Fast determination of polybrominated diphenyl ethers in human milk using gas chromatography-negative chemical ionization/mass spectrometry

A method for the quantitative determination of eight polybrominated diphenyl ethers (PBDEs) in human milk was established using gas chromatography-negative chemical ionization/mass spectrometry (GC-NCI/MS). After extraction using the Soxhlet extractor, the lipid in the extract was removed by acidic silica, and the analytes were further purified by the multiplayer silica-alumina column. The concentrations of BDE28, BDE47, BDE99, BDE100, BDE153, BDE154, BDE183, and BDE209 in human milk were quickly determined by GC-NCI/MS, in selected ion monitoring (SIM) mode on a 7 m column. The quantitative analysis was performed using the isotope dilution method for BDE209 and internal standard method for other PBDEs. The limits of detection (LODs) of PBDEs in the lipid ranged from 1.74 to 6.35 pg/g. The recoveries of the spiked PBDEs were between 61.5% and 108%, and their relative standard deviations (RSDs) (n = 6) were between 2.06% and 10.1%. The method was further validated by the analysis of the reference materials of human milk. It was demonstrated to be a rapid, economical and reliable alternative for the trace analysis of selected PBDEs, especially for BDE209 in human milk.