Secondary Organic Aerosol Generated from Biomass Burning Emitted Phenolic Compounds: Oxidative Potential, Reactive Oxygen Species, and Cytotoxicity

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(19), P. 8194 - 8206

Published: April 29, 2024

Phenolic compounds are largely emitted from biomass burning (BB) and have a significant potential to form SOA (Phc-SOA). However, the toxicological properties of Phc-SOA remain unclear. In this study, phenol guaiacol were chosen as two representative phenolic gases in BB plumes, water-soluble components their generated under different photochemical ages NOx levels investigated. contribute greatly oxidative (OP) biomass-burning SOA. OH-adducts (e.g., 2-methoxyhydroquinone) identified (GSOA) with high OP. The addition nitro groups 2,5-dimethyl-1,4-benzoquinone, surrogate quinone compound Phc-SOA, increased its toxicity both (PSOA) GSOA vitro human alveolar epithelial cells decreased aging terms cell death cellular reactive oxygen species (ROS), possibly due more ring-opening products relatively low toxicity. influence was consistent between ROS for but not PSOA, indicating that production does necessarily represent all processes contributing caused by PSOA. Combining acellular assays can provide comprehensive understanding aerosol properties.

Language: Английский

---

Nitroaromatic Compounds from Secondary Nitrate Formation and Biomass Burning Are Major Proinflammatory Components in Organic Aerosols in Guangzhou: A Bioassay Combining High-Resolution Mass Spectrometry Analysis

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(51), P. 21570 - 21580

Published: Nov. 21, 2023

The limited characterization and detection capacity of unknown compounds hinder our understanding the molecular composition toxic in PM2.5. present study applied Fourier transform ion cyclotron resonance mass spectrometry coupled with negative positive electrospray ionization sources (ESI–/ESI+ FT-ICR-MS) to probe characteristics dynamic formation processes effective proinflammatory components organic aerosols (OAs) PM2.5 Guangzhou for one year. We detected abundant molecules OAs, mainly classified as CHON (compounds composed C, H, O, N atoms) elemental nitroaromatic (NACs) structures. From perspective process, we discovered that these molecules, especially NACs, were largely driven by secondary nitrate biomass burning (in emission source), well SO2 atmospheric evolution). In addition, results indicated had replaced primary main contributing source OAs. This highlights importance community measures control production derived from urban areas.

Language: Английский

---

Aqueous-Phase Reactions of Anthropogenic Emissions Lead to the High Chemodiversity of Atmospheric Nitrogen-Containing Compounds during the Haze Event

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(43), P. 16500 - 16511

Published: Oct. 16, 2023

Nitrogen-containing organic compounds (NOCs), a type of important reactive-nitrogen species, are abundant in aerosols haze events observed Northern China. However, due to the complex nature NOCs, sources, formation, and influencing factors still ambiguous. Here, molecular composition matters (OMs) hourly PM2.5 samples collected during event China was characterized using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We found that CHON (formulas containing C, H, O, N atoms) dominated OM fractions showed high chemodiversity transformability. Relying on newly developed revised-workflow oxidation-hydrolyzation knowledge for compounds, 64% major aromatic (>80%) could be derived from oxidization or hydrolyzation processes. Results FT-ICR MS data analysis further aerosol liquid water (ALW)-involved aqueous-phase reactions distribution aromatic-CHON besides coal combustion, ALW-involved compound formation daytime nighttime different. Our results improve understanding composition, potential which can help advance evolution, control haze.

Language: Английский

---

Insight into the Role of NH₃/NH₄⁺ and NO_x/NO₃^– in the Formation of Nitrogen-Containing Brown Carbon in Chinese Megacities

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: unknown

Published: Feb. 23, 2024

Particulate brown carbon (BrC) plays a crucial role in the global radiative balance due to its ability absorb light. However, effect of molecular formation on light absorption properties BrC remains poorly understood. In this study, atmospheric samples collected from six Chinese megacities winter and summer were characterized through ultrahigh-performance liquid chromatography coupled with Orbitrap mass spectrometry (UHPLC-Orbitrap MS) measurements. The average values coefficient at wavelength 365 nm (babs365) approximately 4.0 times higher than those summer. Nitrogen-containing organic molecules (CHNO) identified as critical components light-absorbing substances both seasons, underscoring importance N-addition BrC. These nitrogen-containing chromophores more closely related nitro-containing compounds originating biomass burning nitrogen oxides (NOx)/nitrate (NO3–) reactions winter. summer, they reduced N-containing formed ammonia (NH3)/ammonium (NH4+) reactions. NH3/NH4+-mediated contributed secondary winter, particularly southern cities. Compared O/Cw, lower molecule conjugation indicator (double bond equivalent, DBE), babs365 suggest possible bleaching mechanism during oxidation process. findings strengthen connection between composition BrC, providing insights into mechanisms across northern cities different seasons.

Language: Английский

---

Unraveling the Ultrafast Photochemical Dynamics of Nitrobenzene in Aqueous Solution

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10407 - 10417

Published: April 4, 2024

Nitroaromatic compounds are major constituents of the brown carbon aerosol particles in troposphere that absorb near-ultraviolet (UV) and visible solar radiation have a profound effect on Earth's climate. The primary sources include biomass burning, forest fires, residential burning biofuels, an important secondary source is photochemistry aqueous cloud fog droplets. Nitrobenzene smallest nitroaromatic molecule model for photochemical behavior larger compounds. Despite obvious importance its droplet to atmospheric environment, there not been any detailed studies ultrafast dynamics nitrobenzene solution. Here, we combine femtosecond transient absorption spectroscopy, time-resolved infrared quantum chemistry calculations investigate steps following near-UV (λ ≥ 340 nm) photoexcitation nitrobenzene. To understand role surrounding water molecules nitrobenzene, compare results these investigations with analogous measurements solutions methanol, acetonitrile, cyclohexane. We find vibrational energy transfer environment quenches internal excitation, therefore, unlike gas phase, do observe evidence formation photoproducts timescales up 500 ns. also hydrogen bonding between slows S1/S0 conversion process.

