HR: 0800h
AN: A51B-0033    [Abstracts]
TI: Ponderosa pine forest volatiles: comparison of PTR-MS and PIT-MS instruments
AU: * Welsh-Bon, D
EM: daniel.welshbon@noaa.gov
AF: NOAA, Aeronomy Laboratory, Boulder, CO 80305 United States
AU: * Welsh-Bon, D
EM: daniel.welshbon@noaa.gov
AF: CIRES, Coorperative Institute for Research in Environmental Sciences, Boulder, CO 80309 United States
AU: * Welsh-Bon, D
EM: daniel.welshbon@noaa.gov
AF: University of Colorado, Department of Chemistry, Boulder, CO 80309 United States
AU: Warneke, C
EM: carsten.warneke@noaa.gov
AF: NOAA, Aeronomy Laboratory, Boulder, CO 80305 United States
AU: Warneke, C
EM: carsten.warneke@noaa.gov
AF: CIRES, Coorperative Institute for Research in Environmental Sciences, Boulder, CO 80309 United States
AU: de Gouw, J A
EM: Joost.DeGouw@noaa.gov
AF: NOAA, Aeronomy Laboratory, Boulder, CO 80305 United States
AU: de Gouw, J A
EM: Joost.DeGouw@noaa.gov
AF: CIRES, Coorperative Institute for Research in Environmental Sciences, Boulder, CO 80309 United States
AU: Holzinger, R
EM: holzing@nature.Berkeley.EDU
AF: University of California Berkeley, Department of Environmental Science, Berkeley, CA 94720 United States
AU: Palitzsch, K
EM: kat_in_india@yahoo.com
AF: University of California Berkeley, Department of Environmental Science, Berkeley, CA 94720 United States
AU: Bouvier-Brown, N
EM: nbouvier@nature.berkeley.edu
AF: University of California Berkeley, Department of Environmental Science, Berkeley, CA 94720 United States
AU: Goldstein, A
EM: ahg@nature.berkeley.edu
AF: University of California Berkeley, Department of Environmental Science, Berkeley, CA 94720 United States
AU: Fall, R
EM: fall@colorado.edu
AF: CIRES, Coorperative Institute for Research in Environmental Sciences, Boulder, CO 80309 United States
AU: Fall, R
EM: fall@colorado.edu
AF: University of Colorado, Department of Chemistry, Boulder, CO 80309 United States
AB: Proton-transfer-reaction mass spectrometry (PTR-MS) has become a standard tool for measurement of volatile organic compounds in ambient air. During a field campaign in a ponderosa pine forest (Blodgett Forest Research Station) in July of 2005, we used a recently-developed ion trap version of this instrument (PIT-MS) for parallel measurements with PTR-MS. Ambient air measurements (16 days) were followed by branch enclosure measurements (6 days). Preliminary analysis suggests good agreement between the two instruments. Local plant emissions of reactive VOCs consist largely of 2-methyl-3-buten-2-ol (MBO) but daily wind patterns transport isoprene and its oxidation products from lower elevations to the research station. PTR-MS alone cannot easily distinguish MBO from isoprene because much of the MBO fragments in the PTR-MS drift tube to m69, the same mass as isoprene. PTR-MS also cannot distinguish the two primary oxidation products of isoprene, methyl vinyl ketone (MVK) and methacrolein (MACR) which have the same protonated mass (m71). Collision induced dissociation (CID), a tool for compound identification, was performed using PIT-MS to attempt to resolve the presence of these species. CID was also used to examine other masses where isomers could occur including m59 (acetone and propanal), m73 (methyl ethyl ketone and butanal), m87 (MBO and butanedione) and m137 (monoterpenes).
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005