includes a DC regulated power supply 14, a cathode metal tube 9 and a capillary 6, a platinum wire 7 is wound around the capillary 6, the capillary 6 is fixed on a liquid storage tank 5, the bottom end of the platinum wire 7 is connected to the positive electrode of the DC regulated power supply 14, the cathode metal tube 9 is connected to the negative electrode of the DC regulated power supply 14, and a resistor 13 is connected in series between the cathode metal tube 9 and the negative electrode of the power supply.

[0039] The magnetic field confinement system includes a circular magnet N pole 10 and a circular magnet S pole 11. The circular magnet N pole 10 is arranged on one side of the lower end of the cathode metal tube 9, and the circular magnet S pole 11 is arranged on the other side of the lower end of the cathode metal tube 9 and is maintained on a horizontal line with the magnet N pole 10.

[0040] The detection and analysis system includes a lens 17, a fiber optic probe 18, a spectrometer 19 and a data processing system 20. The lens 17 is arranged at a horizontal position close to the lower end of the cathode metal tube 9. The fiber optic spectrometer 19 is arranged on the other side of the lens 17. The signal output end of the spectrometer 19 is connected to the data processing system 20.

[0041] The waste liquid discharge system includes a waste liquid tank 15 and a liquid discharge port 8 . The liquid discharge port 8 is disposed at the lower end of the liquid storage tank 5 . The liquid discharge port 8 discharges the waste liquid into the waste liquid tank 15 through a silicone tube.

[0042] Example 1

[0043] The DC stabilized power supply 14 adopts LW100J2 power supply, providing voltage 0-1000V and current 0-500mA. A shunt resistor 13 of 1-10kΩ is connected in series between the cathode metal tube 9 and the negative pole of the DC stabilized power supply 14 to protect the cathode metal tube 9 from being damaged due to excessive current. The inner diameter of the capillary 6 is 0.5-1.5mm, and a platinum wire 7 is wound 3-6mm below the top of the capillary, and the diameter of the platinum wire is 0.5-1mm. The inner diameter of the cathode metal tube 9 is 0.5-2mm, and the cathode metal tube 9 is set on an adjustable three-dimensional translation stage to facilitate the adjustment of the distance between the metal tube and the capillary.

[0044] The sample solution is driven by the flow injection injector 3 to enter the quartz tube 6 at a flow rate of 2 to 5 mL / min. The liquid flows out from the top of the quartz tube 6 to form a convex liquid surface, and the waste liquid flows out through the drain port 8. The gas is transported to the glow plasma region 12 through the metal tube 9. When the discharge voltage applied between the two electrodes is increased to 500 to 800 V and the current is 15 to 30 mA, the electrolyte is broken down, a stable glow is generated, and a glow discharge plasma 12 is formed. The magnetic field generated by the relative N (10)-S (11) poles of the two circular magnets is applied to the glow plasma region 12, which produces a magnetic confinement effect on the plasma, causing the response signal of the element to be enhanced. The magnetic field strength of the two magnets is 0.1 to 1 T.

[0045] The diameter of the lens 17 is 5 to 10 cm. The lens 17 is fixed on an adjustable three-dimensional translation stage with a micron precision. The position of the lens 17 is adjusted by adjusting the three-dimensional translation stage so that the glow 12 generated by the cathode metal tube 9 and the overflow liquid at the upper end of the capillary 6, the center of the lens 17 and the optical fiber probe 18 are in a straight line, so that the glow discharge plasma 12 is focused by the lens 17 and enters the optical fiber probe 18 of the spectrometer 19. The spectrometer 19 adopts the AvaSpec-ULS2048-8-usb2 optical fiber spectrometer with a wavelength response range of 200-1100nm, a spectral resolution of 0.1nm, and a grating of 1800mm. -1 , integration time 500ms, and then transmit the collected signal to the data processing system 20, so as to realize the qualitative or quantitative detection of the metal elements in the solution. The data processing system 20 can be realized by a PC.

[0046] The present invention takes the determination of metal elements indium (In), bismuth (Bi) and mercury (Hg) in a solution as an example for further explanation, and the specific steps of the detection method are as follows:

[0047] Step 1: Turn on the flow injection injector 3, and the solution to be tested flows into the capillary 6 at a flow rate of 2-5 mL / min, generating a fountain-like convex liquid surface at the top of the capillary. The liquid surface is kept at a distance of 0.5-3 mm from the lower end of the cathode metal tube 9, and the supporting electrolyte is HNO3 with a pH of 1-2.0.

[0048] Step 2: Turn on the gas switch and pass the gas into the cathode metal tube 9 at a gas flow rate of 200-500 mL / min, and adjust the cathode metal tube 9 and the capillary 6 to be in a vertical line through the adjustable three-dimensional translation stage.

[0049] Step 3: Turn on the DC regulated power supply 14. When a voltage of 450 to 800 V is applied between the electrodes, the liquid is vaporized and broken down, generating a glow, thereby forming a stable glow discharge plasma 12.

[0050] Step 4: By adjusting the position of the lens 17 , the glow discharge plasma 12 generated by the excitation source is converged into the optical fiber probe 18 .

[0051] Step 5: Turn on the fiber optic spectrometer 19 and the data processing system 20 to analyze the optical signal, and complete the qualitative or quantitative detection of metal elements such as In, Bi and Hg in the solution. By analyzing the characteristic spectrum of the elements, the composition and concentration information of the metal elements in the measured substance are obtained, thereby realizing the detection of the metal elements in the solution. The detection system of the present invention can quantitatively and qualitatively detect the metal elements and their contents in the liquid online, and can also continuously monitor the metal ions in the water body of the field environment online.

[0052] Example 2

[0053] In order to further illustrate the effect of the magnetic field introduced in the present invention on the generation of glow discharge plasma, Figure 2 It shows that the metal tube is a titanium tube, the capillary is a quartz tube, the jet gas is argon, the discharge spacing is 2.0 mm, the argon flow rate is 300 mL / min, the solution flow rate is 3 mL / min, the discharge voltage is 660 V, and the pH = 1.6 HNO3 solution is the optimal operating parameters. The In solution with a concentration of 0.3 mg / L is detected at magnetic field strengths of 0 T (a) and 0.46 T (b), respectively. Figure 3 It shows that the metal tube is a titanium tube, the capillary is a quartz tube, the jet gas is argon, the discharge interval is 2.5mm, the argon flow rate is 300mL / min, the solution flow rate is 3mL / min, the discharge voltage is 640V, and the pH=1.7HNO3 solution is used as the optimal parameters. The Bi solution with a concentration of 0.3mg / L is detected at a magnetic field strength of 0T (a) and 0.46T (b), respectively. Figure 4 It shows that the metal tube is a titanium tube, the capillary is a quartz tube, the jet gas is argon, the discharge interval is 2.5mm, the gas flow rate is 300mL / min, the solution flow rate is 3mL / min, the discharge voltage is 650V, and the pH is 1.6HNO3 solution as the optimal parameters. The Hg solution with a concentration of 0.3mg / L is detected at a magnetic field strength of 0T (a) and 0.46T (b). Figures 2 to 4 It can be seen that the emission line of In was detected at a wavelength of 451.1nm, the emission line of Bi was detected at a wavelength of 306.7nm, and the emission line of Hg was detected at a wavelength of 253.7nm. It was also found that when a magnetic field of 0.46T was applied, the net signal intensity of In, Bi and Hg was significantly enhanced, indicating that the magnetic field has a significant effect on enhancing the signal intensity of the elements.

[0054] Figure 5The figure shows the discharge images of glow plasma taken by an ICCD camera under 0T (a) and 0.46T (b) magnetic fields. By comparing the two pictures, it can be seen that after the magnetic field is applied, the volume of the plasma decreases, indicating that the plasma is pinched and confined in a certain small area by the magnetic field, resulting in an increase in the electron density in the area, which increases the probability of collision between the metal element to be measured and the plasma and improves the excitation efficiency.

[0055] Figure 6 The relationship between the signal intensity of In, Bi and Hg and the time is shown. It can be seen that the signal intensity of the elements is enhanced after the addition of the magnetic field, and within 60 minutes, the relative standard deviation (RSD) of the signal intensity of In, Bi and Hg is less than that without the magnetic field, indicating that the magnetic field can not only enhance the signal intensity of the elements, but also improve the stability of the discharge. It proves that the glow discharge plasma signal intensity generated by the device of the present invention is stable, and the determination of metal elements in the solution can be realized for a long time.

[0056] Example 3

[0057] The present invention is used to determine the In, Bi and Hg elements in the solution respectively, and 1000 mg / L standard test solution is prepared with HNO3. During the determination, the series of standard solutions are diluted step by step to 0.005-3 mg / L, and the series of standard solutions configured above are driven by the flow injection injector 3 to enter the quartz tube 6. The convex liquid surface of the overflow liquid of the quartz tube 6 is kept at a certain distance from the cathode metal tube 9 into which argon gas is introduced. The DC voltage-stabilized power supply 14 is turned on, and a voltage of 660 V is applied between the two electrodes. After conversion, the optical fiber spectrometer 19 measures the spectral signal online on the data processing system 20, and each condition is measured 11 times, and the signal intensity average is taken.

[0058] The net signal intensities of In, Bi and Hg were measured at the emission lines 451.1 nm, 306.7 nm and 253.7 nm, respectively, and the net signal intensities were plotted against the concentrations of metal ions. The results are shown in Figure 7 As shown. Figure 7It can be seen that as the concentration of the solution to be tested increases, the net signal intensity of the spectrum increases successively. At the same time, the detection of elements of different concentrations was carried out again with the assistance of a 0.46T magnetic field. It was found that when a magnetic field was added, the detection system could detect elements with even lower concentrations; secondly, the sensitivity of the analysis and detection of In, Bi and Hg elements was increased by 2.1, 2.0 and 1.7 times, and a lower detection limit was obtained. This is because under the action of the magnetic field, it provides a Lorentz force for electrons. Electrons no longer move in a straight line only under the action of the electric field force, but under the joint action of the electric field force and the Lorentz force, electrons move in a curved spiral trajectory. High-energy electrons are then pinched and confined in the effective space. More electrons appear in the effective field, changing the spatial distribution of the plasma, thereby increasing collisions with metal elements, which is beneficial for the detection system to capture more response signals of metal elements.

