Ping Liu, Xiang Ding*, Daniel J. Bryant, Yu-Qing Zhang, Jun-Qi Wang, Kong Yang, Qian Cheng, Hao Jiang, Zi-Rui Wang, Yun-Feng He, Bo-Xuan Li, Mei-Yu Zhao, Jacqueline F. Hamilton, Andrew R. Rickard* and Xin-Ming Wang,
{"title":"城市和森林站点异戊二烯衍生的二次有机气溶胶形成途径的比较","authors":"Ping Liu, Xiang Ding*, Daniel J. Bryant, Yu-Qing Zhang, Jun-Qi Wang, Kong Yang, Qian Cheng, Hao Jiang, Zi-Rui Wang, Yun-Feng He, Bo-Xuan Li, Mei-Yu Zhao, Jacqueline F. Hamilton, Andrew R. Rickard* and Xin-Ming Wang, ","doi":"10.1021/acsearthspacechem.4c00398","DOIUrl":null,"url":null,"abstract":"<p >In isoprene oxidation, epoxides are crucial for forming isoprene-derived secondary organic aerosol (iSOA), significantly impacting the global atmospheric aerosol burden and composition. Isoprene dihydroxyepoxydiols (IEPOX) and hydroxymethyl–methyl-α-lactone (HMML) are key reactive gas-phase intermediates under low- and high-NO conditions, respectively. IEPOX and/or HMML can undergo nucleophilic reactions with both sulfate and water, producing isoprene-derived organosulfates (iOSs) and oxygen-containing tracers (iOTs). In this study, high temporal observations of iSOA species indicate that although OS formation in the urban and forest areas exhibited similar diurnal variations, the average concentrations of biogenic OSs decreased significantly from the urban site to the forest site. Additionally, at the urban site, the nucleophilic addition reaction is more likely to occur with sulfate (iOSs/iOTs = 1.51), while at the forest site, water serves as the dominant reactant (iOSs/iOTs = 0.81). We have also estimated the branching ratios of nucleophilic reaction pathways with sulfate and water at the different sites. At the Guangzhou urban site, the branching ratio of IEPOX with sulfate:water has a mean of 42.4%:57.6%, whereas for HMML, it is 64.3%:35.7%. At the forest site, the branching ratio of IEPOX with sulfate:water is roughly equal at 48.3%:51.7%, while for HMML, the preference is for reaction with water with a ratio of 33.7%:66.3%. Furthermore, the concentrations of iOSs were significantly correlated with the product of [O<sub>3</sub>]·[SO<sub>4</sub><sup>2–</sup>]. This correlation was stronger than the individual correlations of major iOSs with [O<sub>3</sub>] and [SO<sub>4</sub><sup>2–</sup>]. Thus, higher levels of OS were attributed to enhanced photochemical processing and increased levels of sulfate. This research offers valuable insights into the impacts of biogenic–anthropogenic interactions and the factors controlling the formation of iSOA in polluted areas via nucleophilic addition reactions.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 7","pages":"1752–1767"},"PeriodicalIF":2.9000,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Comparison of Isoprene-Derived Secondary Organic Aerosol Formation Pathways at an Urban and a Forest Site\",\"authors\":\"Ping Liu, Xiang Ding*, Daniel J. Bryant, Yu-Qing Zhang, Jun-Qi Wang, Kong Yang, Qian Cheng, Hao Jiang, Zi-Rui Wang, Yun-Feng He, Bo-Xuan Li, Mei-Yu Zhao, Jacqueline F. Hamilton, Andrew R. Rickard* and Xin-Ming Wang, \",\"doi\":\"10.1021/acsearthspacechem.4c00398\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >In isoprene oxidation, epoxides are crucial for forming isoprene-derived secondary organic aerosol (iSOA), significantly impacting the global atmospheric aerosol burden and composition. Isoprene dihydroxyepoxydiols (IEPOX) and hydroxymethyl–methyl-α-lactone (HMML) are key reactive gas-phase intermediates under low- and high-NO conditions, respectively. IEPOX and/or HMML can undergo nucleophilic reactions with both sulfate and water, producing isoprene-derived organosulfates (iOSs) and oxygen-containing tracers (iOTs). In this study, high temporal observations of iSOA species indicate that although OS formation in the urban and forest areas exhibited similar diurnal variations, the average concentrations of