AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Analysis of Atmospheric Water-Soluble Organic Compounds Using H-NMR and Liquid Chromatography High Resolution Mass Spectrometry
VERA SAMBUROVA, Lynn Mazzoleni, Alexander Laskin, Julia Laskin, Parichehr Saranjampour, Anna Gannet Hallar, Douglas Lowenthal, Barbara Zielinska, Desert Research Institute
Abstract Number: 531 Working Group: Aerosol Chemistry
Abstract It is well known that atmospheric aerosols play an important role in many atmospheric processes, such as cloud formation, light absorption-reflection, droplets formation, etc. Many studies have shown that organic compounds are a major fraction of the total aerosol mass. Inorganic components are well studied at the present time, while the fraction of organic compounds requires more investigation and analysis. The chemical characterization of the organic fraction is a challenging task, because this fraction is a complex mixture of different individual organic species, with a various functional groups (e.g. carboxylic, aliphatic, aromatic, phenolic, sulfate, nitrate, etc.).
In the present study, H-NMR and liquid chromatography (LC) high resolution mass spectrometry (MS) were used to characterize atmospheric water-soluble organic compounds and analyze their functional groups. Aerosol samples were collected during the summer of 2010 at the Storm Peak Laboratory on Mt. Werner, Steamboat, CO (3210 m AMSL). High-volume samplers equipped with size-selective PM2.5 inlets were used to collected particles on pre-cleaned 8”×10” Teflon-impregnated glass fiber filters. 38 aerosol samples were extracted with high purity water and combined into six composites. The aqueous composites were pre-concentrated using freeze-drying technique which prevents losses of light organic compounds. XAD-8 / XAD-4 resin columns were applied for separation of water-soluble organic matter from inorganic constituents. A high resolution LTQ-Orbitrap mass spectrometer (Thermo Electron, Inc.) equipped with an electrospray ionization (ESI) source was used to acquire mass spectra after LC separation with C18 LC column. Molecular formulas of organic species were assigned using accurate mass measurements (m/z) of detected ions. In addition, the aliphatic, arylic, phenolic, and carboxylic functional groups were quantified using H-NMR. All the results were evaluated and compared with ultra-high resolution Fourier Transform-Ion Cyclotron Resonance MS analysis (see abstract Mazzoleni et al.).