Halogen bonding for increasing efficiency in liquid-liquid microextraction: Application to the extraction of hexabromocyclododecane enantiomers in river water.

•Halogen bonding is proposed to raise efficiency in liquid-liquid microextraction.•A supramolecular solvent with electron density donor atoms is used as extractant.•Hexabromocyclododecane enantiomers are quantitatively extracted from natural waters.•Operational and analytical characteristics surpass those of previous reported methods.•The approach is valuable for the environmental monitoring of halogenated compounds.