Investigation on the occurrence of polyhalogenated (Br/Cl) dibenzodioxins and dibenzofurans in cow's milk and fish tissue

Capillary column gas chromatography/medium resolution negative chemical ionization (NCI) and electron impact (EI) mass spectrometry was used for the search on the occurrence of polybrominated or mixed brominated/chlorinated dibenzo-p-dioxins (PB/C-DDs) and dibenzofurans (PB/C-DFs) in cow's milk and fish tissue. In fish tissue, a tetrabromo-DD and a tetrabromo-DF were identified, both not having the 2,3,7,8-substitution pattern. In a cow's milk sample from the vicinity of a municipal waste incinerator (MWI), four compounds were found which were tentatively identified as two tribomo, a tetrabromo and a pentabromodibenzofurans, all four non 2,3,7,8-substituted. Consequently, the TCDD-toxicity (TEQ) level in milk of cows exposed to flyash was not significantly affected by PB/C-DD/Fs.