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ANALYSIS OF SECONDARY ORGANIC AEROSOL COMPOUNDS FROM THE PHOTOOXIDATION OF D-LIMONENE IN THE PRESENCE OF NO X AND THEIR DETECTION IN AMBIENT PM 2.5
Citation:
JAOUI, M., E. CORSE, T. E. KLEINDIENST, J. H. OFFENBERG, M. LEWANDOWSKI, AND E. O. EDNEY. ANALYSIS OF SECONDARY ORGANIC AEROSOL COMPOUNDS FROM THE PHOTOOXIDATION OF D-LIMONENE IN THE PRESENCE OF NO X AND THEIR DETECTION IN AMBIENT PM 2.5. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 40(12):3807-3828, (2006).
Impact/Purpose:
1. Conduct laboratory studies with scientists from Caltech, the University of Antwerp, and the NOAA Aeronomy Laboratory to improve treatments of SOA Chemistry and N2O5 chemistry in CMAQ.
2. Analyze ambient PM2.5 samples in Research Triangle Park, NC, Detroit, MI and Pasadena, CA and when available compare field data with CMAQ predictions obtained from AMD.
3. In 2005 recommend improvements to AMD for the treatment of SOA chemistry in CMAQ.
4. By the end of FY06, deliver an improved SOA chemistry model to AMD who will incorporate the model into CMAQ.
5. By the end of 2007, deliver an improved N2O5 chemistry model to AMD who will incorporate the model into CMAQ.
Description:
Chemical analysis of secondary organic aerosol (SOA) from the photooxidation of a d-limonene/NOx/air mixture was carried out. SOA, generated in a smog chamber, was collected on Zefluor filters. To determine the structural characteristics of the compounds, the filter samples were solvent extracted and derivatized using analytical techniques that characterize functional groups contained in the compound: BF3-methanol derivatization was used for carboxylic groups, BSTFA for acidic and nonacidic hydroxyl groups, and PFBHA for ketone and aldehyde groups. The resulting derivative compounds were analyzed by GC-MS in the methane CI and EI modes. GC-MS analysis showed the occurrence of 103 oxygenated organic compounds in the filter extracts, 28 of which were identified. The major components include five tracer compounds previously identified from the photooxidation of α-pinene/NOX or β-pinene/NOx systems, C4-C6 linear dicarboxylic acids, ketolimononaldehyde, limonic acid, and ketolimonic acid. Time profiles, yields, and proposed reaction schemes are provided for selected compounds. The laboratory SOA yield was 0.51 at a SOA concentration of 1470 µg m-3. To determine the contributions of SOA products from d-limonene to ambient PM2.5, an analysis was performed for eight ambient PM2.5 samples collected in the southeastern United States in summer 2003. GC-MS analysis showed the occurrence of 21 d-limonene SOA compounds, indicating the impact of d-limonene on the regional aerosol burden. Based on our analysis, two compounds (# 55 and 69), not observed from the photooxidation of α-pinene or β-pinene, are candidate tracers for d-limonene in atmospheric particulate matter.