PuSH - Publication Server of Helmholtz Zentrum München

Cottrell, B.A.* ; Gonsior, M.* ; Isabelle, L.M.* ; Luo, W.* ; Perraud, V.* ; McIntire, T.M.* ; Pankow, J.F.* ; Schmitt-Kopplin, P. ; Cooper, W.J.* ; Simpson, A.J.*

A regional study of the seasonal variation in the molecular composition of rainwater.

Atmos. Environ. 77, 588-597 (2013)
Publ. Version/Full Text Volltext DOI
Open Access Green as soon as Postprint is submitted to ZB.
Rainwater is not only a critical source of drinking and agricultural water but it plays a key role in the fate and transport of contaminants through their removal by wet deposition. Rainwater is a complex mixture of organic compounds yet despite its importance its spatial and temporal variability are not well understood and less than 50% of the organic matter has been characterized. In-depth analytical approaches were used in this study to characterize the seasonal variation in rainwater composition. Rainwater samples were collected over a one-year period in Scarborough, Ontario, Canada. The seasonal variation of atmospheric organic carbon (AOC) in rainwater was analyzed by excitation-emission matrix spectroscopy (EEMs), 1D and 2D NMR with compound identification by spectral database matching, GC-MS, FT-ICR-MS, and GC×GC-TOFMS. This combination of techniques provided four complementary datasets, with less than 10% overlap, of anthropogenic and biogenic AOC. NMR with database matching identified over 100 compounds, primarily carboxylic acids, carbohydrates, and nitrogen-containing compounds. GC×GC-TOFMS analysis identified 344 compounds in two rain events with 33% of the compounds common to both events. FT-ICR-MS generated a seasonally dependent profile of 1226-1575 molecular ions of CHO, CHOS, and CHON elemental composition. FT-ICR-MS and GC×GC-TOFMS datasets were compared using van Krevelen diagrams (H/C vs. O/C), the H/C ratio vs. mass/charge (m/z), and the carbon oxidation state/carbon number matrix. Fluorescence patterns were correlated with NMR results resulting in the identification one seasonally-dependent component of chromophoric dissolved organic matter (CDOM). This study demonstrated the importance of using of an integrated analytical approach to monitor the compositional variation of AOC.
Additional Metrics?
Edit extra informations Login
Publication type Article: Journal article
Document type Scientific Article
Keywords Carbon oxidation state; FTICR-NS; GC×GC-TOFMS; NMR; Van Krevelen diagrams; Dissolved Organic-matter ; Polycyclic Aromatic-hydrocarbons ; Magnetic-resonance-spectroscopy ; Diffusion-ordered Spectroscopy ; Atomic-force Microscopy ; Mass-spectrometry ; Atmospheric Aerosols ; Fluorescence Spectroscopy ; Compound Emissions ; Los-Angeles
Reviewing status