Studies of the Atmospheric Chemistry of Energy-Related Volatile Organic Compounds and of Their Atmospheric Reaction Products
Roger Atkinson
Air Pollution Research Center
University of California
Riverside, CA 92521
909-787-4191
fax 909-423-4908
ratkins@mail.ucr.edu
J. Arey
Air Pollution Research Center
University of California
Large quantities of volatile organic compounds (VOCs) are emitted into the atmosphere from biogenic and anthropogenic sources. In the atmosphere, these VOCs are transformed by photolysis and/or reaction with OH radicals, NO3 radicals and O3. There is therefore a need to understand, in detail, the reactions involved in the atmospheric degradation of emitted organic compounds. This includes not only measurements of the rates of reaction and identification and quantification of products formed from the atmospheric reactions of directly emitted chemicals, but also corresponding studies of the first- and later-generation products. In this experimental program, we are using the analytical methods and facilities available at the Air Pollution Research Center at the University of California, Riverside, to investigate the atmospherically important reactions of selected VOCs emitted from biogenic and anthropogenic sources and of their reaction products. We will use our PE SCIEX direct air sampling, atmospheric pressure ionization tandem mass spectrometer (API-MS/MS) in conjunction with in situ Fourier transform infrared (FT-IR) spectroscopy, gas chromatography (GC-FID, GC-FTIR and GC-MS), and product derivatization with GC analyses to identify and quantify VOC reaction products, and to address critical gaps in our understanding of VOC chemistry.
Alkyl-PAH are present in diesel fuel, exhaust from diesel-fueled vehicles and other combustion sources, and they have been observed in ambient air. During the first year of this program, we have begun studies of the atmospheric chemistry of alkyl-PAH, including 1- and 2-methylnaphthalene and the 12 dimethylnaphthalene isomers, and will examine the products of the OH radical-initiated reactions as a function of NO2 concentration to attempt to determine whether the OH-PAH adducts are reacting with NO2 or O2. We will also continue methods development for using our API-MS to quantify multifunctional product species such as hydroxynitrates, hydroxycarbonyls, carbonyl-nitrates, etc., from the atmospheric reactions of anthropogenic and biogenic VOCs. This will include the synthesis of hydroxynitrates and carbonyl-nitrates to be used as quantitative standards.
More information about this research cn be found in the viewgraphs from a presentation at the Atmospheric Sciences Program Annual Meeting held in March 2002.
General information on research activities by the principle investigators can be found online at