Abstract: By the method of SPE-GC/ECD, this paper studied the distribution and composition of organochlorine pesticides (OCPs) in the surface water body of Chaohu Lake. At the 13 sampling sites of study area, a total of 16 kinds of OCPs, including HCHs, DDTs, β-Endosulfan, Aldrin, hexachlorobenzene, and Heptachlor, were detected. The total OCPs concentration was 0.54-64.01 ng·L^-1, and the main components were HCHs and DDTs, whose average concentrations were 5.56 ng·L^-1 and 16.57 ng·L^-1, respectively, accounting for about 84.75% of the total. The origins of OCPs in study area were historical residues and the recent discharge of pesticides. The concentrations of all existences accorded with the target values of GB 3838-2002. The concentrations of OCPs in the surface water body of Chaohu Lake were much lower, and the risk was low in general.

Key words: Chaohu Lake, water body, organochlorine pesticides, GC-ECD, carbon source, carbon sink, net carbon emission intensity, Yangtze River Delta, spatiotemporal pattern.