On-line coupling of thermal extraction with gas chromatography / tandem mass spectrometry for the analysis of semivolatile organic compounds in a few milligrams of indoor dust.

An original multiresidue method based on thermal extraction (TE) and gas chromatography/tandem mass spectrometry (GC/MS/MS) was developed to simultaneously quantify, from a very small amount of sample (a few milligrams), a wide range of concerning SVOCs, including polycyclic musks, organochlorines (OCs), organophosphates (OPs), oxadiazolones, polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), phthalates and pyrethroids, in indoor settled dust. Method limits of quantification (LOQs) ranged from 5 ng g-1 for PCBs, oxadiazon, 4,4'-DDE and 4,4'-DDT to 2000 ng g-1 for DEHP for a 2 mg sample of sieved dust. The proposed method was successfully validated in terms of accuracy and precision via replicate analysis of four different standard reference materials (SRMs 1649b (Urban Dust), 2585 (Organic Contaminants in House Dust), 2786 and 2787 (Fine Atmospheric Particulate Matter)) supplied by the National Institute of Standards and Technology (NIST) and was applied to five real indoor settled dust samples collected in French schools. In addition, its performance was compared to that of a previously published method based on pressurized liquid extraction (PLE) and GC/MS/MS. The different results obtained demonstrate the advantages of the proposed method over conventional methods and illustrate its two main features: i) its ease of use and very rapid implementation in only three steps (sieving, weighing and analysis), which make it particularly appropriate for environmental monitoring programs and large-scale studies, and ii) its ability to precisely and accurately quantify a wide range of SVOCs from trace (a few ng g-1) to highly concentrated (several mg g-1) compounds from only 2 mg of sieved dust.