3P-22 PDF
Structural analysis of unidentified dioxin related compounds in bivalves
Although two major brominated dibenzo-p-dioxins (1,3,7-/1,3,8-triBDDs) and their related compounds (DRCs) were detected at relatively high levels in bivalves and crustaceans from Scandinavian countries and Japan, the chemical structure of several DRCs have been not yet identified. This study examined the EI mass spectrum of unidentified DRCs in bivalves using GCxGC–HRTOFMS and magnetic sector GC–HRMS. Structurally unknown DRCs were tentatively identified as dibrominated monochlorinated dibenzo-p-dioxins (DiBMoCDDs) based on their exact mass, halogen isotope ratio and fragment patterns. Additionally, hydroxylated tetrabrominated monochlorinated diphenyl ethers (HO-TeBMoCDEs), which has been reported as potential precursors of DiBMoCDDs, were also detected in the same specimens. Considering the substitution positions of chlorine in HO-TeBMoCDEs, it was theoretically estimated that DiBMoCDDs are comprised of four isomers. Actually, these isomers were confirmed by magnetic sector GC–HRMS measurement.