Portable morphological analysis device for SO3 < 2-> / S < 2-> in environmental water sample

Abstract

The utility model discloses a portable SO3 < 2-> / S < 2-> form analysis device in an environmental water sample. The device comprises a chemical gas phase generation assembly, a micro-plasma reactor and a visual colorimetric detector, the chemical gas phase generation assembly comprises a reaction bottle with an open end and a cover body covering the open end of the reaction bottle in a sealing manner, the reaction bottle is provided with an argon introducing pipe and a gas phase discharging pipe, and the other end of the gas phase discharging pipe is connected to the gas inlet end of the micro-plasma reactor; the exhaust end of the micro-plasma reactor is connected with an exhaust pipe, and the other end of the exhaust pipe is connected to the air inlet end of the visual colorimetric detector; the visible colorimetric detector comprises a transparent colorimetric reaction chamber, and a fluorescein derivative which is subjected to a color fading reaction with SO2 is arranged in the transparent colorimetric reaction chamber. The portable SO3 < 2-> / S < 2-> morphological analysis device in the environmental water sample can be used for field detection, and is simple and quick to operate.

Description

Technical Field

[0001] This utility model relates to the field of environmental water sample analysis, specifically to a portable method for analyzing SO3 in environmental water samples. 2- / S 2- Morphological analysis device. Background Technology

[0002] Existing technologies for detecting SO3 in environmental water samples 2- and S 2- The main method for morphological analysis is chromatography, which uses large-scale chromatographic analyzers. Not only is the equipment expensive, but chromatographic detection also requires professional technicians to operate, and the operation steps are complex.

[0003] Furthermore, because the chromatography analyzer is a large piece of equipment and is only installed in the laboratory, it is not suitable for analyzing SO3 in environmental water samples. 2- and S 2- For speciation analysis, environmental water samples need to be transported from the sampling site to a laboratory equipped with a chromatography analyzer for analysis. However, SO3... 2- and S 2- Both are toxic substances. SO2 is part of flue gas, and directly emitting SO2 into the surrounding environment will form SO3. 2- This leads to environmental problems such as acid rain, ecosystem destruction, and building damage, and excessive exposure to sulfur dioxide (S₂O₃) can cause these problems. 2- and SO3 2- It can lead to diseases of the nervous system, respiratory system, and other systems. Furthermore, during the transportation of environmental samples, these analytes may be oxidized or reduced, causing changes in their form, which can lead to biases in environmental water sample testing and the risk of excessive exposure to sulfur. 2- and SO3 2- The risks.

[0004] Existing technologies for detecting SO3 in environmental water samples 2- and S 2- The main method for speciation analysis is chromatography, which uses liquid samples for detection. Liquid samples are prone to matrix interference, which reduces the accuracy of detection.

[0005] The applicant has discovered that the prior art has at least the following technical problems:

[0006] 1. Existing technologies for detecting sulfur in environmental water samples 2- and SO3 2- The main method for morphological analysis is chromatography. However, chromatography requires expensive large-scale instruments, professional technicians, and complex operating procedures.

[0007] 2. Current technologies cannot analyze environmental water samples on-site; environmental water samples are transported and...2- and SO3 2- It may be oxidized or reduced, causing changes in its form, which will lead to deviations in environmental water sample testing and the possibility of excessive contact with S. 2- and SO3 2- The risks.

[0008] 3. Existing technologies for detecting sulfur in environmental water samples 2- and SO3 2- The main method for speciation analysis is chromatography, which uses liquid samples for detection. Liquid samples are prone to matrix interference. Utility Model Content

[0009] The purpose of this invention is to provide a portable method for detecting SO3 in environmental water samples. 2- / S 2- A speciation analysis device to address the limitations of existing technologies in analyzing sulfur in environmental water samples. 2- and SO3 2- The main method for speciation analysis is chromatography; however, chromatography requires expensive, large-scale instruments, specialized technicians, and involves complex operational procedures. The preferred technical solutions provided by this invention offer numerous technical benefits, which are detailed below.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] This utility model provides a portable method for detecting SO3 in environmental water samples. 2- / S 2- The speciation analysis device includes a chemical vapor generation assembly, a microplasma reactor, and a visual colorimetric detector; among which,

[0012] The chemical vapor generation assembly includes a reaction bottle with an open end and a cap that is sealed to the open end of the reaction bottle. The reaction bottle is provided with an argon gas inlet pipe and a gas phase outlet pipe. The other end of the gas phase outlet pipe is connected to the gas inlet end of the micro plasma reactor.

[0013] The exhaust end of the microplasma reactor is connected to an exhaust pipe, and the other end of the exhaust pipe is connected to the air inlet of the visual colorimetric detector.

[0014] The visual colorimetric detector includes a transparent colorimetric reaction chamber, which contains a fluorescein derivative that reacts with SO2 to decolorize.

[0015] Furthermore, the top of the reaction flask is an open end; the cover includes a hollow plastic cap and a circular rubber gasket located inside the plastic cap, the dimensions of which are matched to the open top of the reaction flask.

[0016] Furthermore, the transparent colorimetric reaction chamber includes a centrifuge tube and a sealing cap that matches the open end of the centrifuge tube. An air inlet pipe is inserted through the sealing cap. When the sealing cap is placed on the open end of the centrifuge tube, one end of the air inlet pipe extends into the centrifuge tube and is close to the bottom of the centrifuge tube, while the other end of the air inlet pipe is located outside the centrifuge tube and connected to the exhaust pipe.

[0017] Furthermore, the microplasma reactor is a tip discharge (PD) microplasma reactor, comprising a power supply, a regulator, a T-shaped quartz tube, a conical tungsten rod electrode, a hollow copper electrode, and a switch;

[0018] The T-shaped quartz tube includes a horizontal quartz tube and a vertical quartz tube, with one end of the vertical quartz tube connected to the middle of the horizontal quartz tube and the vertical quartz tube communicating with the horizontal quartz tube; the other end of the vertical quartz tube is connected to an exhaust pipe.

