A5081353141- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Indoor Air Quality and Microbial Exposure
- Spectroscopy and Laser Applications
- Atmospheric aerosols and clouds
- Advanced Chemical Sensor Technologies
- Vehicle emissions and performance
- Mass Spectrometry Techniques and Applications
- Biosensors and Analytical Detection
- Adsorption, diffusion, and thermodynamic properties of materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Advanced biosensing and bioanalysis techniques
- Water Quality Monitoring and Analysis
- Aquaculture Nutrition and Growth
- Plant responses to elevated CO2
- Catalytic Processes in Materials Science
- Atmospheric and Environmental Gas Dynamics
National Institute for Environmental Studies
2017-2023
Kyoto University
2016-2020
Madurai Kamaraj University
2014
Chromophoric water-soluble organic matter in atmospheric aerosols potentially plays an important role aqueous reactions and light absorption by organics. The fluorescence chemical–structural characteristics of the chromophoric submicron collected urban, forest, marine environments (Nagoya, Kii Peninsula, tropical Eastern Pacific) were investigated using excitation–emission matrices (EEMs) a high-resolution aerosol mass spectrometer. A total three types chromophores, two with similar to those...
Water-soluble organic nitrogen (WSON) affects the formation, chemical transformations, hygroscopicity, and acidity of aerosols as well biogeochemical cycles nitrogen. However, large uncertainties exist in origins formation processes WSON. Submicrometer aerosol particles were collected at a suburban forest site Tokyo summer 2015 to investigate relative impacts anthropogenic biogenic sources on WSON formations their linkages with liquid water (ALW). The concentrations (ave. 225 ± 100 ngN m–3)...
Abstract. Secondary organic aerosols (SOAs) affect human health and climate change prediction; however, the factors (e.g., temperature, acidity of pre-existing particles, oxidants) influencing their formation are not sufficiently resolved. Using a compact chamber, temperature dependence SOA yields chemical components in from α-pinene ozonolysis were systematically investigated under 278, 288, 298 K temperatures using neutral ((NH4)2SO4) acidic (H2SO4+((NH4)2SO4)) seed aerosols. with m/z less...
A simple method was developed for the preparation of gold nanorods embedded in an amine functionalized silicate sol–gel matrix (Au–TPDT NRs) aqueous medium and its application towards optical sensing mercuric (Hg2+) ions demonstrated. colorimetric sensor Hg2+ using Au NRs matrix. The detection carried out a based on localized surface plasmon resonance (LSPR) absorption spectra showed significant blue shift LSPR band upon addition ions. It observed that optimum concentration into Au–TPDT NR...
To better understand precursors of dicarboxylic acids in ambient secondary organic aerosol (SOA), we studied C4–C9 present SOA formed from the oxidation toluene, naphthalene, α-pinene, and isoprene. were analyzed by offline derivatization gas chromatography–mass spectrometry. We revealed that C4 including succinic acid, maleic fumaric malic DL-tartaric meso-tartaric acid are produced photooxidation toluene. Since barely occurs nature, it is a potential tracer photochemical reaction products....
Abstract. HO2 uptake kinetics onto ambient aerosols play pivotal roles in tropospheric chemistry but are not fully understood. Field measurements of aerosol chemical and physical properties should be linked to molecular-level kinetics; however, given that the reactivity is low, traditional analytical techniques unable achieve this goal. We developed an online approach precisely investigate lower-limit values (i) reactivities gases (ii) coefficients (γ) during 2019 Air QUAlity Study (AQUAS)...
Abstract. Traditional yield curve analysis shows that semi-volatile organic compounds are a major component of secondary aerosols (SOAs). We investigated the volatility distribution SOAs from α-pinene ozonolysis using positive electrospray ionization mass and dilution- heat-induced evaporation measurements. Laboratory chamber experiments were conducted on ozonolysis, in presence absence OH scavengers. Among these, we identified not only products, but also less volatile highly oxygenated...
Volatility determines the gas–particle partitioning of organic compounds. is thus a key property needed to understand behavior aerosol (OA) in atmosphere. Various studies have been conducted experimentally measure and numerically simulate distributions OA volatility. The observed evaporation rates generally slower than assuming instantaneous equilibrium volatility estimated from secondary (SOA) formation experiments. Particle-phase diffusion and/or low-volatility compounds, such as oligomers...
The atmospheric oxidation of monoterpenes leads to the formation secondary organic aerosol (SOA). While numerous works have been carried out in past characterise SOA at a molecular level, structural elucidation compounds remains challenging owing lack authentic standard compounds. In this work, structures α-pinene originating dimeric esters with m/z 357 (C17H25O8-) and 367 (C19H27O7-) were characterised using UPLC/ESI(-)IMS-TOFMS2 (ultra-performance liquid chromatography coupled ion mobility...
The gas-particle mixture produced in a smog chamber from the ozonolysis of limonene was further oxidised with NO3 radicals, O3 and OH radicals to study NO3, initiated aging biogenic secondary organic aerosol (SOA). results mass spectrometry analysis showed that similar yields SOA were by all three oxidants used experiments after 1-h aging, suggesting have formation potentials aging. proton transfer reaction-quadrupole interface time-of-flight signals m/z 139, 151, 153 167 decreased upon...
Abstract. Traditional yield curve analysis shows that semi-volatile organic compounds are a major component of secondary aerosols (SOAs). We investigated the volatility distribution SOAs from α-pinene ozonolysis using positive electrospray ionization mass and dilution- heat-induced evaporation measurements. Laboratory chamber experiments were conducted on ozonolysis, in presence absence OH scavengers. Among these, we identified not only products, but also less volatile highly oxygenated...
For source apportionment by tracer method of secondary organic aerosol (SOA), the ratios to total SOA mass (fSOA) were determined during oxidation toluene, naphthalene, α-pinene, and isoprene a series laboratory experiments. Seven anthropogenic tracers maintaining an aromatic ring structure, including 4-nitrophthalic acid 3,5-dinitrosalicylic, newly investigated as chamber study together with 21 traditional biogenic SOA. Experiments OH-initiated VOCs conducted function initial VOC/NOx ratio....
Abstract. Secondary organic aerosol (SOA) is of great importance, affecting human health and the prediction climate change; however, factors (e.g., temperature, acidity pre-existing particles, oxidants) influencing its formation are not sufficiently resolved. In this study, a compact Teflon atmospheric simulation chamber developed, in which reactions pressure conditions can be performed with controlled humidity, oxidation agents, seed particle acidity. Using chamber, α-pinene ozonolysis SOA...