title: Fragmentation analysis of water-soluble atmospheric organic matter using ultrahigh-resolution FT-ICR mass spectrometry.
abstract: Isolated water-soluble atmospheric organic matter (AOM) analytes extracted from radiation fogwater samples were analyzed using collision induced dissociation with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Tandem mass analysis was performed on several mass ranges between 100 and 400 Da to characterize the functional groups of AOM species. Compounds containing nitrogen and/or sulfur were targeted because of the high number of oxygen atoms contained in their molecular formulas. Due to the large number of isobaric ions in the precursor isolation ranges, large numbers of product ions resulted from collision induced dissociation. Common neutral losses were assigned by matching the molecular formulas of the expected product ions with the detected product ions within the appropriate mass spectra. Since polar functional groups are expected to affect the hygroscopic properties of aerosols, the losses of H(2)O, CO(2), CH(3)OH, HNO(3), CH(3)NO(3), SO(3), SO(4) and combinations of these were specifically targeted. Among the 421 compounds studied, the most frequently observed neutral losses were CO(2) (54%), H(2)O (43%) and CH(3)OH (40%). HNO(3) losses were observed for 63% of the studied nitrogen containing compounds and 33% of the studied compounds containing both nitrogen and sulfur. SO(3) losses were observed for 85% of the studied sulfur containing compounds and 42% of studied compounds containing both nitrogen and sulfur. A number of molecular formulas matching those of monoterpene ozonolysis SOA were observed; they include organonitrates, organosulfates, and nitroxy-organosulfates. Overall, the results of fragmentation analysis of 400+ individual molecular precursors elucidate the complexity and multifunctional nature of the isolated water-soluble AOM.
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Leclair
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Collett
authors.forename: Lynn R
authors.initials: LR
authors.lastname: Mazzoleni
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D002140:California; D004784:Environmental Monitoring; D009584:Nitrogen / Q000737:chemistry; D009930:Organic Chemicals / Q000032:analysis* / Q000737:chemistry; D012995:Solubility; D013457:Sulfur Compounds / Q000032:analysis / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods; D014867:Water / Q000737:chemistry; D014887:Weather
chemical_list: D000393:Air Pollutants; D009930:Organic Chemicals; D013457:Sulfur Compounds; D014867:Water; D009584:Nitrogen