HR: 1340h
AN: A43C-0068    [Abstracts]
TI: Measurements of C$_{1}$-C$_{5}$ Alkyl Nitrates Using Gas Chromatography/Negative Ion Chemical Ionization Mass Spectrometry
AU: * Sato, K
EM: sato.keiichi@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 3058506 Japan
AU: Tanimoto, H
EM: tanimoto@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 3058506 Japan
AU: Imamura, T
EM: imamura@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 3058506 Japan
AB: We applied gas chromatography/negative ion chemical ionization mass spectrometry (GC/NI-CIMS) technique for measurements of alkyl nitrates (RONO$_{2}$) in the atmosphere, since it could be sensitive to high electron affinity species as well as selective by making use of the selected ion monitoring detection. In this study, a number of experiments have been made to improve its performance using multi-components RONO$_{2}$ standard gases, which were gravimetrically prepared in high-pressurized gas cylinders. We found that RONO$_{2}$s typically produced [RO-H$_{2}$]$^{-}$ and NO$_{2}$$^{-}$ as their NI-CIMS fragment ions except MeONO$_{2}$ and tert-RONO$_{2}$, producing RO$^{-}$ and NO$_{2}$$^{-}$. Relative abundance of [RO-H$_{2}$]$^{-}$ to NO$_{2}$$^{-}$ showed distinct increasing features as the increase of the carbon numbers of RONO$_{2}$. Based on these results, the instrument, particularly a gas chromatograph, an ion source, and a quadrupole mass filter were optimized to achieve both sensitivity and selectivity simultaneously. Excellent linearity was confirmed in the ppbv regions. The detection limit and precision were in the sub-ppbv range and less than 10% for 7 RONO$_{2}$s studied, respectively. Experimental details, the instrument performance, and the stability of the standard gases will be presented.
DE: 0365 Troposphere--composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting