Graphite furnace atomizer sulfate radical shielding preposed device and use method thereof

Abstract

The invention relates to a graphite furnace atomizer sulfate radical shielding preposed device, which comprises a sample introduction pipe, one end of which is connected with a sample peristaltic pump for inputting a sample, and the other end of which is connected in parallel with a dilute nitric acid liquid inlet pipe and a barium nitrate liquid inlet pipe which are respectively supplied with liquid by the peristaltic pump. And after parallel convergence, the liquid enters the first rotational flow mixing chamber, and mixed acidification of the sample is completed. And the liquid enters the second rotational flow mixing chamber through a bottom communicating pipe and reacts with barium nitrate to generate barium sulfate precipitate. The mixed liquid flows into the collection area through the inverted umbrella-shaped disperser and the rotary reaction generator, and when the mixed liquid flows through the narrow pipeline, the photoelectric sensor monitors the sediment content. And after entering the settling zone, the liquid is discharged through a discharge valve plate. And the three-way electromagnetic valve adjusts the direction of the fluid according to a detection result to complete sample injection or waste liquid conveying switching. The device is high in integration level, simple and convenient to operate, suitable for high-efficiency and accurate requirements of modern analytical chemistry, and particularly capable of remarkably improving the working stability and safety of the graphite furnace atomizer in trace analysis.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental monitoring, and in particular relates to a sulfate shielding pre-position device of a graphite furnace atomizer and a use method thereof. Background Art

[0002] At present, the graphite furnace atomizer, as an important component of the non-flame atomizer, has been widely used in trace element analysis, especially in the detection of resources and environment, since it was first used in atomic absorption spectrometry by Soviet physicist GB Lvov in 1959. However, when the graphite furnace atomizer atomizes the sample for detection, samples containing sulfate ions are often encountered. Sulfate ions easily react with graphite in the graphite tube under high temperature conditions to produce carbon dioxide, sulfur dioxide and water vapor. At present, automatic sampling equipment is fully popularized and unmanned laboratories are gaining momentum. The immediate reaction of sulfate entering the graphite tube not only leads to the gradual consumption of the graphite tube, but also increases the risk of ablation and perforation of the graphite tube, which affects the accuracy and precision of the instrument at the least, and even causes damage to the instrument and even creates a fire hazard at the worst. At present, laboratories generally strictly control the composition of the sample to prevent sulfate ions from entering the graphite furnace, but sulfate is commonly present in various samples and is difficult to completely avoid, which leads to an accelerated replacement frequency of the graphite tube. Moreover, as a customized consumable, the graphite tube has a high replacement cost. Every time the graphite tube is replaced, all samples need to be re-measured, resulting in lower instrument analysis efficiency and higher maintenance costs.

[0003] Currently, the commonly used methods for sulfate detection include weight method, turbidimetry, colorimetry or ion chromatography. The principle of the gravimetric determination of sulfate is that under slightly acidic conditions, Ba2+ reacts with SO42- to form barium sulfate precipitate, which is then measured after drying. This method is suitable for environments with high sulfate concentrations, and the determination requires separation, drying, and weighing of the sample. This method cannot be used for continuous sample measurement by analytical instruments. The barium chromate colorimetric method is to add a barium chromate suspension to a water sample under slightly acidic conditions to generate a barium sulfate precipitate, thereby releasing chromate. After the solution is neutralized, the excess barium chromate and the generated barium sulfate are still in a precipitated state, and the precipitate is removed by filtration. Under alkaline conditions, chromate is yellow and can be measured using a spectrophotometer. This method will introduce other ions and requires separation of the precipitate. Ion chromatography is sensitive and suitable for clean water samples. It can simultaneously measure multiple other anions, but the measurement time is long, and the chromatographic column takes about 30 minutes to separate sulfate, which cannot meet the needs of rapid measurement. The turbidimetric method directly adds a certain amount of barium chloride-hydrochloric acid solution to the sample. If the solution contains sulfate, a barium sulfate precipitate will be generated and cause the turbidity of the test solution to change. It has the advantages of rapid response and a wide detection range. All of the above methods require individual determination of the samples to be tested. Most of them are based on basic chemical tests, with relatively large sample requirements, poor detection sensitivity, complex test operations, bulky test equipment, poor integration, and long measurement time. The determination and pretreatment technology of sulfate is still in the traditional titration test stage. This is inconsistent with the characteristics of modern analytical chemistry, which requires fast and accurate, trace samples, and trace determination. In actual operation, the number of samples sent for inspection by large instruments is calculated in the thousands, and the volume of the samples sent for inspection is limited. It is not feasible to carry out constant chemical titration tests one by one. Therefore, there is an urgent need for a pre-sampling device with online detection of sulfate, a certain sulfate shielding function, and automatic interruption of excessive sulfate. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a graphite furnace atomizer sulfate shielding pre-device, and the specific technical scheme is as follows:

[0005] The present invention provides a graphite furnace atomizer sulfate shielding pre-device, which includes: a sample inlet tube, one end of which is provided with a sample peristaltic pump for sample input, and the other end is connected in parallel with a dilute nitric acid inlet tube, which is used to transport the dilute nitric acid by the dilute nitric acid peristaltic pump, and a barium nitrate inlet tube is separately provided for the input of barium nitrate, the parallel pipelines are connected to a spherical first cyclone mixing chamber after merging, the first cyclone mixing chamber is symmetrically provided with a spherical second cyclone mixing chamber backward, and a hollow mixing chamber bottom connecting tube is arranged through the connection, which is connected in series with the barium nitrate inlet tube, the second cyclone mixing chamber is connected in series with an inverted umbrella-shaped diffuser and a cylindrical rotary reaction generator, the inner wall of the rotary reaction generator is embedded with an oblique spoiler ring, and along the sample A lotus-shaped collecting area is connected to the flow direction, and a narrow pipe is provided at the outlet of the collecting area. A photoelectric transmitter and a photoelectric sensor receiver vertically corresponding thereto are clamped above and below the narrow pipe, which are used to monitor the sediment content (turbidity of the sample after pretreatment) in real time. The narrow pipe is connected in series with a lotus-shaped sedimentation area, and a vertical sedimentation discharge pipe is provided at the bottom of the sedimentation area. A discharge valve plate with a rubidium magnet attached is embedded in the junction of the sedimentation discharge pipe, and a polytetrafluoroethylene O-ring is provided under it. An electromagnet is attached to the outer tube surface of the sedimentation discharge pipe, which is used to power on and adjust the rubidium magnet to open and close the discharge valve plate, and a three-way solenoid valve is connected along the fluid direction of the sedimentation area, which adjusts the fluid direction of the graphite furnace feed pipe and the waste liquid discharge pipe in different directions according to the photoelectric detection result.

[0006] As a preferred technical solution of the present invention, the device is provided with a cleaning pipeline, one end of which is provided with a hot EDTA solution pump, and the other end is connected in parallel with the sample injection tube, so as to avoid the influence of residual liquid in the pipeline on subsequent operations;

[0007] First, when the photoelectric transmitter and the photoelectric sensor receiver identify the presence of excess sulfate ions in the sample, the hot EDTA solution pump is started immediately to pump 10 mL of EDTA solution into the pipeline to complete the initial cleaning of the pipeline. Then the dilute nitric acid peristaltic pump pumps 5 mL of dilute nitric acid into the pipeline for secondary pickling to complete the sulfate shielding operation. Next, the three-way solenoid valve and the electromagnet are energized to complete the complete discharge of the cleaning waste liquid. Finally, the pipeline returns to the initial sampling state.

[0008] As a preferred technical solution of the present invention, the pipeline part is composed of polytetrafluoroethylene.

[0009] As a preferred technical solution of the present invention, the diffuser and the rotary reaction generator are manufactured by photosensitive 3D printing, and the materials are reinforced SLA resin and weak alkaline curing agent.

[0010] As a preferred technical solution of the present invention, a plurality of inspection ports are provided at the pipeline interface, which are fixed by bolts and sealed by polytetrafluoroethylene O-rings.

[0011] As a preferred technical solution of the present invention, the temperature of the EDTA solution is 75°C.

[0012] As a preferred technical solution of the present invention, the volume ratio of the dilute nitric acid is 5%.

[0013] As a preferred technical solution of the present invention, the matrix of the barium nitrate solution is 5% dilute nitric acid, and the mass ratio thereof is 5%.

[0014] The present invention also discloses a method for using a sulfate shielding pre-position device of a graphite furnace atomizer. A 100 μL sample containing sulfate delivered by a sample peristaltic pump and a sample inlet tube merges with 20 μL of dilute nitric acid delivered by a dilute nitric acid peristaltic pump and a dilute nitric acid inlet tube and enters a first cyclone mixing chamber, where the mixture is fully mixed and acidification treatment is completed. The mixed liquid enters a second cyclone mixing chamber through a connecting tube at the bottom of the mixing chamber, and fully reacts with 50 μL of barium ions delivered by a barium nitrate peristaltic pump and a barium nitrate inlet tube to generate a barium sulfate precipitate. Subsequently, the mixed liquid passes through a diffuser and a rotary reaction generator in turn, and an obliquely arranged spoiler ring helps the mixed liquid to be fully mixed to form a pretreatment liquid. Immediately after the pretreatment liquid flows through the convergence area, the fluid channel gradually decreases, so that the flow rate of the fluid gradually increases. When the pretreatment liquid passes through the pipeline section directly opposite to the photoelectric transmitter and the photoelectric sensor receiver, the flow rate reaches the maximum value, and the barium sulfate precipitate is measured simultaneously. After that, the fluid enters the precipitation zone, the flow rate slows down, and the fluid residence time is prolonged, so that the barium sulfate precipitate is fully deposited in the precipitation zone. When the precipitation process is completed, the three-way solenoid valve switches the channel from the sample injection tube-graphite atomizer to the sample injection-waste liquid discharge pipe, and the sample peristaltic pump and the dilute nitric acid peristaltic pump stop working immediately. At this time, the electromagnet is energized to control the rubidium magnet on the discharge valve plate. The discharge valve plate opens to discharge the barium sulfate precipitate through the precipitation discharge pipe and the waste liquid pipe. After discharge, the solenoid valve is de-energized, and the rubidium magnet is adjusted to reset and drive the discharge valve plate to close, completing the entire treatment process.

