Studies were performed using (1) Diesel particles collected from the undiluted exhaust of a single-cylinder engine, operated at constant speed and load, using a binary pure hydrocarbon fuel with air or gas mixture oxidizers, and (2) Diesel particles collected from the diluted exhaust of a multicylinder engine operated on a commercial fuel. The physicochemical properties of the particles were determined by static and dynamic methods. The organic adsorbate was characterized by chromatographic and mass spectrometric procedures and by microbial testing protocols. Electron paramagnetic resonance spectrometry and high performance liquid chromatography were used to study reactivity of the organic adsorbate. The particles collected from the exhaust of Diesel engines operated on binary pure hydrocarbons and on commercial fuels contained similar compounds in the organic adsorbates. The nitrogen in these compounds is derived mainly from the oxidizer (Air). The microbial mutagenic activities of the organic adsorbates found on the surface of both types of Diesel particles are comparable. These microbial mutagenic activities can be attributed mainly to the presence of nitrated polnuclear aromatic hydrocarbons.

Includes bibliographical references (p. 99-104). "PB84-122910." "EPA-600/3-83-106"--T.p. "November 1983." "EPA Grant Number R-806558"--T.p. "Project Officer John E. Sigsby"--T.p.

Studies were performed using (1) Diesel particles were collected from the undiluted exhaust of a single-cylinder engine, operated at a constant speed and load, using a binary pure hydrocarbon fuel with air or gas mixture oxidizers, and (2) Diesel particles collected from the diluted exhaust of a multicylinder engine operated on a commercial fuel. The physiochemical properties of the particles were determined by static and dynamic methods. The organic adsorbate was characterized by chromatographic and mass spectrometric procedures and by microbial testing protocols. Electron paramagnetic resonance spectrometry and high performance liquid chromatography were used to study reactivity of the organic adsorbate. The particles collected from the exhaust of Diesel engines operated on binary pure hydrocarbons and on commercial fuels contained similar compounds in the organic adsorbates. The nitrogen in these compounds is derived mainly from the oxidizer (Air). The microbial mutagenic activities of the organic adsorbates found on the surface of both types of Diesel particles are comparable. These microbial mutagenic activities can be attributed mainly to the presence of nitrated polynuclear aromatic hydrocarbons.