A method for rapid, non-targeted screening for environmental contaminants in household dust

Household dust can be a major source of human exposure to environmental contaminants such as polybrominated diphenyl ethers, pesticides, and other compounds. This work shows a screening technique that may be used to identify components in an environmental sample as xenobiotics based on mass spectral characteristics of classes of compounds that may be expected to be present in the environment. Household dust (SRM-2585) from the National Institute of Standards and Technology (NIST) was extracted with hexane using accelerated solvent extraction. Large molecules, such as triglycerides and fatty acids were removed with gel permeation chromatography. The extract was then concentrated and analyzed by comprehensive two dimensional gas chromatography coupled to a time of flight mass spectrometer. The resulting peak table was automatically filtered to identify compound classes such as phthalates, polycyclic aromatic hydrocarbons and their heterocyclic analogs, chlorinated compounds, brominated compounds, and nitro compounds. While phthalates can be identified by abundances at specific masses, the identification of the remaining classes is based on the identification of the molecular ion and identification of isotope clusters or other spectral characteristics. The technique detected compounds identified and quantified by NIST as well as compounds not identified by NIST in the sample. By comparison with concentrations determined by NIST for the analytes found, the technique is able to identify analytes in these compound classes at concentrations as low as 10-20 ng/g dust.