Molecular Characterization of Polar Compounds in Urban Organic Aerosols Using Negative-Ion Electrospray Ionization (ESI) Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

摘要

Organic compounds, which contribute a significant fraction of particle matter (PM), have been demonstrated to play active roles in several areas of atmospheric chemistry. Their effects on the environment, human health, and climate change are determined by the molecular nature of these chemical species. Due to the high complexity of the molecular composition, identification of organic compounds is still challenging. Recently, ultra-high resolution mass spectrometers have been used to characterize the organic compounds in aerosol, which has led to breakthroughs in aerosol chemistry. Published works mostly focused on the extracts obtained by polar solvents, such as methanol and water. However, the organic compounds with relative lower polarity, which could account for the major components of the organic compounds in PM2.5, were rarely investigated by high resolution mass spectrometry. In this work, we compare the organic compounds in dichloromethane (DCM), methanol, and water extracts of ambient aerosols.