Device and method for detecting peroxy hydroxyl radicals in atmosphere based on chemiluminescence detection method

Abstract

The invention provides a device and a method for detecting peroxy hydroxyl radicals in atmosphere based on a chemiluminescence method. The device comprises a sampling unit, a dilution unit, a chemiluminescence detection unit and pipelines for connecting the sampling unit, the dilution unit and the chemiluminescence detection unit, wherein the sampling unit is configured to collect an atmospheric sample and convert peroxy hydroxyl free radicals in the atmospheric sample into superoxide free radicals through an alkali buffer absorption liquid to obtain a buffer solution containing the superoxide free radicals; the dilution unit is configured to mix and dilute a buffer solution containing superoxide radicals and a diluent to obtain a diluted sample; the chemiluminescence detection unit is configured to collect a chemiluminescence signal generated by mixing and reacting the diluted sample with a chemiluminescence reagent.

Description

Technical Field

[0001] This disclosure relates to the field of atmospheric environmental monitoring, and in particular to an apparatus and method for detecting peroxyhydroxyl radicals in the atmosphere based on chemiluminescence. Background Technology

[0002] Peroxyhydroxyl (HO2) radicals in the atmosphere are key intermediates in atmospheric photochemical processes, playing a decisive role in crucial atmospheric chemical processes such as ozone formation, secondary organic aerosol (SOA) formation, and the hydroxyl (OH) radical cycle. Achieving high-precision and high-temporal-resolution online continuous monitoring of atmospheric HO2 radical concentration is essential for a deeper understanding of atmospheric oxidation, photochemical pollution mechanisms, and for evaluating the effectiveness of pollution control strategies. However, atmospheric HO2 radicals have low concentrations, high chemical reactivity, and short lifetimes, and are easily affected by interference from numerous reactive oxygen species (ROSs) with similar properties. Furthermore, the instruments used for detection are complex and expensive, making them unsuitable for continuous online monitoring in the field. Existing technologies (such as gas expansion fluorescence analysis (FAGE) and peroxyl radical chemical amplification combined with chemical ionization mass spectrometry (PERCA-CIMS)) rely on laser or mass spectrometry detectors, resulting in large equipment size, high maintenance costs, and difficulties in miniaturization. Therefore, a measurement device and method for atmospheric HO2 radicals are needed. Summary of the Invention

[0003] In view of this, in order to at least partially solve at least one of the aforementioned technical problems, this disclosure provides an apparatus and method for detecting peroxyhydroxyl radicals in the atmosphere based on chemiluminescence detection.

[0004] According to one aspect of this disclosure, an apparatus for detecting peroxyhydroxyl radicals in the atmosphere based on chemiluminescence is provided, comprising a sampling unit, a dilution unit, a chemiluminescence detection unit, and conduits connecting them; wherein, the sampling unit is configured to collect an atmospheric sample and convert peroxyhydroxyl radicals in the atmospheric sample into superoxide radicals using an alkaline buffer absorber to obtain a buffer solution containing superoxide radicals; the dilution unit is configured to mix and dilute the buffer solution containing superoxide radicals with a diluent to obtain a diluted sample; and the chemiluminescence detection unit is configured to collect a chemiluminescence signal generated by mixing and reacting the diluted sample with a chemiluminescence reagent.

[0005] According to another aspect of this disclosure, a method for detecting peroxyhydroxyl radicals in the atmosphere using the apparatus described above is provided, comprising: collecting an atmospheric sample and converting the peroxyhydroxyl radicals in the atmospheric sample into superoxide radicals using an alkaline buffer absorber to obtain a buffer solution containing superoxide radicals; mixing and diluting the buffer solution containing superoxide radicals with a diluent to obtain a diluted sample; and collecting a chemiluminescent signal generated by mixing and reacting the diluted sample with a chemiluminescent reagent.

