In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 5 ( 2018-03-07), p. 3299-3319
Kurzfassung:
Abstract. Volatile and intermediate-volatility non-methane organic gases (NMOGs) released from biomass burning were measured during
laboratory-simulated wildfires by proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF). We identified NMOG
contributors to more than 150 PTR ion masses using gas chromatography (GC) pre-separation with electron ionization,
H3O+ chemical ionization, and NO+ chemical ionization, an extensive literature review, and
time series correlation, providing higher certainty for ion identifications than has been previously available. Our
interpretation of the PTR-ToF mass spectrum accounts for nearly 90 % of NMOG mass detected by PTR-ToF across all fuel
types. The relative contributions of different NMOGs to individual exact ion masses are mostly similar across many fires
and fuel types. The PTR-ToF measurements are compared to corresponding measurements from open-path Fourier transform
infrared spectroscopy (OP-FTIR), broadband cavity-enhanced spectroscopy (ACES), and iodide ion chemical ionization mass
spectrometry (I− CIMS) where possible. The majority of comparisons have slopes near 1 and values of the linear
correlation coefficient, R2, of 〉 0.8, including compounds that are not frequently reported by PTR-MS such as
ammonia, hydrogen cyanide (HCN), nitrous acid (HONO), and propene. The exceptions include methylglyoxal and compounds that
are known to be difficult to measure with one or more of the deployed instruments. The fire-integrated emission ratios to
CO and emission factors of NMOGs from 18 fuel types are provided. Finally, we provide an overview of the chemical
characteristics of detected species. Non-aromatic oxygenated compounds are the most abundant. Furans and aromatics, while
less abundant, comprise a large portion of the OH reactivity. The OH reactivity, its major contributors, and the
volatility distribution of emissions can change considerably over the course of a fire.
Materialart:
Online-Ressource
ISSN:
1680-7324
DOI:
10.5194/acp-18-3299-2018
DOI:
10.5194/acp-18-3299-2018-supplement
Sprache:
Englisch
Verlag:
Copernicus GmbH
Publikationsdatum:
2018
ZDB Id:
2092549-9
ZDB Id:
2069847-1
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