SIMS analysis of motor vehicle flue gas aerosols

The composition of the flue gas deposits from an Otto-cycle and a diesel engine was investigated by SIMS. The flue gas aerosol was collected by impactors directly from the tail pipe of the motor vehicles. In order to prevent the condensation of water vapor and the coagulation of the aerosol, a dilution stage was placed between the tail pipe and the impactor.The main constituents of the flue gas deposits were unburned hydrocarbons and carbonaceous materials. Moreover, in the deposits produced by the Otto-cycle engine, Na⁺, Cl^?, Ca⁺ and Br^? were detected. In addition, the deposits of the diesel engine contained H₂O⁺ and K⁺, but no Br⁺. No involatile compounds of sulfur or nitrogen were detected in the flue gas aerosol deposits of either engine.