Methylamine’s Effects on Methylglyoxal-Containing Aerosol: Chemical, Physical, and Optical Changes

ACS Earth and Space Chemistry, Год журнала: 2019, Номер 3(9), С. 1706 - 1716

Опубликована: Июль 30, 2019

Methylamine, a common atmospheric amine species, is found in the gas, particle, and aqueous phases. It has been shown to form light-absorbing, oligomeric species reactions with methylglyoxal other aldehyde bulk aqueous-phase experiments when mixed into seed aerosol as sulfate salt. Here, we explore influence of multiphase methylamine chemistry on production, properties, molecular composition. When particles were exposed ∼2 ppm gas humid chamber, rapid browning was observed, but not growth. Aerosol bounce measurements indicated that became slightly more viscous hydrophobic upon exposure. Subsequent cloud processing increased both viscosity hygroscopicity had little effect browning, consistent high-resolution mass spectrometry results showing oligomer dicarbonyl functional groups transformed cationic imidazole rings. Photolytic triggered incorporation hydroxyacetone acetal radicals oligomers. Because are major component particles, these suggest exposure will slowly increase brown carbon content, viscosity, aerosol.

Язык: Английский

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Modeling Photosensitized Secondary Organic Aerosol Formation in Laboratory and Ambient Aerosols

Environmental Science & Technology, Год журнала: 2017, Номер 51(13), С. 7496 - 7501

Опубликована: Июнь 12, 2017

Photosensitized reactions involving imidazole-2-carboxaldehyde (IC) have been experimentally observed to contribute secondary organic aerosol (SOA) growth. However, the extent of photosensitized in ambient aerosols remains poorly understood and unaccounted for atmospheric models. Here we use GAMMA 4.0, a photochemical box model that couples gas-phase aqueous-phase chemistry, along with recent laboratory measurements kinetics IC photochemistry, analyze IC-photosensitized SOA formation settings. Analysis results Aregahegn et al. (2013) suggests production from limonene, isoprene, α-pinene, β-pinene, toluene by 3IC* occurs at or near surface particle. Reactive uptake coefficients were derived experimental data using 4.0. Simulations aqueous remote conditions including photosensitizer chemistry indicate less than 0.3% contribution growth direct toluene, an enhancement 0.04% other precursors due radicals bulk phase. Other, more abundant species, such as humic-like substances (HULIS), may significantly production.

Язык: Английский

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Modeling Secondary Organic Aerosol Production from Photosensitized Humic-like Substances (HULIS)

Environmental Science & Technology Letters, Год журнала: 2018, Номер 5(5), С. 255 - 259

Опубликована: Апрель 3, 2018

Humic-like substances (HULIS) are ubiquitous in atmospheric aerosols. Despite experimental evidence that HULIS can catalyze secondary organic aerosol (SOA) formation through photosensitizer chemistry, the potential contribution of this pathway to ambient SOA has not been quantified. In study, GAMMA, a photochemical box model, was used analyze data Monge et al. ( Proc. Natl. Acad. Sci. U. S. A. 2012, 109, 6840−6844) quantify kinetics uptake limonene by particles containing humic acid, laboratory proxy for HULIS. The results indicate is taken up irradiated acid efficiently, with reactive coefficient 1.6 × 10–4. Consequently, simulations limonene–HULIS chemistry under conditions, simultaneously other aqueous processes, show could contribute 65% total at pH 4. importance warrants further studies and representation source models.

Язык: Английский

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Formation of highly oxygenated multifunctional compounds from cross-reactions of carbonyl compounds in the atmospheric aqueous phase

Atmospheric Environment, Год журнала: 2019, Номер 219, С. 117046 - 117046

Опубликована: Окт. 10, 2019

Язык: Английский

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Nitrogen-containing secondary organic aerosol formation by acrolein reaction with ammonia/ammonium

Atmospheric chemistry and physics, Год журнала: 2019, Номер 19(2), С. 1343 - 1356

Опубликована: Фев. 1, 2019

Abstract. Ammonia-driven carbonyl-to-imine conversion is an important formation pathway to the nitrogen-containing organic compounds (NOCs) in secondary aerosols (SOAs). Previous studies have mainly focused on dicarbonyl as precursors of light-absorbing NOCs. In this work, we investigated whether acrolein could also act NOC precursor. Acrolein simplest α, β-unsaturated mono-carbonyl compound, and it ubiquitous atmosphere. Experiments probing multiphase reactions well bulk aqueous-phase experiments were carried out study reactivity towards ammonia ammonium ions. Molecular characterization products based gas chromatography mass spectrometry, high-resolution surface-enhanced Raman spectrometry ultraviolet/visible spectrophotometry was used propose possible reaction mechanisms. We observed 3-methylpyridine (commonly known 3-picoline) phase Tedlar bags filled with gaseous or aerosols. ammonium-containing aqueous phase, oligomeric formulas (C3H4O)m(C3H5N)n pyridinium like (C3H4O)2C6H8N+ products. The proposed be intramolecular carbon–carbon addition hemiaminal, which resulted from sequential conversions molecules. formed but some revolatilize explaining observation bags. a carbonyl-to-hemiaminal product dimer 3-methylpyridine, while polymers acroleins propylene imines via condensation reactions. pH value effect liquid studied experiments. While forming both acidic alkaline conditions, favored moderately conditions. Both salts are materials. This work suggests that may serve precursor heterocyclic NOCs SOA. Therefore, aldehydes reduced nitrogen should taken into account source

Язык: Английский

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