[Determination of polybrominated diphenyl ethers in human serum using solid-phase extraction and gas chromatography...

A simplified analytical method comprised of solid-phase extraction (SPE) and gas chromatography coupled with negative chemical ionization mass spectrometry (GC-NCI/MS) has been developed for the determination of 10 polybrominated diphenyl ethers (PBDEs) congeners in human serum. After the extraction by Oasis HLB custom-made SPE cartridges, the lipids in serum were decomposed by concentrated sulfuric acid directly added on the SPE column. The solvent for protein cleanup and the SPE conditions, such as elution solvent and its volume were optimized. The recoveries of the PBDEs spiked in fetal bovine serum relative to internal standards were in the range of 78.5% - 109.7% at five spiked levels (three spiked levels for BDE-209). The intra-day relative standard deviations (RSDs) were between 0.3% and 7.4%, while the inter-day RSDs were between 1.42% and 14.1%. The limits of detection (LOD, S/N = 3) and the limits of quantification (LOQ, S/N = 10) were in the range of 0.10 - 0.27 ng/L and 0.35 -0.91 ng/L respectively for all PBDEs, except BDE-209. The LOQ (blank concentration value x 3) for BDE-209 was 7.91 ng/L. The method was verified by accurate analysis of organic contaminant standard reference materials (SRM) 1957 and 1958. The results indicated that the proposed method is sensitive, accurate, fast, simple, low solvent consumption and suitable for the determination of tri- to deca-BDE in human serum.