Rs. Martin et al., Nonmethane hydrocarbon, monocarboxylic acid, and low molecular weight aldehyde and ketone emissions from vegetation in central New Mexico, ENV SCI TEC, 33(13), 1999, pp. 2186-2192
Citations number
29
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
Direct emissions of nonmethane hydrocarbons, monocarboxylic acids, and low
molecular weight carbonyl compounds were measured from vegetation typical t
o central New Mexico. These species included quaking aspen, cottonwood, Gam
bel oak, Douglas fir, Engelmann spruce, Rocky Mountain juniper, pinyon pine
, and ponderosa pine. The hydrocarbon emissions from most of the coniferous
trees were dominated by alpha-pinene. In general, alpha-pinene emissions w
ere 100-10 000 ng g(-1) h(-1) and displayed the expected temperature depend
ence. Other identified hydrocarbons included isoprene, camphene, beta-pinen
e, myrcene, Delta(3)-carene, and d-limonene, The deciduous trees as well as
the spruce and fir trees showed isoprene emission rates of 100-100 000 ng
g(-1) h(-1). Formaldehyde and acetaldehyde were the most common low molecul
ar weight carbonyl compounds measured. The carbonyl emissions averaged 50-1
660 ng g(-1) h(-1), depending an the compound and the trees species. Unlike
the hydrocarbons, the carbonyl emissions displayed little correlation with
enclosure temperature. Formic acid emissions averaged 15-920 ng g(-1) h(-1
), and acetic acid emissions averaged 50-1300 ng g(-1) h(-1). As with the c
arbonyls, poor correlation was found between the acid emissions and the enc
losure temperature. The deciduous trees were found to have average (mass-ba
sed) emissions of 98% hydrocarbons, 1% carbonyls, and 1% organic acids. The
coniferous trees averaged 80%, 8%, and 12%, respectively.