HR: 1340h
AN: A13C-0942    [Abstracts]
TI: Intercomparison of Chemically Independent Peroxide Observations During INTEX-NA
AU: * O'Sullivan, D W
EM: osulliva@usna.edu
AF: U.S. Naval Academy, Chemistry Department 572 Holloway Road, Annapolis, MD 21402 United States
AU: Shen, H
EM: hshen@gso.uri.edu
AF: University of Rhode Island, GSO/CACS South Ferry Road, Narragansett, RI 02882 United States
AU: Heikes, B G
EM: bheikes@gso.uri.edu
AF: University of Rhode Island, GSO/CACS South Ferry Road, Narragansett, RI 02882 United States
AU: Crounse, J D
EM: crounjd@caltech.edu
AF: California Institute of Technology, MC 150-21 1200 E. California Blvd, Pasadena, CA 91106 United States
AU: Kwan, A J
EM: kwan@its.caltech.edu
AF: California Institute of Technology, MC 150-21 1200 E. California Blvd, Pasadena, CA 91106 United States
AU: Wennberg, P O
EM: wennberg@gps.caltech.edu
AF: California Institute of Technology, MC 150-21 1200 E. California Blvd, Pasadena, CA 91106 United States
AU: Pippin, M R
EM: m.r.pippin@larc.nasa.gov
AF: NASA Langley Research Center, Atmospheric Sciences Division , Hampton, VA 23681-0001 United States
AU: Crawford, J H
EM: James.H.Crawford@nasa.gov
AF: NASA Langley Research Center, Atmospheric Sciences Division , Hampton, VA 23681-0001 United States
AB: Gas phase peroxide measurements were preformed with two analytical techniques during the INTEX-NA field project. In the first method peroxides were partitioned into an aqueous phase in cyclone separators, the aqueous collection solution was injected on to an HPLC to separate hydrogen peroxide and organic peroxides. Separated peroxides were quantified by a post column derivatization reaction with p-hydroxyphenyl acetic acid and horse radish peroxidase forming a fluorescent dimer. This method is capable of identification and quantification of C₁ and C₂ organic peroxides. With the dual HPLC system a 30 sec integrated sample was analyzed every 90 sec. The second method employed chemical ionization mass spectrometry to quantify the peroxides via a direct gas phase ion-molecule reaction between the peroxide and a CFO₃^- ion. The Caltech CIMS technique makes a 0.5 sec measurement every 5 sec. Comparison of the observations of hydrogen peroxide by both techniques on the same time base results in nearly a 90% correspondence between the techniques. Both systems also quantified peroxyacetic acid (PAA) with a 72% correspondence between observations. The majority of discrepancies between the techniques occur for observations approaching the respective detection limits. The PAA observations are the first measurements for this compound in the troposphere. The specificity of the enzyme catalyzed technique for the peroxide moiety and the characteristic retention time, coupled to the unique mass number identification using CIMS lends confidence to the correct identification and quantification of PAA.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005