[0015] As a preferred technical solution of the present invention, a plurality of oblique spirally arranged spoiler rings are movably embedded in the rotary reaction generator, and the spacing increases linearly along the fluid flow direction, so as to accelerate the flow rate of the fluid and promote the reaction.

[0016] As a preferred technical solution of the present invention, the device is mounted on a machine platform.

[0017] Beneficial effects of the present invention:

[0018] The sulfate shielding pre-device of the graphite furnace atomizer achieves effective shielding and pretreatment of sulfate ions through a series of process treatments, and has significant beneficial effects. First, the device ensures the precise mixing of the sample and dilute nitric acid through the parallel flow of the sample peristaltic pump and the dilute nitric acid peristaltic pump, and completes the acidification treatment in the first cyclone mixing chamber. This process ensures that the sulfate ions can be fully released and effectively react in subsequent treatments. Secondly, the barium ions are introduced into the second cyclone mixing chamber through the series-connected barium nitrate inlet pipe, and fully react with the sulfate in the sample to generate barium sulfate precipitate. This process is optimized in the built-in rotary reaction generator of the device, and the obliquely arranged spoiler ring can effectively improve the reaction efficiency of the mixed solution and make the barium sulfate precipitation more uniform.

[0019] The device further monitors the sediment content in the fluid in real time through photoelectric transmitters and photoelectric sensor receivers to ensure the stability and accuracy of the precipitation process. When the amount of sediment generated reaches a certain threshold, the system can automatically determine that the reaction is complete, and adjust the channel of the three-way solenoid valve through the electronic control system, thereby realizing the automatic switching of the injection and waste liquid discharge pipes, preventing unclean samples from entering the graphite furnace atomizer, and preventing graphite tube loss or even safety accidents caused by sulfate residues. In addition, the design of the precipitation zone slows down the flow rate of the fluid, providing enough time for the sediment to fully settle, avoiding the loss or accumulation of sediment.

[0020] Through the precise control of the discharge valve plate by the electromagnet, the sediment can be discharged from the system in time, ensuring the waste discharge function of the device, effectively extending the service life of the device, and reducing the maintenance workload. This design not only reduces the loss of sulfate to the graphite tube and reduces the experimental cost, but also improves the laboratory's operational safety and the analytical efficiency of the instrument. Overall, the device is highly integrated and easy to operate, suitable for the efficient and precise needs of modern analytical chemistry, especially in the field of trace analysis, and can significantly improve the working stability and safety of the graphite furnace atomizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The overall structural diagram of the present invention is shown;

[0022] Figure 2 A schematic diagram of the process of the present invention is shown;

[0023] Figure 3 A schematic diagram of the three-dimensional structure of the present invention is shown;

[0024] Figure 4 A front view of the present invention is shown;

[0025] Figure 5 A front view of a rotary reaction generator of the present invention is shown;

[0026] Figure 6 A cross-sectional view of a rotary reaction generator in the present invention is shown;

[0027] Figure 7 A schematic diagram of the three-dimensional structure of the spoiler ring in the present invention is shown;

[0028] As shown in the figure: 1. Barium nitrate peristaltic pump; 101. Barium nitrate inlet pipe; 2. Hot EDTA solution pump; 201. Cleaning pipeline; 3. Dilute nitric acid peristaltic pump; 301. Dilute nitric acid inlet pipe; 4. Sample peristaltic pump; 401. Sample injection pipe; 5. First cyclone mixing chamber; 6. Mixing chamber bottom connecting pipe; 7. Second cyclone mixing chamber; 8. Spreader; 9. Rotary reaction generator; 91. Turbine ring; 10. Collection area; 11. Photoelectric transmitter; 12. Photoelectric sensor receiver; 13. Rubidium magnet; 14. Discharge valve plate; 15. Electromagnet; 16. Polytetrafluoroethylene O-ring; 17. Sedimentation area; 18. Sedimentation discharge pipe; 19. Three-way solenoid valve; 20. Waste liquid discharge pipe; 21. Graphite furnace feed pipe; 22. Narrow pipe; 23. Inspection port; 24. Machine. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Embodiment 1

[0031] In order to solve the technical problems in the background technology, the following graphite furnace atomizer sulfate shielding pre-device is provided:

