A5067202043- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric Ozone and Climate
- Atmospheric aerosols and clouds
- Ferroelectric and Piezoelectric Materials
- Air Quality Monitoring and Forecasting
- Indoor Air Quality and Microbial Exposure
- Diabetes, Cardiovascular Risks, and Lipoproteins
- Vehicle emissions and performance
- Marine and coastal ecosystems
- Photorefractive and Nonlinear Optics
- Plant responses to elevated CO2
- Toxic Organic Pollutants Impact
- Spectroscopy and Laser Applications
- Isotope Analysis in Ecology
- Diabetes Management and Research
- Energy and Environment Impacts
- Adipose Tissue and Metabolism
- Impact of Light on Environment and Health
- Environmental Chemistry and Analysis
- X-ray Diffraction in Crystallography
- Liver Disease Diagnosis and Treatment
- Chronic Kidney Disease and Diabetes
- Thyroid Cancer Diagnosis and Treatment
- Acoustic Wave Resonator Technologies
China Southern Power Grid (China)
2024
Savannah River National Laboratory
2024
University of Georgia
2024
Purdue University West Lafayette
2017-2023
Southern Medical University
2022-2023
Qilu Hospital of Shandong University
2014-2023
Daping Hospital
2023
Army Medical University
2023
Division of Chemistry
2023
Nanfang Hospital
2022-2023
Emissions from biomass burning are a significant source of brown carbon (BrC) in the atmosphere. In this study, we investigate molecular composition freshly emitted organic aerosol (BBOA) samples collected during test burns sawgrass, peat, ponderosa pine, and black spruce. We demonstrate that both BrC absorption chemical light-absorbing compounds depend significantly on type fuels. Common chromophores selected BBOA include nitro-aromatics, polycyclic aromatic hydrocarbon derivatives,...
Lag Ba'Omer, a nationwide bonfire festival in Israel, was chosen as case study to investigate the influence of major biomass burning event on light absorption properties atmospheric brown carbon (BrC). The chemical composition and optical BrC chromophores were investigated using high performance liquid chromatography (HPLC) platform coupled photo diode array (PDA) resolution mass spectrometry (HRMS) detectors. Substantial increase coefficient observed during night-long event. Most attributed...
Atmospheric brown carbon (BrC) is a significant contributor to light absorption and climate forcing. However, little known about fundamental relationship between the chemical composition of BrC its optical properties. In this work, light-absorbing secondary organic aerosol (SOA) was generated in PNNL chamber from toluene photo-oxidation presence NOx (Tol-SOA). Molecular structures components were examined using nanospray desorption electrospray ionization (nano-DESI) liquid chromatography...
The HUmic-LIke Substances (HULIS) fraction isolated from aerosol samples collected at a rural location of the Pearl River Delta Region (PRD), China, during harvest season was analyzed by both positive and negative mode electrospray ionization (ESI) coupled with an ultrahigh resolution mass spectrometer (UHRMS). With remarkable resolving power accuracy ESI-UHRMS, thousands elemental formulas were identified. Formulas detected in (ESI+) (ESI-) complement each other due to differences...
Light-absorbing components of atmospheric organic aerosols, which are collectively termed "brown carbon" (BrC), ubiquitous in the atmosphere. They affect absorption solar radiation by aerosols atmosphere and human health as some them have been identified potential toxins. Understanding sources, formation, evolution, environmental effects BrC requires molecular identification characterization light-absorption properties chromophores. Identification is challenging due to complexity aerosols....
Particulate matter (PM)-mediated reactive oxygen species (ROS) generation has been implicated in health effects posed by PM. Humic-like substances (HULIS) are an unresolved mixture of water-extracted organic compounds from atmospheric aerosol particles or isolated fog/cloudwater samples. In this study, we use a cell-free dithiothreitol (DTT) assay to measure ROS production mediated HULIS. The HULIS samples aerosols collected at rural location and suburban the Pearl River Delta, China. our...
Atmospheric brown carbon (BrC) is an important contributor to light absorption and climate forcing by aerosols. Reactions between small water-soluble carbonyls ammonia or amines have been identified as one of the potential pathways BrC formation. However, detailed chemical characterization chromophores has challenging their formation mechanisms are still poorly understood. Understanding impeded lack suitable methods which can unravel variability complexity mixtures. This study applies high...
Humic-like substances (HULIS) in ambient aerosols collected at seven locations East Asia were analyzed using electrospray ionization (ESI) coupled with an ultra-high-resolution mass spectrometer (UHRMS). Locations included a 3 km high mountaintop site Taiwan, rural, suburban, and urban the Pearl River Delta (PRD), South China, Taiwan. Organosulfates (OS) HULIS fraction tentatively identified through accurate measurements MS/MS spectra interpretation. In two samples regional background...
Abstract. The light-absorbing organic aerosol (OA) commonly referred to as “brown carbon” (BrC) has attracted considerable attention in recent years because of its potential affect atmospheric radiation balance, especially the ultraviolet region and thus impact photochemical processes. A growing amount data indicated that BrC is prevalent atmosphere, which motivated numerous laboratory field studies; however, our understanding relationship between chemical composition optical properties...
