Diastereoisomer- and enantiomer-specific determination of hexabromocyclododecane in fish oil for food and feed

Fish oils are one of the main sources of ω-3 fatty acids. However, they can present elevated levels of some lipophilic pollutants, such as hexabromocyclododecanes (HBCDs). Since data about HBCDs in fish oil samples are very limited, in this study, 25 samples of fish oil for feed and food have been analyzed. Total HBCDs, as well as, α-, β- and γ-diastereoisomers have been determined. Total HBCDs ranged from 0.09 to 26.8ngg^-1, with higher concentrations in fish oil for feed (average value of 9.69ngg^-1) than those for food (1.14ngg^-1). Concentrations of α-HBCD (average value of 4.12ngg^-1 in feed samples and 0.48ngg^-1 in food samples) and γ-HBCD (5.05 and 0.43ngg^-1 respectively) were higher than that of β-HBCD (0.52 and 0.19ngg^-1 respectively) in most of the samples. However, none of them was predominant in the samples. Concentrations of HBCDs were compared to concentrations of other pollutants and correlation between dioxin and dioxin-like PCBs levels and HBCDs levels were observed. Intake of HBCDs was calculated for fish oil with human consumption purposes and it ranged from 0.08 to 5.38ng HBCDsd^-1, which could contribute significantly to HBCDs total intake. Enantiomeric fractions were also determined. No clear enrichment was observed for γ-HBCD, while (-)-α-HBCD enrichment was detected in some samples.