[0032] Combination Figure 1-4As shown, a sulfate shielding pre-device for a graphite furnace atomizer comprises: a sample inlet tube 401, one end of which is provided with a sample peristaltic pump 4 for inputting samples, and the other end is connected in parallel with a dilute nitric acid inlet tube 301, which is used to transport dilute nitric acid by the dilute nitric acid peristaltic pump 3, and a barium nitrate inlet tube 101 is separately provided for inputting barium nitrate, the parallel pipelines are connected to a spherical first cyclone mixing chamber 5 after confluence, the first cyclone mixing chamber 5 is symmetrically provided with a spherical second cyclone mixing chamber 7 backwards, and a hollow mixing chamber bottom connecting tube 6 is provided through the connection, which is connected in series with the barium nitrate inlet tube 101, the second cyclone mixing chamber 7 is connected in series with an inverted umbrella-shaped diffuser 8 and a cylindrical rotary reaction generator 9, the inner wall of the rotary reaction generator 9 is embedded with an oblique spoiler ring, and a lotus is connected along the sample flow direction. A lotus-shaped collection area 10 has a narrow pipe 22 at the outlet of the collection area 10, and a photoelectric transmitter 11 and a photoelectric sensor receiver 12 vertically corresponding thereto are clamped above and below the narrow pipe 22 for real-time monitoring of the sediment content. The narrow pipe 22 is connected in series with a lotus-shaped sedimentation area 17, and a vertical sedimentation discharge pipe 18 is provided downward at the bottom of the sedimentation area 17. A discharge valve plate 14 attached to a rubidium magnet 13 is embedded at the intersection of the sedimentation discharge pipe 18, and a polytetrafluoroethylene O-ring 16 is provided under it. An electromagnet 15 is attached to the outer tube surface of the sedimentation discharge pipe 18 for electrically regulating the rubidium magnet 13 to open and close the discharge valve plate 14, and a three-way solenoid valve 19 is connected along the fluid direction of the sedimentation area 17, which adjusts the fluid direction of the graphite furnace feed pipe 21 and the waste liquid discharge pipe 20 in different directions according to the photoelectric detection result.

[0033] Based on the method for using the sulfate shielding pre-position device of the graphite furnace atomizer, when sulfate ions are detected, first, 100 μL of the sample containing sulfate delivered by the sample peristaltic pump 4 and the sample inlet tube 401 is combined with 20 μL of dilute nitric acid introduced by the dilute nitric acid peristaltic pump 3 and the dilute nitric acid inlet tube 301 and then enters the first cyclone mixing chamber 5, where it is fully mixed and acidification is completed. The mixed liquid enters the second cyclone mixing chamber 7 through the connecting tube at the bottom of the mixing chamber, and fully reacts with 50 μL of barium ions introduced by the barium nitrate peristaltic pump 1 and the barium nitrate inlet tube 101 to generate barium sulfate precipitate. Subsequently, the mixed liquid passes through the diffuser 8 and the rotary reaction generator 9 in turn, and the obliquely arranged spoiler ring helps the mixed liquid to be fully mixed to form a pretreatment liquid. When the pretreatment liquid flows through the collection area 10, the fluid channel gradually decreases, so that the flow rate of the fluid gradually increases. When passing through the pipeline section directly opposite the photoelectric transmitter 11 and the photoelectric sensor receiver 12, the flow rate reaches the maximum value, and the barium sulfate precipitate is measured simultaneously. After that, the fluid enters the precipitation area 17, the flow rate slows down, and the fluid residence time is extended, so that the barium sulfate precipitate is fully deposited in the precipitation area 17. When the precipitation process is completed, the three-way solenoid valve 19 switches the channel from the injection tube 401-graphite atomizer to the injection-waste liquid discharge pipe 20, and the sample peristaltic pump 4 and the dilute nitric acid peristaltic pump 3 stop working immediately. At this time, the electromagnet 15 is energized to control the rubidium magnet 13 on the discharge valve plate 14. The discharge valve plate 14 is opened to discharge the barium sulfate precipitate through the precipitation discharge pipe 18 and the waste liquid pipe. After the discharge, the solenoid valve is powered off, and the rubidium magnet 13 is adjusted to reset and drive the discharge valve plate 14 to close, completing the entire treatment process.

[0034] Through the above-mentioned technical means, the sulfate shielding pre-device of the graphite furnace atomizer realizes effective shielding and pretreatment of sulfate ions through a series of process treatments, and has significant beneficial effects. First, the device ensures the precise proportion of mixing of the sample and dilute nitric acid through the parallel flow of the sample peristaltic pump 4 and the dilute nitric acid peristaltic pump 3, and completes the acidification treatment in the first cyclone mixing chamber 5. This process ensures that the sulfate ions can be fully released and effectively reacted in subsequent treatments. Secondly, barium ions are introduced into the second cyclone mixing chamber 7 through the series-connected barium nitrate inlet pipe 101, and fully react with the sulfate in the sample to generate barium sulfate precipitate. This process is optimized in the rotary reaction generator 9 built into the device, and the obliquely arranged spoiler ring can effectively improve the reaction efficiency of the mixed solution and make the barium sulfate precipitation more uniform.

[0035] The device further monitors the sediment content in the fluid in real time through the photoelectric transmitter 11 and the photoelectric sensor receiver 12 to ensure the stability and accuracy of the precipitation process. When the amount of sediment generated reaches a certain threshold, the system can automatically determine that the reaction is complete, and adjust the channel of the three-way solenoid valve 19 through the electronic control system, so as to realize the automatic switching of the injection and waste liquid discharge pipes 20, avoid unclean samples from entering the graphite furnace atomizer, and prevent the loss of graphite tubes or even safety accidents caused by residual sulfate. In addition, the design of the precipitation zone 17 slows down the flow rate of the fluid, providing enough time for the sediment to fully settle, avoiding the loss or accumulation of sediment.

[0036] Through the precise control of the rubidium magnet 13 embedded in the discharge valve plate 14 by the electromagnet 15, the sediment can be discharged from the system in time, ensuring the waste discharge function of the device, effectively extending the service life of the device, and reducing the maintenance workload. This design not only reduces the loss of sulfate to the graphite tube and reduces the experimental cost, but also improves the laboratory's operational safety and the analytical efficiency of the instrument. On the whole, the device has high integration and is easy to operate. It is suitable for the efficient and precise requirements of modern analytical chemistry, especially in the field of trace analysis, and can significantly improve the working stability and safety of the graphite furnace atomizer.

[0037] Embodiment 2

[0038] like Figure 2-4 As shown, based on the above embodiment, this embodiment further provides the following contents:

[0039] In this embodiment, the device is provided with a cleaning pipeline 201, one end of which is provided with a hot EDTA solution pump 2, and the other end is connected in parallel with the sample injection tube 401, so as to avoid the influence of residual liquid in the pipeline on subsequent operations;

[0040] First, when the photoelectric transmitter 11 and the photoelectric sensor receiver 12 identify the presence of excess sulfate ions in the sample, the hot EDTA solution pump 2 is immediately started to pump 10 mL of EDTA solution into the pipeline to complete the initial cleaning of the pipeline. Then, the dilute nitric acid peristaltic pump 3 pumps 5 mL of dilute nitric acid into the pipeline for secondary pickling to complete the sulfate shielding operation. Next, the three-way solenoid valve 19 and the electromagnet 15 are energized to complete the complete discharge of the cleaning waste liquid. Finally, the pipeline returns to the initial sampling state.

[0041] Through the above-mentioned technical means, the device adds a cleaning pipeline 201 and a hot EDTA solution pump 2, which further improves the cleaning efficiency and operational safety of the system, and has obvious beneficial effects. By setting the cleaning pipeline 201, when the photoelectric transmitter 11 and the photoelectric sensor receiver 12 detect the presence of excessive sulfate ions in the sample, the hot EDTA solution pump 2 will start immediately and inject 10mL of EDTA solution into the pipeline. This process ensures that the sulfate and other potential interfering substances remaining in the pipeline can be quickly removed to prevent them from affecting subsequent sample analysis. Immediately afterwards, the dilute nitric acid peristaltic pump 3 injects 5mL of dilute nitric acid for secondary pickling, which further ensures the cleanliness of the pipeline and the chemical stability of the system, avoids the residue and accumulation of sulfate in the pipeline, and enhances the sulfate shielding effect.

[0042] Subsequently, by controlling the power-on operation of the three-way solenoid valve 19 and the electromagnet 15, the device can quickly and completely discharge the cleaning waste liquid from the system, ensuring that there is no residual liquid in the pipeline, and fully preparing for the next injection. This automated cleaning process not only greatly improves the cleaning efficiency of the system, but also reduces the need for manual intervention, ensuring the continuity of the experiment and the accuracy of the data. Overall, the design effectively solves the problem of interference of sulfate residues on the graphite furnace injection and analysis process, significantly improves the safety, accuracy and efficiency of laboratory operations, and meets the requirements of modern trace analysis equipment for efficient cleaning and automated operation.

[0043] Embodiment 3

[0044] like Figure 2-3 As shown, based on the above embodiment, this embodiment further provides the following contents:

[0045] In this embodiment, a plurality of oblique spirally arranged spoiler rings 91 are movably embedded in the rotary reaction generator 9, and the spacing increases linearly along the fluid flow direction, so as to accelerate the flow rate of the fluid and promote the reaction.

[0046] The pipe section is composed of polytetrafluoroethylene.

[0047] The diffuser 8 and the rotary reaction generator 9 are manufactured by photosensitive 3D printing, and the materials are reinforced SLA resin and weak alkaline curing agent.

[0048] The pipeline interface is provided with a plurality of inspection ports 23, which are fixed by bolts and sealed by polytetrafluoroethylene O-rings.

