The Isotopic Composition of Nonmethane Hydrocarbons in the Pollution Sources

The carbon isotopic composition of nonmethane hydrocarbons (NMHCs) in anthropogenic sources, such as fuel volatiles, vehicle exhaust, coal-combustion exhaust has been determined by Thermal Desorption-Gas Chromatography-Isotope Ratio Mass Chromatography. And it can be concluded that different pollution sources have different δ¹³C values, the δ¹³C values of vehicle exhaust are higher than those of diesel oil volatile, gasoline volatile and air in underground parking lots, and lower than those of coal-combustion exhaust. On average alkene is enriched in ¹³C relative to the average of alkane by about 2%. Furthermore, differences among the pollution sources are of significance in constraining the sources of pollutants in environmental air.