Oxygenates in Exhaust from Simple Hydrocarbon Fuels

Abstract

Photochemical air pollution is known to be caused largely by automotive emissions such as hydrocarbons and oxygenated hydrocarbon derivatives. Unlike the hydrocarbons, the contribution of the oxygenates has been virtually unexplored, mainly because of lack of appropriate analytical methods. The objective of this study was to identify and estimate the levels of oxygenated hydrocarbon derivatives in exhaust from simple hydrocarbon fuels. This information is expected to yield ultimately estimates of the relative levels of various classes of oxygenates in exhaust from full-boiling-range gasolines. Identification and measurement of oxygenates in exhaust from the simplified fuels were accomplished using gas chromatography in conjunction with time-of-flight mass spectrometry. The analytical procedure involved concentration of the exhaust organics, followed by a two-stage chromatographic separation of the resultant mixture of oxygenates and hydrocarbons. Identified oxygenates in exhaust from nine test fuels included saturated and unsaturated aldehydes, ketones, and alcohols, as well as ethers, esters, and nitroalkanes; analytical data on organic acids were inconclusive. Of the identified noncarbonyl oxygenates, phenols, cyclic ethers and nitromethane appear to be relatively the most abundant.

Application of Directly Coupled High Performance Liquid Chromatography-NMR-Mass Spectometry and 1H NMR Spectroscopic Studies to the Investigation of 2,3-Benzofuran Metabolism in Sprague-Dawley Rats

“…The general population is potentially exposed to 2,3-benzofuran (BF 4 ) through its release into the environment as a result of waste incineration (Junk and Ford, 1980) and from exhaust gases from gasoline and diesel engines (Seizinger and Dimitriades, 1972;Hampton et al, 1982). The use of BF in the manufacture of coumaroneindene resins is an industrial hazard and may result in environmental contamination with BF via various waste streams (Budavari, 1989).…”

Investigation on VOC Emissions from Automobile Sources by Means of Online Mass Spectrometry

“…The result indicated the presence of nitro-organic compounds, such as nitromethane, nitrophenols, and dihydroxynitrobenzenes in diesel exhaust, along with hydrocarbons, aromatics, and oxygenated VOCs. The presence of acetonitrile in diesel-powered engine exhaust has been shown by means of PTR-MS [13,14], and vehicular exhaust has been shown to emit nitromethane [55] and gaseous nitrophenols by means of GC/MS [49,56].…”

Theoretical study of the Cl-initiated atmospheric oxidation of methyl isopropenyl ketone

“…Methyl isopropenyl ketone (MIK, H 2 C]C(CH 3 )C(O)CH 3 ) is an important a,b-unsaturated ketone and has been observed from anthropogenic sources (plants, solvent use, biomass burning, fossil fuel combustion, etc.). [1][2][3][4] In addition, MIK has been found to be an intermediate product in synthesis and in the catalysis industry. 5 It is reported that MIK can be widely used in the polymer manufacturing industry.…”

“…10 Although the reaction of MIK with OH radicals is generally considered to be the predominant degradation pathway among these various species, the reaction of MIK with Cl atoms also represents a signicant loss process in some special regions, such as coastal regions, the marine boundary layer and some polluted mid-continental regions with high chlorine emissions. [11][12][13] According to Chang's report, the average concentration of Cl atoms is estimated to be as high as 3 Â 10 5 molecules per cm 3 or more in the marine boundary layer. 14 In addition, the Cl atoms reactions with organic compounds have been reported to be much faster than OHparticipated reactions.…”