HR: 1340h
AN: A33D-1568    [Abstracts]
TI: High Resolution LC/MS Identification of Water Soluble Organic Matter in Atmospheric Fog Water Samples
AU: * Mazzoleni, L R
EM: mazzoleni@lanl.gov
AF: Los Alamos National Laboratory, Earth and Environmental Sciences Mail Stop D469, Los Alamos, NM 87545, United States
AU: Shen, X
EM: shen@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science Campus Delivery 1371, Fort Collins, CO 80523, United States
AU: Sullivan, A P
EM: sullivan@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science Campus Delivery 1371, Fort Collins, CO 80523, United States
AU: Collett, J L
EM: collett@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science Campus Delivery 1371, Fort Collins, CO 80523, United States
AB: Polar organic compounds are found ubiquitously in ambient aerosol, cloud, and fog water samples. Many of these compounds are highly water soluble and have been suspected to affect aerosol and water uptake properties. Despite many efforts, the nature, identity, and origin of these compounds are still not well understood. This stems largely from the many analytical challenges these compounds present. To overcome the presented analytical challenges we have used a combination of liquid chromatography and high resolution mass spectrometry with accurate mass measurement. Our interest is to first understand the identity of these compounds. The high resolution mass spectrometer measurements with 3 ppm mass accuracy allow us to calculate the empirical formulas giving strong indications to the identity of unknown organic compounds. Additionally, the high sensitivity of this instrument allows for the analysis of water samples without pre- concentration or chemical derivatization techniques. We found hundreds of individual organic components in our fog water samples collected in Fresno, California. These organic compounds include molecules containing oxides of nitrogen, oxides of sulfur, and sometimes both together in the same molecule. We studied 25 of these compounds across a 9 hour fog event and measured the changes in concentration during the event. These changes were grouped into three trends implying differences in fog processing of polar organic compounds.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0330 Geochemical cycles (1030)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting