AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Characterization of Organic Precursors and Products during Aqueous Hydroxyl Radical Oxidation of Po Valley, Italy and Fresno, CA Fog Water
Jeffrey R. Kirkland, Yong Lim, Lynn Mazzoleni, Jeffrey Collett, Stefano Decesari, M. Cristina Facchini, Amy P. Sullivan, Frank Keutsch, BARBARA TURPIN, Rutgers University
Abstract Number: 424 Working Group: Aerosol Chemistry
Abstract Aqueous chemistry in clouds, fogs and aerosols is known to alter properties of aerosols and budgets of gases. However, this chemistry remains only partially understood. Laboratory studies with simplified systems have been used to refine our understanding of aqueous processing and further our understanding of aqueous chemical mechanisms. However, few studies have explored aqueous chemistry in the complex mixtures found in atmospheric waters. Such studies will aid the identification of potentially important precursors to aqueous processing and organic aerosol formation.
In this work, fogwater samples collected in Fresno, CA and Po Valley, Italy (winter 2006; 2011-2012) were oxidized with hydroxyl radicals. Hydroxyl radicals were generated in situ by photolysis of hydrogen peroxide at a rate of 0.2 - 0.4 M/s. Experimental samples were analyzed by ion chromatography, electrospray ionization (ESI) mass spectrometry (MS), ultra-high resolution Fourier transform ion cyclotron resonance MS, and MS-MS to characterize precursors and products. Control experiments were also conducted. Oxalate and pyruvate were among the products in all experiments conducted with OH, but not in control experiments (with UV or hydrogen peroxide). Several reactive species were identified in the ESI positive mode. Based on mass fragments, several precursors of OH oxidation were identified.