Abstract: By the methods of shaking extraction-silica gel pole purification-high performance liquid chromatography detection with fluorescence detector and DAD detector, this paper measured the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) listed in the USEPA blacklist in the surface water of Taizi River. In dry season (April), wet season (July), and median water period (October), the total PAHs (TPAHs) concentration in the surface water was ranged in 454.5-1379.7 ng·L^-1, 1801.6-5868.9 ng·L^-1, and 367.0-5794.5 ng·L^-1, respectively. The surface water of Taizi River was more seriously contaminated by PAHs, compared with that of other rivers in the world. The distribution characteristics of PAHs differed greatly with seasons. In each sampling station, the TPAHs concentration in wet season was much higher than that in dry season. The 2-ring and 3-ring PAHs were the most common components in Taizi River, either in dry season, wet season, or in median water period. The representative speciation of PAHs also differed with seasons. The source identification of PAHs inferred that petroleum was the main PAHs source in dry season, while the combination of petroleum discharge and fuel combustion contributed most to the PAHs in wet season and median water period.

Key words: Biorational pesticide, Agricultural methods, Rice, Pest organism, Efficacy