HR: 08:30h
AN: A51H-02    [Abstracts]
TI: Measurement of aerosol organic compounds during TexAQS 2006 using a novel collection/thermal-desorption PTR-ITMS instrument
AU: * Thornberry, T
EM: troy.thornberry@noaa.gov
AF: NOAA Earth System Research Laboratory, Chemical Sciences Division, 325 Broadway, Boulder, CO 80305, United States
AU: * Thornberry, T
EM: troy.thornberry@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80309, United States
AU: Murphy, D M
EM: daniel.m.murphy@noaa.gov
AF: NOAA Earth System Research Laboratory, Chemical Sciences Division, 325 Broadway, Boulder, CO 80305, United States
AU: Thomson, D S
EM: david.s.thomson@noaa.gov
AF: NOAA Earth System Research Laboratory, Chemical Sciences Division, 325 Broadway, Boulder, CO 80305, United States
AU: Thomson, D S
EM: david.s.thomson@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80309, United States
AU: Welsh-Bon, D
EM: daniel.welshbon@noaa.gov
AF: NOAA Earth System Research Laboratory, Chemical Sciences Division, 325 Broadway, Boulder, CO 80305, United States
AU: Welsh-Bon, D
EM: daniel.welshbon@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80309, United States
AU: Warneke, C
EM: carsten.warneke@noaa.gov
AF: NOAA Earth System Research Laboratory, Chemical Sciences Division, 325 Broadway, Boulder, CO 80305, United States
AU: Warneke, C
EM: carsten.warneke@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80309, United States
AU: Bates, T S
EM: tim.bates@noaa.gov
AF: NOAA Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115, United States
AU: Coffman, D
EM: derek.cofffman@noaa.gov
AF: NOAA Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115, United States
AU: Lerner, B
EM: brian.lerner@noaa.gov
AF: NOAA Earth System Research Laboratory, Chemical Sciences Division, 325 Broadway, Boulder, CO 80305, United States
AU: Lerner, B
EM: brian.lerner@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80309, United States
AU: Williams, E J
EM: eric.j.williams@noaa.gov
AF: NOAA Earth System Research Laboratory, Chemical Sciences Division, 325 Broadway, Boulder, CO 80305, United States
AU: Williams, E J
EM: eric.j.williams@noaa.gov
AF: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80309, United States
AB: Knowledge of the organic species present in atmospheric aerosols is needed in order to understand their effect on aerosol microphysical and optical properties, to resolve outstanding questions about important organic aerosol sources and formation mechanisms, and to elucidate the role of aerosols in the chemistry of the atmosphere through their interaction with gas-phase compounds. The measurement of aerosol organic compounds poses a significant experimental challenge due to the complexity and large number of organic species and the low concentration at which individual species are present. A new instrument that utilizes proton- transfer-reaction mass spectrometry (PTR-MS) to probe the organic composition of atmospheric aerosols has been developed to investigate semi-volatile and condensed-phase organic species in the atmosphere. Aerosols are collected by impaction and then thermally desorbed into a carrier gas that transports the organic analyte molecules into a drift tube where they are ionized by reaction with H₃O⁺ ions. Analyte ions are detected using an ion trap mass spectrometer. The instrument was deployed for the first time during summer 2006 in the Texas Air Quality Study (TexAQS 2006) aboard NOAA R.V. Ronald H. Brown. Signals significantly above detection limit were observed at a number of masses during periods of elevated photochemical activity when aerosol loading increased in the 0.5-1 μm size range and aerosol mass spectrometer (AMS) measurements indicated increased organic mass. Different masses exhibited different temporal behaviors, indicating varying composition of the aerosol organic fraction even during periods when the AMS organic mass (OA) loading was relatively constant. Plumes of aerosol-phase pyridine were observed during sampling near the entrance to the Houston Ship Channel, indicating a relatively local source and rapid partitioning to the aerosol phase. These field results and results of laboratory instrument performance experiments will be presented.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting