Production of Secondary Organic Aerosols by Heterogeneous Photocatalytic Oxidation of Isoprene

Secondary organic aerosols (SOA) have been associated with poor air quality and ill health effects, such as cardiopulmonary disease. Recent evidence has associated isoprene in the formation of significant amounts of SOA, but its mechanism is poorly understood. In this study we will describe studies on semiconductor or dust partial mediated photocatalytic oxidation of isoprene resulting in the formation SOA. The experimental approach involves simulating atmospheric conditions under UV light on dust particles and isoprene, as well as first generation atmospheric oxidation products such as methacrolein and methyl vinyl ketone. We have characterized reaction products through the use of high performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC-MS).  A number of oxidized products have been identified and are being investigated.