Simultaneous quantitation of multiple classes of organohalogen compounds in fish oils with direct sample introduction comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry

Authors: Hoh, Eunha; Lehotay, Steven; Mastovska, Katerina; Ngo, Helen; VETTER, WALTER - UNIV. OF HOHENHEIM; PANGALLO, KRISTIN - MIT/WHOI; REDDY, CHRISTOPHER - WOODS HOLE OCEAN. INST.

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2009
Publication Date: 3/5/2009
Citation: Hoh, E., Lehotay, S.J., Mastovska, K., Ngo, H., Vetter, W., Pangallo, K., Reddy, C. 2009. Simultaneous quantitation of multiple classes of organohalogen compounds in fish oils with direct sample introduction comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry. Journal of Agricultural and Food Chemistry. 57(7):2653-2660.

Interpretive Summary: Persistent organic pollutants (POPs) have accumulated and biomagnified in the environmnent and animals (including humans) for many years. They are being studied and monitored by many organizations worldwide for scientific and regulatory purposes. The presence of these contaminants, including naturally occurring halogenated compounds (NHCs) having physico/chemical properties similar to POPs, is a food safety concern, especially in food supplements marketed for improved health. New analytical methods are needed to more efficiently and effectively detect these kinds of chemicals in foods, such as fish oil supplements. In this paper, we describe the use of the advantageous analytical method we developed to measure the presence and amounts of many POPs and NHCs simultaneously in cod liver oil supplements. This method enabled us to discover an unexpected contaminant, oxybenzone, which is a UV stabilizer, in the cod liver oil supplements. We also found that the cod liver oil supplements treated for removal of contaminants worked partially, but we still detected higher molecular weight POPs. This research allows improved measurement of daily human intakes and risk assessment of POPs and NHCs for improved food safety, as well as to provide help to environmental scientists studying these chemicals in the environment and marine ecosystem.

Technical Abstract: We successfully quantified multiple groups of targeted persistent organic pollutants (POPs) and halogenated natural products (HNPs) and screened for untargeted organic compounds in 3 dietary cod liver oil supplements using the novel analytical method described in Part 1 of this study. The relatively volatile contaminants were detected at a much lower level in “PCB-free” cod liver oil but less volatile compounds were detected at similar levels in all three sample types. This suggests that a common treatment for removal of organic and inorganic toxic contaminants works only for lighter organic chemicals. The heavier organic contaminants were also detected in a salmon oil supplement made from Alaskan wild Sockeye and a dolphin oil prepared from the blubber of a Delphinus delphis from the northern Atlantic Ocean. For the first time, we report the identification of other congeners of halogenated 1,1’-dimethyl-2,2’-bipyrroles in salmon oil. The concentrations of the heavy HNPs were equal to or higher than those for PBDEs in the fish and dolphin oils. Higher concentrations of HNPs in the dolphin oil compared to cod liver or salmon oils suggest that the HNPs undergo biomagnification. We estimated daily human intakes of the POPs and HNPs found per serving size of the three cod liver oil supplements, which was 2.2 µg per serving (5 mL) of non-treated cod liver oil, which was 4-7 times higher than the treated cod liver oil. In addition, we found high levels of oxybenzone, which may have leached from packaging materials.