Screening 31 endocrine-disrupting pesticides in water and surface sediment samples from Beijing Guanting reservoir

For screening 31 potential or suspected endocrine-disrupting pesticides in water and surface sediments, a multiresidue analysis method based on gas chromatography with electron capture detection (GC/ECD) was developed. Solid phase extraction (SPE) technology with Oasis (R) HLB cartridge was also applied in sample extraction. The relevant mean recoveries were 70-103% and 71-103% for water and sediment, respectively. Relative standard deviations (RSD) are 2.0-7.0%, 4.0-8.0% for water and sediment, respectively. Thirty one pesticides (alpha-HCH, beta-HCH, gamma-HCH, delta-HCH, hexachlorobenzene (HCB), aldrin, heptachlor, endosulfan I & II, p,p'-DDD, o,p'-DDT, p,p'-DDT, p,p'-DDE, endrin aldehyde, endosulfan sulphate, methoxychlor, hepachlor epoxide, alpha-chlordane, gamma-chlordane, dieldrin, endrin,. dicofol, acetochlor, alachlor, metolachlor, chlorpyriphos, nitrofen, trifluralin, cypermethrin, fenvalerate, deltamethrin) in water and surface sediment samples from Beijing Guanting reservoir were analyzed. Concentrations of pesticides ranged from 7.59 to 36.0 ng g(-1) on a dry wt. basis for sediment samples, from 279.3 to 2740 ng l(-1) for pore waters and from 48.8 to 890 ng l(-1) for water samples, respectively, with a mean concentration of 10.7 ng g(-1) in sediment, 735 ng l(-1) in pore water and 295 ng l(-1) in water, respectively. The data obtained provides information on the levels and sources of endocrine-disrupting pesticides in Guanting reservoir. These results underscore the need to improved environmental protection measures in order to reduce the exposure of the population and aquatic biota to these endocrine-disrupting compounds. (c) 2005 Elsevier Ltd. All rights reserved.