Elucidating Secondary Organic Aerosol Processes through High-Resolution Aerosol Mass Spectrometry in Beijing

Advances in Atmospheric Sciences, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 24, 2025

Language: Английский

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Effects of significant emission changes on PM2.5 chemical composition and optical properties from 2019 to 2021 in a typical industrial city of eastern China

Atmospheric Research, Journal Year: 2024, Volume and Issue: 301, P. 107287 - 107287

Published: Feb. 8, 2024

Language: Английский

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Interpreting hourly mass concentrations of PM2.5 chemical components with an optimal deep-learning model

Journal of Environmental Sciences, Journal Year: 2024, Volume and Issue: 151, P. 125 - 139

Published: March 29, 2024

Language: Английский

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The search for sparse data in molecular datasets: Application of active learning to identify extremely low volatile organic compounds

Journal of Aerosol Science, Journal Year: 2024, Volume and Issue: 179, P. 106375 - 106375

Published: March 30, 2024

The formation of aerosol particles in the atmosphere is driven by gas to particle conversion extremely low volatile organic compounds (ELVOC), with a particularly saturation vapor pressure (pSat). Identifying ELVOCs and their chemical structures both experimentally theoretically challenging: Measuring very pSat difficult, computing for these often large molecules computationally costly. Moreover, are underrepresented available datasets atmospheric species, which reduces value statistical models built on such data. We propose an active learning (AL) approach efficiently identify data pool species initially unknown pSat. assess performance our AL comparing it traditional machine regression methods, as well ELVOC classification based molecular properties. proves be highly efficient method identification limitations type can identify. also show that or property-based methods adequate tools depending desired degree efficiency.

Language: Английский

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Volatility Basis Set Distributions and Viscosity of Organic Aerosol Mixtures: Insights from Chemical Characterization Using Temperature-Programmed Desorption–Direct Analysis in Real-Time High-Resolution Mass Spectrometry

Analytical Chemistry, Journal Year: 2024, Volume and Issue: 96(23), P. 9524 - 9534

Published: May 30, 2024

Quantitative assessment of gas-particle partitioning individual components within complex atmospheric organic aerosol (OA) mixtures is critical for predicting and comprehending the formation evolution OA particles in atmosphere. This investigation leverages previously documented data obtained through a temperature-programmed desorption–direct analysis real-time, high-resolution mass spectrometry (TPD-DART-HRMS) platform. methodology facilitates bottom-up construction volatility basis set (VBS) distributions constituents found three biogenic secondary (SOA) produced ozonolysis α-pinene, limonene, ocimene. The apparent enthalpies (ΔH*, kJ mol–1) saturation concentrations (CT*, μg·m–3) SOA components, determined as function temperature (T, K), facilitated an changes VBS with respect to T total loadings (tOM, μg·m–3). reveal distinct differences volatilities among monomers, dimers, trimers, categorized into separate bins. At ambient = 298 K, only monomers efficiently partition between gas particle phases across broad range atmospherically relevant tOM values 1–100 μg·m–3. Partitioning dimers trimers becomes notable at > 360 K 420 respectively. viscosity assessed using calculation approach, incorporating input elemental formulas, ΔH*, CT*, particle-phase fractions components. Through this we are able accurately estimate variations that result from evaporation its These are, turn, influenced by T. Comparison calculated diffusivity literature reported experimental results shows close agreement, thereby validating employed approach. findings underscore significant potential TPD-DART-HRMS measurements enabling untargeted molecules mixtures. approach quantitative their allows estimation condensed-phase diffusion, contributing valuable insights models.

