showing 4 related works from this author
Reactive oxygen species formed in aqueous mixtures of secondary organic aerosols and mineral dust influencing cloud chemistry and public health in th…
2017
Mineral dust and secondary organic aerosols (SOA) account for a major fraction of atmospheric particulate matter, affecting climate, air quality and public health. How mineral dust interacts with SOA to influence cloud chemistry and public health, however, is not well understood. Here, we investigated the formation of reactive oxygen species (ROS), which are key species of atmospheric and physiological chemistry, in aqueous mixtures of SOA and mineral dust by applying electron paramagnetic resonance (EPR) spectrometry in combination with a spin-trapping technique, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and a kinetic model. We found that substantial amounts of ROS includi…
Radical Formation by Fine Particulate Matter Associated with Highly Oxygenated Molecules
2019
Highly oxygenated molecules (HOMs) play an important role in the formation and evolution of secondary organic aerosols (SOA). However, the abundance of HOMs in different environments and their relation to the oxidative potential of fine particulate matter (PM) are largely unknown. Here, we investigated the relative HOM abundance and radical yield of laboratory-generated SOA and fine PM in ambient air ranging from remote forest areas to highly polluted megacities. By electron paramagnetic resonance and mass spectrometric investigations, we found that the relative abundance of HOMs, especially the dimeric and low-volatility types, in ambient fine PM was positively correlated with the formatio…
Atmospheric protein chemistry influenced by anthropogenic air pollutants: nitration and oligomerization upon exposure to ozone and nitrogen dioxide
2017
The allergenic potential of airborne proteins may be enhanced via post-translational modification induced by air pollutants like ozone (O3) and nitrogen dioxide (NO2). The molecular mechanisms and kinetics of the chemical modifications that enhance the allergenicity of proteins, however, are still not fully understood. Here, protein tyrosine nitration and oligomerization upon simultaneous exposure of O3 and NO2 were studied in coated-wall flow-tube and bulk solution experiments under varying atmospherically relevant conditions (5–200 ppb O3, 5–200 ppb NO2, 45–96% RH), using bovine serum albumin as a model protein. Generally, more tyrosine residues were found to react via the nitration pathw…
Reactive species formed upon interaction of water with fine particulate matter from remote forest and polluted urban air
2020
Interaction of water with fine particulate matter leads to the formation of reactive species (RS) that may influence the aging, properties, and health effects of atmospheric aerosols. In this study, we explore the RS yields of fine PM from remote forest (Hyytiälä, Finland) and polluted urban air (Mainz, Germany and Beijing, China) and relate these yields to different chemical constituents and reaction mechanisms. Ultrahigh-resolution mass spectrometry was used to characterize organic aerosol composition, electron paramagnetic resonance (EPR) spectroscopy with a spin-trapping technique was used to determine the concentrations •OH, O2•−, and carbon- or oxygen-centered organic radicals, …