[0006] According to embodiments of this disclosure, the sampling unit collects atmospheric samples and selectively captures chemically unstable peroxyhydroxyl radicals in the atmospheric samples using an alkaline buffer absorbent, converting them into chemically stable superoxide (O2). - The alkaline buffer absorbent not only acts as a buffer but also suppresses interference from other atmospheric components, improving selectivity for the target HO2 radical. This, in turn, enhances the stability, accuracy, and sensitivity of the signal measurement from the source. The dilution unit is effective against O2-containing free radicals. - Diluting the sample with a free radical buffer prevents excessively high ionic strength in the buffer from affecting the subsequent chemiluminescence reaction rate, the efficiency of chemiluminescence signal generation, or the stability of the chemiluminescence probe. This allows the diluted sample to quickly reach and maintain an acid-base balance conducive to efficient and stable luminescence reactions when mixed with the chemiluminescence reagent, thereby improving the reliability and sensitivity of the detection signal. The chemiluminescence detection unit utilizes the reaction between the chemiluminescence reagent and O2. - Free radicals undergo specific chemical reactions, producing compounds that react with O2. - The chemiluminescence signal is directly related to the concentration of free radicals (i.e., the original atmospheric HO2 concentration), which improves the accuracy of capturing the target signal. In addition, it suppresses the interference of background luminescence signals that may be generated by other ROSs in the chemiluminescence reaction system, ensuring the specificity of the detection signal and improving the sensitivity of the detection signal.

[0007] This disclosure constructs a complete online detection process through the collaborative design of sampling unit, dilution unit and chemiluminescence detection unit. The whole device has a compact structure, high degree of automation and simple operation. It can meet the needs of monitoring HO2 free radical concentration in the atmospheric environment in an outdoor field, online, continuous and with high time resolution. It provides an effective tool for solving key technical bottlenecks in atmospheric free radical chemistry research and environmental monitoring. Attached Figure Description

[0008] The above and other objects, features, and advantages of this disclosure will become clearer from the following description of embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0009] Figure 1This is a schematic diagram of the device structure for detecting peroxyhydroxyl radicals in the atmosphere using chemiluminescence detection, according to an embodiment of this disclosure.

[0010] Figure 2 This is a schematic diagram of the sampling unit structure according to an embodiment of the present disclosure;

[0011] Figure 3 This is a schematic diagram illustrating the signal response of different combinations of alkaline buffer solutions and alcohols in the embodiments of this disclosure;

[0012] Figure 4 This is a schematic diagram of the dilution unit and mixing chamber according to an embodiment of the present disclosure;

[0013] Figure 5 This is a schematic diagram of the structure of the chemiluminescence detection unit and the signal processing unit according to an embodiment of the present disclosure. Detailed Implementation

[0014] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0015] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The term "comprising" as used herein indicates the presence of features, steps, or operations, but does not exclude the presence or addition of one or more other features.

[0016] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). When using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0017] Atmospheric HO2 radicals have low concentrations, high chemical reactivity, and short lifespans. Meanwhile, the atmosphere contains numerous potential interfering species with similar properties, such as organic peroxide radicals (RO2), ozone (O3), hydroxyl radicals (·OH), hydrogen peroxide (H2O2), and other reactive oxygen species (ROSs). These factors affect the accuracy of atmospheric HO2 radical detection, posing challenges to the development of highly selective atmospheric HO2 radical measurement technologies that can meet the needs of continuous online monitoring in the field.

[0018] Currently, methods for measuring atmospheric HO2 radicals typically include matrix isolated electron spin resonance (MIESR), laser-induced fluorescence (LIF), gas expansion fluorescence analysis (FAGE), and peroxy radical chemical amplification (PERCA) combined with LIF or chemical ionization mass spectrometry (CIMS). However, these techniques generally have limitations. For example, MIESR cannot achieve online monitoring; some FAGE / LIF techniques may face challenges in distinguishing HO2 from specific RO2 radicals under certain complex atmospheric conditions (such as high RO2 concentration environments), and the instruments are complex and bulky; PERCA technology carries the risk of signal distortion, and the LIF or CIMS detectors it relies on are costly and complex to maintain. Therefore, there is a need for an atmospheric HO2 radical detection device and technology that is highly selective, highly sensitive, has a fast response rate, a compact structure, is easy to operate, has a low cost, and meets the requirements for long-term continuous online operation in the field. In particular, it needs to effectively distinguish HO2 radicals and eliminate interference from other ROSs.

