Organic Peroxides in Aerosol: Key Reactive Intermediates for Multiphase Processes in the Atmosphere

Chemical Reviews, Год журнала: 2023, Номер 123(4), С. 1635 - 1679

Опубликована: Янв. 11, 2023

Organic peroxides (POs) are organic molecules with one or more peroxide (−O–O−) functional groups. POs commonly regarded as chemically labile termination products from gas-phase radical chemistry and therefore serve temporary reservoirs for oxidative radicals (HOx ROx) in the atmosphere. Owing to their ubiquity, active gas-particle partitioning behavior, reactivity, key reactive intermediates atmospheric multiphase processes determining life cycle (formation, growth, aging), climate, health impacts of aerosol. However, there remain substantial gaps origin, molecular diversity, fate due complex nature dynamic behavior. Here, we summarize current understanding on POs, a focus identification quantification, state-of-the-art analytical developments, molecular-level formation mechanisms, chemical transformation pathways, well environmental impacts. We find that interactions SO2 transition metal ions generally fast PO pathways liquid water, lifetimes estimated be minutes hours, while hydrolysis is particularly important α-substituted hydroperoxides. Meanwhile, photolysis thermolysis likely minor sinks POs. These distinctly different fates, such reaction OH radicals, which highlights need understand By summarizing advances remaining challenges investigation propose future research priorities regarding fate,

Язык: Английский

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Recent advances in mass spectrometry techniques for atmospheric chemistry research on molecular‐level

Mass Spectrometry Reviews, Год журнала: 2023, Номер 43(5), С. 1091 - 1134

Опубликована: Июль 13, 2023

Abstract The Earth's atmosphere is composed of an enormous variety chemical species associated with trace gases and aerosol particles whose composition chemistry have critical impacts on the climate, air quality, human health. Mass spectrometry analysis as a powerful popular analytical technique has been widely developed applied in atmospheric for decades. allows effective detection, identification, quantification broad range organic inorganic high sensitivity resolution. In this review, we summarize recently mass techniques, methods, applications research past several years molecular‐level. Specifically, new developments ion‐molecule reactors, various soft ionization unique coupling separation techniques are highlighted. laboratory studies field measurements focused improving detection limits traditional emerging volatile compounds, characterizing multiphase highly oxygenated molecules, monitoring particle bulk surface compositions.

Язык: Английский

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Synthesis and Characterization of Organic Peroxides from Monoterpene-Derived Criegee Intermediates in Secondary Organic Aerosol

Environmental Science & Technology, Год журнала: 2024, Номер 58(7), С. 3322 - 3331

Опубликована: Фев. 7, 2024

Ozonolysis of alkenes is known to produce reactive intermediates─stabilized Criegee intermediates (SCIs), and their subsequent bimolecular reactions with various carboxylic acids can form α-acyloxyalkyl hydroperoxides (AAHPs), which considered a major class organic peroxides in secondary aerosol (SOA). Despite atmospheric health importance, the molecular-level identification aerosols highly challenging, preventing further assessment environmental fate. Here, we synthesize 20 atmospherically relevant AAHPs through liquid-phase ozonolysis, two types monoterpene-derived SCIs from either α-pinene or 3-carene are scavenged by 10 different diverse structures. These identified individually liquid chromatography coupled high-resolution mass spectrometry. were previously thought decompose quickly an aqueous environment such as cloud droplets, but demonstrate here that hydrolysis rates compound-dependent rate constants differing 2 orders magnitude. In contrast, aqueous-phase formation between SCI vary only within factor 2–3. Finally, synthesized SOA SOA, contributing ∼0.3% total mass. Our results improve current understanding useful for more accurate fate impact.

Язык: Английский

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Acylperoxy Radicals as Key Intermediates in the Formation of Dimeric Compounds in α-Pinene Secondary Organic Aerosol

Environmental Science & Technology, Год журнала: 2022, Номер 56(20), С. 14249 - 14261

Опубликована: Сен. 30, 2022

High molecular weight dimeric compounds constitute a significant fraction of secondary organic aerosol (SOA) and have profound impacts on the properties lifecycle particles in atmosphere. Although different formation mechanisms involving reactive intermediates and/or closed-shell monomeric species been proposed for particle-phase dimers, their relative importance remains debate. Here, we report unambiguous experimental evidence important role acyl peroxy radicals (RO2) small but non-negligible contribution from stabilized Criegee (SCIs) dimers during ozonolysis α-pinene, one most precursors biogenic SOA. Specifically, find that RO2-involved reactions explain 50-80% total oxygenated dimer signals (C15-C20, O/C ≥ 0.4) 20-30% less (O/C < signals. In particular, they contribute to 70% C15-C19 ester formation, likely mainly via decarboxylation diacyl peroxides arising RO2 cross-reactions. comparison, SCIs play minor esters react noticeably with abundant C9 C10 carboxylic acids carbonyl products form C19 C20 peroxides, which are prone transformation more stable without peroxide functionality. This work provides clearer view pathways α-pinene oxidation would help reduce uncertainties future atmospheric modeling budget, properties, health climate

Язык: Английский

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Effect of relative humidity on the molecular composition of secondary organic aerosols from α-pinene ozonolysis

Environmental Science Atmospheres, Год журнала: 2024, Номер 4(5), С. 519 - 530

Опубликована: Янв. 1, 2024

Secondary organic aerosols (SOAs) originating from the oxidation of biogenic volatile compounds such as monoterpenes by atmospheric oxidants ( e.g. OH, ozone, and NO 3 ), constitute a widespread source in atmosphere.

