Measurement and Chemical Characterization of Vapor-Phase Mutagens in Diesel Exhaust

摘要

Methods for the collection, extraction, fractionation, and concentration of vapor-phase compounds from the undiluted exhaust of a medium heavy-duty diesel truck were developed and integrated with chemical analysis and a sensitive mutagenicity bioassay. A sampling system composed of a Teflon filter, polyurethane foam (PUF) and XAD-4 (XAD) adsorbents, in series, was used to directly trap PM and VM in the diesel truck exhaust. The VM on the PUF and XAD adsorbents were extracted with supercritical carbon dioxide (s-CO2) into concentrated methanol fractions which were directly analyzed by a specially modified Ames Salmonella mutagenicity assay and gas chromatograph interfaced to a quadrupole mass spectrometer (GC-MS). The PM-associated mutagens were extracted with organic solvents and assayed for mutagenicity.