Exploring the formation potential and optical properties of secondary organic aerosol from the photooxidation of selected short aliphatic ethers
Lin Du , Jianqiang Zhu , Jianlong Li , Tao WANG , Jianmin CHEN , Abdelwahid Mellouki , Christian GEORGE , Yujing MU , Hong LI
DOI:10.1016/j.jes.2020.03.050
Received September 30, 2019,Revised , Accepted March 20, 2020, Available online April 16, 2020
Volume 32,2020,Pages 82-90
Secondary organic aerosol (SOA) formation potential for six kinds of short aliphatic ethers has been studied. The size distribution, mass concentration, and yield of SOA formed by ethers photooxidation were determined under different conditions. The results showed that all six ethers can generate SOA via reaction with OH radicals even under no seed and NOx-free condition. The mass concentration for six seedless experiments was less than 10 µg/m3 and the SOA yields were all below 1%. The strong increase in the SOA formation was observed when the system contained ammonium sulfate seed particles, while SOA yield decreased under the high-NOx condition. SOA composition was analyzed using offline methods. Infrared spectra indicated that there are complex components in the particle-phase including carbonyls acid and aldehydes species. Moreover, the aqueous filter extracts were analyzed using ultraviolet-visible spectrometer and fluorescence spectrophotometer. For the fresh methyl n-butyl ether SOA, the largest absorption peak occurs at 280 nm and there exists slightly absorption in the 300–400 nm. Excitation-emission matrices display the distinct peak at excitation/emission = 470 nm/480 nm according to the fluorescence spectrum. These findings are important considerations of formation for ether SOA that can eventually be included in atmospheric models.
