title: Thermal dissociation cavity attenuated phase shift spectroscopy for continuous measurement of total peroxy and organic nitrates in the clean atmosphere.
abstract: A thermal dissociation cavity attenuated phase shift spectroscopy (TD-CAPS) instrument was developed for measuring total peroxy nitrates (PNs) and organic nitrates (ONs) concentrations in the clean atmosphere. This instrument is easy to operate and can be applied to continuous measurement of PNs and ONs. A continuously measurable system is convenient to perform observations, especially in remote areas. Three lines (NO2, PNs, and ONs lines) were used for thermal dissociation. The NO2 line contains a quartz tube that is not heated, while the PN and ON lines contain quartz tubes that are heated at 433 K and 633 K, respectively. The concentrations of NO2, NO2 + PNs, and NO2 + PNs + ONs can be obtained from the NO2, PN, and ON lines, respectively. The lower limit values of the detection limit (3σ) for PNs and ONs were estimated to be 21 parts per trillion by volume with an integration time of 2 min. PNs were selectively thermally decomposed in the PNs line and formed NO2 quantitatively. In the ONs line, both PNs and ONs were thermally decomposed to produce NO2 quantitatively, but partial decomposition of HNO3 at 633 K interfered with the ONs measurement. Therefore, a HNO3 scrubber is required before the ONs line. Continuous observations were conducted with the TD-CAPS instrument in a remote area, and the instrument performed well for obtaining PNs and ONs concentrations.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sadanaga
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Takaji
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Ayana
authors.initials: A
authors.lastname: Ishiyama
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Institute of Nature and Environmental Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Matsuki
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Bandow