Determination of brominated flame retardants in food by LC--MS/MS: diastereoisomer-specific hexabromocyclododecane and tetrabromobisphenol A

The levels of the brominated flame retardants (BFRs) hexabromocyclododecane (alpha, beta and gammaHBCD diastereoisomers) and tetrabromobisphenol A (TBBPA) have been determined in two studies using LC-MS/MS. The methodology developed was validated in-house and used to analyse UK 2004 Total Diet Study (TDS) samples and shellfish (oysters, mussels and scallops) collected from Scotland. HBCD was detected in most samples; in both studies the alphaHBCD diastereoisomer was generally the most abundant as opposed to the gamma diastereoisomer that tends to dominate in environmental samples and manufactured products. It is reported that selective metabolism or biotransformation of the beta and gamma diastereoisomers may be taking place. TBBPA was not detected in any samples above the limit of detection, which was as low as 0.05 microg kg(-1). This may be because TBBPA, unlike HBCD, is chemically bound to the polymer matrix during manufacture and not readily leached. The UK Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) concluded that the concentrations of HBCD and TBBPA detected in the TDS study did not raise toxicological concerns and, as levels in the shellfish samples were in a similar concentration range, it was concluded that exposure to the BFRs measured is not significant when compared to exposure from the rest of the diet.