[0049] By the above-mentioned technical means, first, a plurality of oblique spirally arranged spoiler rings 91 are arranged in the rotary reaction generator 9, and this design greatly optimizes the flow state of the fluid. Through the arrangement of the spoiler ring 91, the laminar flow state of the fluid can be effectively broken to form a complex turbulent structure. This turbulence can not only significantly accelerate the flow velocity of the fluid, but also enhance the mixing and reaction efficiency in the fluid, thereby promoting the occurrence of chemical reactions. This design makes the flow of the fluid in the reaction generator more uniform, avoids the problem of dead angle and too slow flow velocity, thereby improving the overall efficiency and reaction rate of the reactor. Especially in the design of the linear increase in the spacing of the spoiler ring 91 arranged along the flow direction of the fluid, the flow trajectory of the fluid can be further optimized, ensuring the full mixing and reaction of the fluid in each region during the reaction process, avoiding the problem of insufficient or excessive local reaction. The overall design promotes the rapid response of the fluid, is suitable for processing various complex fluids, and enhances the adaptability of the reactor.

[0050] Secondly, the pipeline part is made of polytetrafluoroethylene material, which has excellent corrosion resistance and high temperature resistance in industrial applications. Polytetrafluoroethylene can effectively prevent various chemicals from corroding the pipeline and extend the service life of the equipment. At the same time, the smooth surface of the polytetrafluoroethylene material can reduce the resistance of the fluid in the pipeline, further improving the flow rate and delivery efficiency of the fluid. In addition, polytetrafluoroethylene has excellent heat resistance and can withstand higher temperature fluids. It is suitable for high temperature reaction scenarios, which is especially important for occasions where chemical reactions need to be carried out at high temperatures. Therefore, the application of polytetrafluoroethylene material not only improves the durability of the device, but also enhances its adaptability in complex environments.

[0051] In addition, the diffuser 8 and the rotary reaction generator 9 are manufactured by photosensitive 3D printing, and this manufacturing process has extremely high precision and flexibility. Photosensitive 3D printing can be precisely molded according to complex structural designs, ensuring that the detailed designs of the spoiler ring 91 and the diffuser 8 are perfectly realized. This manufacturing process enhances the structural strength and durability of the device by strengthening the cooperation of SLA resin and weak alkaline curing agent. SLA resin material not only has excellent mechanical properties, but also can resist a certain degree of chemical corrosion, and is suitable for high-intensity and long-term industrial applications. The use of weak alkaline curing agent further improves the stability of the material, ensuring that the device can still maintain excellent physical properties and long service life in a complex chemical environment. The 3D printing manufacturing method reduces errors and material waste in traditional manufacturing, and improves production efficiency and product precision.

[0052] In addition, the device is provided with a plurality of inspection ports 23 at the pipe interface, which greatly improves the maintenance convenience of the device. By providing inspection ports 23 at key positions of the pipe, users can conveniently perform regular inspections, cleaning or replacement of damaged parts to ensure the long-term stable operation of the device. These inspection ports 23 are fixed by bolts and sealed with polytetrafluoroethylene O-rings 16, which ensures that the pipe will not leak during operation, further improving the safety and sealing of the equipment. With its excellent corrosion resistance and sealing performance, the polytetrafluoroethylene O-ring 16 ensures the sealing effect of the pipe system in long-term operation, reducing the maintenance cost and potential risks caused by leakage.

[0053] Embodiment 4

[0054] like Figure 2-4 As shown, based on the above embodiment, this embodiment further provides the following contents:

[0055] In this embodiment, the temperature of the EDTA solution is 75°C.

[0056] The volume ratio of the dilute nitric acid is 5%.

[0057] The matrix of the barium nitrate solution is 5% dilute nitric acid, and the mass ratio thereof is 5%.

[0058] The device is mounted on the top of the machine platform 24 and is surrounded by a partition window.

[0059] Through the above technical means, firstly, the 75°C EDTA solution has high reactivity and solubility, which can more effectively complex and remove the residual metal ions and sulfate in the pipeline, thereby ensuring the cleanliness of the pipeline and avoiding the interference of residues in subsequent experiments. The moderate temperature not only improves the cleaning efficiency, but also ensures the safety and stability of the cleaning process.

[0060] The volume ratio of dilute nitric acid is 5%, which is an optimized choice. It can provide sufficient acidity to promote the reaction between sulfate ions in the sample and barium nitrate to form barium sulfate precipitation. At the same time, this concentration also avoids excessive corrosiveness and reduces damage to device materials, thereby extending the service life of the equipment. The matrix and mass ratio of barium nitrate solution are both 5%, which further ensures the stability and thoroughness of the precipitation reaction, optimizes the conditions for the formation of barium sulfate, avoids side reactions and deposition problems in the device that may be caused by excessive barium ions, and improves the accuracy of experimental data.

[0061] The design of the device being mounted on the top of the machine 24 and wrapped by a partition window further improves the convenience and safety of operation. The top installation makes the device operation more intuitive and easy to maintain, reducing the risk of failure caused by improper operation. The wrapping of the partition window not only provides physical isolation to prevent liquid splashing or gas leakage that may occur during the experiment, but also has a certain sound insulation and heat insulation effect, reducing the noise and temperature impact of the operating environment, and improving the quality of the laboratory's working environment. This series of designs work together to significantly improve the operating efficiency, safety and long-term stability of the system, ensuring the reliability of the experiment and the accuracy of the data. .