[0019] Figure 1 This is a schematic diagram of the device structure for detecting peroxyhydroxyl radicals in the atmosphere using chemiluminescence detection, according to an embodiment of this disclosure.

[0020] Specifically, such as Figure 1 As shown, according to one aspect of this disclosure, an apparatus for detecting peroxyhydroxyl radicals in the atmosphere based on chemiluminescence is provided, comprising a sampling unit, a dilution unit, a chemiluminescence detection unit, and conduits connecting them; wherein, the sampling unit is configured to collect an atmospheric sample and convert peroxyhydroxyl radicals in the atmospheric sample into superoxide radicals using an alkaline buffer absorber to obtain a buffer solution containing superoxide radicals; the dilution unit is configured to mix and dilute the buffer solution containing superoxide radicals with a diluent to obtain a diluted sample; the chemiluminescence detection unit is configured to collect a chemiluminescence signal generated by mixing and reacting the diluted sample with a chemiluminescence reagent.

[0021] According to embodiments of this disclosure, the sampling unit collects atmospheric samples and selectively captures chemically unstable peroxyhydroxyl radicals in the atmospheric samples using an alkaline buffer absorbent, converting them into chemically stable superoxide (O2).- The dilution unit targets O2-containing free radicals and suppresses interference from other atmospheric components, improving selectivity for the target HO2 free radicals and thus enhancing the stability, accuracy, and sensitivity of signal measurement from the source. - The free radical buffer solution is diluted to prevent excessively high ionic strength from affecting the subsequent chemiluminescence reaction rate, the efficiency of chemiluminescence signal generation, or the stability of the chemiluminescence probe. This ensures that the diluted sample, when mixed with the chemiluminescence reagent, can quickly reach and maintain an acid-base balance conducive to efficient and stable luminescence reaction, thereby improving the reliability and sensitivity of the detection signal. The chemiluminescence detection unit utilizes the chemiluminescence reagent and O2... - Free radicals undergo specific chemical reactions, producing compounds that react with O2. - The chemiluminescence signal is directly related to the concentration of free radicals, which improves the accuracy of capturing the target signal. In addition, it suppresses the interference of background luminescence signals that may be generated by other ROSs in the chemiluminescence reaction system, ensuring the specificity of the detection signal and improving the sensitivity of the detection signal.

[0022] According to embodiments of this disclosure, continuing as follows Figure 1 As shown, the above-mentioned device also includes a signal processing unit electrically connected to the chemiluminescence detection unit. Furthermore, the signal processing unit can be configured to be a computer, which is configured to convert the acquired chemiluminescence signal into an HO2 free radical concentration signal and control the operation of the entire device (e.g., liquid flow rate, data acquisition, etc.).

[0023] Figure 2 This is a schematic diagram of the sampling unit structure according to an embodiment of the present disclosure.

[0024] According to embodiments of this disclosure, such as Figure 2 As shown, the sampling unit is equipped with a sampling pipeline. This sampling pipeline has: an inlet for supplying atmospheric samples (such as actual air), an inlet for supplying alkaline buffer absorbent, an outlet for discharging the buffer solution containing superoxide radicals, and an outlet for discharging waste gas (such as air). Further, the sampling unit also includes an alkaline buffer absorbent storage bottle, with the inlet of the sampling pipeline connected to the storage bottle to allow the alkaline buffer absorbent stored in the storage bottle to be introduced into the sampling pipeline. Optionally, the sampling pipeline also includes a thermostatic component (such as a thermostatic water circulation component), nested outside the sampling pipeline. This thermostatic component includes a shell, and a thermostatic medium inlet and outlet disposed on the shell, with the inlet and outlet arranged obliquely symmetrically. By nesting a thermostatic component outside the sampling pipeline, the conversion of HO2 radicals to O2 can be improved. -The stability of free radical reactions. Furthermore, an air pump is installed in the sampling line to increase the atmospheric sample collection rate, while also facilitating air intake and exhaust.

[0025] According to embodiments of this disclosure, the alkaline buffer absorbent includes a buffer, an ozone interference inhibitor, a metal ion chelating agent, and an alcohol. The buffer can capture HO2 free radicals in the atmosphere and rapidly convert them into chemically stable O2. - Free radicals; ozone interference inhibitors can effectively quench or convert O3, significantly reducing O3 interference with subsequent detection; metal ion chelators can chelate trace metal ions (e.g., Fe). 2+ Cu 2+ (etc.), effectively inhibiting the catalytic decomposition of O2 by trace metal ions. - Free radicals ensure the stability of the target signal and the accuracy of the measurement, improve the sensitivity of signal detection, and enhance the selectivity of the entire device for HO2 in the atmosphere; alcohols can improve the sensitivity of the signal.

[0026] Specifically, the buffer includes a borate buffer system and / or a tris(hydroxymethyl)aminomethane (TRIS) buffer system; the ozone interference inhibitor includes sodium sulfite and / or sodium nitrite; the metal ion chelating agent includes at least one of ethylenediaminetetraacetic acid (EDTA) and its derivatives (e.g., EDTA salt, triethylenetetraaminehexaacetic acid, etc.); and the alcohol is ethanol or mannitol. Preferably, the pH of the alkaline buffer absorption solution is 9-11, such as 9.5, 10, 10.5, etc., and the buffer is selected as a borate buffer system with a total borate concentration of 1-5 mM, such as 1, 2, 3, 4, 5 mM, etc. Through the above technical solution, the rapid conversion of HO2 free radicals to O2 can be effectively promoted. - The ozone interference inhibitor is sodium sulfite, with a concentration of 2-80 μM, such as 10, 20, 30, 40, 50, 60, or 70 μM. This technical solution ensures complete removal of O3 from the collected atmospheric samples, and that sodium sulfite reacts with O2 in the chemiluminescence detection unit. - The reaction rate of free radicals is much lower than that of the MCLA probe with O2. - The reaction rate of free radicals improves the sensitivity of detection; EDTA is selected as the metal ion chelating agent, with a concentration of 2-10 μM, such as 4, 6, or 8 μM; the concentration of alcohols is 10 μM-5 mM.

[0027] Furthermore, according to embodiments of this disclosure, the alkaline buffer absorbent flows through the inner wall of the sampling pipeline, forming a continuous liquid film to capture HO2 free radicals in the atmospheric sample and convert them into stable O2. -By eliminating free radicals and adding O3 interference inhibitors and metal ion chelating agents, the influence of major interfering substances was reduced, laying the foundation for high-selectivity measurement in this device.

[0028] Figure 4 This is a schematic diagram of the dilution unit and mixing chamber according to an embodiment of the present disclosure.

[0029] According to embodiments of this disclosure, such as Figure 4 As shown, the dilution unit includes a dilution container, a diluent storage unit, and a diluent injection line. The dilution container is connected to the outlet of the sampling line and is configured to receive a solution containing superoxide radicals and mix it with the diluent entering the dilution container to obtain a diluted sample. One end of the dilution injection line is connected to the dilution container, and the other end is connected to the diluent storage unit. It is configured to deliver the diluent stored in the diluent storage unit to the dilution container. Further, the diluent may include ultrapure water or an ultrapure aqueous solution containing a small amount of EDTA, with a dilution ratio of 1:1 to 1:1.34, such as 1:1.1, 1:1.2, 1:1.3, 1:1.32, etc., to obtain better signal sensitivity.

[0030] According to embodiments of this disclosure, the dilution container is connected to the outlet of the sampling line to receive a buffer solution containing the conversion product O2 free radicals from the sampling unit. A dilution solution containing a small amount of EDTA is then used to dilute the O2-containing solution. - Online dilution of the free radical solution can maintain the stability of the EDTA concentration in the entire liquid system, prevent signal baseline drift caused by fluctuations in EDTA concentration, and effectively reduce the potential negative impact of high concentrations of buffer salt ions on the subsequent chemiluminescence reaction system (such as affecting the reaction rate, luminescence efficiency, or stability of the chemiluminescence probe). This is beneficial for the diluted sample to quickly reach and maintain a more efficient and stable acid-base environment for the chemiluminescence reaction after being mixed with the chemiluminescence reagent, thereby ensuring the reliability and sensitivity of the detection signal.

