Development of a selective light-emitting diode photolytic NO(2) converter for continuously measuring NO(2) in the atmosphere.
A photolytic converter of nitrogen dioxide (NO(2)) to nitric oxide (NO) using light-emitting diodes (LEDs) has been designed to measure NO(2) in the troposphere. The typical electrical power consumption of the photolytic converter (PLC) is only 44 W. The maximum conversion efficiency of NO(2) to NO of the photolytic converter is around 90%, which is higher than that of metal halides or high-pressure Xe arc lamps (up to ∼70%). The conversion efficiency of the PLC was almost constant for at least 2.5 months. The conversion efficiency of peroxyacetyl nitrate by the LED-PLC was measured to be 2.6 ± 0.1% (1σ). The interference of HONO using the PLC was experimentally estimated to be less than 3%, which is within the uncertainty of the instrument. An intercomparison of NO(2) measurements between the PLC-CLD and the laser-induced fluorescence (LIF) technique was conducted, and the NO(2) concentrations measured by the PLC-CLD method were in agreement with those obtained by the LIF technique, within the uncertainties of the instruments. Continuous observations were made on Fukue Island, a remote area. These results demonstrate the performance of the PLC for continuous ambient measurements.
Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan. sadanaga@chem.osakafu-u.ac.jp
Yasuhiro
Y
Sadanaga
Yuki
Y
Fukumori
Tadashi
T
Kobashi
Makoto
M
Nagata
Norimichi
N
Takenaka
Hiroshi
H
Bandow
D001272:Atmosphere / Q000737:chemistry*; D004566:Electrodes; D007834:Lasers; D009569:Nitric Oxide / Q000737:chemistry; D009585:Nitrogen Dioxide / Q000032:analysis* / Q000737:chemistry*; D009608:Nitrous Acid / Q000737:chemistry; D010463:Peracetic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D010782:Photolysis; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014466:Ultraviolet Rays
D009569:Nitric Oxide; D010463:Peracetic Acid; D009585:Nitrogen Dioxide; C004185:peroxyacetyl nitrate; D009608:Nitrous Acid