HR: 0830h
AN: A11F-0051    [PDF]
TI: Test of practical utilization of PTR-MS and observation of the urban air in Tokyo during summer time
AU: * Miyakawa, Y
EM: yunko@atmchem.apchem.metro-u.ac.jp
AF: Applied Chemistry, Faculty of Engineering, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji-shi, Tokyo, 1920397 Japan
AU: Kato, S
EM: shungo@atmchem.apchem.metro-u.ac.jp
AF: Japan Science and Technology Corporation, 1-8, Honcho 4-chome, Kawaguchi City, Saitama, 3320012 Japan
AU: Hayashi, I
EM: ichiro@atmchem.apchem.metro-u.ac.jp
AF: Applied Chemistry, Faculty of Engineering, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji-shi, Tokyo, 1920397 Japan
AU: Ichikawa, M
EM: ichikawa@atmchem.apchem.metro-u.ac.jp
AF: Applied Chemistry, Faculty of Engineering, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji-shi, Tokyo, 1920397 Japan
AU: Kajii, Y
EM: kajii@atmchem.apchem.metro-u.ac.jp
AF: Applied Chemistry, Faculty of Engineering, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji-shi, Tokyo, 1920397 Japan
AB: Proton transfer reaction mass spectrometry (PTR-MS) is a technique that has been developed recently. It has several advantages for measurement of volatile organic compounds (VOCs) in the atmosphere. PTR-MS instrument can observe VOCs with high time resolution, and can also measure oxygenated volatile organic compounds (OVOCs). Furthermore, PTR-MS does not require carrier gases. Although PTR-MS is available as a commercial instrument from the company (IONICON), the instrument is not enough characterized for general users. In this study, PTR-MS was calibrated with a permeator, several kinds of standard gases and data from PTR-MS were compared with that of GC-FID. Substances used to try calibration with the permeator were follows; acetonitryle (CH$_{3}$CN), methanol (CH$_{3}$OH), acetone (CH$_{3}$COCH$_{3}$), acetaldehyde (CH$_{3}$CHO). Results of these substances had good linearity. In the case of standard gases that contained aromatics, isoprene and dimethylsulfide (DMS), they also showed good linearities. Measurements in the urban air in Tokyo from June to August were carried out. Tokyo Metropolitan University (TMU) is located in the west of Tokyo. Although TMU is urban site, there are many trees near the observation site. Therefore, the results were affected by the emission from plants. Aromatics, isoprene, terpenes were also measured by GC-FID in the beginning in June, and the results of PTR-MS were compared with the result of GC-FID. There was good correlation for all substances, especially of benzene, toluene, and xylene. CH$_{3}$CHO and isoprene showed clear diurnal changes. These concentrations were higher in the daytime and lower at night. HCHO signal was much lower than actual concentration because protonated ion had a reverse reaction with water. But clear diurnal change was observed. If proper correction is applied, HCHO could be measured by PTR-MS. Acetone did not show such clear diurnal changes. This result suggested that acetone had been affected by solvent emission rather than photochemical production. Peaks of methylvinylketone (MVK) and methacroleine (MACR) were shifted to later time than isoprene because MVK and MACR were produced by the oxidation of isoprene.
DE: 0317 Chemical kinetic and photochemical properties
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting