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Titel |
Volatilizable Biogenic Organic Compounds (VBOCs) with two dimensional Gas Chromatography-Time of Flight Mass Spectrometry (GC×GC-TOFMS): sampling methods, VBOC complexity, and chromatographic retention data |
VerfasserIn |
J. F. Pankow, W. Luo, A. N. Melnychenko, K. C. Barsanti, L. M. Isabelle, C. Chen, A. B. Guenther, T. N. Rosenstiel |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 2 ; Nr. 5, no. 2 (2012-02-14), S.345-361 |
Datensatznummer |
250002462
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Publikation (Nr.) |
copernicus.org/amt-5-345-2012.pdf |
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Zusammenfassung |
Two dimensional gas chromatography (GC × GC) with detection by
time-of-flight mass spectrometry (TOFMS) was applied in the rapid analysis
of air samples containing highly complex mixtures of volatilizable biogenic
organic compounds (VBOCs). VBOC analytical methodologies are briefly
reviewed, and optimal conditions are discussed for sampling with both
adsorption/thermal desorption (ATD) cartridges and solid-phase
microextraction (SPME) fibers. Air samples containing VBOC emissions from
leaves of two tree species (Cedrus atlantica and Calycolpus moritzianus) were obtained by both ATD and SPME. The
optimized gas chromatographic conditions utilized a 45 m, 0.25 mm I.D. low-polarity
primary column (DB-VRX, 1.4 μm film) and a 1.5 m, 0.25 mm I.D. polar
secondary column (StabilwaxTM, 0.25 μm film).
Excellent separation was achieved in a 36 min temperature programmed
GC × GC chromatogram. Thousands of VBOC peaks were present in the
sample chromatograms; hundreds of tentative identifications by NIST mass
spectral matching are provided. Very few of the tentatively identified
compounds are currently available as authentic standards. Minimum detection
limit values for a 5 l ATD sample were 3.5 pptv (10 ng m−3) for
isoprene, methyl vinyl ketone, and methacrolein, and ~1.5 pptv
(~10 ng m−3) for monoterpenes and sesquiterpenes. Kovats-type
chromatographic retention index values on the primary column and relative
retention time values on the secondary column are provided for 21 standard
compounds and for 417 tentatively identified VBOCs. 19 of the 21 authentic
standard compounds were found in one of the Cedrus atlantica SPME samples. In addition,
easily quantifiable levels of at least 13 sesquiterpenes were found in an
ATD sample obtained from a branch enclosure of Calycolpus moritzianus. Overall, the results
obtained via GC × GC-TOFMS highlight an extreme, and largely
uncharacterized diversity of VBOCs, consistent with the hypothesis that
sesquiterpenes and other compounds beyond the current list of typically
determined VBOC analytes may well be important contributors to global
atmospheric levels of organic particulate matter. |
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