title: Characterizations of organic compounds in diesel exhaust particulates.
abstract: To characterize how the speed and load of a medium-duty diesel engine affected the organic compounds in diesel particle matter (PM) below 1 μm, four driving conditions were examined. At all four driving conditions, concentration of identifiable organic compounds in PM ultrafine (34-94 nm) and accumulation (94-1000 nm) modes ranged from 2.9 to 5.7 μg/m(3) and 9.5 to 16.4 μg/m(3), respectively. As a function of driving conditions, the non-oxygen-containing organics exhibited a reversed concentration trend to the oxygen-containing organics. The identified organic compounds were classified into eleven classes: alkanes, alkenes, alkynes, aromatic hydrocarbons, carboxylic acids, esters, ketones, alcohols, ethers, nitrogen-containing compounds, and sulfur-containing compounds. At all driving conditions, alkane class consistently showed the highest concentration (8.3 to 18.0 μg/m(3)) followed by carboxylic acid, esters, ketones and alcohols. Twelve polycyclic aromatic hydrocarbons (PAHs) were identified with a total concentration ranging from 37.9 to 174.8 ng/m(3). In addition, nine nitrogen-containing polycyclic aromatic compounds (NPACs) were identified with a total concentration ranging from 7.0 to 10.3 ng/m(3). The most abundant PAH (phenanthrene) and NPACs (7,8-benzoquinoline and 3-nitrophenanthrene) comprise a similar molecular (3 aromatic-ring) structure under the highest engine speed and engine load.
authors.affiliation: Division of Global Environment Research, National Institute of Environmental Research, Incheon, Republic of Korea. Electronic address: dr4earth@unitel.co.kr.
authors.forename: Jaehyun
authors.initials: J
authors.lastname: Lim
authors.affiliation: Division of Global Environment Research, National Institute of Environmental Research, Incheon, Republic of Korea.
authors.forename: Cheolsoo
authors.initials: C
authors.lastname: Lim
authors.affiliation: Division of Global Environment Research, National Institute of Environmental Research, Incheon, Republic of Korea.
authors.forename: Sangkyun
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Climate and Air Quality Research, National Institute of Environmental Research, Incheon, Republic of Korea.
authors.forename: Jihyung
authors.initials: J
authors.lastname: Hong
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000473:Alkanes / Q000032:analysis; D001372:Aza Compounds / Q000032:analysis; D004784:Environmental Monitoring; D052638:Particulate Matter / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D000473:Alkanes; D001372:Aza Compounds; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons; D001335:Vehicle Emissions
keywords: Diesel particle matter; Nitrogen-containing polycyclic aromatic compounds; Organic compounds; Polycyclic aromatic hydrocarbons