Technical Paper
FINE, ULTRAFINE AND NANOPARTICLE TRACE ORGANIC COMPOSITIONS NEAR A MAJOR FREEWAY WITH A HIGH HEAVY DUTY DIESEL FRACTION
2007-09-16
2007-24-0108
Individual organic compounds such as hopanes and steranes (originating in lube oil) and selected polycyclic aromatic compounds (PAHs) (generated via combustion) found in particulate emissions from vehicles have proven useful in source apportionment of ambient particulate matter. Currently, little ambient data exists for a majority of these species. Trace organic species in the size-segregated ultrafine (<0.18 µm) and accumulation (0.18-2.5 µm) particulate matter (PM) modes were measured during the winter season next to a busy Southern California freeway with significant (∼20%) diesel traffic. The ultrafine mode was further segregated into 4 size ranges (18-32 nm, 32-56 nm, 56-100 nm, and 100-180nm) with a NanoMOUDI low-pressure cascade impactor sampler. Both ambient and concentrated size-segregated impactor samples were taken in order to collect enough mass for chemical analysis.