[0019] The conical tungsten rod electrode is inserted into one of the openings of the transverse quartz tube; the hollow copper electrode is a hollow copper tube, which is inserted into the other opening of the transverse quartz tube.

[0020] Both the conical tungsten rod electrode and the hollow copper tube are wound with copper coil one and copper coil two on their outer sides.

[0021] The gas phase discharge pipe is connected to the hollow copper pipe;

[0022] The power supply, regulator, and switch are connected in series, and copper coil one and copper coil two are connected in parallel to the regulator.

[0023] Furthermore, the regulator is a high-voltage pulse reaction block.

[0024] Furthermore, it also includes a mounting base, which, from top to bottom, comprises an upper mounting platform, a middle mounting platform, and a lower mounting platform; wherein,

[0025] The T-shaped quartz tube, conical tungsten rod electrode, and hollow copper electrode of the microplasma reactor are all mounted on the upper platform.

[0026] The reaction flask, colorimetric reaction chamber, and switch are all mounted on the central mounting platform; the central mounting platform is provided with mounting platform one and mounting platform two for placing the reaction flask and colorimetric reaction chamber;

[0027] Both the power supply and the regulator are mounted on the lower mounting platform.

[0028] The top of the upper mounting platform is provided with a mounting groove for a T-shaped quartz tube, which is installed in the mounting groove. The top of the upper mounting platform is also provided with an upper closed door that matches the mounting groove. One side of the upper closed door is hinged to the edge of the upper mounting platform, and the other side of the upper closed door is movably connected to the upper mounting platform. The upper closed door is made of transparent material.

[0029] The lower mounting platform has mounting slot one and mounting slot two on its side wall for mounting a power supply and regulator; a lower sealing door is provided on the outside of mounting slot one and mounting slot two; one side of the lower sealing door is hinged to the edge of the lower mounting platform, and the other side of the lower sealing door is movably connected to the lower mounting platform; the lower sealing door is made of transparent material.

[0030] Furthermore, the upper mounting platform has a visualization window on the side wall corresponding to the mounting T-shaped quartz tube for observing the reaction inside the micro-plasma reactor.

[0031] Based on the above technical solution, the embodiments of this utility model can produce at least the following technical effects:

[0032] (1) SO3 in portable environmental water samples provided by this utility model 2- / S 2- This speciation analysis device effectively combines a chemical vapor generation component, a micro-plasma reactor, and a visual colorimetric detector. By simply turning the micro-plasma reactor on or off, it can perform standard analysis of sulfur compounds within a one-minute response time, making it suitable for analyzing SO3 in environmental water samples. 2- / S 2- On-site morphological analysis can effectively avoid morphological changes in environmental samples during transportation; it improves the accuracy of detection and avoids excessive contact with S. 2- and SO3 2- The risks.

[0033] (2) SO3 in portable environmental water samples provided by this utility model 2- / S 2-This speciation analysis device eliminates the need for complex and time-consuming chromatographic separation processes, representing a non-chromatographic on-site analytical method. During detection, the sample enters the reaction vessel of the chemical vapor generation unit. An acid is injected to react with the sample, generating gaseous analytes (H2S and / or SO2). Argon gas carries the gaseous analytes into a micro-plasma reactor, where the H2S is oxidized to SO2. The original SO2 in the gaseous analytes does not react. Therefore, the SO2 generated from the oxidation of H2S and the original SO2 in the gaseous analytes enters a visual colorimetric detector together. The SO2 reacts with a fluorescein derivative, causing a fading reaction. By observing the color of the fluorescein derivative after the fading reaction and comparing it with a visual colorimetric image, the sulfur content in the sample can be determined. In this invention, the fluorescein derivative is used as a selective gaseous absorbent for SO2. The chemical adsorption of SO2 onto the fluorescein derivative is mainly based on the strong interaction between anions, and further reacts with the negative oxygen ions in the phenoxy molecules to generate a colorless product. SO2 causes the fluorescein derivative to gradually fade from yellow, while H2S does not react with it to change its color. However, H2S treated in the micro-plasma chamber, having been converted into SO2, can cause the fluorescein derivative to undergo a fading reaction, with the fading reaction time being 40 seconds. Therefore, by causing the fluorescein derivative in the transparent colorimetric reaction chamber to undergo a fading reaction with SO2, SO3 can be absorbed. 2- / S 2- On-site morphological analysis. This invention introduces the sample through chemical vapor generation, effectively avoiding matrix interference from liquid samples and improving detection accuracy. The detection limit of this method is 6.22 μmol·L⁻¹. -1 60 μmol·L⁻¹ can be distinguished by the naked eye -1 The method has been successfully applied to visual colorimetric analysis of field water samples and has shown its potential for field analysis of various environmental samples. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present invention.

[0036] Figure 2 yes Figure 1 Top view;

[0037] Figure 3This is a schematic diagram showing the connection between the chemical vapor generation component, the micro plasma reactor, and the visual colorimetric detector in Embodiment 1 of this utility model;

[0038] Figure 4 The UV-Vis absorption spectra of the seven test solutions 1 and the blank solution when the micro-plasma was turned off;

[0039] Figure 5 The standard curve for SO2 was established when the microplasma was turned off;

[0040] Figure 6 Standard curves for SO2 and H2S under three experimental conditions: 3.2.1, 3.2.2, and 3.2.3.

[0041] Figure 7 (a) Visual colorimetric results of SO2 and H2S under the experimental conditions in 3.2.4;

[0042] Figure 7 (b) Visual colorimetric results of SO2 and H2S under experimental conditions 3.2.5;

[0043] Figure 7 (c) Visual colorimetric results of SO2 and H2S under the experimental conditions in 3.2.6;

[0044] Figure 8 It is a standard colorimetric card for SO2 and H2S;

[0045] Figure 9 This is a graph showing the change in absorbance with the concentration of the fluorescein derivative as the variable (ΔA is the absorbance).

