- Day 2, May 16（Thu.） 09:30-09:50 Room E (201)
Structural Analysis and Evaluation of Accumulation Properties of Unknown Mixed Halogenated Dibenzo-p-Dioxins
We screened mixed halogenated (brominated/chlorinated) dibenzo-p-dioxins/dibenzofurans (PXDD/Fs, X = Br and Cl) in marine sediments and bivalves collected from Seto Inland Sea, Japan, using two-dimensional gas chromatograph–time-of-flight mass spectrometer (GC×GC–ToFMS) and gas chromatograph–high resolution magnetic sector mass spectrometer (GC–HRMS). In addition to anthropogenic PCDD/Fs, natural PBDDs (e.g. 1,3,7-/1,3,8-TriBDDs) and unknown PXDDs were detected in marine sediment and bivalve samples. By analyzing the accurate mass, halogen isotope ratio, and fragment pattern of PXDDs, they were identified as dibromo/monochloro dioxins (DiBMoCDDs). Interestingly, biota–sediment accumulation factors (BSAFs) of DiBMoCDDs and 1,3,7-/1,3,8-TriBDDs were clearly higher than those of major PCDD/F congeners. This result suggests that DiBMoCDDs are derived from natural origin(s) as well as 1,3,7-/1,3,7-TriBDDs.