Title: | Light Absorption of Secondary Organic Aerosol: Composition and Contribution of Nitroaromatic Compounds |
Author(s): | Xie M; Chen X; Hays MD; Lewandowski M; Offenberg J; Kleindienst TE; Holder AL; |
Address: | "School of Environmental Science and Engineering, Nanjing University of Information Science & Technology , Nanjing 210044, China" |
ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Print) 0013-936X (Linking) |
Abstract: | "Secondary organic aerosol (SOA) can affect the atmospheric radiation balance through absorbing light at shorter visible and UV wavelengths. However, the composition and optical properties of light-absorbing SOA is poorly understood. In this work, SOA filter samples were collected during individual chamber experiments conducted with three biogenic and eight aromatic volatile organic compound (VOC) precursors in the presence of NO(X) and H(2)O(2). Compared with the SOA generated using the aromatic precursors, biogenic SOA generally exhibits negligible light absorption above 350 nm; the aromatic SOA generated in the presence of NO(X) shows stronger light absorption than that generated with H(2)O(2). Fifteen nitroaromatic compound (NAC) chemical formulas were identified and quantified in SOA samples. Their contributions to the light absorption of sample extracts were also estimated. On average, the m-cresol/NO(X) SOA sample has the highest mass contribution from NACs (10.4 +/- 6.74%, w/w), followed by naphthalene/NO(X) (6.41 +/- 2.08%) and benzene/NO(X) (5.81 +/- 3.82%) SOA. The average contributions of NACs to total light absorption were at least two times greater than their average mass contributions at 365 and 400 nm, revealing the potential use of chromophoric NACs as brown carbon (BrC) tracers in source apportionment and air quality modeling studies" |
Keywords: | *Aerosols Carbon *Hydrogen Peroxide Molecular Weight; |
Notes: | "MedlineXie, Mingjie Chen, Xi Hays, Michael D Lewandowski, Michael Offenberg, John Kleindienst, Tadeusz E Holder, Amara L eng EP-C-15-008/EPA/EPA/ EPA999999/ImEPA/Intramural EPA/ 2017/09/21 Environ Sci Technol. 2017 Oct 17; 51(20):11607-11616. doi: 10.1021/acs.est.7b03263. Epub 2017 Sep 29" |