AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Understanding the Relationship between Aerosol Oxidative Potential, Electrophilicity, and Chemical Composition: Role of Particle-Phase Carbonyl Compounds
JIN CHEN, Cody Cullen, Justin Dingle, Alexander Frie, Stephen Zimmerman, Justin Min, Roya Bahreini, Ying-Hsuan Lin, University of California, Riverside
Abstract Number: 405 Working Group: Linking Aerosol Oxidative Potential with Chemical Composition and Biological Endpoints
Abstract Recent toxicological and epidemiological studies have shown strong evidence for adverse effects of ambient particulate matter (PM) on human health such as respiratory and cardiovascular diseases. PM represents a complex mixture consisting of numerous individual chemicals. Carbonyl compounds, which play an important role in atmospheric oxidation processes, are ubiquitous in the environment in both gas and particle phases. Carbonyls, such as aldehydes, are electrophiles that can react with biological nucleophiles (e.g., cysteine and histidine residues), and result in cellular oxidative stress and cell death. Studies have shown that structurally different aldehyde derivatives vary in electrophilic activities which can lead to different levels of cytotoxicity. The connections between their oxidative potential (thiol reactivity) and chemical characteristics have not been fully understood. In this study, we will measure the oxidative potential of representative particle-phase carbonyl compounds with authentic standards using dithiothreitol (DTT) assay, and compare the consumption of DTT with their electrophilicity index. Further, we will test the oxidative potential of selected model systems from mixtures generated in controlled chamber experiments. Gas chromatography-mass spectrometry (GC-MS) with O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBHA) derivatization will be used to identify and quantify the carbonyl compounds from chamber samples. The relationship between aerosol oxidative potential, electrophilicity, and chemical composition will be discussed.