[0031] Figure 5 This is a schematic diagram of the structure of the chemiluminescence detection unit and the signal processing unit according to an embodiment of the present disclosure.

[0032] According to embodiments of this disclosure, such as Figure 5As shown, the chemiluminescence detection unit includes a mixing chamber and a photodetector. The mixing chamber is a Y-shaped conduit consisting of a sample channel, a chemiluminescence reagent injection line, and a mixing channel. The sample channel is connected to the drain port of the dilution container and is configured to introduce the diluted sample from the dilution container into the mixing channel. The chemiluminescence reagent injection line is connected to a chemiluminescence reagent storage device and is configured to introduce the chemiluminescence reagent (i.e., the chemiluminescence probe) stored in the storage device into the mixing channel. The mixing channel is configured to mix the diluted sample with the chemiluminescence reagent and perform a chemical reaction to generate a chemiluminescence signal. The photodetector, facing the mixing chamber, is used to detect the chemiluminescence signal generated in the mixing channel, which is generated by O2. - It is generated by a specific reaction between free radicals and chemiluminescent probes.

[0033] Specifically, the chemiluminescent reagent is a chemiluminescent probe solution. The diluted sample and the chemiluminescent probe solution are introduced into the mixing chamber and undergo a chemical reaction to generate a chemiluminescent signal. The mixing channel principle has a drain port at one end of the sample channel and the chemiluminescent reagent injection pipeline. The waste liquid after the reaction is discharged through the drain port.

[0034] According to embodiments of this disclosure, the chemiluminescent reagent (chemiluminescent probe) includes 2-methyl-6-phenyl-3-hydroxyimidazo[1,2-a]pyrazine and its derivatives, such as 2-methyl-6-phenylimidazo[1,2-a]pyridine-3,7-dione (CLA), 2-methyl-6-(4-methoxyphenyl)imidazo[1,2-a]pyridine-3,7-dione (MCLA), 2-methyl-6-phenyl-8-carboxyimidazo[1,2-a]pyridine-3,7-dione (PCLA), etc. Further, the concentration of the chemiluminescent probe solution is 0.2-5 μM, for example, it can be 1 μM, 2 μM, 3 μM, 4 μM, etc. The above-mentioned chemiluminescent probe is responsive to O2. - Free radicals have high selectivity and react with O2. - The efficiency of the free radical reaction and the intensity of the chemiluminescent signal produced are higher than those of the reaction with common interfering ROSs such as H2O2, OH radicals, and RO2 radicals. Therefore, it can effectively suppress the background luminescence signal that may be generated by other ROSs in the reaction system, ensuring high specificity of the detection signal, that is, high selectivity for the target atmospheric HO2 radical, and improving the sensitivity of detection.

[0035] According to embodiments of this disclosure, the device further includes a defoamer, which is a branch channel disposed on the sample channel. One end of the branch channel is connected to the sample channel, and the other end is exposed to air, and it is configured to eliminate air bubbles in the diluted sample. Further, the defoamer can also be disposed on the chemiluminescent reagent injection line and at one end of the mixing channel near the sample channel to eliminate air bubbles in the chemiluminescent reagent and the mixed solution, preventing air bubbles from interfering with the acquisition of the chemiluminescent signal.

[0036] According to another aspect of this disclosure, a method for detecting peroxyhydroxyl radicals in the atmosphere using the above-described apparatus is provided, comprising: collecting an atmospheric sample and converting the peroxyhydroxyl radicals in the atmospheric sample into superoxide radicals using an alkaline buffer absorber to obtain a buffer solution containing superoxide radicals; mixing and diluting the buffer solution containing superoxide radicals with a diluent to obtain a diluted sample; and collecting a chemiluminescent signal generated by mixing and reacting the diluted sample with a chemiluminescent reagent.