Abstract. To better understand the effects of wildfires on air quality and climate, it is important to assess occurrence chromophoric compounds in smoke characterize their optical properties. This study explores molecular composition light-absorbing organic aerosol, or brown carbon (BrC), sampled at Missoula Fire Sciences laboratory as a part FIREX Fall 2016 lab intensive. A total 12 biomass fuels from different plant types were tested, including gymnosperm (coniferous) angiosperm...
The inclusion of organic compounds in freshly emitted sea spray aerosol (SSA) has been shown to be size-dependent, with an increasing fraction smaller particles. Here we have used electrospray ionization-high resolution mass spectrometry negative ion mode identify nascent collected throughout a 25 day mesocosm experiment. Over 280 from ten major homologous series were tentatively identified, including saturated (C8–C24) and unsaturated (C12–C22) fatty acids, acid derivatives (including...
Abstract. Secondary organic aerosol (SOA) accounts for a large fraction of submicron particles in the atmosphere. SOA can occur amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The transition between occurs at glass temperature (Tg). We have recently developed method to estimate Tg pure compounds containing carbon, hydrogen, oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based their atomic O : C ratio....
Abstract. HUmic-LIke Substances (HULIS) are an abundant unresolved mixture of organic compounds present in atmospheric samples. Biomass burning (BB) has been recognized as important primary source HULIS, but measurements HULIS various fresh BB particles lacking. In this work, emissions rice straw was measured a number field and chamber experiments. The average HULIS/OC ratio 0.34±0.05 μg/μgC, showing small variance among under different conditions. influence on ambient levels investigated by...
Ambient particulate matter (PM) can cause adverse health effects via their ability to produce reactive oxygen species (ROS). Humic-like substances (HULIS), a complex mixture of amphiphilic organic compounds, have been demonstrated contain the majority redox activity in water-extractable fraction PM. Reduced nitrogen such as alkaloids resulting from biomass burning emissions, are among HULIS constituents. In this study, we examined activities pyridine, imidazole and alkyl derivatives using...
Organic carbon (OC) and elemental (EC) in PM 2.5 were measured hourly with a semicontinuous thermal‐optical analyzer Beijing, China, during four seasons from November 2005 to October 2006. The average OC concentrations at Peking University (PKU) site urban Beijing 20 ± 19, 12 7, 10 5, 18 11 μ gC/m 3 winter, spring, summer, autumn, respectively. Distinct seasonal diurnal patterns of observed, their significantly influenced by the changes sources, emission rates, mesoscale meteorology. impacts...
Methacryloyl peroxynitrate (MPAN), the acyl of methacrolein, has been suggested to be an important secondary organic aerosol (SOA) precursor from isoprene oxidation. Yet, mechanism by which MPAN produces SOA through reaction with hydroxyl radical (OH) is unclear. We systematically evaluate three proposed mechanisms in controlled chamber experiments and provide first experimental support for theoretically-predicted lactone formation pathway + OH reaction, producing...
Concentrations of elemental carbon (EC), monoxide (CO), and dioxide (CO 2 ) were measured in Beijing between 2005 2006. EC was every hour with a semicontinuous thermal optical analyzer. The observed concentrations rather uniform over distance about 50 km from the observation site. annual average CO 6.9 μ gC m −3 1120 parts per billion by volume, respectively. these species increased decreasing near‐surface wind speed (WS). slopes CO‐CO , EC‐CO correlations are used to estimate major sources....
Abstract The radiative effects of biomass‐burning aerosols on regional and global scales can be substantial. Accurate modeling the smoke requires wavelength‐dependent measurements parameterizations their optical properties in UV visible spectral ranges along with improved description chemical composition. To address this issue, we used a recently developed approach to retrieve time‐ spectral‐dependent ambient from 300 650 nm wavelengths during nighttime bonfire festival Israel. During...
Abstract. Humic-like substances (HULIS), the hydrophobic part of water-soluble organic carbon (WSOC), account for a significant fraction PM2.5 mass. Their source studies are so far largely qualitative. In this study, HULIS and WSOC were determined in 100 samples collected 2009 at an urban site (Guangzhou) suburban (Nansha) Pearl River Delta South China. The annual average concentration was 4.83 4.71 μg m−3, constituting 8.5 10.2% mass, while HULIS-C (the component HULIS) contributed 48 57%...
Low bulk diffusivity inside viscous semisolid atmospheric secondary organic aerosol (SOA) can prolong equilibration time scale, but its broader impacts on growth and size distribution dynamics are poorly understood. Here, we present quantitative insights into the effects of evaporation kinetics SOA formed under dry conditions from photooxidation isoprene in presence a bimodal consisting Aitken (ammonium sulfate) accumulation (isoprene or α-pinene SOA) mode particles. Aerosol composition...
The molecular composition of humic-like substances (HULIS) in different aerosol samples was analyzed using an ultrahigh-resolution mass spectrometer to investigate the influence biomass burning on ambient composition. HULIS background aerosols were characterized with numerous formulas similar biogenic secondary organic aerosols. abundance nitrogen-containing compounds (NOC), including bases (N-bases) and nitroaromatics, increased dramatically affected by crop residue farm field. distribution...