The Levels and Analytical Developments of Brominated Flame Retardant Hexabromocyclododecanes from Various Environmental Media

Hexabromocyclododecanes (HBCDs) are used as flame retardants primarily in thermal insulation building materials, upholstery textiles, and a little in electronics. During 2006, the production and use of penta- and octa-bromodiphenyl ethers was restricted in Europe, and therefore HBCDs may be used as an alternative for polybrominated diphenyl ethers (PBDEs) in some applications. The atmosphere and bodies of water are the two main persistent reservoirs. The high content of HBCDs was detected in the environmental medium adjacent to the point source, which was much higher than that in the region without any point source. According to the different compound structure, environmental condition and biological metabolism processing, synthetic HBCDs were mainly γ-HBCD and the biotic HBCDs were α-HBCD. Although the Gas Chromatography-Mass Spectrometry (GC-MS) technique has high sensitive detection for HBCDs, it is restricted to isomer analysis of compounds by thermal recomposition and thermal degradation of HBCDs. LC-MS overcame these restrictions and was applied to distinguish enantiomer and diastereomer. The detection limit was improved by the coupling technique of MS/MS. This review summarizes the levels and analytical developments of HBCDs. HBCD stereoisomers transform and degrade during production, which is a potential avenue for future research work. Further study on the environmental behaviour of HBCDs, their evolvement trend, control measures and alternative development are suggested in order to to build a larger HBCD database to meet the convention and to prepare more efficient risk management.