[0037] This disclosure achieves efficient capture, stable conversion, specific detection, and signal processing of atmospheric HO2 free radicals through a specific chemical reaction pathway and optimized process design. A complete online detection process is constructed through the collaborative design and optimization of a sampling unit suitable for collecting atmospheric samples and efficiently and selectively converting atmospheric HO2 free radicals into stable intermediates; a dilution unit suitable for optimizing the converted samples; a chemiluminescence detection unit suitable for generating and detecting luminescent signals using highly specific chemical reactions; and a signal processing unit suitable for signal acquisition, conversion, processing, and device operation control. The innovative alkaline buffer absorption solution design and conversion pathway ensure high selectivity from the source; the optimized dilution process ensures the stability and sensitivity of the detection reaction; and the application of highly specific chemiluminescence probes achieves precise capture of the target signal. The entire device has a compact structure and a high degree of automation, making it particularly suitable for the needs of monitoring atmospheric HO2 free radical concentrations in the field, online, continuously, and with high temporal resolution. It provides an effective tool for solving key technical bottlenecks in atmospheric free radical chemistry research and environmental monitoring.

[0038] Example 1

[0039] The alkaline buffer absorption solution is a boric acid-borax buffer system with a pH of 11, which includes 5 mM borate buffer (i.e., boric acid-borax buffer), 10 μM nitrite, 5 μM EDTA, and 1 mM ethanol. The diluent is an ultrapure aqueous solution containing 5 μM EDTA at a dilution ratio of 1:1. The chemiluminescent reagent is 1 μM MCLA. The device is started and the chemiluminescent signal is collected.

[0040] Example 2

[0041] The difference from Example 1 is that the alkaline buffer absorption solution is a TRIS-HCl buffer system with a pH of 11, which includes 5 mM TRIS, 10 μM nitrite, 5 μM EDTA and 1 mM ethanol.

[0042] Example 3

[0043] The difference from Example 1 is that the alkaline buffer absorbent includes 5 mM borate, 10 μM nitrite, 5 μM EDTA, and 1 mM mannitol.

[0044] Example 4

[0045] The difference from Example 2 is that the alkaline buffer absorbent contains 5 mM TRIS, 10 μM nitrite, 5 μM EDTA, and 1 mM mannitol.

[0046] With fixed O3 interference inhibitors, metal ion chelating agents, chemiluminescent reagents, and test samples, borate-borax buffer or TRIS buffer was used as buffer, and ethanol (EtOH) and mannitol were used as alcohols. The chemiluminescent signals generated by the device were detected to investigate the effects of the type of buffer and the type of alcohol on the chemiluminescent signal.

[0047] Figure 3 This diagram illustrates the signal response of different combinations of alkaline buffer solutions and alcohols in embodiments of this disclosure. Figure 3 As shown, compared to the combination of TRIS and ethanol, or TRIS and mannitol, the combination of borate-borax and ethanol, or borate-borax and mannitol, has a stronger signal response, indicating that borates are more compatible with alcohols than TRIS.

[0048] To evaluate and optimize system performance under the aforementioned reagent and piping conditions (including peristaltic pump tubing size, flow rate, dilution factor, etc.), a generator capable of stably producing HO2 radicals in a concentration range of 80 pptv to 1 ppbv was installed at the front end of the sampling unit. Using this generator, for example, by introducing a constant HO2 concentration of 100 pptv, the system response under different parameter combinations was tested. The optimization objective was to effectively exclude O3 and NO... x Under the premise of interference from coexisting atmospheric components such as H2O2, the system achieves a relatively high sensitivity to the detection signal of HO2 free radicals.

[0049] According to actual measurements, the device disclosed herein has a detection limit of 2 pptv (2σ) for HO2, a time resolution of ≤1 minute, a signal fluctuation of <5% (n=60) at a HO2 concentration of 100 pptv, and an interference suppression rate of >99% for 150 ppbv O3 and 40 ppb NO2.

