Application of gas chromatography high-resolution mass spectrometry to the determination of trace monobromopolychlorodibenzo-p-dioxins in environmental samples

Abstract

A capillary column gas chromatographic/high resolution mass spectrometric method was developed for the determination of monobromopolychlorodibenzo-p-dioxins (BPCDDs) in environmental samples. The mass spectrometer was operated at high resolution (> 10,000) in the selected ion monitoring mode with magnet switching among tetra through octa groups to achieve low or subpicogram detection limits. Standard BPCDDs (tetracongener through octacongener groups) were utilized to measure accurately the mass spectrometric relative response factors for these compounds, and linear calibrations were achieved by using these standard compounds at different concentrations. The method detection limit is low or sub-parts-per-trillion levels for BPCDDs, the accuracy better than 80% and the precision better than ± 10%. Quantification of BPCDDs and preliminary identification of some specific BPCDD isomers in fly ash samples are also reported.

Dioxin and Related Compounds

“…There are 1,436 mixed bromo/chloro dioxins congeners [212][213][214] and chloro/fluoro dioxins [215,216] and only a few bromochloro standards are available commercially. Mixed halogenated dioxins and furans are at least as toxic as chlorinated dioxins [217].…”

“…Imaeda et al [214] investigated PCDD/Fs, PCBs, and dl-PCBs in the blubber of Baikal seals collected in 1992 and 2005. Dl-PCBs were one of the dominant contaminants, with concentrations ranging from 480 to 3,600 ng/g ww.…”

“…Concentrations of PCDFs and non-ortho PCBs were significantly lower in 2005 than 1992, but no decreasing temporal trend of PCDDs, mono-ortho PCBs, or most non-dioxin like PCBs was observed. In 2005, TEQ levels in 40% of the specimens exceeded the threshold level for adverse effects in harbor seals (209 pg/g ww) [214], which raises concern for the future of the population.…”

“…Nonetheless, with some exceptions (PFOS; [211]), it is generally legacy compounds such as PCBs that trigger exceedances of thresholds, either for the consumption of fish by humans [212] or the consumption of fish by wildlife (e.g. fish flesh criteria for piscivorous wildlife; [213]), or the consumption of wildlife by other wildlife [214]. Monitoring programmes provide sound science-based information that can be used not just by scientists but also by policy makers and risk managers.…”

The analysis of dioxins and related compounds

“…Mixed halogenated dioxins and furans are the most challenging group of DLCs to analyze. There are very few standards available for the 1,436 congeners of mixed bromo/ chloro dioxins Huang et al, 1992;Chatkittikunwong & Creasei, 1994) and chloro/fluoro dioxins (Weber et al, 1995;Weber & Hagenmaier, 1997). Levels are typically an order of magnitude or more lower than the chlorinated PCDD/Fs (Donnelly et al, 1990;Wiberg, Rappe, & Haglund, 1992;Hayakawa et al, 2004).…”