[0062] The working principle and use process of the present invention:

[0063] The use process of the sulfate shielding pre-device of the graphite furnace atomizer begins with the sample injection operation. First, the sample peristaltic pump 4 inputs 100 μL of the sample containing sulfate into the system through the injection tube 401. At the same time, the dilute nitric acid peristaltic pump 3 inputs 20 μL of dilute nitric acid into the device through the dilute nitric acid inlet tube 301, and mixes with the sample in the first cyclone mixing chamber 5, and the dilute nitric acid acidifies the sample. The acidified sample enters the second cyclone mixing chamber 7 from the first cyclone mixing chamber 5 through the bottom connecting tube. At this time, the barium nitrate peristaltic pump 1 inputs 50 μL of barium nitrate solution through the barium nitrate inlet tube 101, and the sulfate reacts chemically with the barium ion to generate barium sulfate precipitation. After the mixed solution flows into the second cyclone mixing chamber 7 through the connecting tube, it passes through the inverted umbrella-shaped diffuser 8 and the cylindrical rotary reaction generator 9. The oblique arrangement of the spoiler ring helps to fully mix the liquid, the reaction is strengthened, and the precipitate is further formed.

[0064] The mixed liquid then enters the lotus-shaped collection area 10, and the fluid channel gradually narrows from wide, and the flow rate gradually increases. When the fluid passes through the narrow pipe 22 where the photoelectric transmitter 11 and the photoelectric sensor receiver 12 are located, the photoelectric device detects the content of barium sulfate precipitate in the mixed liquid in real time. After that, the liquid enters the precipitation area 17, the flow rate slows down, and the precipitate is fully settled in this area. A precipitation discharge pipe 18 is provided at the bottom of the precipitation area 17. When the barium sulfate precipitate is detected to exceed the standard, the discharge valve plate 14 is opened and closed by the power-on control of the embedded rubidium magnet 13 and the external electromagnet 15. When the precipitate is fully formed, the electromagnet 15 is energized to attract the rubidium magnet 13, the discharge valve plate 14 is opened, and the precipitate is discharged from the system through the precipitation discharge pipe 18. Then the three-way solenoid valve 19 adjusts the liquid flow direction and discharges the waste liquid into the waste liquid discharge pipe 20 to complete the waste discharge; when the barium sulfate precipitate is detected to be qualified, the three-way solenoid valve 19 adjusts the liquid flow direction and discharges the mixed liquid into the feed pipe to complete the feed detection.

[0065] After completing the detection and precipitation discharge, the system will enter the cleaning process. First, when the photoelectric device detects the presence of sulfate ions in the system, the hot EDTA solution pump 2 is started, and the 75°C EDTA solution is injected into the system through the cleaning pipe 201 for initial cleaning to remove residues in the pipe. Subsequently, the dilute nitric acid peristaltic pump 3 injects 5 mL of dilute nitric acid into the pipe for secondary pickling to further remove residual sulfate ions. After the cleaning is completed, the three-way solenoid valve 19 switches the flow direction of the pipeline, and the waste liquid is discharged from the system through the waste liquid discharge pipe 20. The electromagnet 15 is powered off, the rubidium magnet 13 is reset, the discharge valve plate 14 is closed, and the cleaning process ends.

[0066] The entire device is operated by setting up the top of the machine 24, with a partition window to ensure that the operator can easily perform daily operations and maintenance. The partition window design effectively prevents splashes and leaks that may occur during the experiment, improving the safety of the experiment. Finally, the pipeline returns to the initial injection state, and the device is ready for the next sample processing cycle.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sulfate shielding pre-device for a graphite furnace atomizer, characterized in that: include: A sample inlet tube (401) is provided at one end with a sample peristaltic pump (4) for inputting the sample, and the other end is connected in parallel with a dilute nitric acid inlet tube (301) for conveying dilute nitric acid by the dilute nitric acid peristaltic pump (3). A barium nitrate inlet pipe (101) is provided for inputting barium nitrate. The parallel pipes are connected to a spherical first cyclone mixing chamber (5) after merging. The first cyclone mixing chamber (5) is symmetrically provided with a spherical second cyclone mixing chamber (7) backwards, and a hollow mixing chamber bottom connecting pipe (6) is provided through the connection point thereof, which is connected in series with the barium nitrate inlet pipe (101). The second cyclone mixing chamber (7) is provided with an inverted umbrella-shaped diffuser (8) and a cylindrical rotary reaction generator (9) in series. The inner wall of the rotary reaction generator (9) is embedded with an oblique spoiler ring, and a lotus-shaped collection area (10) is connected along the sample flow direction. The outlet of the collection area (10) is extended with a narrow pipe (22), which is provided with a photoelectric transmitter (11) and a photoelectric sensor receiver (12) vertically corresponding thereto, for real-time monitoring of the sediment content. The narrow pipe (22) is connected in series with a lotus-shaped sedimentation area (17), and a sedimentation discharge pipe (18) is provided at the bottom of the sedimentation area (17) and extends vertically downward. A discharge valve plate (14) attached to a rubidium magnet (13) is embedded at the intersection of the sedimentation discharge pipe (18), and a polytetrafluoroethylene O-ring (16) is provided under the discharge valve plate. An electromagnet (15) is attached to the outer tube surface of the sedimentation discharge pipe (18) for electrically regulating the rubidium magnet (13) to open and close the discharge valve plate (14). A three-way electromagnetic valve (19) is connected along the direction of the fluid in the sedimentation area (17), and the three-way electromagnetic valve (19) is used to adjust the direction of the fluid in the graphite furnace feed pipe (21) and the waste liquid discharge pipe (20) in different directions according to the photoelectric detection result.