[0046] Figure 10 The graph shows the absorbance change when the time of the fluorescein derivative reacts with SO2 as the variable (ΔA is absorbance);

[0047] Figure 11 This is a graph showing the change in absorbance when the type of acid is the variable (ΔA is absorbance);

[0048] Figure 12 This is a graph showing the change in absorbance with the concentration of acid as the variable (ΔA is absorbance);

[0049] Figure 13 This is a graph showing the change in absorbance with the flow rate of argon gas as the variable (ΔA is the absorbance);

[0050] Figure 14 This is a graph showing the change in absorbance when the gap of the micro-plasma discharge is the variable (ΔA is the absorbance);

[0051] Figure 15This is a diagram showing the change in absorbance when the components in the micro-plasma reactor in Embodiment 1 of this utility model are connected.

[0052] In the diagram: 1. Reaction flask; 2. Cap; 3. Argon gas inlet pipe; 4. Gas phase outlet pipe; 5. Exhaust pipe; 6. Centrifuge tube; 7. Sealing cap; 8. Gas inlet pipe; 9. Power supply; 10. Regulator; 11. T-shaped quartz tube; 1101. Horizontal quartz tube; 1102. Vertical quartz tube; 12. Conical tungsten rod electrode; 13. Hollow copper electrode; 14. Switch; 15. Pipe 1; 16. Copper coil 1; 17. Copper coil 2; 18. Visualization window; 19. Argon gas delivery pipe; 20. Sample to be tested; 21. Syringe; 22. Fluorescein derivative; 23. Standard color chart; 24. Mounting through hole; 25. Mounting base; 26. Upper mounting platform; 27. Middle mounting platform; 28. Lower mounting platform; 29. ​​Mounting platform 1; 30. Mounting platform 2. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0054] I. Example:

[0055] Example 1:

[0056] like Figures 1-3 and Figure 15 As shown:

[0057] This utility model relates to a portable environmental water sampler containing SO3. 2- / S 2- The speciation analysis device includes a chemical vapor generation assembly, a microplasma reactor, and a visual colorimetric detector; among which,

[0058] The chemical vapor generation assembly includes a reaction bottle 1 with an open end and a cap 2 with a sealing cap 7 attached to the open end of the reaction bottle 1. The reaction bottle 1 is provided with an argon gas inlet pipe 3 and a gas phase outlet pipe 4. The other end of the gas phase outlet pipe 4 is connected to the gas inlet end of the micro plasma reactor. During detection, an argon gas delivery pipe 19 is connected to the argon gas inlet pipe 3 to deliver argon gas into the reaction bottle 11.

[0059] The exhaust end of the microplasma reactor is connected to an exhaust pipe 5, and the other end of the exhaust pipe 5 is connected to the air inlet of the visual colorimetric detector.

[0060] The visual colorimetric detector includes a transparent colorimetric reaction chamber, which contains a fluorescein derivative 22 that reacts with SO2 to decolorize.

[0061] As an optional implementation, the top of the reaction flask 1 is open, and the argon gas inlet pipe 3 and the gas phase outlet pipe 4 are respectively located on opposite sides of the reaction flask 1; the cover 2 includes a hollow plastic cover and a circular rubber gasket located inside the plastic cover, the dimensions of which are matched to the open top of the reaction flask 1. The circular rubber gasket serves two purposes: firstly, it provides a seal, and secondly, it facilitates the injection of acids into the reaction flask 1 using a syringe 21.

[0062] As an optional implementation, the transparent colorimetric reaction chamber includes a centrifuge tube 6 and a sealing cap 7 that matches the open end of the centrifuge tube 6. An air inlet pipe 8 is provided through the sealing cap 7. When the sealing cap 7 is placed on the open end of the centrifuge tube 6, one end of the air inlet pipe 8 extends into the centrifuge tube 6 and is close to the bottom of the centrifuge tube 6, and the other end of the air inlet pipe 8 is located outside the centrifuge tube 6 and is connected to the exhaust pipe 5.

[0063] As an optional implementation, the microplasma reactor is a tip discharge (PD) microplasma reactor, including a power supply 9, a regulator 10, a T-shaped quartz tube 11, a conical tungsten rod electrode 12, a hollow copper electrode 13, and a switch 14.

[0064] The T-shaped quartz tube 11 includes a horizontal quartz tube 1101 and a vertical quartz tube 1102, with one end of the vertical quartz tube 1102 connected to the middle of the horizontal quartz tube 1101 and communicating with the horizontal quartz tube 1101; the other end of the vertical quartz tube 1102 is the exhaust end of the micro-plasma reactor and is connected to the exhaust pipe 5.

[0065] The conical tungsten rod electrode 12 is inserted into one of the openings of the transverse quartz tube 1101; the hollow copper electrode 13 is a hollow copper tube, which is inserted into the other opening of the transverse quartz tube 1101.

[0066] The outer sides of the conical tungsten rod electrode 12 and the hollow copper tube are both wound with copper coil 16 and copper coil 17.

[0067] The gas phase discharge pipe 4 is connected to the hollow copper pipe through pipe 15.

[0068] The power supply 9, regulator 10, and switch 14 are connected in series, and the copper coil 16 and copper coil 17 are connected in parallel to the regulator 10. When the switch 14 is turned on to supply power, the hollow copper electrode 13 and the conical tungsten rod electrode 12 will form a micro-plasma discharge.

[0069] As an optional implementation, the regulator 10 is a high-voltage pulse reaction block.

[0070] As an optional implementation, it also includes a mounting base 25, which is provided with an upper mounting platform 26, a middle mounting platform 27, and a lower mounting platform 28 from top to bottom; wherein,

[0071] The T-shaped quartz tube 11, the conical tungsten rod electrode 12, and the hollow copper electrode 13 of the microplasma reactor are all mounted on the upper mounting platform 26.

