TY - JOUR
T1 - Development and characterization of an airborne-based instrument used to measure nitric acid during the NASA Transport and Chemical Evolution over the Pacific field experiment
AU - Zondlo, Mark Andrew
AU - Mauldin, R. Leon
AU - Kosciuch, Ed
AU - Cantrell, Christopher A.
AU - Eisele, Fred L.
PY - 2003/10/27
Y1 - 2003/10/27
N2 - A new inlet and instrument have been developed for the rapid measurement of gas phase nitric acid (HNO3) from an airborne platform. The inlet was kept near ambient temperatures with a very short sampling time (100 ms) to minimize desorption of particle nitrates. In addition, inlet surface adsorption problems were minimized by the use of extruded perfluoroalkoxy as a sampling material. Nitric acid was detected by selected ion chemical ionization mass spectrometry using deprontonated methanesulfonic acid as a reagent ion. Laboratory tests showed no interferences from NO, NO2, NO3, and N2O5 under wet (relative humidity (RH) = 100%) or dry (RH = 0%) conditions at levels exceeding those found in the troposphere. The inlet and instrument were flown on the NASA P-3B aircraft as part of the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) field campaign off the coast of Asia during February-April 2001. Nitric acid was measured every 5 s for a 3 s integration period with a limit of detection of ∼ 10 parts per trillion by volume (pptv). The instrument was calibrated by the addition of isotopically labeled H15 NO3 near the front of the ion source on a continual basis. Absolute uncertainties including systematic errors are the limit of detection (10 pptv) plus ±20% for HNO3 > 200 pptv, ±25% for HNO3 100-200 pptv, and ±30% for HNO3 < 100 pptv (±2 σ). Rapid changes in ambient HNO3 were resolved, suggesting minimal influences from instrument surfaces. Finally, the measurements compared favorably with the University of New Hampshire's mist chamber/ion chromatography instrument flown on board the NASA DC-8 aircraft during two intercomparison flights. The in-flight performance of the instrument is demonstrated under the wide range of conditions observed in TRACE-P.
AB - A new inlet and instrument have been developed for the rapid measurement of gas phase nitric acid (HNO3) from an airborne platform. The inlet was kept near ambient temperatures with a very short sampling time (100 ms) to minimize desorption of particle nitrates. In addition, inlet surface adsorption problems were minimized by the use of extruded perfluoroalkoxy as a sampling material. Nitric acid was detected by selected ion chemical ionization mass spectrometry using deprontonated methanesulfonic acid as a reagent ion. Laboratory tests showed no interferences from NO, NO2, NO3, and N2O5 under wet (relative humidity (RH) = 100%) or dry (RH = 0%) conditions at levels exceeding those found in the troposphere. The inlet and instrument were flown on the NASA P-3B aircraft as part of the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) field campaign off the coast of Asia during February-April 2001. Nitric acid was measured every 5 s for a 3 s integration period with a limit of detection of ∼ 10 parts per trillion by volume (pptv). The instrument was calibrated by the addition of isotopically labeled H15 NO3 near the front of the ion source on a continual basis. Absolute uncertainties including systematic errors are the limit of detection (10 pptv) plus ±20% for HNO3 > 200 pptv, ±25% for HNO3 100-200 pptv, and ±30% for HNO3 < 100 pptv (±2 σ). Rapid changes in ambient HNO3 were resolved, suggesting minimal influences from instrument surfaces. Finally, the measurements compared favorably with the University of New Hampshire's mist chamber/ion chromatography instrument flown on board the NASA DC-8 aircraft during two intercomparison flights. The in-flight performance of the instrument is demonstrated under the wide range of conditions observed in TRACE-P.
KW - CIMS TRACE-P inlet instrument
UR - http://www.scopus.com/inward/record.url?scp=0346020438&partnerID=8YFLogxK
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U2 - 10.1029/2002jd003234
DO - 10.1029/2002jd003234
M3 - Article
AN - SCOPUS:0346020438
SN - 0148-0227
VL - 108
SP - GTE 14-1 - 14-18
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
IS - 20
ER -