HR: 1340h
AN: A13C-0927 [Abstracts]
TI: Measurement Of Atmospheric Peroxy Radicals By Chemical Conversion And Laser-induced Fluorescence
Technique
AU: * Ren, X
EM: xur1@psu.edu
AF: Pennsylvania State University, 503 Walker Building, University Park, PA 16801
United States
AU: Naik, C
EM: cvn1@psu.edu
AF: Pennsylvania State University, 503 Walker Building, University Park, PA 16801
United States
AU: Mao, J
EM: jzm145@psu.edu
AF: Pennsylvania State University, 503 Walker Building, University Park, PA 16801
United States
AU: Harder, H
EM: harder@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Postfach 3060, Mainz, 55020
Germany
AU: Martinez, M
EM: martinez@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Postfach 3060, Mainz, 55020
Germany
AU: Lesher, R
EM: lesher@essc.psu.edu
AF: Pennsylvania State University, 503 Walker Building, University Park, PA 16801
United States
AU: Brune, W H
EM: brune@meteo.psu.edu
AF: Pennsylvania State University, 503 Walker Building, University Park, PA 16801
United States
AB:
A new method for measuring atmospheric peroxy radicals is described based on chemical conversion and laser-induced
fluorescence (LIF) technique. Peroxy radicals are quantitatively converted into hydroperoxyl radicals (HO2) by the reactions
with NO in a low-pressure reactor. The produced HO2 is then detected with an LIF instrument. The characterization and
response of this instrument has been evaluated through the laboratory experiments as well as numeric simulations. Relative
responses of different organic groups of peroxy radicals to HO2 were measured and the conversion coefficients agree generally
well with the model calculations. The dependence of conversion coefficients on different experiment conditions was
investigated. For HO2, the LIF signal is calibrated with an HO2 source produced by the photolysis of H2O via a low-pressure
mercury lamp. Field measurements of peroxy radicals using this method were conducted at a rural site and preliminary results
are presented. The estimated accuracy of the derived HOxROx concentrations is about 40% with a 2¢ confidence level.
Typical detection limit is about 0.2 pptv for 1-minute averaging times.
DE: 0317 Chemical kinetic and photochemical properties
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005