Язык: Английский

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Rapid Iron-Mediated Aqueous-Phase Reactions of Organic Peroxides from Monoterpene-Derived Criegee Intermediates and Implications for Aerosol and Cloud Chemistry

Environmental Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 19, 2025

Fenton-like reactions between organic peroxides and transition-metal ions in the atmospheric aqueous phase have profound impacts on chemistry, composition, health effects of aerosols. However, kinetics, mechanisms, key influencing factors such remain poorly understood. In this study, we synthesized a series monoterpene-derived α-acyloxyalkyl hydroperoxides (AAHPs), an important class formed from Criegee intermediates during ozonolysis alkenes, investigated their with iron phase. We found that AAHPs are essentially chemically inert to Fe3+ but highly reactive toward Fe2+. The aqueous-phase reaction rate constant Fe2+ (kIIAAHP+Fe(II)) was determined range 11.0 ± 0.8 150.0 3.3 M–1 s–1, depending positively solution pH (1–3), water content (50%–90%), temperature (8–25 °C). Meanwhile, kIIAAHP+Fe(II) value is linearly correlated O/C ratio AAHPs, which allows for estimation reactivity based oxygenation level. addition, decomposition via predominantly yields alkoxy (RO) radicals production yield OH smaller than 16%. Similar several abundant including pinonic acid-derived AAHP exhibit high low dissolved α-pinene secondary aerosol. A quantitative analysis measured kinetics suggests even dominant drivers behind transformation atmosphere, would significantly affect multiphase chemistry aerosol impacts.

Язык: Английский

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Short-lived reactive components substantially contribute to particulate matter oxidative potential

Science Advances, Год журнала: 2025, Номер 11(12)

Опубликована: Март 19, 2025

Exposure to airborne particulate matter (PM) has been attributed millions of deaths annually. However, the PM components responsible for observed health effects remain unclear. Oxidative potential (OP) gained increasing attention as a key property that may explain toxicity. Using online measurement methods impinge particles OP quantification within seconds, we reveal 60 99% reactive oxygen species (ROS) and in secondary organic aerosol combustion-generated have lifetime minutes hours ROS activity ambient decays substantially before offline analysis. This implies current underestimate true PM. We demonstrate short-lived activate different toxicity pathways upon direct deposition onto reconstituted human bronchial epithelia. Therefore, suggest future air pollution studies should include quantification, allowing more accurate assessments links between effects.

Язык: Английский

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Photooxidation and ozonolysis of α-pinene and limonene mixtures: Mechanisms of secondary organic aerosol formation and cross-dimerization

Journal of Environmental Sciences, Год журнала: 2025, Номер unknown

Опубликована: Апрель 1, 2025

Язык: Английский

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Stability of Terpenoid-Derived Secondary Ozonides in Aqueous Organic Media

The Journal of Physical Chemistry A, Год журнала: 2022, Номер 126(32), С. 5386 - 5397

Опубликована: Авг. 3, 2022

1,2,4-Trioxolanes, known as secondary ozonides (SOZs), are key products of ozonolysis biogenic terpenoids. Functionalized terpenoid-derived SOZs readily taken up into atmospheric aerosols; however, their condensed-phase fates remain unknown. Here, we report the results a time-dependent mass spectrometric investigation liquid-phase C10 and C13 synthesized by monoterpene alcohol (α-terpineol) in water:acetone (1:1 = vol:vol) mixtures. Isomerization Criegee intermediates bimolecular reaction with acetone produced SOZs, respectively, which were detected Na+-adducts positive-ion electrospray spectrometry. Use CD3COCD3, D2O, H218O solvents enabled identification three types (aldehyde, ketone, lactol) other products. These surprisingly stable (1:1) mixtures at T 298 K, some persisting for least week. Theoretical calculations supported high stability lactol-type SOZ formed from aldehyde-type via intramolecular rearrangement. The present suggest that can persist condensed phases, potentially until they delivered to epithelial lining fluid pulmonary alveoli inhaled particulate matter, where may exert hitherto unrecognized adverse health effects.

Язык: Английский

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Relative humidity-dependent evolution of molecular composition of α-pinene secondary organic aerosol upon heterogeneous oxidation by hydroxyl radicals

Journal of Environmental Sciences, Год журнала: 2023, Номер 148, С. 210 - 220

Опубликована: Авг. 24, 2023

Язык: Английский

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