Size-Resolved Mixing States and Sources of Amine-Containing Particles in the East China Sea

Single-particle aerosol mass spectrometry was employed during a cruise campaign from 3 to 27 June 2017 to investigate the mixing states and sources of amine-containing particles in the East China Sea. A total of 271,160 particles were successfully identified, and 19,861 of these particles contained amines. Monomethylamine (MMA), trimethylamine (TMA), and diethylamine (DEA) were the most abundant amines. They accounted for 50%, 16%, and 29%, respectively, of the amine-containing particles. The size distributions (mean +/- geometric standard deviation) of the MMA-, TMA-, and DEA-containing particles peaked at 0.58 +/- 0.12, 0.56 +/- 0.10, and 0.40 +/- 0.10 mu m, respectively. Using an adaptive resonance theory neural network algorithm, four major clusters of amine-containing particles were categorized: carbon-rich particles, K-rich particles, Na-rich particles, and metal-rich particles. The MMA-containing particles contained abundant elemental carbon-, K-, Mn-, and Fe-rich particles, which exhibit higher concentrations in land air masses, indicating that the MMA mainly originated from terrestrial anthropogenic sources. The TMA-containing particles contained abundant organic and elemental carbon-, EC-, K-, and V-rich particles. High concentrations of TMA-containing particles were measured near ports, indicating the significant contribution of the ports. The DEA-containing particles contained abundant organic and elemental carbon-, K-, Mn-, Cu-, and Na-rich particles, and high concentrations of DEA-containing particles were observed in remote marine areas, suggesting that both terrestrial anthropogenic and marine sources are important contributors to DEA-containing particles.