A gaseous nitric acid analyzer for the remote atmosphere based on the scrubber difference/NO-ozone chemiluminescence method.
An in situ nitric acid analyzer has been designed for sensing in the remote atmosphere. Its operation is based on measuring the concentration difference between the total odd nitrogen species (NO(y)) and HNO(3)-scrubbed NO(y). NO(y) was measured by an NO-ozone chemiluminescent detector equipped with a molybdenum converter. A temperature-controlled annular denuder coated with NaCl was used as a scrubber of gaseous HNO(3). The current detection limit of the HNO(3) analyzer was estimated to be 158 and 71 pptv (parts per trillion by volume) with an integration time of 2 and 10 min (2sigma), respectively. The analyzer was calibrated using standard gaseous HNO(3) to verify its performance. The HNO(3) concentrations measured by the scrubber difference and the NO-ozone chemiluminescence methods (SDCL method) were in agreement with those obtained by the denuder method within the experimental uncertainties (more than +/-4%). We conducted limited field observations of NO(y) and HNO(3) in the remote atmosphere using the newly designed SDCL method at Cape Hedo, Okinawa, Japan.
Sadanaga
Yasuhiro
Y
Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka, Sakai, Osaka 599-8531, Japan. sadanaga@chem.osakafu-u.ac.jp
Yuba
Akie
A
Kawakami
Jun-Ichi
J
Takenaka
Norimichi
N
Yamamoto
Masatoshi
M
Bandow
Hiroshi
H
D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000032:analysis*; D002138:Calibration; D002947:Cities; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D007564:Japan; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D008982:Molybdenum / Q000737:chemistry; D017942:Nitric Acid / Q000032:analysis*; D009569:Nitric Oxide / Q000032:analysis; D010126:Ozone / Q000032:analysis*; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
D000393:Air Pollutants; D009569:Nitric Oxide; D017942:Nitric Acid; D012965:Sodium Chloride; D010126:Ozone; D008982:Molybdenum