Polynuclear aromatic hydrocarbons diesel exhausts

The black material in diesel exhaust consists of small particles that are rich in polynuclear aromatic hydrocarbons. 

Rappaport, S.M. Jin, Z.L. Xu, X.B. High-performance liquid chromatography with reductive electrochemical detection of mutagenic nitro-substituted polynuclear aromatic hydrocarbons in diesel exhausts. J. Chromatogr. 1982, 240, 145-154. 

Breuer GM, 1984. Solvents and techniques for the extraction of polynuclear aromatic hydrocarbons from filter samples of diesel exhaust. Anal Lett 17 1293-1306. 

The aromatic hydrocarbon content of diesel fuel affects the cetane number and exhaust emissions. One test method (ASTM D-5186) is applicable to diesel fuel and is unaffected by fuel coloration. Aromatics concentration in the range 1-75 mass% and polynuclear aromatic hydrocarbons in the range 0.5-50 mass% can be determined by this test method. In the method, a small aliquot of the fuel sample is injected onto a packed silica adsorption column and eluted with supercritical carbon dioxide mobile phase. Mono- and polynuclear aromatics in the sample are separated from nonaromatics and detected with a flame ionization detector. The detector response to hydrocarbons is recorded throughout the analysis time. The chromatographic areas corresponding to the mononuclear aromatic constituents, polynuclear aromatic constituents, and nonaromatic constituents are determined, and the mass-percent content of each of these groups is calculated by area normalization. 

In addition to the exhaust gas components legislated for, the diesel oxidation catalyst also reduces the emissions of exhaust gas components such as aldehydes and polynuclear aromatic hydrocarbons, see Fig. Ill [70]. 

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