Enhanced oxidative potential of methoxyphenol in the presence of Fe(III) in the atmosphere: Effects and mechanisms

IF 3.8 2区环境科学与生态学 Q2 ENVIRONMENTAL SCIENCES

Atmospheric Environment Pub Date : 2026-03-15 Epub Date: 2026-01-20 DOI:10.1016/j.atmosenv.2026.121809

Jinwen Li , Shaoxun Guo , Yongcheng Jia , Tianzeng Chen , Wei Ma , Veli-Matti Kerminen , Tuukka Petäjä , Markku Kulmala , Hui Li , Yongchun Liu

{"title":"Enhanced oxidative potential of methoxyphenol in the presence of Fe(III) in the atmosphere: Effects and mechanisms","authors":"Jinwen Li , Shaoxun Guo , Yongcheng Jia , Tianzeng Chen , Wei Ma , Veli-Matti Kerminen , Tuukka Petäjä , Markku Kulmala , Hui Li , Yongchun Liu","doi":"10.1016/j.atmosenv.2026.121809","DOIUrl":null,"url":null,"abstract":"<div><div>Coupling effects among different components of atmospheric particulate matter (PM) may influence the oxidative potential (OP) of PM, whereas the mechanism remains unclear. In this study, we investigate the OP of binary organics/inorganics mixtures, typically present in PM, using a dithiothreitol assay under dark conditions. The binary mixture of 2-methoxyphenol (2-MET, a typical biomass burning marker) and FeCl<sub>3</sub> shows a 23 times increase in OP (380 pmol min<sup>−1</sup>·μg<sup>−1</sup>) compared to the individual species. A synergistic mechanism has been revealed through comprehensive characterization of reactive oxygen species (ROS) and relevant intermediates, by ROS probe technology, spectroscopy, and mass spectrometry. Mass spectrometry indicates that diphenyl-p-benzoquinones, like 5,5′-dihydroxy-3,3′-dimethoxy-[1,1′-bi(cyclohexane)]-2,2′,5,5′-tetraene-4,4′-dione‌, can be produced in the presence of Fe<sup>3+</sup>, subsequently promoting ROS formation (·OH and ·O<sub>2</sub><sup>−</sup>) through free radical chain reaction induced by semiquinone. The OP achieves a maximum when the mass ratio of 2-MET to FeCl<sub>3</sub> is 1.0 at 37°C. It persists around 60% of the initial OP over 31 h, which indicates the possible contribution of the mixture of methoxyphenol and Fe(III) to environmental persistent free radicals in the atmosphere. Our findings provide a new insight into the non-linear dependence of PM oxidative toxicity on composition and meaningful guidance for future PM health risk reduction.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121809"},"PeriodicalIF":3.8000,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Atmospheric Environment","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1352231026000385","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/1/20 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}

引用次数: 0

Abstract

Coupling effects among different components of atmospheric particulate matter (PM) may influence the oxidative potential (OP) of PM, whereas the mechanism remains unclear. In this study, we investigate the OP of binary organics/inorganics mixtures, typically present in PM, using a dithiothreitol assay under dark conditions. The binary mixture of 2-methoxyphenol (2-MET, a typical biomass burning marker) and FeCl₃ shows a 23 times increase in OP (380 pmol min⁻¹·μg⁻¹) compared to the individual species. A synergistic mechanism has been revealed through comprehensive characterization of reactive oxygen species (ROS) and relevant intermediates, by ROS probe technology, spectroscopy, and mass spectrometry. Mass spectrometry indicates that diphenyl-p-benzoquinones, like 5,5′-dihydroxy-3,3′-dimethoxy-[1,1′-bi(cyclohexane)]-2,2′,5,5′-tetraene-4,4′-dione‌, can be produced in the presence of Fe³⁺, subsequently promoting ROS formation (·OH and ·O₂⁻) through free radical chain reaction induced by semiquinone. The OP achieves a maximum when the mass ratio of 2-MET to FeCl₃ is 1.0 at 37°C. It persists around 60% of the initial OP over 31 h, which indicates the possible contribution of the mixture of methoxyphenol and Fe(III) to environmental persistent free radicals in the atmosphere. Our findings provide a new insight into the non-linear dependence of PM oxidative toxicity on composition and meaningful guidance for future PM health risk reduction.

查看原文本刊更多论文

大气中Fe（III）存在时甲氧基苯酚氧化电位的增强：影响和机制

大气颗粒物（PM）不同组分之间的耦合效应可能影响PM的氧化电位（OP），但其机制尚不清楚。在这项研究中，我们研究了二元有机物/无机物混合物的OP，通常存在于PM中，在黑暗条件下使用二硫苏糖醇测定。2-甲氧基酚（2-MET，一种典型的生物质燃烧标志物）和FeCl3的二元混合物的OP （380 pmol min−1·μg−1）比单个物种增加了23倍。通过对活性氧（ROS）及其相关中间体的综合表征，利用ROS探针技术、光谱学和质谱分析，揭示了一种协同机制。质谱分析表明，在Fe3+的存在下，可以生成5,5 ' -二羟基-3,3 ' -二甲氧基-[1,1 ' -双（环己烷）]-2,2 ',5,5 ' -四烯-4,4 ' -二酮等二苯基对苯醌类化合物，并通过半醌诱导的自由基链式反应促进活性氧（·OH和·O2−）的形成。在37℃下，当2-MET与FeCl3的质量比为1.0时，OP达到最大值。它在31 h内保持在初始OP的60%左右，这表明甲氧基酚和Fe（III）的混合物可能对大气中环境持久性自由基有贡献。我们的研究结果为PM氧化毒性对成分的非线性依赖提供了新的见解，并为未来降低PM健康风险提供了有意义的指导。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Atmospheric Environment 环境科学-环境科学

CiteScore

9.40

自引率

8.00%

发文量

458

审稿时长

53 days

期刊介绍： Atmospheric Environment has an open access mirror journal Atmospheric Environment: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review. Atmospheric Environment is the international journal for scientists in different disciplines related to atmospheric composition and its impacts. The journal publishes scientific articles with atmospheric relevance of emissions and depositions of gaseous and particulate compounds, chemical processes and physical effects in the atmosphere, as well as impacts of the changing atmospheric composition on human health, air quality, climate change, and ecosystems.