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Recent changes in regulatory practices have brought about a need for speciated analysis of the volatile organic components of vehicle exhaust. The purpose of this study was to allow interested laboratories to participate in a Round Robin so that each could assess their speciation methodologies. “Synthetic exhaust” samples were prepared of mixed DNPH-carbonyl standards deposited on DNPH cartridges, and solutions of alcohol in water. The fifteen participating laboratories included automotive, contract, petroleum and regulatory organizations. The results described in this paper consider only variability associated with the analytical measurement of samples that have already been collected in impingers or on cartridges. In general, alcohols (methanol and ethanol) were quantified without difficulty. With the exception of acrolein and crotonaldehyde, the quantitation of the carbonyl samples was very good considering the variety of analytical methods that were used.

This study shows conclusively that some of the direct microbial mutagenic activity of the soluble-organie-fraction from Diesel particulate matter can be attributed to 1-nitropyrene. 1-nitropyrene has been shown to be formed by the nitration of pyrene, and pyrene is one inherent product of the diffusion-controlled-combustion of hycrocarbons that occurs with Diesel engine operation. Nitrogen dioxide, in the presence of water vapor, is shown to be a potential nitrating agent, and this gas can be produced by the high temperature oxidation of the nitrogen contained in the oxidant. These results are based on studies which used a well-documented engine, model fuel, model oxidants, and synthetic lubricant.