Atmospheric Environment, Год журнала: 2024, Номер 337, С. 120775 - 120775
Опубликована: Авг. 27, 2024
Язык: Английский
Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(4), С. 2859 - 2875
Опубликована: Март 2, 2023
Abstract. Aromatic carbonyls (e.g., methoxybenzaldehydes), an important class of photosensitizers, are abundant in the atmosphere. Photosensitization and nitrate-mediated photo-oxidation can occur simultaneously, yet studies about their interactions, particularly for aqueous secondary organic aerosol (aqSOA) formation, remain limited. This study compared non-phenolic (3,4-dimethoxybenzaldehyde, DMB) phenolic (vanillin, VL) methoxybenzaldehydes as photosensitizers aqSOA formation via guaiacol (GUA) oxidation absence presence ammonium nitrate (AN) under atmospherically relevant cloud fog conditions. GUA by triplet excited states DMB (3DMB∗) (GUA + was ∼ 4 times faster exhibited greater light absorption than 3VL∗ VL). Both VL formed composed oligomers, functionalized monomers, oxygenated ring-opening species, N-containing products AN. The observation N-heterocycles such imidazoles indicates participation reactions. majority generated comprises potential brown carbon (BrC) chromophores. Oligomerization functionalization dominated VL, but appeared to be more due contributions from itself. AN did not significantly affect kinetics, it had distinct effects on product distributions, likely differences photosensitizing abilities structural features VL. In particular, extensive fragmentation AN, increased oligomers may VL-derived phenoxy radicals induced ⚫OH or ⚫NO2 photolysis. Furthermore, nitrated observed both alone imply that photosensitized reactions promote nitration. work demonstrates how non-carbonyl phenol oxidation. Potential interactions between photosensitization photolysis were also elucidated. These findings facilitate a better understanding highlight importance these
Язык: Английский
Процитировано
26
Environmental Science & Technology, Год журнала: 2024, Номер 58(10), С. 4716 - 4726
Опубликована: Фев. 27, 2024
The mechanism and kinetics of reactive oxygen species (ROS) formation when atmospheric secondary organic aerosol (SOA) is exposed to solar radiation are poorly understood. In this study, we combined an in situ UV–vis irradiation system with electron paramagnetic resonance (EPR) spectroscopy characterize the photolytic ROS aqueous extracts SOA formed by oxidation isoprene, α-pinene, α-terpineol, toluene. We observed substantial free radicals, including •OH, superoxide (HO2•), radicals (R•/RO•) upon irradiation. Compared dark conditions, radical yield was enhanced a factor ∼30 for •OH 2–10 emergence radicals. Total peroxide measurements showed decreases contents after photoirradiation, indicating that peroxides can be important source A liquid chromatography interfaced high-resolution mass spectrometry used detect number form adducts spin trap, BMPO. types detected photolysis model compounds indicated carbonyls Norrish type I mechanisms plays role formation. serves as driving force cloud fog processing SOA.
Язык: Английский
Процитировано
12
The Science of The Total Environment, Год журнала: 2024, Номер 919, С. 170836 - 170836
Опубликована: Фев. 10, 2024
Язык: Английский
Процитировано
11
Environmental Science & Technology, Год журнала: 2024, Номер 58(35), С. 15722 - 15731
Опубликована: Авг. 23, 2024
Nitrites (NO
Язык: Английский
Процитировано
5
The Journal of Physical Chemistry A, Год журнала: 2023, Номер 127(24), С. 5209 - 5221
Опубликована: Июнь 7, 2023
The photochemical aging of biomass-burning organic aerosols (BBOAs) by exposure to sunlight changes the chemical composition over its atmospheric lifetime, affecting toxicological and climate-relevant properties BBOA particles. This study used electron paramagnetic resonance (EPR) spectroscopy with a spin-trapping agent, 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO), high-resolution mass spectrometry, kinetic modeling photosensitized formation reactive oxygen species (ROS) free radicals in mixtures benzoquinone levoglucosan, known tracer molecules. EPR analysis irradiated solutions showed dominant hydroxyl (•OH), which are products reaction triplet-state water, also yielding semiquinone radicals. In addition, hydrogen (H•) were observed, not detected previous studies. They most likely generated decomposition irradiation levoglucosan led substantial carbon- oxygen-centered radicals, became prominent higher fraction levoglucosan. High-resolution spectrometry permitted direct observation BMPO-radical adducts demonstrated •OH, derived from oxidation Mass superoxide radical (BMPO-OOH) that did appear spectra. Kinetic processes successfully reproduced time evolution observed BMPO •OH H• EPR. model was then applied describe would occur absence BMPO, predicting generation HO2• due dissolved oxygen. These results imply photoirradiation containing photosensitizers induces ROS secondary chemistry drive atmosphere.
Язык: Английский
Процитировано
12
Environmental Science & Technology, Год журнала: 2023, Номер 57(28), С. 10295 - 10307
Опубликована: Июль 7, 2023
Elevated particulate sulfate concentrations have been frequently observed in coastal areas when air masses are influenced by continental emissions, especially combustion sources like biomass burning. We studied the SO2 uptake laboratory-generated droplets containing incense smoke extracts and sodium chloride (IS–NaCl) under irradiation found enhanced production over pure NaCl droplets, attributable to photosensitization induced constituents IS. Low relative humidity high light intensity facilitated formation increased coefficient IS–NaCl particles. Aging of IS particles further production, secondary oxidant promoted proportions nitrogen-containing CHN oxygen- CHON species air. Experiments using model compounds syringaldehyde, pyrazine, 4-nitroguaiacol verified enhancements formation. This work provides experimental evidence via triggered multiphase oxidation processes Our results can shed on possible interactions between sea salt burning aerosols enhancing production.
Язык: Английский
Процитировано
11
Analytical Chemistry, Год журнала: 2025, Номер unknown
Опубликована: Фев. 19, 2025
In this study, we present the formation of artifacts from simple phenolic compounds and derivatives in SFC-UV-MS analysis. These ions were detected only when UV detector was turned on, demonstrating that light is necessary for their formation. Based on high-resolution mass spectrometry (HRMS) analysis 21 standards negative electrospray ionization mode, annotated as where CO2 or NO2 had been added to molecular ion an lost a functional group. approximately half cases, MS signal artifact higher than ion. Although can complicate nontarget does not match with analyzed standard, demonstrated phenomenon aid structural identification isomers due specific ions. addition, overall increased which help detection low-abundance compounds, one compound─ anisole─ thanks artifact. Thus, aim article make researchers aware effect together advantages disadvantages
Язык: Английский
Процитировано
0
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Год журнала: 2025, Номер 335, С. 125948 - 125948
Опубликована: Фев. 22, 2025
Язык: Английский
Процитировано
0
Air Quality Atmosphere & Health, Год журнала: 2025, Номер unknown
Опубликована: Март 1, 2025
Язык: Английский
Процитировано
0
Atmospheric Environment, Год журнала: 2025, Номер unknown, С. 121189 - 121189
Опубликована: Март 1, 2025
Язык: Английский
Процитировано
0