[0072] The reaction bottle 1, the colorimetric reaction chamber, and the switch 14 are all mounted on the central mounting platform 27; the central mounting platform 27 is provided with mounting platform 29 and mounting platform 30 for placing the reaction bottle 1 and the colorimetric reaction chamber.

[0073] Both the power supply 9 and the regulator 10 are mounted on the lower mounting platform 28.

[0074] The top of the upper mounting platform 26 is provided with a mounting groove for a T-shaped quartz tube 11, and the T-shaped quartz tube 11 is installed in the mounting groove; and the top of the upper mounting platform 26 is also provided with an upper sealing door that matches the mounting groove; one side of the upper sealing door is hinged to the edge of the upper mounting platform 26, and the other side of the upper sealing door is movably connected to the upper mounting platform 26; the upper sealing door can be made of transparent material.

[0075] The lower mounting platform 28 has mounting slot 1 and mounting slot 2 on its side wall for mounting a power supply and regulator; a lower sealing door is provided on the outside of mounting slot 1 and mounting slot 2; one side of the lower sealing door is hinged to the edge of the lower mounting platform 28, and the other side of the lower sealing door is movably connected to the lower mounting platform 28; the lower sealing door can be made of transparent material.

[0076] As an optional implementation, the upper mounting platform 26 has a visualization window 18 on the side wall corresponding to the mounting T-shaped quartz tube 11 for observing the reaction inside the micro-plasma reactor. The working status of the micro-plasma reactor on the upper mounting platform 26 can be observed through the visualization window 18 to ensure the entire detection process proceeds normally.

[0077] As an optional implementation, the mounting base 25 is made of photosensitive resin, and the entire mounting base 25 can be 3D printed.

[0078] As an optional implementation, a standard color chart 23 for color matching is also included, which is affixed to the mounting base 25.

[0079] As an optional implementation, the mounting base 25 is provided with several mounting through holes 24 for pipe insertion.

[0080] The environmental water sample analysis was performed using the aforementioned equipment, and the specific analytical method included the following steps:

[0081] S1. Place the sample to be tested into the reaction flask and cover it; then inject argon gas through the argon inlet tube at a flow rate of 10-300 mL / min. -1 ;

[0082] S2. Inject the acid into the reaction flask, and the sample to be tested reacts with the acid to generate a gaseous analyte, wherein the gaseous analyte is H2S and / or SO2;

[0083] The acids are sulfuric acid, hydrochloric acid, nitric acid, acetic acid, acetic acid, or phosphoric acid;

[0084] S3. Argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase exhaust pipe. The gap of the micro-plasma discharge in the micro-plasma reactor is 1-6 mm. H2S in the gaseous analyte is oxidized to SO2 in the micro-plasma reactor.

[0085] S4 and SO2 enter a visual colorimetric detector from the exhaust pipe. The visual colorimetric detector is equipped with a fluorescein derivative at a concentration of 40-140 μmol·L⁻¹. -1 After SO2 reacts with the fluorescein derivative, the fluorescein derivative reacts with SO2 and the fading reaction takes 10-60 seconds, completing the detection.

[0086] II. Optimal experimental conditions for using the screening and analysis device

[0087] 2.1. Prepare sample 20 to be tested:

[0088] ① Preparation of test sample 20: Test sample 20a was prepared by dissolving Na2SO3 in pure water, and test sample 20b was prepared by dissolving Na2S in pure water.

[0089] Sample 20a to be tested: SO3 2- The concentration is 150 μmol·L. -1 ;

[0090] Sample 20b to be tested: S 2- The concentration is 150 μmol·L. -1 ;

[0091] 2.2 Screening for optimal experimental conditions using a single variable

[0092] 2.2.1 The analytical method used is as follows:

[0093] S1. Place the sample 20 to be tested into reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 10-300 mL / min.-1 ;

[0094] S2. The acid is injected into the reaction bottle 1 through the syringe 21. The sample to be tested 20 reacts with the acid to generate a gaseous analyte, which is H2S and / or SO2.

[0095] The acids are sulfuric acid, hydrochloric acid, nitric acid, acetic acid, acetic acid, or phosphoric acid;

[0096] S3. Argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase discharge pipe 4. The gap of the micro-plasma discharge in the micro-plasma reactor is 1-6 mm. H2S in the gaseous analyte is oxidized to SO2 in the micro-plasma reactor.

[0097] S4 and SO2 enter the visual colorimetric detector from the exhaust pipe 5. The visual colorimetric detector is equipped with a fluorescein derivative 22, and the concentration of the fluorescein derivative 22 is 40-140 μmol·L. -1 After SO2 reacts with fluorescein derivative 22, the decolorization reaction takes 10-60 seconds. The decolorized fluorescein derivative 22 is then placed in a double-beam UV-Vis spectrophotometer for detection. Quantitative speciation analysis of H2S / SO2 is achieved through precise measurement using a double-beam UV-Vis spectrophotometer (Shanghai Youke Instrument Co., Ltd., model: T2602, Shanghai, China).

[0098] 2.2.2 Screening process and results:

[0099] 2.2.2.1 Using the concentration of fluorescein derivative 22 as the variable, the concentration of fluorescein derivative 22 was 40-140 μmol·L. -1 SO3 2- and S 2- The concentrations were all 150 μmol·L. -1 The reaction time was 30 seconds; the acid was sulfuric acid; and the acid concentration was 4 mol / L. -1 The argon flow rate is 200 mL / min. -1 The gap for micro-plasma discharge is 4 mm.

[0100] Concentration of fluorescein derivative 22: 40 μmol·L⁻¹ -1 60 μmol·L -1 80 μmol·L -1 100 μmol·L -1 120 μmol·L -1 140 μmol·L -1 The experiments were conducted at these six concentrations respectively.

