Flame retardants are added to consumer products to retard the ignition of combustible materials. Technical mixtures of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) were massively used for several decades. They are bioaccumulative, persistent, and have adverse effects on organisms. Recognised as persistent organic pollutants, they are banned almost worldwide. Food is the principal source of human exposure. Yet, no maximum residue limits for food have been established in the EU. Nevertheless, monitoring of specific congeners is recommended. Simultaneous analysis of HBCDDs and PBDEs is rarely encountered, especially including BDE-209, as this thermally unstable congener is particularly challenging for analysis. We have developed a method for the simultaneous determination of all relevant PBDEs and HBCDDs recommended for monitoring by the EU. In the method, single sample preparation is used for different types of foodstuffs, applying ultrasound-assisted extraction, clean-up by gel permeation, and adsorption chromatography. Analyses were performed on the same extract, first by GC-MS/MS(EI) method for PBDEs and followed by LC-MS/MS(ESI) method for HBCDDs. The analytical method was validated on a blank sample of milk formula at 2-3 fortification levels, including recommended LOQ level of 0.01 µg/kg wet weight. Satisfactory accuracy with recoveries 85-119%, intra-day precision (1.5-11.3%), and inter-day precision (4.3-18.4%) was obtained. The method ensures LOQs that are compliant with the EU recommendations for all PBDEs and HBCDDs, including BDE-209. Method applicability was further confirmed on proficiency testing samples of baby food, fish, and citrus.
Keywords: GC-MS/MS; LC-MS/MS; POPs; brominated flame retardants; clean-up; hexabromocyclododecane—HBCDD; polybrominated diphenyl ethers—PBDE; ultrasound-assisted extraction; validation.