Peatland Wildfires Enhance Nitrogen-Containing Organic Compounds in Marine Aerosols over the Western Pacific

Environmental Science & Technology, Год журнала: 2024, Номер 58(25), С. 10991 - 11002

Опубликована: Июнь 3, 2024

Peatland wildfires contribute significantly to the atmospheric release of light-absorbing organic carbon, often referred as brown carbon. In this study, we examine presence nitrogen-containing compounds (NOCs) within marine aerosols across Western Pacific Ocean, which are influenced by peatland fires from Southeast Asia. Employing ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in electrospray ionization (ESI) positive mode, discovered that NOCs predominantly composed reduced nitrogenous bases, including CHN+ and CHON+ groups. Notably, count NOC formulas experiences a marked increase plumes compared those found typical air masses. These NOCs, identified N-heterocyclic alkaloids, serve potential chromophores. Furthermore, many demonstrate pyrolytic stability, engage variety substitution reactions, display enhanced hydrophilic properties, attributed chemical processes such methoxylation, hydroxylation, methylation, hydrogenation occur during emission subsequent aging. During daytime transport, aging aromatic compounds, particularly aliphatic amines prone oxidation reactions with amine, was observed. The findings underscore critical role augmenting organics aerosols, underscoring need for in-depth research into their effects on ecosystems regional climatic conditions.

Язык: Английский

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Enhancing characterization of organic nitrogen components in aerosols and droplets using high-resolution aerosol mass spectrometry

Atmospheric measurement techniques, Год журнала: 2024, Номер 17(2), С. 423 - 439

Опубликована: Янв. 22, 2024

Abstract. This study aims to enhance the understanding and application of Aerodyne high-resolution aerosol mass spectrometer (HR-AMS) for comprehensive characterization organic nitrogen (ON) compounds in particles atmospheric droplets. To achieve this goal, we analyzed 75 N-containing compounds, representing a diverse range ambient non-organonitrate ON (NOON) types, including amines, amides, amino acids, N heterocycles, protein, humic acids. Our results show that NOON can produce significant levels NHx+ NOx+ ion fragments, which are typically recognized as ions representative inorganic species. We also identified presence CH2N+ at m/z = 28.0187, an fragment rarely quantified datasets due substantial interference from N2+. As result, utilization updated calibration factor 0.79 is necessary accurate quantification via HR-AMS. assessed relative ionization efficiencies (RIEs) various species found average RIE (1.52 ± 0.58) aligns with commonly used default value 1.40 aerosol. Moreover, through careful examination HR-AMS spectral features propose fingerprint series aid speciation analysis. For instance, CnH2n+2N+ closely linked CH4N+ indicating primary C2H6N+ suggesting secondary C3H8N+ tertiary amines. CnH2nNO+ (especially n values 1–4) very likely derived amides. The co-existence three ions, C2H4NO2+, C2H3NO+, CH4NO+, serves indicator Additionally, CxHyN2+ indicates occurrence 2N-heterocyclic compounds. Notably, elevated abundance NH4+ distinct signature amines ammonium salts only negligible amounts Finally, contents submicron (PM1) fog water Fresno, California, PM1 New York City (NYC). revealed both Fresno NYC aerosols, whereas concurrently collected contained broader species, aromatic heterocycle (e.g., imidazoles) These findings highlight potential employing widespread measurements aerosols droplets our sources, transformation processes, environmental impacts associated atmosphere.

Язык: Английский

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Variabilities in Primary N-Containing Aromatic Compound Emissions from Residential Solid Fuel Combustion and Implications for Source Tracers

Environmental Science & Technology, Год журнала: 2022, Номер 56(19), С. 13622 - 13633