[0101] Experimental results: such as Figure 9 As shown, with the increase of fluorescein concentration, the change in absorbance gradually increases, and the solution color gradually becomes lighter. When the fluorescein concentration is 100 μmol·L⁻¹, the change in absorbance gradually increases. -1 At this time, the absorbance change value tends to stabilize, and the solution color tends to stabilize. Therefore, the final concentration of fluorescein derivative 22 was selected as 100 μmol·L⁻¹. -1 .

[0102] 2.2.2.2 The decolorization reaction time of fluorescein derivative 22 with SO2 was used as a variable, with a reaction time ranging from 10 to 60 seconds. SO3 2- and S 2- The concentrations were all 150 μmol·L. -1 The concentration of fluorescein derivative 22 was 100 μmol·L⁻¹. -1 The acid is sulfuric acid; the concentration of the acid is 4 mol / L. -1 The gas flow rate is 200 mL / min. -1 The gap for micro-plasma discharge is 4 mm.

[0103] Reaction time: Experiments were conducted at six different times: 10s, 20s, 30s, 40s, 50s, and 60s.

[0104] Experimental results: such as Figure 10 As shown, the inflection points of the SO2 and H2S curves occur at 40s and 20s, respectively. Therefore, a reaction time of 40s was ultimately chosen.

[0105] 2.2.2.3 Using the type of acid as the variable, the types of acids are sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, formic acid, and acetic acid. SO3 2- and S 2- The concentrations were all 150 μmol·L. -1 The concentration of fluorescein derivative 22 was 100 μmol·L⁻¹. -1 The reaction time was 40 seconds; the acid concentration was 4 mol / L. -1 The flow rate of argon gas is 100 mL / min. -1 The gap for micro-plasma discharge is 4 mm.

[0106] Types of acids: Six acids were selected for the experiment: sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, formic acid, and acetic acid.

[0107] Experimental results: such as Figure 11 As shown, HCOOH, CH3COOH, HCl, and HNO3 are all strong volatile acids that would affect gas absorption, while H3PO4 is a moderately strong acid, less acidic than H2SO4. Therefore, sulfuric acid was ultimately chosen as the acid.

[0108] 2.2.2.4 The concentration of acid is a variable, ranging from 1 to 6 mol / L. -1 SO3 2- and S 2- The concentrations were all 150 μmol·L. -1 The concentration of fluorescein derivative 22 was 100 μmol·L⁻¹. -1 The reaction time was 40 seconds; the acid was sulfuric acid; and the argon gas flow rate was 100 mL / min. -1 The gap for micro-plasma discharge is 4 mm.

[0109] Acid concentration: 1 mol / L -1 2 mol L -1 3 mol L -1 4 mol L -1 5 mol L -1 6 mol L -1 The experiments were conducted at these six concentrations respectively.

[0110] Experimental results: such as Figure 12 As shown, because low concentrations of H2SO4 cannot satisfy S 2- or SO3 2- Sufficient acidification is necessary, but excessive H2SO4 would waste reagents. Therefore, a sulfuric acid concentration of 4 mol / L was ultimately chosen. -1 .

[0111] 2.2.2.5 Taking the argon gas flow rate as a variable, the argon gas flow rate is 10-300 mL·min. -1 SO3 2- and S 2- The concentrations were all 150 μmol·L. -1 The concentration of fluorescein derivative 22 was 100 μmol·L⁻¹. -1 The reaction time was 40 seconds; the acid was sulfuric acid; and the sulfuric acid concentration was 4 mol / L. -1 The gap for micro-plasma discharge is 4 mm.

[0112] Argon flow rate: 10 mL / min -1 50 mL·min -1 100 mL·min -1 150 mL·min -1 200 mL·min -1 250 mL·min -1 300mL·min -1 The experiments were conducted at each of the seven flow rates.

[0113] Experimental results: such as Figure 13The argon flow rate had almost no effect on SO2 absorption, likely because the absorption of SO2 by fluorescein derivative 22 is instantaneous. Therefore, a more stable gas flow rate (150 mL / min) was used in subsequent experiments. -1 Therefore, a gas flow rate of 150 mL / min was ultimately chosen. -1 .

[0114] 2.2.2.6 The gap of the micro-plasma discharge is used as a variable, with a discharge gap of 1-6 mm. SO3 2- and S 2- The concentrations were all 150 μmol·L. -1 The concentration of fluorescein derivative 22 was 100 μmol·L⁻¹. -1 The reaction time was 40 seconds; the acid was sulfuric acid; and the sulfuric acid concentration was 4 mol / L. -1 The argon flow rate is 150 mL / min. -1 .

[0115] Discharge gap: Six discharge gaps of 1mm, 2mm, 3mm, 4mm, 5mm, and 6mm were selected for experiments. Experimental results: As shown... Figure 14 The signal response was highest when the discharge gap was 5 mm. Therefore, a gap of 5 mm was ultimately chosen for the micro-plasma discharge.

[0116] III. Establishing a standard curve and standard color chart under optimal experimental conditions 23

[0117] The analytical performance of this method was tested using the on-site speciation analysis method (visual colorimetry) and ultraviolet-visible absorption spectroscopy, and a standard curve and standard color chart 23 were established. When using ultraviolet-visible absorption spectroscopy, the gaseous analyte (SO2) enters the fluorescein derivative 22 (colorimetric reagent) from the exhaust pipe 5 for absorption. The fluorescein derivative 22 (colorimetric reagent) is then placed in a double-beam ultraviolet-visible spectrophotometer for detection. Quantitative speciation analysis of H2S / SO2 was achieved through precise measurement using a double-beam ultraviolet-visible spectrophotometer (Shanghai Youke Instrument Co., Ltd., model: T2602, Shanghai, China).

