Outbreaks of Ethyl-Amines during Haze Episodes in North China Plain: A Potential Source of Amines from Ethanol Gasoline Vehicle Emission

Abstract

Amines, as the vital precursors of new particle formation (NPF), have received considerable attention because of their outbreak characteristics and sources of haze episodes. During the hourly resolution haze observations conducted in Hebei Province, a significant outbreak of amine concentrations, four times higher in the burst periods (BPs, 625 ± 383 ng m–3) than that in nonburst periods (NBPs, 164 ± 62.1 ng m–3), was observed. Especially for ethyl-amines (sum of diethylamine and triethylamine), its ratio to methyl-amines (sum of monomethylamine, dimethylamine, and trimethylamine) increased from 0.62 ± 0.35 (NBPs) to 3.28 ± 2.04 (BPs). This is the first study to determine the amine composition profiles of three types of sources, namely, mobile sources, residential solid fuel combustion sources (RSFC), and biological sources (BS), for exploring the sources of ethyl-amines. The widely used ethanol gasoline vehicles (EGVs) in Hebei Province were found to primarily emit ethyl-amines, and the ratio to methyl-amine emitted from EGVs (2.82 ± 1.1) is much larger than RSFC (0.94 ± 0.4) and BS (0.87 ± 0.4). Considering the widespread application of EGVs in China, the role of EGV emissions in haze outbreaks requires urgent attention.