Variations of aminiums in fine particles at a suburban site in Guangzhou, China: Importance of anthropogenic and natural emissions

Abstract

Amines are important nitrogen-containing compounds in fine particles (PM2.5) in the atmosphere. Observations are necessary for in-depth understanding on the characteristics, sources and atmospheric processes of aminiums. In this study, the observation of ten C1–C4 aminiums in PM2.5 was conducted in January and March of 2021 in suburban Guangzhou. The concentration and composition of aminiums showed significant differences between the pollution episodes and non-episode periods. Seasonal difference was also observed between winter and spring. The influence of meteorological factors (i.e., wind speed, atmospheric pressure, temperature and relative humidity) was investigated. The variations of aminiums were also affected by different sources. Anthropogenic sources were suggested to be major contributor to aminiums in the pollution episodes, while biological sources were important sources to aminiums in the non-episode periods, especially in spring. Positive matrix factorization receptor model was applied to investigate the source contributions, and four major sources were identified. The results show that vehicular emission, industrial production, biological emission and soil/dust were the major sources of aminiums. This study emphasizes the importance of source contribution and meteorological conditions on the variations of aminiums, which provides further understanding of organic nitrogen in the atmosphere.