[0118] 3.1 Preparation of test solution:

[0119] 3.1.1 Preparation of test solution 1: Dissolve different masses of Na2SO3 in pure water to obtain SO3 2- The concentrations were 30 μmol·L⁻¹. -1 60 μmol·L -1 90 μmol·L -1 120 μmol·L -1 150 μmol·L -1 180 μmol·L-1 210 μmol·L -1 The test solution 1;

[0120] 3.1.2 Preparation of test solution 2: Dissolve different masses of Na₂S in pure water to obtain S 2- The concentrations were 30 μmol·L⁻¹. -1 60 μmol·L -1 90 μmol·L -1 120 μmol·L -1 150 μmol·L -1 180 μmol·L -1 210 μmol·L -1 The test solution 2;

[0121] 3.1.3 Use pure water as the blank test solution.

[0122] 3.2 Experimental conditions and methods:

[0123] 3.2.1 After shutting down the plasma, the absorbance of seven different concentrations of test solution 1 was analyzed using a double-beam UV-Vis spectrophotometer.

[0124] The specific experimental steps are as follows:

[0125] S1. Pour 2 mL of the test solution 1 into reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 150 mL / min. -1 ;

[0126] S2, Using syringe 21, dispense 2 mL of 4 mol·L⁻¹ solution. -1 Sulfuric acid is injected into reaction flask 1, and the test solution 1 reacts with sulfuric acid to generate a gaseous analyte, namely SO2.

[0127] S3. Argon gas carrying the gaseous analyte enters the micro-plasma reactor from the gas phase discharge pipe 4, and the micro-plasma reactor is in the closed state.

[0128] S4. The gaseous analyte (SO2) enters the colorimetric reagent through the exhaust pipe 5 for absorption. The colorimetric reagent is then placed in a double-beam UV-Vis spectrophotometer for detection.

[0129] 3.2.2 Turn on the plasma and analyze the absorbance of seven test solutions of different concentrations using a double-beam UV-Vis spectrophotometer.

[0130] The specific experimental steps are as follows:

[0131] S1. Pour 2 mL of the test solution 1 into reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 150 mL / min.-1 ;

[0132] S2, Using syringe 21, dispense 2 mL of 4 mol·L⁻¹ solution. -1 Sulfuric acid is injected into reaction flask 1, and the test solution 1 reacts with the acid to generate a gaseous analyte, namely SO2;

[0133] S3. Argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase discharge pipe 4. The gap of the micro-plasma discharge in the micro-plasma reactor is 5 mm. The gaseous analyte is SO2 and does not change.

[0134] S4. The gaseous analyte (SO2) enters the colorimetric reagent through the exhaust pipe 5 for absorption. The colorimetric reagent is then placed in a double-beam UV-Vis spectrophotometer for detection.

[0135] 3.2.3 Turn on the plasma and use a double-beam UV-Vis spectrophotometer to analyze the absorbance of seven test solutions 2 at different concentrations.

[0136] The specific experimental steps are as follows:

[0137] S1. Pour 2 mL of the test solution 2 into reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 150 mL / min. -1 ;

[0138] S2, Using syringe 21, dispense 2 mL of 4 mol·L⁻¹ solution. -1 Sulfuric acid is injected into reaction bottle 1, and the test solution 2 reacts with sulfuric acid to generate a gaseous analyte, namely H2S.

[0139] S3. Argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase discharge pipe 4. The gap of the micro-plasma discharge in the micro-plasma reactor is 5 mm. H2S is completely oxidized to SO2 in the micro-plasma reactor.

[0140] S4. The gaseous analyte (SO2) enters the colorimetric reagent through the exhaust pipe 5 for absorption. The colorimetric reagent is then placed in a double-beam UV-Vis spectrophotometer for detection.

[0141] 3.2.4 After turning off the plasma, analyze the seven different concentrations of test solution 1 and blank solution using a visual colorimetric detector.

[0142] The specific experimental steps are as follows:

[0143] S1. Add 2 mL of the test solution 1 or blank solution to reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 150 mL / min. -1 ;

[0144] S2, Using syringe 21, dispense 2 mL of 4 mol·L⁻¹ solution. -1 Sulfuric acid is injected into reaction flask 1. If it is test solution 1, test solution 1 reacts with sulfuric acid to generate a gaseous analyte, which is SO2. If it is blank solution, blank solution will not react with sulfuric acid to generate a gaseous analyte.

[0145] S3. If the test solution is 1, argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase discharge pipe 4. The micro-plasma reactor is in a closed state, and the gaseous analyte is not subjected to micro-plasma discharge treatment. If the blank test solution is 1, argon gas enters the micro-plasma reactor from the gas phase discharge pipe 4.

[0146] S4. If the test solution is 1, the gaseous analyte (SO2) enters the visual colorimetric detector from the exhaust pipe 5. The visual colorimetric detector is equipped with fluorescein derivative 22, and the concentration of fluorescein derivative 22 is 100 μmol·L⁻¹. -1 SO2 reacts with fluorescein derivative 22 in a decolorization reaction, which takes 40 seconds, completing the detection. If a blank solution is used, argon gas enters the visual colorimetric detector from exhaust pipe 5. The visual colorimetric detector contains fluorescein derivative 22 at a concentration of 100 μmol·L⁻¹. -1 However, since no gaseous analyte (SO2) is generated, fluorescein derivative 22 will not undergo a fading reaction.

[0147] 3.2.5 Turn on the plasma and analyze seven different concentrations of test solution 1 and blank solution using a visual colorimetric detector.

[0148] The specific experimental steps are as follows:

[0149] S1. Add 2 mL of the test solution 1 or blank solution to reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 150 mL / min. -1 ;

[0150] S2, Using syringe 21, dispense 2 mL of 4 mol·L⁻¹ solution. -1 Sulfuric acid is injected into reaction flask 1. If it is test solution 1, test solution 1 reacts with sulfuric acid to generate a gaseous analyte, which is SO2. If it is blank solution, blank solution will not react with sulfuric acid to generate a gaseous analyte.

