Validation of a pressurized solvent extraction and GC-NCI-MS method for the low level determination of 40 polybrominated diphenyl ethers in mothers' milk

Chemosphere. 2008 Aug;73(1):70-5. doi: 10.1016/j.chemosphere.2008.05.021. Epub 2008 Jun 25.

Abstract

This study reports an efficient method for the determination of 40 PBDEs from mono- to hepta-brominated in human milk. Pressurized liquid extraction (PLE) was optimized to recover PBDEs in a quantitative way using 1g of freeze dried milk. Due to the great amount of coextracted compounds, the clean-up step was optimized using alumina SPE disposable cartridges of 2 and 5 g. Whereas 2g alumina SPE failed in providing good extraction yields, all PBDEs were satisfactorily recovered using 5 g alumina SPE cartridges. Detection was performed with gas chromatography coupled to mass spectrometry with negative chemical ionization and method detection limits ranged from 0.01 to 0.05 microg kg(-1) wet weight (ww) with a good intra and inter-day variation (coefficient of variation lower than 13.4%). This method was validated by participating in an interlaboratory exercise from Quasimeme (United Kingdom), where a standard solution containing seven congeners and a certified unspiked mothers' milk were analyzed. In the standard mixture, levels between 96.915 and 570.172 microg l(-1) were quantified, whereas in certified mothers' milk, BDEs 47, 99, 100 and 154 were detected at levels from 0.010 and 0.061 microg kg(-1) ww, with an error <30%. The applicability of the method was tested experimentally in five mothers' milk samples, where only BDE 47 was detected at a maximum concentration of 10.45 microg kg(-1) lipid weight (lw). PLE succeeded in extracting all PBDEs from the sample with good reproducibility although the clean-up step had to be severely performed to eliminate sample interferences such as milk lipids and proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aluminum Oxide / chemistry
  • Female
  • Flame Retardants / analysis*
  • Flame Retardants / isolation & purification
  • Gas Chromatography-Mass Spectrometry / methods*
  • Halogenated Diphenyl Ethers / analysis*
  • Halogenated Diphenyl Ethers / isolation & purification
  • Humans
  • Milk, Human / chemistry*
  • Reproducibility of Results
  • Solid Phase Microextraction / methods*
  • Spectrometry, Mass, Electrospray Ionization / methods*

Substances

  • Flame Retardants
  • Halogenated Diphenyl Ethers
  • Aluminum Oxide