title: Characterization of organosulfates from the photooxidation of isoprene and unsaturated fatty acids in ambient aerosol using liquid chromatography/(-) electrospray ionization mass spectrometry.
abstract: In the present study, we have characterized in detail the MS(2) and MS(3) fragmentation behaviors, using electrospray ionization (ESI) in the negative ion mode, of previously identified sulfated isoprene secondary organic aerosol compounds, including 2-methyltetrols, 2-methylglyceric acid, 2-methyltetrol mononitrate derivatives, glyoxal and methylglyoxal. A major fragmentation pathway for the deprotonated molecules of the sulfate esters of 2-methyltetrols and 2-methylglyceric acid and of the sulfate derivatives of glyoxal and methylglyoxal is the formation of the bisulfate [HSO(4)](-) anion, while the deprotonated sulfate esters of 2-methyltetrol mononitrate derivatives preferentially fragment through loss of nitric acid. Rational interpretation of MS(2), MS(3) and accurate mass data led to the structural characterization of unknown polar compounds in K-puszta fine aerosol as organosulfate derivatives of photooxidation products of unsaturated fatty acids, i.e. 2-hydroxy-1,4-butanedialdehyde, 4,5- and 2,3-dihydroxypentanoic acids, and 2-hydroxyglutaric acid, and of alpha-pinene, i.e. 3-hydroxyglutaric acid. The deprotonated molecules of the sulfated hydroxyacids, 2-methylglyceric acid, 4,5- and 2,3-dihydroxypentanoic acid, and 2- and 3-hydroxyglutaric acids, showed in addition to the [HSO(4)](-) ion (m/z 97) neutral losses of water, CO(2) and/or SO(3), features that are characteristic of humic-like substances. The polar organosulfates characterized in the present work are of climatic relevance because they may contribute to the hydrophilic properties of fine ambient aerosol. In addition, these compounds probably serve as ambient tracer compounds for the occurrence of secondary organic aerosol formation under acidic conditions.
authors.affiliation: Department of Pharmaceutical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Antwerp, Belgium.
authors.forename: Yadian
authors.initials: Y
authors.lastname: Gómez-González
authors.forename: Jason D
authors.initials: JD
authors.lastname: Surratt
authors.forename: Filip
authors.initials: F
authors.lastname: Cuyckens
authors.forename: Rafal
authors.initials: R
authors.lastname: Szmigielski
authors.forename: Reinhilde
authors.initials: R
authors.lastname: Vermeylen
authors.forename: Mohammed
authors.initials: M
authors.lastname: Jaoui
authors.forename: Michael
authors.initials: M
authors.lastname: Lewandowski
authors.forename: John H
authors.initials: JH
authors.lastname: Offenberg
authors.forename: Tadeusz E
authors.initials: TE
authors.lastname: Kleindienst
authors.forename: Edward O
authors.initials: EO
authors.lastname: Edney
authors.forename: Frank
authors.initials: F
authors.lastname: Blockhuys
authors.forename: Christian
authors.initials: C
authors.lastname: Van Alsenoy
authors.forename: Willy
authors.initials: W
authors.lastname: Maenhaut
authors.forename: Magda
authors.initials: M
authors.lastname: Claeys
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D000393:Air Pollutants / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry; D000447:Aldehydes / Q000032:analysis; D002070:Butadienes / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods; D005231:Fatty Acids, Unsaturated / Q000737:chemistry*; D005977:Glutarates / Q000032:analysis; D045782:Hemiterpenes / Q000737:chemistry*; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry; D010420:Pentanes / Q000737:chemistry*; D010421:Pentanoic Acids / Q000032:analysis; D010777:Photochemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013458:Sulfur Dioxide / Q000737:chemistry; D013463:Sulfuric Acid Esters / Q000032:analysis* / Q000737:chemistry
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D000447:Aldehydes; D002070:Butadienes; D005231:Fatty Acids, Unsaturated; D005977:Glutarates; D045782:Hemiterpenes; D009589:Nitrogen Oxides; D010420:Pentanes; D010421:Pentanoic Acids; D013463:Sulfuric Acid Esters; C005059:isoprene; D013458:Sulfur Dioxide