biogenic OSs decreased significantly from the urban site to the forest site. Additionally, at the urban site, the nucleophilic addition reaction is more likely to occur with sulfate (iOSs/iOTs = 1.51), while at the forest site, water serves as the dominant reactant (iOSs/iOTs = 0.81). We have also estimated the branching ratios of nucleophilic reaction pathways with sulfate and water at the different sites. At the Guangzhou urban site, the branching ratio of IEPOX with sulfate:water has a mean of 42.4%:57.6%, whereas for HMML, it is 64.3%:35.7%. At the forest site, the branching ratio of IEPOX with sulfate:water is roughly equal at 48.3%:51.7%, while for HMML, the preference is for reaction with water with a ratio of 33.7%:66.3%. Furthermore, the concentrations of iOSs were significantly correlated with the product of [O<sub>3</sub>]·[SO<sub>4</sub><sup>2–</sup>]. This correlation was stronger than the individual correlations of major iOSs with [O<sub>3</sub>] and [SO<sub>4</sub><sup>2–</sup>]. 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Comparison of Isoprene-Derived Secondary Organic Aerosol Formation Pathways at an Urban and a Forest Site
In isoprene oxidation, epoxides are crucial for forming isoprene-derived secondary organic aerosol (iSOA), significantly impacting the global atmospheric aerosol burden and composition. Isoprene dihydroxyepoxydiols (IEPOX) and hydroxymethyl–methyl-α-lactone (HMML) are key reactive gas-phase intermediates under low- and high-NO conditions, respectively. IEPOX and/or HMML can undergo nucleophilic reactions with both sulfate and water, producing isoprene-derived organosulfates (iOSs) and oxygen-containing tracers (iOTs). In this study, high temporal observations of iSOA species indicate that although OS formation in the urban and forest areas exhibited similar diurnal variations, the average concentrations of biogenic OSs decreased significantly from the urban site to the forest site. Additionally, at the urban site, the nucleophilic addition reaction is more likely to occur with sulfate (iOSs/iOTs = 1.51), while at the forest site, water serves as the dominant reactant (iOSs/iOTs = 0.81). We have also estimated the branching ratios of nucleophilic reaction pathways with sulfate and water at the different sites. At the Guangzhou urban site, the branching ratio of IEPOX with sulfate:water has a mean of 42.4%:57.6%, whereas for HMML, it is 64.3%:35.7%. At the forest site, the branching ratio of IEPOX with sulfate:water is roughly equal at 48.3%:51.7%, while for HMML, the preference is for reaction with water with a ratio of 33.7%:66.3%. Furthermore, the concentrations of iOSs were significantly correlated with the product of [O3]·[SO42–]. This correlation was stronger than the individual correlations of major iOSs with [O3] and [SO42–]. Thus, higher levels of OS were attributed to enhanced photochemical processing and increased levels of sulfate. This research offers valuable insights into the impacts of biogenic–anthropogenic interactions and the factors controlling the formation of iSOA in polluted areas via nucleophilic addition reactions.
期刊介绍：
The scope of ACS Earth and Space Chemistry includes the application of analytical, experimental and theoretical chemistry to investigate research questions relevant to the Earth and Space. The journal encompasses the highly interdisciplinary nature of research in this area, while emphasizing chemistry and chemical research tools as the unifying theme. The journal publishes broadly in the domains of high- and low-temperature geochemistry, atmospheric chemistry, marine chemistry, planetary chemistry, astrochemistry, and analytical geochemistry. ACS Earth and Space Chemistry publishes Articles, Letters, Reviews, and Features to provide flexible formats to readily communicate all aspects of research in these fields.
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