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| Titel |
A novel fast gas chromatography method for higher time resolution measurements of speciated monoterpenes in air |
| VerfasserIn |
C. E. Jones, S. Kato, Y. Nakashima, Y. Kajii |
| 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 ; 7, no. 5 ; Nr. 7, no. 5 (2014-05-15), S.1259-1275 |
| Datensatznummer |
250115756
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| Publikation (Nr.) |
 copernicus.org/amt-7-1259-2014.pdf |
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| Zusammenfassung |
| Biogenic emissions supply the largest fraction of non-methane volatile
organic compounds (VOC) from the biosphere to the atmospheric boundary
layer, and typically comprise a complex mixture of reactive terpenes. Due to
this chemical complexity, achieving comprehensive measurements of biogenic
VOC (BVOC) in air within a satisfactory time resolution is analytically
challenging. To address this, we have developed a novel, fully automated
Fast Gas Chromatography (Fast-GC) based technique to provide higher time
resolution monitoring of monoterpenes (and selected other C9-C15
terpenes) during plant emission studies and in ambient air. To our
knowledge, this is the first study to apply a Fast-GC based separation
technique to achieve quantification of terpenes in ambient air. Three
chromatography methods have been developed for atmospheric terpene analysis
under different sampling scenarios. Each method facilitates chromatographic
separation of selected BVOC within a significantly reduced analysis time
compared to conventional GC methods, whilst maintaining the ability to
quantify individual monoterpene structural isomers. Using this approach, the
C9-C15 BVOC composition of single plant emissions may be
characterised within a 14.5 min analysis time. Moreover, in-situ
quantification of 12 monoterpenes in unpolluted ambient air may be achieved
within an 11.7 min chromatographic separation time (increasing to 19.7 min
when simultaneous quantification of multiple oxygenated C9-C10
terpenoids is required, and/or when concentrations of anthropogenic VOC are
significant). These analysis times potentially allow for a twofold to fivefold
increase in measurement frequency compared to conventional GC methods. Here we outline the technical
details and analytical capability of this chromatographic approach, and
present the first in-situ Fast-GC observations of 6 monoterpenes and the
oxygenated BVOC (OBVOC) linalool in ambient air. During this field
deployment within a suburban forest ~30 km west of central
Tokyo, Japan, the Fast-GC limit of detection with respect to monoterpenes
was 4–5 ppt, and the agreement between Fast-GC and PTR-MS derived total
monoterpene mixing ratios was consistent with previous GC/PTR-MS
comparisons. The measurement uncertainties associated with the Fast-GC
quantification of monoterpenes are ≤ 12%, while larger uncertainties
(up to ~25%) are associated with the OBVOC and
sesquiterpene measurements. |
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