[0151] S3. If the test solution is 1, argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase discharge pipe 4. The gap of the micro-plasma discharge in the micro-plasma reactor is 5 mm. If the gaseous analyte is SO2, there is no change. If the blank test solution is 1, argon gas enters the micro-plasma reactor from the gas phase discharge pipe 4.

[0152] S4. If the test solution is 1, the gaseous analyte (SO2) enters the visual colorimetric detector from the exhaust pipe 5. The visual colorimetric detector is equipped with fluorescein derivative 22, and the concentration of fluorescein derivative 22 is 100 μmol·L⁻¹. -1 After SO2 reacts with fluorescein derivative 22, the decolorization reaction takes 40 seconds, completing the detection. If a blank solution is used, argon gas enters the visual colorimetric detector from exhaust pipe 5. The visual colorimetric detector contains fluorescein derivative 22 at a concentration of 100 μmol·L⁻¹. -1 However, since no gaseous analyte (SO2) is generated, fluorescein derivative 22 will not undergo a fading reaction.

[0153] 3.2.6 Turn on the plasma and analyze seven different concentrations of test solution 2 and blank solution using a visual colorimetric detector.

[0154] The specific experimental steps are as follows:

[0155] S1. Add 2 mL of the test solution 2 or blank solution to reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 150 mL / min. -1 ;

[0156] S2, Using syringe 21, dispense 2 mL of 4 mol·L⁻¹ solution. -1 Sulfuric acid is injected into reaction flask 1. If it is test solution 2, test solution 2 reacts with sulfuric acid to generate a gaseous analyte, which is H2S. If it is blank solution, the blank solution will not react with sulfuric acid to generate a gaseous analyte.

[0157] S3. If the test solution is 2, argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase discharge pipe 4. The gap of the micro-plasma discharge in the micro-plasma reactor is 5 mm. The gaseous analyte is H2S, which is oxidized to SO2 in the micro-plasma reactor. If the test solution is blank, argon gas enters the micro-plasma reactor from the gas phase discharge pipe 4.

[0158] S4. If the test liquid is 2, the gaseous analyte (SO2) enters the visual colorimetric detector from the exhaust pipe 5. The visual colorimetric detector is equipped with fluorescein derivative 22, and the concentration of fluorescein derivative 22 is 100 μmol·L⁻¹. -1 SO2 reacts with fluorescein derivative 22 in a decolorization reaction, which takes 40 seconds, completing the detection. If a blank solution is used, argon gas enters the visual colorimetric detector from exhaust pipe 5. The visual colorimetric detector contains fluorescein derivative 22 at a concentration of 100 μmol·L⁻¹. -1However, since no gaseous analyte (SO2) is generated, fluorescein derivative 22 will not undergo a fading reaction.

[0159] 3. Experimental results and establishment of standard curve and standard color card 23

[0160] like Figure 4 As shown, the UV-Vis absorption spectra of seven test solutions 1 are displayed when the plasma is turned off. Figure 4 It can be seen that with SO3 2- With increasing concentration, the absorption peaks at 454 nm and 482 nm decrease.

[0161] from Figure 5 It can be seen that in the range of 30-210 μmol·L⁻¹ -1 Within the concentration range, the calibration curve showed good linearity with a correlation coefficient of 0.997.

[0162] like Figure 6 As shown, the standard curves for SO2 and H2S under the three conditions described in 3.2.1, 3.2.2, and 3.2.3 are almost identical. This confirms that within this concentration range, H2S can be completely converted to SO2 through discharge treatment. This indicates that the standard curve for SO2 under micro-plasma shutdown can be used uniformly for quantitative analysis of H2S and SO2. Therefore, by analyzing the data precisely measured by a dual-beam UV-Vis spectrophotometer, a standard curve for H2S / SO2 can be obtained for the analysis of unknown samples. Simultaneously, the SO2 / H2S or SO3 ratio can also be obtained. 2- / S 2- The limits of detection (LOD) for all samples were 6.22 μmol / L. -1 It is obtained by dividing the standard deviation of 3 times 11 blank solutions by the slope.

[0163] like Figure 7 (a) Figure 7 (b) Figure 7 (c) shows the visual colorimetric results of SO2 and H2S under the three conditions described in 3.2.4, 3.2.5 and 3.2.6. Under these three conditions, as the concentration of the analyte increases, the color of fluorescein derivative 22 gradually becomes lighter until it becomes colorless.

[0164] like Figure 8 As shown, to facilitate the on-site speciation analysis of sulfur compounds, a standard color chart 23 was prepared under experimental conditions 3.2.4, with a concentration range of 30–210 μmol L. -1 At the same time, from Figure 8 , Figure 7 (a) Figure 7 (b) and Figure 7(c) The color change shows that the concentration is 30 μmol·L⁻¹ -1 The difference is not very obvious, but it can be directly distinguished by the naked eye at 60 μmol·L⁻¹. -1 The analytes.

[0165] IV. Experimental Examples:

[0166] Spike recovery tests were conducted on environmental water samples.

[0167] 4.1 Sample:

[0168] In June 2024, tap water and pool water samples were collected at Sichuan Normal University; lake water samples were collected at Qinglong Lake (Chengdu, Sichuan). 90 μmol·L⁻¹ was added to each of the three water samples beforehand according to Table 1. -1 SO3 2- and / or S 2- Each sample 20 was tested three times.

[0169] 4.2 Analytical Methods:

[0170] The analysis was performed using the portable analysis device described in Example 1. The specific analysis method included the following steps:

[0171] S1. Add 2 mL of the sample 20 to be tested to reaction flask 1 and cover it with cap 2; then inject argon gas through argon gas inlet tube 3 at a flow rate of 150 mL / min. -1 ;

[0172] S2, Using syringe 21, dispense 2 mL of 4 mol·L⁻¹ solution. -1 Sulfuric acid is injected into reaction flask 1 using syringe 21. The sample to be tested 20 reacts with sulfuric acid to generate gaseous analytes, namely H2S and / or SO2.

