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 May 7, 2013 | Supplemental Material
Journal Article Open

Reactive Uptake and Photo-Fenton Oxidation of Glycolaldehyde in Aerosol Liquid Water


The reactive uptake and aqueous oxidation of glycolaldehyde were examined in a photochemical flow reactor using hydrated ammonium sulfate (AS) seed aerosols at RH = 80%. The glycolaldehyde that partitioned into the aerosol liquid water was oxidized via two mechanisms that may produce aqueous OH: hydrogen peroxide photolysis (H_(2)O_(2) + hν) and the photo-Fenton reaction (Fe_(II) + H_(2)O_(2) + hν). The uptake of 80 (±10) ppb glycolaldehyde produced 2–4 wt % organic aerosol mass in the dark (k_(H)* = (2.09–4.17) × 10^6 M atm^(–1)), and the presence of an OH source increased the aqueous uptake by a factor of 4. Although the uptake was similar in both OH-aging mechanisms, photo-Fenton significantly increased the degree of oxidation (O/C = 0.9) of the aerosols compared to H_(2)O_(2) photolysis (O/C = 0.5). Aerosol organics oxidized by photo-Fenton and H_(2)O_(2) photolysis resemble ambient "aged" and "fresh" OA, respectively, after the equivalent of 2 h atmospheric aging. No uptake or changes in particle composition occurred on dry seed aerosol. This work illustrates that photo-Fenton chemistry efficiently forms highly oxidized organic mass in aerosol liquid water, providing a possible mechanism to bridge the gap between bulk-phase experiments and ambient particles.

Additional Information

© 2013 American Chemical Society. Received: February 2, 2013; Revised: April 2, 2013; Accepted: April 4, 2013; Published: April 4, 2013. This research was supported by the National Science Foundation grant AGS-1057183. T. B. Nguyen acknowledges funding from the Coco and Foster Stanback Postdoctoral Fellowship in Global Environmental Science. We are grateful to Prof. S. A. Nizkorodov (UC Irvine) for his contribution of a portion of the equipment used in this work. We thank Prof. P. O. Wennberg and Prof. M. R. Hoffman for helpful discussions.


The Henry's law constant (k_H) of glycolaldehyde, adapted from Betterton and Hoffmann (1988), should have been written as 4.14 × 10^4 M atm^(-1) instead of 4.14 × 10^5 M atm^(-1).

Attached Files

Supplemental Material - es400538j_si_001.pdf


Files (1.6 MB)
Name Size Download all
1.6 MB Preview Download

Additional details

August 19, 2023
October 20, 2023