Diesel fuels and emissions are composed of numerous hydrocarbon species. Combustion generated or pyrogenic polycyclic aromatic hydrocarbons (PAHs) derived from premixed and diffusion flames often consists of the most stable benzenoid PAHs. In contrast, diesel fuels from the UK,  US  and the current work contain petrogenic alkyl-PAHs with high hydrogen content. Laser microprobe mass spectrometry (LMMS) and gas chromatography/mass spectrometry (GC/MS) are used in a complementary manner to differentiate the (PAHs) originating in the fuel from those produced by engine combustion in particulate emission samples.Diesel emissions from circa 1990s engines (a NIST SRM 1650a and ambient roadway tunnel samples) display the full mass range of PAHs from 128 u to 376 u including both the benzenoid PAHs and alkyl-PAHs. The chemical nature and absence of petrogenic species larger than 206 u facilitates their detection and delineation from pyrogenic PAHs by mass spectrometry.
Citation: Combustion and Flame
Pub Type: Journals
diesel fuel, diesel particulate, laser microprobe, polycyclic aromatic hydrocarbon