Characterization of gas-phase organics using proton transfer reaction time-of-flight mass spectrometry: fresh and aged residential wood combustion emissions
Organic gases emitted during the flaming phase of residential wood combustion are characterized individually and by functionality using proton transfer reaction time-of-flight mass spectrometry. The evolution of the organic gases is monitored during photochemical aging. Primary gaseous emissions are...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/17/705/2017/acp-17-705-2017.pdf |
| Summary: | Organic gases emitted during the flaming phase of residential wood
combustion are characterized individually and by functionality using proton
transfer reaction time-of-flight mass spectrometry. The evolution of the
organic gases is monitored during photochemical aging. Primary gaseous
emissions are dominated by oxygenated species (e.g., acetic acid,
acetaldehyde, phenol and methanol), many of which have deleterious health
effects and play an important role in atmospheric processes such as
secondary organic aerosol formation and ozone production. Residential wood
combustion emissions differ considerably from open biomass burning in both
absolute magnitude and relative composition. Ratios of acetonitrile, a
potential biomass burning marker, to CO are considerably lower
( ∼ 0.09 pptv ppbv<sup>−1</sup>) than those observed in air masses
influenced by open burning ( ∼ 1–2 pptv ppbv<sup>−1</sup>), which may
make differentiation from background levels difficult, even in regions
heavily impacted by residential wood burning. A considerable amount of formic acid forms
during aging ( ∼ 200–600 mg kg<sup>−1</sup> at an OH exposure of
(4.5–5.5) × 10<sup>7</sup> molec cm<sup>−3</sup> h), indicating residential
wood combustion can be an important local source for this acid, the
quantities of which are currently underestimated in models. Phthalic
anhydride, a naphthalene oxidation product, is also formed in considerable
quantities with aging ( ∼ 55–75 mg kg<sup>−1</sup> at an OH exposure
of (4.5–5.5) × 10<sup>7</sup> molec cm<sup>−3</sup> h). Although total NMOG
emissions vary by up to a factor of ∼ 9 between burns, SOA
formation potential does not scale with total NMOG emissions and is similar
in all experiments. This study is the first thorough characterization of
both primary and aged organic gases from residential wood combustion and
provides a benchmark for comparison of emissions generated under different
burn parameters. |
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| ISSN: | 1680-7316 1680-7324 |