A New Method for Purifying Fat-Containing Extracts in the Determination of Polybrominated Diphenyl Ethers

Resumo

We developed a sample preparation method for the determination of polybrominated diphenyl ethers (PBDEs) with from one to ten bromine atoms in samples of feed and food products containing approximately 0.5 g of animal fat or vegetable oil. The method involves gas chromatography with high-resolution mass spectrometry or tandem mass spectrometry. A possibility of using various reagents for the purification of extracts by chemical reactions and fractionation is studied. The physicochemical properties of PBDEs and polychlorinated biphenyls (PCBs) have significant differences, and to determine the full range of PBDEs, it is necessary to use other methods of sample preparation than in the case of PCBs. The conditions selected for the purification of extracts in a column filled with potassium silicate, Florisil, and silica impregnated with sulfuric acid and for their fractionation using activated neutral alumina ensure the PBDE recoveries of at least 75%. Purification of the extracts can be carried out without the use of chlorinated organic solvents. Applied aspects of instrumental analysis and measurement quality assurance are also described.