Опубликована: Сен. 21, 2022

Nitroaromatic compounds (NACs) not only are strongly absorbing chromophores but also adversely affect human health. NACs can be emitted from incomplete combustions and derive secondarily through photochemical reactions. Here, emission experiments were conducted for 31 fuel–stove combinations to elucidate variations in, influencing factors of, NAC (EF∑NACs) explore potential tracers different combustion sources. EF∑NACs varied by 2 orders of magnitude among combinations. Differences in fuel type contributed more than the stove difference observed variation. biomass pellets was approximately 66% lower that raw biomass, although bulk organic brown carbon EFs 95% lower. 2-Nitro-1-naphthol most abundant individual compound, followed 4-nitrocatechol, while acid (salicylic benzoic acid) low abundance (<1%). Substantially profiles between coal burning emissions. Biomass had single-ring-based phenolic with combustion, two-ring products produced. This study demonstrated much ratios 2-nitro-1-naphthol/4-nitrocatechol both traditional (2.0 ± 3.5) improved stoves (3.0 2.1) coals (15 6). Coal differed compound profile, consequently leading distinct health climate impacts; moreover, ratio may used source apportionment NACs.

Язык: Английский

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Molecular compositions and optical properties of water-soluble brown carbon during the autumn and winter in Guangzhou, China

Atmospheric Environment, Год журнала: 2022, Номер 296, С. 119573 - 119573

Опубликована: Дек. 30, 2022

Язык: Английский

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Revealing Molecular Structures of Nitrogen-Containing Compounds in Dissolved Black Carbon Using Ultrahigh-Resolution Mass Spectrometry Combined with Thermodynamic Calculations

Environmental Science & Technology, Год журнала: 2024, Номер 58(27), С. 11998 - 12007

Опубликована: Июнь 27, 2024

Landscape wildfires generate a substantial amount of dissolved black carbon (DBC) annually, yet the molecular nitrogen (N) structures in DBC are poorly understood. Here, we systematically compared chemodiversity N-containing molecules among three different samples from rice straw biochar pyrolyzed at 300, 400, and 500 °C, one leached organic (LDOC) sample composted straw, fire-affected soil matter (SDOMFire) using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). N-Containing contributed 20.0%, 36.1%, 43.7% total compounds Combined (pooling together DBC), LDOC, SDOMFire, respectively, with fewer N atoms had higher proportions (i.e., N1 > N2 N3). The were dominated by polycyclic aromatic (62.2%) (14.4%) components, while those LDOC lignin-like (50.4%) (30.1%) components. composition SDOMFire more similar to than LDOC. As temperature rose, proportion nitrogenous component significantly increased concurrent enhanced oxidation unsaturation N. indicated density functional theory (DFT)-based thermodynamic calculations, aliphatic amide decreased 23.2% 7.9%, whereas that nitroaromatic 10.0% 39.5% as 300 °C; alternatively, 5/6 membered ring remained relatively stable (∼31%) peaked 400 °C (32.7%). Our work first provides comprehensive thorough description DBC, which helps better understand predict their fate biogeochemical behavior.

Язык: Английский

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Molecular insight into biomass-burning smoke water-soluble organic matter binding with Cd(II): Comprehensive analysis from fluorescence EEM-PARAFAC, FT-ICR-MS and two-dimensional correlation spectroscopy

Journal of Hazardous Materials, Год журнала: 2024, Номер 479, С. 135754 - 135754

Опубликована: Сен. 4, 2024

Язык: Английский

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Factors Influencing the Molecular Compositions and Distributions of Atmospheric Nitrogen‐Containing Compounds

Journal of Geophysical Research Atmospheres, Год журнала: 2022, Номер 127(7)

Опубликована: Март 23, 2022

Abstract Atmospheric nitrogen‐containing organic compounds (NOCs) are critical components of global nitrogen deposition and light‐absorption species. The sources compositions NOCs complex remain largely unknown. Here, in 55 ambient aerosol samples collected Guangzhou, South China, were analyzed via ultrahigh‐resolution Fourier transform ion cyclotron resonance mass spectrometry negative‐ion positive‐ion electrospray ionization (ESI) modes. molecular measured ESI– ESI+ exhibited considerable differences. detected the negative mode mainly composed highly oxygenated nitrates (O/N = 6), whereas positive reduced (e.g., amides amino acids). CHN potentially corresponding to amines alkaloids showed low abundance detection Non‐metric multidimensional scaling individual compound correlation analyses that affected by anthropogenic activities meteorological parameters. For example, such as biomass burning secondary nitrogen‐chemistry processes led accumulation aromatic during winter. During summer, higher OH radical concentrations temperatures will result more prevalent or persistent aliphatic NOCs, particularly lipid‐like amines. Some variables relative humidity) have distinct effects on variation different types NOCs. More research is needed reveal influencing mechanisms. This study clarifies mechanisms which various factors influence variations. findings can guide assessment evolution deposition.