Language: Английский

---

Nitroaromatic compounds in six major Chinese cities: Influence of different formation mechanisms on light absorption properties

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 930, P. 172672 - 172672

Published: April 23, 2024

Language: Английский

---

Comparative study of atmospheric brown carbon at Shanghai and the East China Sea: Molecular characterization and optical properties

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 941, P. 173782 - 173782

Published: June 5, 2024

Language: Английский

---

Atmospheric Nitrated Phenolic Compounds in Particle, Gaseous, and Aqueous Phases During Cloud Events at a Mountain Site in North China: Distribution Characteristics and Aqueous‐Phase Formation

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(18)

Published: Sept. 19, 2022

Abstract Nitrated phenolic compounds in the atmosphere are receiving increasing attention due to their light absorption and biological toxicity. In this study, particulate, gaseous, cloud water samples were simultaneously collected during events at summit of Mount Tai northern China spring, summer, winter contents 11 nitrated determined. The seasonal average concentrations total particles range 7.3–27.1 ng m −3 , a little lower than those measured gas‐phase (18.3–70.6 ). Their levels 168.4–438.5 μg L −1 . 4‐Nitrophenol nitrosalicylic acids dominant particles, while 4‐nitrophenol 2,4‐dinitrophenol most abundant gas phase samples. During events, mainly distributed particle phase, except dinitrophenols which winter. field‐derived effective Henry's law coefficients several orders magnitude higher theoretical values pure water. Moreover, particulate substantially greater predictions, especially spring. above results indicate that partly formed via aqueous‐phase reactions inside droplets or on wet surfaces, changed distribution patterns. much ratios sum 5‐nitrosalicylic acid further confirm enhanced formation aqueous processes.

Language: Английский

---

Probing Atmospheric Aerosols by Multimodal Mass Spectrometry Techniques: Revealing Aging Characteristics of Its Individual Molecular Components

ACS Earth and Space Chemistry, Journal Year: 2023, Volume and Issue: 7(12), P. 2498 - 2510

Published: Dec. 11, 2023

Detailed chemical characterization of biomass burning organic aerosol (OA) was performed using a synergistic combination multimodal mass spectrometry techniques. OA analyzed in situ high-resolution time-of-flight spectrometer (HR-ToF-AMS) and an extractive electrospray ionization (EESI-MS) deployed onboard the NASA DC-8 research aircraft. Additionally, complementary filter samples were collected for offline laboratory analysis high-performance liquid chromatography interfaced with photodiode array (HPLC-PDA-HRMS). During flight on August 3, 2019, which focused Williams Flats Fire, WA, HR-ToF-AMS data revealed abundant presence sulfur (OS) species as prominent components OA. These OS identified based their unique fragmentation. Further investigation HPLC-PDA-HRMS MSn fragmentation allowed us to identify molecular characteristics these unusual species. The dominant compounds detected during found be alkylbenzene sulfonates. Organosulfate, nitroaromatic, oxygenated aromatic also identified. Guided by HRMS results, time-resolved aging profiles selected individual retrieved from real-time EESI-MS sets evaluate evolution emission plume. Notably, sulfonate showed remarkable stability over 8 h atmospheric transport. In contrast, common organosulfates displayed short apparent half-life times that low 1.2 h, indicating susceptibility aging. nitroaromatic exhibited relatively slower aging, average 1.8 2.2 respectively.

Language: Английский

---

Nontargeted Screening Nitrogen-Containing Organic Compounds in Frost and Wet Deposition in Rural Northeast China

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 7, 2025

Nitrogen-containing organic compounds (NOCs) in frost serve as a critical pathway for atmospheric nitrogen deposition, significantly impacting the biogeochemical cycles of nitrogen. However, molecular characteristics NOCs and their deposition fluxes are scarcely studied. In this work, samples, collected rural Northeast China winter 2023, were analyzed using nontargeted ultrahigh performance liquid chromatography-orbitrap mass spectrometry (UHPLC-Orbitrap MS) to reveal content nitrogen-containing explore wet fluxes. The average number assigned formulas lager on hazy days compared nonhazy both water-soluble (WSOM) water-insoluble matter (WISOM) (3114 vs. 1934 WSOM 3042 2224 WISOM electrospray ionization (ESI−); 6921 5954 6629 5547 ESI+). Specifically, proportions CHON 35.6–49.9% (724–1517) 47–51.1% (2686–3388) ESI– ESI+ modes, respectively. Nitrophenol (C6H5NO3) methyl nitrophenol (C7H7NO4) most abundant NOCs, with (at maximum concentrations) 22.2 21.2 μg m–2·h–1, On days, reached up 1.73 times that indicating significant ambient during haze episode. This flux positively correlated PM2.5 concentration, implying important role particulates influencing NOC through frost. These findings highlight susceptibility capturing from atmosphere, potentially cycling ecosystems.

Language: Английский

---