The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 800, P. 149419 - 149419
Published: Aug. 2, 2021
Language: Английский
Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(18), P. 7947 - 7957
Published: April 27, 2024
Volatility of organic aerosols (OAs) significantly influences new particle formation and the occurrence particulate air pollution. However, relationship between volatility OA level pollution (i.e., matter concentration) is not well understood. In this study, we compared chemical composition (identified by an ultrahigh-resolution Orbitrap mass spectrometer) (estimated based on a predeveloped parametrization method) OAs in urban PM2.5 (particulate with aerodynamic diameter ≤ 2.5 μm) samples from seven German Chinese cities, where concentration ranged light (14 μg m–3) to heavy (319 level. A large fraction (71–98%) compounds were attributable intermediate-volatility (IVOCs) semivolatile (SVOCs). The low-volatility (LVOCs) extremely (ELVOCs) decreased clean (28%) heavily polluted regions (2%), while that IVOCs increased 34 62%. We found average peak area-weighted different cities showed logarithmic correlation concentration, indicating increases increase Our results provide insights into PM levels deepen understanding pollutant evolution.
Language: Английский
Citations
7
The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 808, P. 152191 - 152191
Published: Dec. 5, 2021
Language: Английский
Citations
40
The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 838, P. 156189 - 156189
Published: May 23, 2022
Language: Английский
Citations
25
Environmental Science & Technology Letters, Journal Year: 2022, Volume and Issue: 9(11), P. 913 - 920
Published: Oct. 18, 2022
Excitation emission matrix (EEM) spectra coupled with parallel factor analysis (PARAFAC) have been used to characterize brown carbon (BrC). The molecular composition of PARAFAC components is not well understood in atmospheric science, which has impeded the accurate interpretation chemical changes and source apportionment BrC using EEM-PARAFAC methods. We assigned numerous formulas identified by Fourier transform ion cyclotron resonance mass spectrometry (both negative positive electrospray ionization modes) each PARAFAC-derived fluorescent component (FC) PM2.5 samples. Obvious differences characteristics sources were observed between hydrospheric FCs, indicating need for caution explaining FC based on FC. Previously protein-like (C4) less-oxidized humic-like (C1) associated mainly highly saturated photoresistant species less-polar anthropogenic emissions. Highly oxidized FCs aromatic unsaturated/phenolic compounds (high oxygen), potentially influenced biomass burning related secondary processes. seasonal variations light absorption similar those fluorescence intensity degree humification, oxygen). These linkages indicated potential investigating absorption, composition, BrC.
Language: Английский
Citations
24
Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(7)
Published: March 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.
Language: Английский
Citations
22
Current Pollution Reports, Journal Year: 2023, Volume and Issue: unknown
Published: Jan. 16, 2023
Language: Английский
Citations
12
Science Advances, Journal Year: 2025, Volume and Issue: 11(4)
Published: Jan. 24, 2025
Glaciers serve as natural archives for reconstructing past changes of atmospheric aerosol concentration and composition. While most ice-core studies have focused on inorganic species, organic compounds, which can constitute up to 90% the submicrometer mass, been largely overlooked. To our knowledge, this study presents first nontarget screening record secondary species preserved in a Belukha ice core (Siberia, Russian Federation), ranging from pre-industrial industrial period (1800-1980 CE). We identified total 398 molecules, primarily polar low-volatile compounds. Since 1950s, composition has changed, with appearance including nitrogen-containing deriving enhanced reactions anthropogenic NOx, or direct emissions. In addition, there was significant increase oxygen-to-carbon ratio (+3%) average carbon oxidation state (+18%) detected molecules compared period, suggesting an increased oxidative capacity atmosphere.
Language: Английский
Citations
0
npj Climate and Atmospheric Science, Journal Year: 2023, Volume and Issue: 6(1)
Published: March 23, 2023
Abstract The implementation of air pollution reduction measures has significantly reduced the concentration atmospheric fine particles (PM 2.5 ) in Beijing, among which “coal-to-gas” conversion may play a crucial role. However, effect this measure on brown carbon (BrC) is not well known. Here, chemical composition BrC humic-like fraction (HULIS-BrC) and water-insoluble (WI-BrC) were characterized for ambient PM samples collected Beijing before after measure. After measure, number HULIS-BrC compounds increased by ~14%, while WI-BrC decreased ~8%. intensity over 90% also correspondingly O/C ratios CHO CHON generally with increase after/before indicating that there more water-soluble highly oxygenated On contrary, than 80% decrease low decreased. This work sheds light differences between suggests future studies residential coal combustion secondary deserve further exploration.
Language: Английский
Citations
10
Atmospheric measurement techniques, Journal Year: 2025, Volume and Issue: 18(3), P. 603 - 618
Published: Feb. 3, 2025
Abstract. Due to US regulations, concentrations of hygroscopic inorganic sulfate and nitrate have declined in recent years, leading an increased importance the nature organic matter (OM). The hygroscopicity OM is poorly characterized because only a fraction multitude compounds atmosphere readily measured, there limited information on their behaviors. Hygroscopicity aerosol traditionally measured using humidified tandem differential mobility analyzer (HTDMA) or electrodynamic balance (EDB). EDB measures water uptake by single particle. For ambient chamber studies, HTDMA measurements provide particle size but not chemical composition. To fill this gap, we developed novel methodology assess particles collected Teflon filters. This method uses same filter sample for both characterization, thereby providing opportunity link with test method, were conducted laboratory ammonium sulfate, sodium chloride, glucose, malonic acid, which 25 mm filters generator sampler. Constant-humidity solutions (CHSs), including potassium barium chloride dihydrate, employed saturated form maintain relative humidity (RH) at approximately 84 %, 90 97 % small chambers. Our preliminary experiments revealed that, without pouch, feasible due rapid loss during weighing. Additionally, observed some absorption aluminum pouch itself. account this, concurrent loaded blank each RH level. Thus, dry placed pouches one side open RH-controlled chambers more than 24 h. wet samples blanks then weighed ultramicrobalance determine respective compound filter. net amount absorbed was calculated subtracting from that Hygroscopic parameters, water-to-solute (W / S) ratio, molality, mass solute (mfs), growth factors (GFs), measurements. results obtained are consistent those reported Extended Aerosol Inorganics Model (E-AIM) previous studies utilizing these compounds, highlighting accuracy new methodology. approach enables composition individual be assessed so complex mixtures, such as samples, total can parsed between components aerosol.
Language: Английский
Citations
0
Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(3)
Published: Feb. 6, 2025
Abstract Brown carbon (BrC) is known to have a great impact on atmospheric radiative forcing, but its absorption characteristics at the molecular level not well understood. This study investigated seasonal variations of light and composition BrC in Xi'an, China. Results showed that exhibited higher capacity cold (autumn winter) than warm seasons (spring summer). Nitrogen‐containing organic compounds were identified as important chromophores. Oxidized‐N originated from biomass burning emissions NO x /NO 3 − mediated oxidation reactions predominant seasons, whereas reduced‐N mainly formed NH /NH 4 + abundant seasons. These results contribute better understanding formation mechanisms nitrogen‐containing chromophores PM 2.5 .
Language: Английский
Citations
0