The analysis of nitrated polycyllc aromatic hydrocarbons (nltro-PAH) In diesel particulate extracts using a combination of high-performance liquid chromatography, gas chromatography/mass spectrometry, hlgh-resolutlon mass spectrometry, and mass spectrometry/mass spectrometry (MS/MS) techniques Is described. Triple stage quadrupole (TSQ)-MSZMS operated In the constant neutral loss mode Is described for the rapid qualitative screening of nltro-PAH Isomer groups In solvent extracts of diesel particulates. Twenty such Isomer groups of nltro-PAH derivatives were found, many of these groups containing a large number of possible compounds.Mass analyzed Ion kinetic energy spectrometry (MIKES)-MS/MS was found to be much less selective than the TSQ-MS/MS for the analysis of nltro-PAH In unfractionated diesel extracts. HPLC prefractlonatlon was required to remove Interferences In the MIKES analysis. Fused silica capillary GC/MS using on-column Injection was found to be necessary for Indentlfylng specific nltro-PAH Isomers and minimizing decomposition. The highly mutagenic 1-nltropyrene (1-NP) was the only compound found In the nltro(pyrenes and fluoranthenes) Isomer group. The MIKES and TSQ techniques gave comparable results for the quantitation of 1-NP.Organic solvent extracts of diesel exhaust particulates exhibit direct-acting (i.e., activation by mammalian tissue homogenate is not required) mutagenicity (1-5) using the Ames assay (6). High-performance liquid chromatography (HPLC) (1,2,4,5), thin-layer chromatography (TLC) (7,8), and liquid chromatography (9) have been used to fractionate diesel particulate extracts for subsequent mutagenicity testing.

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