 |
| Titel |
Evidence and quantitation of aromatic organosulfates in ambient aerosols in Lahore, Pakistan |
| VerfasserIn |
S. Kundu, T. A. Quraishi, G. Yu, C. Suarez, F. N. Keutsch, E. A. Stone |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 9 ; Nr. 13, no. 9 (2013-05-14), S.4865-4875 |
| Datensatznummer |
250018645
|
| Publikation (Nr.) |
 copernicus.org/acp-13-4865-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| Organosulfates are important components of atmospheric organic aerosols, yet
their structures, abundances, sources and formation processes are not
adequately understood. This study presents the identification and
quantitation of benzyl sulfate in atmospheric aerosols, which is the first
confirmed atmospheric organosulfate with aromatic carbon backbone. Benzyl
sulfate was identified and quantified in fine particulate matter (PM2.5)
collected in Lahore, Pakistan, during 2007–2008. An authentic standard of
benzyl sulfate was synthesized, standardized, and identified in atmospheric
aerosols with quadrupole time-of-flight (Q-ToF) mass spectrometry (MS).
Benzyl sulfate was quantified in aerosol samples using ultra performance
liquid chromatography (UPLC) coupled to negative electrospray ionization
triple quadrupole (TQ) MS. The highest benzyl sulfate concentrations were
recorded in November and January 2007 (0.50 ± 0.11 ng m−3)
whereas the lowest concentration was observed in July
(0.05 ± 0.02 ng m−3). To evaluate matrix effects, benzyl sulfate
concentrations were determined using external calibration and the method of
standard addition; comparable concentrations were detected by the two
methods, which ruled out significant matrix effects in benzyl sulfate
quantitation. Three additional organosulfates with m/z 187, 201 and
215 were qualitatively identified as aromatic organosulfates with additional
methyl substituents by high-resolution mass measurements and tandem MS. The
observed aromatic organosulfates form a homologous series analogous to
toluene, xylene, and trimethylbenzene, which are abundant anthropogenic
volatile organic compounds (VOC), suggesting that aromatic organosulfates may
be formed by secondary reactions. However, stronger statistical correlations
of benzyl sulfate with combustion tracers (EC and levoglucosan) than with
secondary tracers (SO42− and α-pinene-derived nitrooxy
organosulfates) suggest that aromatic organosulfates may be emitted from the
combustion sources or their subsequent atmospheric processing. Further
studies are needed to elucidate the sources and formation pathways of
aromatic organosulfates in the atmosphere. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|