2. The graphite furnace atomizer sulfate shielding pre-device according to claim 1, characterized in that: The rotary reaction generator (9) is movably embedded with a plurality of obliquely spirally arranged spoiler rings (91), and the spacing between the spoiler rings increases linearly along the flow direction of the fluid, so as to accelerate the flow rate of the fluid and promote the reaction.

3. The sulfate shielding pre-device of graphite furnace atomizer according to claim 1, characterized in that: The device is provided with a cleaning pipeline (201), one end of which is provided with a hot EDTA solution pump (2), and one end of which is connected in parallel with the sample injection tube (401) to prevent the residual liquid in the pipeline from affecting subsequent operations; The photoelectric transmitter (11) and the photoelectric sensor receiver (12) identify the presence of excessive sulfate ions in the sample, and the hot EDTA solution pump (2) is immediately started to pump EDTA solution into the pipeline to complete the initial cleaning of the pipeline. The dilute nitric acid peristaltic pump (3) pumps dilute nitric acid into the pipeline for secondary pickling to complete the sulfate shielding operation. The three-way solenoid valve (19) and the electromagnet (15) are energized to complete the complete discharge of the cleaning waste liquid, and the pipeline returns to the initial sampling state.

4. The sulfate shielding pre-device of graphite furnace atomizer according to claim 3, characterized in that: The pipe part is composed of polytetrafluoroethylene.

5. The sulfate shielding pre-device of graphite furnace atomizer according to claim 1, characterized in that: The diffuser (8) and the rotary reaction generator (9) are manufactured by photosensitive 3D printing, and the materials are reinforced SLA resin and strong alkaline curing agent.

6. The sulfate shielding pre-device of graphite furnace atomizer according to claim 4, characterized in that: The pipeline interface is provided with a plurality of inspection ports (23), which are fixed by bolts and sealed by polytetrafluoroethylene O-rings.

7. The sulfate shielding pre-device of graphite furnace atomizer according to claim 6, characterized in that: The temperature of the EDTA solution is 75°C.

8. The graphite furnace atomizer sulfate shielding pre-device according to claim 7, characterized in that: The volume ratio of the dilute nitric acid is 5%, and the matrix of the barium nitrate solution is 5% dilute nitric acid, and the mass ratio thereof is 5%.

9. The sulfate shielding pre-device of graphite furnace atomizer according to claim 8, characterized in that: The device is mounted on the top of the machine platform (24) and is wrapped with a partition window.

10. The method for using the sulfate shielding pre-device of a graphite furnace atomizer according to any one of claims 1 to 9, characterized in that: Sulfate ion detection, the sample containing sulfate delivered by the sample peristaltic pump (4) and the sample inlet tube (401) merges with the dilute nitric acid delivered by the dilute nitric acid peristaltic pump (3) and the dilute nitric acid inlet tube (301) and enters the first cyclone mixing chamber (5), where they are fully mixed and acidified; The mixed liquid enters the second cyclone mixing chamber (7) through the connecting pipe at the bottom of the mixing chamber, and fully reacts with the barium ions fed from the barium nitrate peristaltic pump (1) and the barium nitrate inlet pipe (101) to generate barium sulfate precipitate; Then the mixed liquid passes through the diffuser (8) and the rotary reaction generator (9) in sequence, and the obliquely arranged spoiler ring helps the mixed liquid to be fully mixed to form a pre-treated liquid; When the pre-treated liquid flows through the collection area (10), the fluid channel gradually decreases, so that the flow rate of the fluid gradually increases. When the pre-treated liquid passes through the pipeline section directly facing the photoelectric transmitter (11) and the photoelectric sensor receiver (12), the flow rate reaches the maximum value, and the barium sulfate precipitate is measured simultaneously; When the fluid enters the precipitation zone (17), the flow rate slows down and the fluid residence time is prolonged, so that the barium sulfate precipitate is fully deposited in the precipitation zone (17); When the precipitation process is completed, the three-way solenoid valve (19) switches the channel from the sample injection tube (401)-graphite atomizer to the sample injection-waste liquid discharge tube (20), and the sample peristaltic pump (4) and the dilute nitric acid peristaltic pump (3) stop working immediately.

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