English Abstract This report describes the results of a preliminary
investigation on the occurrence of polybrominated and mixed bromo/chloro
dibenzodioxins and furans in cow's milk in the deposition area of the waste
incinerator "Afvalverwerking Rijnmond" (AVR). The investigation was carried
out in a large pooled cow's milk sample containing polychlorodibenzodioxins
and furans (PCDD/F) at a level of 8.14 pg toxic equivalents (TEQ/g) milk
fat. The sample was considered to be representative for a two months milk
production of five dairy farms in the Lickebaert area North of the
incinerators. Analyses were performed by gas chromatography/negative ion
chemical ionization mass spectrometry (GC/NCI-MS) as an initial screening
method to the presence of any brominated or chlorinated compounds, followed
by structure analysis using electron impact GCMS. Four compounds could be
identified of which the structures resembled with polybromodibenzofurans and
were tentatively identified as: two isomers of tribromodibenzofuran, one
isomer of tetrabromodibenzofuran and one pentabromodibenzofuran,
respectively. From comparison with authentic standards it follwed that none
of the identified compounds had the 2,3,7,8-substitution pattern and
consequently may be considered as not extremely toxic. On the basis of
these findings, it is expected that none of the tentatively identified
compounds may not significantly contribute to the increased TEQ values in
cow's milk due to the presence of PCDD/Fs. Parallel to the milk sample a
pooled seafood sample was investigated. Two compounds could be identified
as positional isomers of the tetrabromodibenzodioxin and
tetrabromodibenzofuran congener groups, respectively, both not having a
2,3,7,8-substitution pattern.
