Polynuclear aromatic hydrocarbon , diesel particulates

Gas Chromatography-Mass Spectrometric Characterization of Polynuclear Aromatic Hydrocarbons in Particulate Diesel Emissions... 

Methanol use would also reduce pubHc exposure to toxic hydrocarbons associated with gasoline and diesel fuel, including ben2ene, 1,3-butadiene, diesel particulates, and polynuclear aromatic hydrocarbons. Although pubHc formaldehyde exposures might increase from methanol use in garages and tunnels, methanol use is expected to reduce overall pubHc exposure to toxic air contaminants. 

Standardization. Standardization in analytical chemistry, in which standards are used to relate the instrument signal to compound concentration, is the critical function for determining the relative concentrations of species In a wide variety of matrices. Environmental Standard Reference Materials (SRM s) have been developed for various polynuclear aromatic hydrocarbons (PAH s). Information on SRM s can be obtained from the Office of Standard Reference Materials, National Bureau of Standards, Gaithersburg, MD 20899. Summarized in Table VII, these SRM s range from "pure compounds" in aqueous and organic solvents to "natural" matrices such as shale oil and urban and diesel particulate materials. 

MacCrehan, W. A., W. E. May, S. D. Yang, and G. A. Benner, Jr., Determination of Nitro Polynuclear Aromatic Hydrocarbons in Air and Diesel Particulate Matter Using Liquid Chromatography with Electrochemical and Fluorescence Detection, Anal Chem., 60, 194-199 (1988). 

Howard AG, Mills GA. 1983. Identification of polynuclear aromatic hydrocarbons in diesel particulate emissions. Int J Environ Anal Chem 14 43-54. 

Tan YL. 1988. Analysis of polynuclear aromatic hydrocarbons in shale oil and diesel particulates. Anal Lett 21 553-562. 

A simpler way to achieve a considerable reduction in the mass of particulates emitted, is the use of special diesel oxidation catalysts (Section 1.4). They offer advantages over filtering devices as they are simple, cost effective and can also reduce the emissions of CO, gaseous hydrocarbons, aldehydes and polynuclear aromatic hydrocarbons. Their main disadvantage is that their particulate mass reduction efficiency is only about half that achieved by filtering devices. 

Since about 1991, diesel oxidation catalysts have been generally applied to passenger cars in the European Union and to some medium and heavy duty trucks in the USA. Their principle of operation is shown in Fig. 101. The amount of carbon monoxide, hydrocarbons and aldehydes is reduced by oxidation of these components to carbon dioxide and water. The mass of particulate matter emitted is reduced by the oxidation of the liquid hydrocarbons, which are adsorbed on the particulates. These liquid hydrocarbons originate both from the fuel and the lubricating oil, and are commonly denoted as the soluble organic fraction (SOF). The adsorbed polynuclear aromatic hydrocarbons are also removed by oxidation. 

Schuetzle D, Lee FSC, Prater TJ (1981) The identification of polynuclear aromatic hydrocarbon (PAH) derivatives in mutagenic fractions of diesel particulate extracts. Intern JEnviron Anal Chem 9, 93-144. 

Salmeen, I., Pero, a., Riley, T., Hampton, C., Prater, T., Corse, R. and Schuetzle, D., "Identification and Rigorous Quantitation of Direct-Acting Ames Assay Mutagens in Diesel Particulate Extracts , to be presented at the Sixth International Symposium on Polynuclear Aromatic Hydrocarbons, Columbus, Ohio (Oct. 27-29, 1982). 

The internal combustion engine is a notorious polluter, but the diesel engine has the additional emission of particulate matter (10-25 pg/m ) which is rich in polynuclear aromatic hydrocarbons such as phenanthrene, fluoranthene, benzo(a)pyrene, and benzoperylene—all of which are carcinogenic. 

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