摘要: We used semipermeable membrane devices (SPMDs) to sample water, and achieved sub-211parts-per-quintillion detection limits. We deployed SPMDs during 1997 low-flow 211conditions and 1998 high-flow conditions at nine main-stem sit... 展开 We used semipermeable membrane devices (SPMDs) to sample water, and achieved sub-211parts-per-quintillion detection limits. We deployed SPMDs during 1997 low-flow 211conditions and 1998 high-flow conditions at nine main-stem sites and seven 211tributary sites, spanning approximately 700 miles of the Columbia River. We also 211collected streambed sediment from three sites. SPMD extracts and sediments were 211analyzed for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzo-furans, 211polychlorinated biphenyls, organochlorine pesticides and related transformation 211products, and polycyclic aromatic hydrocarbons. 收起