[0059] The linear fitting related parameters of In, Bi and Hg are shown in Table 1. As can be seen from Table 1, the power consumed in the absence of magnetic field is 9.3-9.6 W, and the power consumed under the magnetic field strength of 0.46 T is 8.9-9.2 W, indicating that magnetic field assistance is beneficial to reducing the power consumption of the device; the correlation coefficient (R 2 ) are all greater than 0.99, indicating that they all have good linear relationships; the detection limits of In, Bi and Hg are 0.80ug / L, 0.57ug / L and 0.93ug / L respectively when there is no magnetic field, however, under the condition of 0.46T magnetic field, the detection limits of In, Bi and Hg are 0.33ug / L, 0.23ug / L and 0.44ug / L respectively. After the magnetic field is assisted, the detection limits of In, Bi and Hg are reduced by 2.4, 2.5 and 2.1 times respectively. It can be judged that the gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer has the advantages of high integration, low power consumption, high sensitivity, low detection limit and good stability.

[0060]

[0061] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A gas jet-magnetic field assisted-solution anode glow discharge atomic emission spectrometer, characterized in that: It includes a sample injection system, a gas jet system, an excitation source system, a magnetic field confinement system, a detection system and a waste liquid discharge system; The injection system includes a sample pool, a flow injection injector and a buffer bottle. The sample pool is connected to the flow injection injector through a silicone tube. The other end of the flow injection injector is connected to the buffer bottle through a silicone tube. Finally, the buffer bottle is connected to the capillary in the excitation source through a silicone tube. The gas jet system comprises a metal tube and jet gas, wherein the metal tube is connected in series with a stabilizing resistor and then connected to the negative electrode of a power supply; The excitation source system includes a DC stabilized power supply, a capillary tube surrounded by platinum wire, and a metal tube of cathode jet gas; the platinum wire is wound below the top of the capillary tube and directly connected to the positive electrode of the DC stabilized power supply, a fountain-like liquid surface is formed at the upper opening of the capillary tube, and the overflowing liquid surface serves as a liquid discharge anode; gas is introduced into the cathode metal tube, a suitable distance is set between the lower port of the cathode metal tube and the overflowing liquid surface, a resistor is connected in series to the upper end of the cathode metal tube, and then connected to the negative electrode of the DC stabilized power supply; the cathode metal tube is fixed on a translation stage; The magnetic field confinement system is composed of two circular magnets, with the N pole and the S pole facing each other, and fixed on a translation stage so that the generated plasma is located exactly in the center of the two magnets; The detection system includes a lens, a spectrometer and a data processing system; the lens is arranged at a horizontal position close to the lower end of the cathode metal tube, and a fiber optic probe is placed on the other side of the lens. The lens focuses the glow generated by the interaction between the jet gas and the convex liquid surface of the overflowing liquid into the fiber optic probe, and the fiber optic probe is connected to the spectrometer. The signal received by the spectrometer is output to the computer data processing system for analysis and detection. The waste liquid discharge system comprises a waste liquid tank and a waste liquid discharge outlet, and the waste liquid discharge outlet is arranged at the lower end of the liquid storage tank.

2. A gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The precision of the support platform and the translation stage is in the micron level. In order to make the distance between the cathode metal tube and the overflow liquid surface of the capillary adjustable, the support platform and the translation stage both adopt adjustable three-dimensional translation stages.

3. The gas jet-magnetic field assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The lens is fixed on an adjustable three-dimensional translation stage with micrometer precision. The position of the lens is adjusted by adjusting the three-dimensional translation stage, so that the glow generated by the excitation source is converged into the probe of the optical fiber spectrometer through the lens.

4. The gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The capillary can be a quartz tube, a ceramic tube, a corundum tube, etc. The inner diameter of the capillary is 0.5-1.5 mm, the diameter of the platinum wire surrounding the capillary is 0.5-1 mm, the distance between the top of the capillary and the surrounding platinum wire is 3-6 mm, and the inner diameter of the cathode metal tube is 0.5-2 mm.

5. The gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The diameter of the lens is 5-10 mm.

6. The gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The circular magnet has a diameter of 18 to 30 mm, a thickness of 5 to 15 mm, and a magnetic field strength of 0.1 to 1 T.

7. The gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The volume of the buffer bottle is 1 to 5 mL.

8. The gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The shunt resistor is 1-10 kΩ, and the distance between the hollow cathode metal tube and the top of the capillary is 1-4 mm.

9. The gas jet-magnetic field-assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The material of the metal tube is tungsten, titanium, platinum, silver, nickel, cobalt and other metals, and the jet gas is argon, helium, nitrogen and the like; 10. The gas jet-magnetic field assisted-solution anode glow discharge atomic emission spectrometer according to claim 1, characterized in that: The wavelength response range of the spectrometer is 200-1100nm; the resolution is 0.1nm, and the grating is 1800mm -1 , integration time 500ms.

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