Язык: Английский

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Impact of fossil and non-fossil fuel sources on the molecular compositions of water-soluble humic-like substances in PM_2.5 at a suburban site of Yangtze River Delta, China

Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(14), С. 8305 - 8324

Опубликована: Июль 25, 2023

Abstract. Atmospheric humic-like substances (HULIS) affect the global radiation balance due to their strong light absorption at ultraviolet wavelength. The potential sources and molecular compositions of water-soluble HULIS a suburban site in Yangtze River Delta from 2017 2018 were discussed, based on results radiocarbon (14C) analysis combining Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) technique this study. 14C showed that averaged non-fossil-fuel source contributions 39 ± 8 % 36 6 summer winter, respectively, indicating significant fossil fuel HULIS. Van Krevelen diagrams obtained FT-ICR-MS proportions tannin-like carbohydrate-like groups higher summer, suggesting contribution biogenic secondary organic aerosols (SOAs). condensed aromatic structures winter suggested increasing anthropogenic emissions. Molecular composition CHO, CHON, CHOS, CHONS subgroups relatively intensities high O-containing macromolecular oligomers CHO compounds further stronger SOA formation summer. High-intensity phenolic flavonoids, which related biomass burning polycyclic hydrocarbon (PAH) derivatives combustion emissions, found compounds. Besides, two high-intensity containing ring (C9H6O7 C10H5O8) identified samples similar those off-road engine samples, traffic emissions one important study site. CHON mainly composed nitro or organonitrates with significantly associated addition enhanced NOx winter. However, formulas referring N-heterocyclic compounds, produced atmospheric processes involving reduced N species (e.g., ammonium). S-containing organosulfates (OSs) derived precursors, namely long-chain alkane hydrocarbon, illustrate mixed Generally, different policies need be considered for each season seasonal (i.e., sources, both seasons, additional coal winter). Measures control motor vehicles industrial Additional measures power plants should applied These findings add our understanding interaction between

Язык: Английский

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Optical Variation and Molecular Transformation of Brown Carbon During Oxidation by NO₃^• in the Aqueous Phase

Environmental Science & Technology, Год журнала: 2024, Номер unknown

Опубликована: Фев. 6, 2024

The NO3•-driven nighttime aging of brown carbon (BrC) is known to greatly impact its atmospheric radiative forcing. However, the oxidation by NO3• on optical properties BrC in waters as well associated reaction mechanism remain unclear. In this work, we found that variation proxies under environmentally relevant exposure depends strongly their sources, with enhanced light absorptivity for biomass-burning but bleaching urban aerosols and humic substances. High-resolution mass spectrometry using FT-ICR MS shows leads formation light-absorbing species (e.g., nitrated organics) while destroying electron donors phenols) within charge transfer complexes substances, evidenced transient absorption spectroscopy NaBH4 reduction experiments well. Moreover, measured rate constants between real BrCs (k = (1.8 ± 0.6) × 107 MC–1s–1, expressed moles carbon) are much higher than those individual model organic (OC), suggesting OCs may be a previously ill-quantified important sink waters. This work provides insights into kinetics molecular transformation during NO3•, facilitating further evaluation BrC's climatic effects levels.

Язык: Английский

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Seasonal characterization of chemical and optical properties of water-soluble organic aerosol in Beijing

The Science of The Total Environment, Год журнала: 2024, Номер 930, С. 172508 - 172508

Опубликована: Апрель 18, 2024

Язык: Английский

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