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Absorption of Inhaled NO_2

Enami, Shinichi and Hoffmann, Michael R. and Colussi, A. J. (2009) Absorption of Inhaled NO_2. Journal of Physical Chemistry B, 113 (23). pp. 7977-7981. ISSN 1520-6106.

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Nitrogen dioxide (NO_2), a sparingly water-soluble π-radical gas, is a criteria air pollutant that induces adverse health effects. How is inhaled NO_2(g) incorporated into the fluid microfilms lining respiratory airways remains an open issue because its exceedingly small uptake coefficient (γ 10^(−7)−10^(−8)) limits physical dissolution on neat water. Here, we investigate whether the biological antioxidants present in these fluids enhance NO_2(g) dissolution by monitoring the surface of aqueous ascorbate, urate, and glutathione microdroplets exposed to NO_2(g) for 1 ms via online thermospray ionization mass spectrometry. We found that antioxidants catalyze the hydrolytic disproportionation of NO_2(g), 2NO_2(g) + H_2O(l) = NO_3^−(aq) + H^+(aq) + HONO, but are not consumed in the process. Because this function will be largely performed by chloride, the major anion in airway lining fluids, we infer that inhaled NO_2(g) delivers H^+, HONO, and NO_3^− as primary transducers of toxic action without antioxidant participation.

Item Type:Article
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URLURL TypeDescription
Enami, Shinichi0000-0002-2790-7361
Hoffmann, Michael R.0000-0001-6495-1946
Colussi, A. J.0000-0002-3400-4101
Additional Information:© 2009 American Chemical Society. Received: March 24, 2009; Revised Manuscript Received: May 5, 2009. Publication Date (Web): May 15, 2009. S.E. thanks the Japan Society for the Promotion of Science Research Fellowship for Young Scientists. This project was supported by the National Science Foundation (ATM-0534990). Supporting Information: Additional data, data analysis, and experimental details. This material is available free of charge via the Internet at
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Japan Society for the Promotion of Science (JSPS)UNSPECIFIED
Issue or Number:23
Record Number:CaltechAUTHORS:20090821-081123560
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:15212
Deposited By: George Porter
Deposited On:09 Sep 2009 17:57
Last Modified:03 Mar 2020 13:01

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