Language: Английский

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Molecular Insights into Gas–Particle Partitioning and Viscosity of Atmospheric Brown Carbon

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

Published: Oct. 4, 2024

Biomass burning organic aerosol (BBOA), containing brown carbon chromophores, plays a critical role in atmospheric chemistry and climate forcing. However, the effects of evaporation on BBOA volatility viscosity under different environmental conditions remain poorly understood. This study focuses molecular characterization laboratory-generated proxies from wood pyrolysis emissions. The initial mixture, "pyrolysis oil (PO

Language: Английский

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Effects of Relative Humidity on Time-Resolved Molecular Characterization of Secondary Organic Aerosols from the OH-Initiated Oxidation of Cresol in the Presence of NO_x

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

Published: Jan. 16, 2025

While biomass burning (BB) is the largest source of fine particles in atmosphere, influence relative humidity (RH) and photochemistry on BB secondary organic aerosol (BB-SOA) formation aging remains poorly constrained. These effects need to be addressed better capture comprehend evolution BB-SOA atmosphere. Cresol (C7H8O) used as a proxy investigate these effects. It emitted directly from has been identified significant SOA precursor residential wood-burning emissions. The gas- particle-phase signal intensities are investigated using online mass spectrometers. An increase yield 7% observed when RH rises 0.5–20 70–87%. At elevated RH, nitrogen-containing compounds due processes. This linked net decrease viscosity, enabling formed greater extent at presence nitrogen oxides. results highlight importance particle water content for molecular compounds.

Language: Английский

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Capturing the Relative‐Humidity‐Sensitive Gas–Particle Partitioning of Organic Aerosols in a 2D Volatility Basis Set

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(3)

Published: Feb. 4, 2024

Abstract Aerosol water affects the physicochemical properties and mass concentration of organic aerosols (OA), but it is typically omitted by air quality, weather, climate models. We compare two classes simplified models to estimate OA uptake gas–particle partitioning compounds. One class uses a single‐hygroscopicity‐parameter ( κ ) approach while other based on reduced‐complexity Binary Activity Thermodynamics (BAT) model. show that BAT‐based two‐dimensional volatility basis set (VBS) model always predicts higher at elevated relative humidity (RH), for example, ∼16% 80% RH, than any variation ‐based method considered—even when BAT‐VBS lower uptake. The main reason being captures variations in effective saturation organics C *) with feature VBS methods lack. framework offers an efficient, RH‐sensitive treatment modeling.

Language: Английский

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Ammonium CI-Orbitrap: a tool for characterizing the reactivity of oxygenated organic molecules

Atmospheric measurement techniques, Journal Year: 2024, Volume and Issue: 17(17), P. 5413 - 5428

Published: Sept. 13, 2024

Abstract. Oxygenated organic molecules (OOMs) play an important role in the formation of atmospheric aerosols. Due to various analytical challenges with respect measuring vapors, uncertainties remain regarding and fate OOMs. The chemical ionization Orbitrap (CI-Orbitrap) mass spectrometer has recently been shown be a powerful technique that is able accurately identify gaseous compounds due its greater resolution. Here, we present ammonium-ion-based CI-Orbitrap (NH4+-Orbitrap) as capable wide range performance NH4+-Orbitrap compared state-of-the-art spectrometers, including nitrate-ion-based pressure interface coupled time-of-flight (NO3--LTOF), new generation proton transfer reaction-TOF (PTR3-TOF), iodide-based CI-TOF equipped Filter Inlet for Gases AEROsols (I−-CIMS). instruments were deployed simultaneously Cosmic Leaving OUtdoors Droplets (CLOUD) chamber at European Organization Nuclear Research (CERN) during CLOUD14 campaign 2019. Products generated from α-pinene ozonolysis under experimental conditions measured by spectrometers. was widest OOMs (i.e., O ≥ 2), less-oxidized species highly oxygenated (HOMs). Excellent agreement found between NO3--LTOF characterizing HOMs PTR3-TOF monomeric species. OOM concentrations estimated using calibration factors derived high time-series correlations side-by-side measurements. As other spectrometry techniques used this campaign, detection sensitivity greatly affected relative humidity, which may related changes efficiency and/or multiphase chemistry. Overall, study shows NH4+-ion-based chemistry associated resolution analyzer can measure almost all inclusive compounds. result, it now possible cover entire compounds, lead better understanding oxidation processes.

Language: Английский

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The effect of temperature and relative humidity on secondary organic aerosol formation from ozonolysis of Δ³-carene

Environmental Science Atmospheres, Journal Year: 2023, Volume and Issue: 4(1), P. 88 - 103

Published: Nov. 29, 2023

This study investigates the effects of temperature and relative humidity on formation secondary organic aerosol from Δ 3 -carene, a prevalent monoterpene in boreal forests.

Language: Английский

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