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| Titel |
Measurement of HONO, HNCO, and other inorganic acids by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS): application to biomass burning emissions |
| VerfasserIn |
J. M. Roberts, P. Veres, C. Warneke, J. A. Neuman, R. A. Washenfelder, S. S. Brown, M. Baasandorj, J. B. Burkholder, I. R. Burling, T. J. Johnson, R. J. Yokelson, J. Gouw |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 3, no. 4 ; Nr. 3, no. 4 (2010-07-23), S.981-990 |
| Datensatznummer |
250001213
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| Publikation (Nr.) |
 copernicus.org/amt-3-981-2010.pdf |
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| Zusammenfassung |
| A negative-ion proton-transfer chemical ionization mass spectrometric
technique (NI-PT-CIMS), using acetate as the reagent ion, was applied to the
measurement of volatile inorganic acids of atmospheric interest:
hydrochloric (HCl), nitrous (HONO), nitric (HNO3), and isocyanic (HNCO)
acids. Gas phase calibrations through the sampling inlet showed the method
to be intrinsically sensitive (6–16 cts/pptv), but prone to inlet effects
for HNO3 and HCl. The ion chemistry was found to be insensitive to
water vapor concentrations, in agreement with previous studies of carboxylic
acids. The inlet equilibration times for HNCO and HONO were 2 to 4 s,
allowing for measurement in biomass burning studies. Several potential
interferences in HONO measurements were examined: decomposition of
HNO3·NO3− clusters within the CIMS, and
NO2-water production on inlet surfaces, and were quite minor (≤1%, 3.3%, respectively). The detection limits of the method were
limited by the instrument backgrounds in the ion source and flow tube, and
were estimated to range between 16 and 50 pptv (parts per trillion by
volume) for a 1 min average. The comparison of HONO measured by CIMS and
by in situ FTIR showed good correlation and agreement to within 17%. The method
provided rapid and accurate measurements of HNCO and HONO in controlled
biomass burning studies, in which both acids were seen to be important
products. |
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