Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 10, 2008 | Supplemental Material
Journal Article Open

Ozonolysis of Uric Acid at the Air/Water Interface


Uric acid (UA) epoxide, peroxide, and ozonide species produced in aqueous UA microdroplets exposed to O3(g) are detected by online mass spectrometry within ∼1 ms. UA conversions are independent of its initial concentration below ∼0.1 mM and are unaffected by addition of excess H2O2 or t-butanol. UA reactivity increases ∼380 times from pH 4 to 7, which is at variance with the pH-independent rates reported for the UA + O3(aq) reaction in bulk water. At pH ∼7, UA and ascorbic acid (AH2) microdroplets react with O3(g) at similar rates, although UA is ∼40 times more reactive than AH2 toward O3(aq) in bulk water. Only the UA epoxide, plus traces of UA peroxide, are formed upon mixing UA(aq) and O3(aq) solutions. We infer that the gas−liquid ozonolysis of UA proceeds in an interfacial aqueous medium quite distinct from bulk water. Thus, UA, a component of the pulmonary epithelial lining fluid that scavenges atmospheric O3(g) into less deleterious species (similar to AH2), is rendered inactive below pH ∼5. The potential implications of these findings on synergistic health effects between tropospheric ozone and acidic particulates are briefly analyzed.

Additional Information

© 2008 American Chemical Society. Received: December 21, 2007; In Final Form: February 25, 2008. Publication Date (Web): March 7, 2008. Project financed by NSF Grant ATM-0714329. C. D. Vecitis helped with MS/MS experiments. S.E. is grateful to the JSPS Research Fellowship for Young Scientists.

Attached Files

Supplemental Material - jp712010k-file003.pdf


Files (164.6 kB)
Name Size Download all
164.6 kB Preview Download

Additional details

August 19, 2023
October 23, 2023