Molecular Characterization of Organic Aerosol in Summer Suburban Shanghai Under High Humidity

Atmosphere, Год журнала: 2025, Номер 16(6), С. 659 - 659

Опубликована: Май 30, 2025

In this study, the chemical compositions of PM2.5 (particulate matter < 2.5 μm) and molecular methanol-soluble organic carbon (MSOC) in suburban Shanghai during summer were measured to investigate characteristics aerosol (OA) under high humidity. Diurnal variation analysis reveals influence relative humidity (RH) on secondary (SOA) components. Organosulfates (OSs), particularly nitrooxy-OSs, exhibit a positive correlation with increasing rather than atmospheric oxidants high-humidity site. This suggests that RH can promote formation OSs, possibly through enhancing particle surface area volume, creating favorable environment for aqueous-phase or heterogeneous reactions phase. A considerable proportion CHOS compounds may be derived from anthropogenic aliphatic hydrocarbon derivatives. These slightly elevated daytime concentrations due increased emissions long-chain aliphatics sources such as diesel combustion, well photochemically enhanced oxidation OSs. contrast, CHONS at night, driven by liquid-phase oxidation. Terpenoid derivatives accounted 13.4% MSOC contributed over 40% nighttime CHONS. findings highlight humidity’s important role driving processing biogenic precursors form SOA, even low SO2 NOx conditions.

Язык: Английский

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Overestimation of Monoterpene Organosulfate Abundance in Aerosol Particles by Sampling in the Presence of SO₂

Environmental Science & Technology Letters, Год журнала: 2020, Номер 8(3), С. 206 - 211

Опубликована: Дек. 22, 2020

Organosulfates derived from monoterpene oxidation (MT-OSs) are ubiquitously abundant in atmospheric aerosol particles. However, to date, potential sampling artifacts MT-OS detection and quantification have been largely ignored. Here, it is demonstrated that collecting particles α-pinene onto filters the presence of SO2 strongly increased OS numbers particle mass-normalized abundances by up 72% 3 orders magnitude, respectively. Similarly, at much lower levels (i.e., conditions), an average decrease 43% MT-OSs was detected during a field study when removed sampling. Additionally, tremendous increase mass spectrometric ion signals OSs observed were analyzed directly (i) electrospray ionization (ESI) S(VI) (ii) extractive ESI (EESI) S(IV). Our findings raise concerns on extent recently suggested formation S(IV) organic peroxides, as none these studies accounted for SO2. Furthermore, likely affected also earlier MT-OSs. In future studies, should be considered more carefully classical filter emerging analytical techniques.

Язык: Английский

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SO&lt;sub&gt;2&lt;/sub&gt; and NH&lt;sub&gt;3&lt;/sub&gt; emissions enhance organosulfur compounds and fine particle formation from the photooxidation of a typical aromatic hydrocarbon

Atmospheric chemistry and physics, Год журнала: 2021, Номер 21(10), С. 7963 - 7981

Опубликована: Май 25, 2021

Abstract. Aromatic hydrocarbons can dominate the volatile organic compound budget in urban atmosphere. Among them, 1,2,4-trimethylbenzene (TMB), mainly emitted from solvent use, is one of most important secondary aerosol (SOA) precursors. Although atmospheric SO2 and NH3 levels affect formation, influenced extent their impact detailed driving mechanisms are not well understood. The focus present study to examine chemical compositions formation SOA TMB photooxidation by and/or NH3. Here, we show that emission could considerably enhance particle due SO2-induced sulfate generation acid-catalyzed heterogeneous reactions. Orbitrap mass spectrometry measurements revealed only typical products but also hitherto unidentified organosulfates (OSs) SO2-added experiments. OSs designated as being unknown origin earlier field were detected SOA, indicating might be originated photooxidation. For NH3-involved experiments, results demonstrated a positive correlation between volume number concentrations. effects on composition slight under SO2-free conditions stronger presence SO2. A series multifunctional with carbonyl, alcohols, nitrate functional groups tentatively characterized experiments based infrared spectra analysis. Plausible pathways proposed for phase. volatility distributions products, estimated using parameterization methods, suggested gradually condense onto nucleation particles contribute growth. Our suggest strict control emissions remarkably reduce burden Updating aromatic oxidation mechanism models result more accurate treatment regions considerable SO2, NH3, aromatics emissions.

Язык: Английский

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Influence of COVID-19 lockdown on the variation of organic aerosols: Insight into its molecular composition and oxidative potential

Environmental Research, Год журнала: 2021, Номер 206, С. 112597 - 112597

Опубликована: Дек. 24, 2021

Язык: Английский

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Biogenic secondary organic aerosol formation in an urban area of eastern central India: Seasonal variation, size distribution and source characterization

Environmental Research, Год журнала: 2021, Номер 195, С. 110802 - 110802

Опубликована: Янв. 28, 2021

Язык: Английский

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