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An analytical method for the determination of hydrocarbon and ether emissions from gasoline-, methanol-, and flexible-fueled vehicles is described. This method was used in Phase I of the Auto/Oil Air Quality Improvement Research Program to provide emissions data for various vehicles using individual reformulated gasolines and alternate fuels. These data would then be used for air modeling studies. Emission samples for tailpipe, evaporative, and running loss were collected in Tedlar bags. Gas chromatographic analysis of the emissions samples included 140 components (hydrocarbons, ethers, alcohols and aldehydes) between C1 and C12 in a single analysis of 54-minutes duration. Standardization, quality control procedures, and inter-laboratory comparisons developed and completed as part of this program are also described.

Ethylene dibromide, a suspected carcinogen, and ethylene dichloride are commonly used in leaded gasoline as scavengers. Ethylene dibromide emission rates were determined from seven automobiles which had a wide range of control devices, ranging from totally uncontrolled to evaporative and catalytic emission controls. The vehicles were operated over a variety of cycles to simulate the normally encountered range of driving conditions. Evaporative losses were also measured. Tailpipe emission rates varied from 0 to 1300 micrograms ethylene dibromide per mile depending upon the control devices present and the operating cycle. Evaporative emission of ethylene dibromide ranged from 0.03 to 0.4 micrograms per mile equivalent. Emission of other lead-related compounds were sought but not found. The consequences of using leaded fuels in vehicles equipped with catalysts was investigated. Emission rates of ethylene dibromide increased with usage and appeared to depend on catalyst activity.

A routine on-line reverse phase high performance liquid chromatography (HPLC)/HPLC fluorescence method has been developed which greatly simplifies the analysis of selected nitroaromatic compounds in complex matrices. Sensitivity of the method is generally in the low picogram to low nanogram levels. The method is based on on-column catalytic reduction of the non-fluorescent nitroaromatic compounds to the corresponding highly fluorescent amine derivatives. Compound selectivity is achieved by chromatographic separation, use of selective wavelengths for fluorescence detection and column switching techniques. The analytical system conveniently eliminates tedious sample clean-up. In most cases only about 25 micrograms of the crude sample is needed per analysis. For 1-nitropyrene, a precision of ± 3% at the one nanogram level is routinely obtained.