![]() Sediment samples had ΣHBCD concentrations ranging from not detected to 1.6 ng/g d.w. Sediments collected in 2004 from along the Detroit River (n = 19) and across all of Lake Erie (n = 18) were analyzed for isomers of the flame retardant chemical, hexabromocyclododecane (HBCD), using liquid chromatography-tandem mass spectrometry. Letcher, Robert J Lu, Zhe Chu, Shaogang Haffner, G Douglas Drouillard, Ken Marvin, Christopher H Ciborowski, Jan J H Hexabromocyclododecane Flame Retardant Isomers in Sediments from Detroit River and Lake Erie of the Laurentian Great Lakes of North America. This event, which returned drainage from the upper lakes to the Lake Erie basin, was a dominant influence on regional stratigraphy, bathymetry, and depositional setting. The presence of both the shell hash layer and relict beach deposit strengthens the interpretation that the Nipissing flood was a critical event in the development of the southwestern area of the central basin of Lake Erie. The Pelee-Lorain moraine, which forms the eastern boundary of the Sandusky subbasin, is an elevated area of till capped by a sand deposit that originated as a beach. This winnowing event may have occurred as a result of the Nipissing flood. These data also suggest that the shell hash layer was derived from erosional winnowing of the underlying soft gray mud layer. New stable isotope data suggest that the soft gray mud unit is of postglacial, rather than proglacial, origin. A fluid mud unit caps the shell hash layer and extends upwards to the sediment-water interface. The lowest of these is a soft gray mud overlain by a shell hash layer containing Sphaerium striatinum fragments. Sediments infilling the Sandusky subbasin consist of three lithologic units overlying glacial deposits. Stable carbon and oxygen isotope data from mollusc aragonite extracted from sediment cores provide new information on the origin and history of sedimentation in the southwestern area of the central basin of Lake Erie. Stable carbon and oxygen isotope record of central Lake Erie sediments production trends for the sum of all fragrance compounds. The HHCB accumulation rates in Lake Erie for 03 correspond to doubling times of 16 ± 4 yr and 8 ± 2 yr, respectively. The input of these compounds to the lakes is increasing. ![]() Using measured fragrance and 210Pb activity, the burden of synthetic musk fragrances estimated from these sediment cores is 1900 kg in Lake Erie and 18000 kg in Lake Ontario. ![]() HHCB was detected in the Lake Erie core while six compounds were detected in the Lake Ontario core. ![]() The chemical signals observed at the two sampling locations were different from each other due primarily to large differences in the sedimentation rates at the two sampling locations. Chemical analysis was performed by gas chromatography/mass spectrometry (GC/MS) and results from Lake Erie were confirmed using gas chromatography/triple-quadrupole mass spectrometry (GC/MS/MS). The nitro musk fragrances were musk ketone and musk xylene. The polycyclic musk fragrances were HHCB (Galaxolide), AHTN (Tonalide), ATII (Traseolide), ADBI (Celestolide), and AHMI (Phantolide). Two sediment cores collected from Lake Ontario and Lake Erie were sectioned, dated, and analyzed for five polycyclic musk fragrances and two nitro musk fragrances. Synthetic Musk Fragrances in Lake Erie and Lake Ontario Sediment Cores
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