[0173] S3. Argon gas carries the gaseous analyte into the micro-plasma reactor from the gas phase discharge pipe 4. The gap of the micro-plasma discharge in the micro-plasma reactor is 5 mm. H2S in the gaseous analyte is oxidized to SO2 in the micro-plasma reactor.

[0174] S4 and SO2 enter the visual colorimetric detector from the exhaust pipe 5. The visual colorimetric detector is equipped with a fluorescein derivative 22 at a concentration of 100 μmol·L⁻¹. -1 After SO2 reacts with fluorescein derivative 22 to cause a fading reaction, the reaction time of fluorescein derivative 22 with SO2 is 40 seconds, and the detection is completed.

[0175] 4.3 Analysis Results

[0176] The analysis results are shown in Table 1 below:

[0177] Table 1. Analysis data of environmental water samples

[0178]

[0179] As shown in Table 1, the colorimetric images that are recognizable to the naked eye and Figure 8 The results were consistent with the standard color chart 23, confirming the reliability of the device and the analytical method for on-site analysis of real samples. The analytical results were satisfactory, with recoveries between 99% and 109% and relative standard deviations (RSDs) less than 5%.

[0180] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A portable method for detecting SO3 in environmental water samples 2- / S 2- The morphological analysis device is characterized in that, This includes a chemical vapor generation assembly, a micro-plasma reactor, and a visual colorimetric detector; among which, The chemical vapor generation assembly includes a reaction bottle with an open end and a cap that is sealed to the open end of the reaction bottle. The reaction bottle is provided with an argon gas inlet pipe and a gas phase outlet pipe. The other end of the gas phase outlet pipe is connected to the gas inlet end of the micro plasma reactor. The exhaust end of the microplasma reactor is connected to an exhaust pipe, and the other end of the exhaust pipe is connected to the air inlet of the visual colorimetric detector. The visual colorimetric detector includes a transparent colorimetric reaction chamber, which contains a fluorescein derivative that reacts with SO2 to decolorize.

2. SO3 in portable environmental water samples according to claim 1 2- / S 2- The morphological analysis device is characterized in that, The top of the reaction flask is an open end; the cap body matches the open end of the top of the reaction flask, and the cap body includes a hollow plastic cap and a circular rubber gasket located inside the plastic cap. The dimensions of the plastic cap and the circular rubber gasket are both matched to the open end of the top of the reaction flask.

3. SO3 in portable environmental water samples according to claim 1 2- / S 2- The morphological analysis device is characterized in that, The transparent colorimetric reaction chamber includes a centrifuge tube and a sealing cap that matches the open end of the centrifuge tube. An air inlet pipe is inserted through the sealing cap. When the sealing cap is placed on the open end of the centrifuge tube, one end of the air inlet pipe extends into the centrifuge tube and is close to the bottom of the centrifuge tube, while the other end of the air inlet pipe is located outside the centrifuge tube and connected to the exhaust pipe.

4. SO3 in portable environmental water samples according to claim 1 2- / S 2- The morphological analysis device is characterized in that, The microplasma reactor is a tip discharge microplasma reactor, including a power supply, a regulator, a T-shaped quartz tube, a conical tungsten rod electrode, a hollow copper electrode, and a switch; The T-shaped quartz tube includes a horizontal quartz tube and a vertical quartz tube, with one end of the vertical quartz tube connected to the middle of the horizontal quartz tube and the vertical quartz tube communicating with the horizontal quartz tube; the other end of the vertical quartz tube is connected to an exhaust pipe. The conical tungsten rod electrode is inserted into one of the openings of the transverse quartz tube; the hollow copper electrode is a hollow copper tube, which is inserted into the other opening of the transverse quartz tube. The outer sides of the conical tungsten rod electrode and the hollow copper tube are respectively wound with copper coil one and copper coil two; The gas phase discharge pipe is connected to the hollow copper pipe; The power supply, regulator, and switch are connected in series, and copper coil one and copper coil two are connected in parallel to the regulator.

5. The portable environmental water sample containing SO3 according to claim 4 2- / S 2- The morphological analysis device is characterized in that, The regulator is a high-voltage pulse reaction block.

6. SO3 in portable environmental water samples according to claim 4 2- / S 2- The morphological analysis device is characterized in that, It also includes a mounting base, which, from top to bottom, comprises an upper mounting platform, a middle mounting platform, and a lower mounting platform; wherein, The T-shaped quartz tube, conical tungsten rod electrode, and hollow copper electrode of the microplasma reactor are all mounted on the upper platform. The reaction flask, colorimetric reaction chamber, and switch are all mounted on the central mounting platform; the central mounting platform is provided with mounting platform one and mounting platform two for placing the reaction flask and colorimetric reaction chamber; Both the power supply and the regulator are mounted on the lower mounting platform. The top of the upper mounting platform is provided with a mounting groove for a T-shaped quartz tube, which is installed in the mounting groove; and the top of the upper mounting platform is also provided with an upper closed door that matches the mounting groove; one side of the upper closed door is hinged to the edge of the upper mounting platform, and the other side of the upper closed door is movably connected to the upper mounting platform; the upper closed door is made of transparent material. The lower mounting platform has mounting slot one and mounting slot two on its side wall for mounting a power supply and regulator; a lower closed door is provided on the outside of mounting slot one and mounting slot two; one side of the lower closed door is hinged to the edge of the lower mounting platform, and the other side of the lower closed door is movably connected to the lower mounting platform; the lower closed door is made of transparent material. The upper and lower installation platforms are equipped with upper and lower closed doors on their outer sides.

7. SO3 in portable environmental water samples according to claim 6 2- / S 2- The morphological analysis device is characterized in that, The upper mounting platform has a visualization window on the side wall corresponding to the mounting T-shaped quartz tube for observing the reaction inside the micro-plasma reactor.

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