[0050] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A device for detecting peroxyhydroxyl radicals in the atmosphere based on chemiluminescence, comprising a sampling unit, a dilution unit, a chemiluminescence detection unit, and pipes connecting them; in, The sampling unit is configured to collect atmospheric samples and convert peroxy hydroxyl radicals in the atmospheric samples into superoxide radicals using an alkaline buffer absorbent to obtain a buffer solution containing superoxide radicals. The dilution unit is configured to mix and dilute the buffer solution containing superoxide radicals with the diluent to obtain a diluted sample; The chemiluminescence detection unit is configured to acquire the chemiluminescence signal generated by the mixing and reaction of the diluted sample with the chemiluminescence reagent.

2. The apparatus according to claim 1, wherein, The sampling unit is equipped with a sampling pipeline; The sampling pipeline is equipped with: an air inlet for supplying atmospheric samples, a liquid inlet for supplying the alkaline buffer absorbent, a liquid outlet for discharging the buffer solution containing superoxide radicals, and an air outlet for discharging waste gas. Optionally, the sampling pipeline is further provided with a temperature control component, which is nested outside the sampling pipeline. The temperature control component includes a housing, and a temperature control medium inlet and a temperature control medium outlet disposed on the housing, and the temperature control medium inlet and the temperature control medium outlet are arranged obliquely symmetrically.

3. The apparatus according to claim 1, wherein, The dilution unit includes: A dilution container, connected to the outlet end of the sampling line, is configured to receive the solution containing superoxide radicals and mix it with the diluent entering the dilution container to obtain a diluted sample; and The diluent injection line, with one end connected to the dilution container and the other end connected to the diluent storage unit, is configured to deliver the diluent present in the diluent storage unit to the dilution container.

4. The apparatus according to claim 3, wherein, The chemiluminescence detection unit includes: The mixing chamber is a Y-shaped pipe consisting of a sample channel, a chemiluminescent reagent injection line, and a mixing channel. The sample channel is connected to the drain port of the dilution container and is configured to pass the diluted sample in the dilution container into the mixing channel; The chemiluminescent reagent injection line is connected to the chemiluminescent reagent storage device and is configured to introduce the chemiluminescent reagent stored in the chemiluminescent reagent storage device into the mixing channel; The mixing channel is configured to mix the diluted sample with the chemiluminescent reagent and carry out a chemical reaction to generate a chemiluminescent signal; Also includes: A photodetector, positioned toward the mixing cavity, is suitable for detecting chemiluminescent signals generated within the mixing channel.

5. The apparatus according to claim 4, wherein, Also includes: A defoamer is a branch channel disposed on the sample channel, one end of which is connected to the sample channel and the other end is exposed to air, and is configured to eliminate air bubbles in the diluted sample.

6. The apparatus according to any one of claims 1-5, further comprising: The signal processing unit, electrically connected to the chemiluminescence detection unit, is configured to convert the acquired chemiluminescence signal into the concentration of peroxyhydroxyl radicals.

7. The apparatus according to claim 1, wherein, The alkaline buffer absorbent includes a buffer, an ozone interference inhibitor, a metal ion chelating agent, and alcohols.

8. The apparatus according to claim 7, wherein, The buffer includes borate buffer and / or tris(hydroxymethyl)aminomethane buffer; The ozone interference inhibitor includes sodium sulfite and / or sodium nitrite; The metal ion chelating agent includes at least one of ethylenediaminetetraacetic acid and its derivatives; The alcohol is ethanol or mannitol.

9. The apparatus according to claim 1, wherein, The chemiluminescent reagents include 2-methyl-6-phenyl-3-hydroxyimidazo[1,2-a]pyrazine and its derivatives.

10. A method for detecting peroxyhydroxyl radicals in the atmosphere using the apparatus as described in any one of claims 1-9, comprising: Atmospheric samples were collected, and the peroxy hydroxyl radicals in the atmospheric samples were converted into superoxide radicals using an alkaline buffer absorption solution to obtain a buffer solution containing superoxide radicals. The buffer solution containing superoxide radicals was mixed with a diluent and diluted to obtain a diluted sample; as well as The chemiluminescence signal generated by the mixture and reaction of the diluted sample with the chemiluminescent reagent is collected.

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