Composition of Volatile Organic Compounds in Ambient Air in Hong Kong

摘要

The composition of volatile organic compounds (VOCs) in ambient air in Hong Kong has been researched using sorbent tubes followed by thermal desorption - GC/MS analysis. The results show the main VOCs are aromatics (BTEX), hydrocarbons and halohydrocarbons. The hydrocarbons are composed of alkane with 6-11 carbons, branched alkanes and cycloalkanes. And the halohydrocarbons include chloroform, dibromomethane, trichloroethylene, tetrachloroethylene, chlorobenzene, 1, 2 — dichlorobenzene, 1, 2 — dichloroethane, and tetra-chloromethane. The hazardous VOCs with the highest contents in the ambient air are benzene, toluene, chloroform, 1,2 — dichloroethane, trichloroethylene, tetrachloroethylene, and tetrachloromethane. The compositions of VOCs in the air are almost the same in the park, living areas, streets, and roads, but their contents change greatly. In general, the contents of the major hazardous VOCs in the former two function areas are lower than that in the latter two. The data suggests that most of the VOCs in Hong Kong air are derived from vehicle exhausts, and the halohydrocarbons possibly from organic building materials, chemical consumer products, and organic solvents used in industrial processes.