Evaluation of SFE--CO2 and Methanol--CO2 Mixtures for the Extraction of Polynuclear Aromatic Hydrocarbons from House Dust

The extraction of native polynuclear aromatic hydrocarbons (PAHs) from house dust is studied using supercritical fluid extraction (SFE—CO2); direct modified SFE; and mixtures of 10, 20, 30, and 40 mole percent methanol in CO2. The temperatures studied are 50, 75, and 100°C. For the direct modified SFE experiments, the effect of adding 100 and 200 µL of methanol and 100 µL of water directly to the sample at 75 and 100°C is studied. The properties of the PAHs and of the dust matrix are used to explain the patterns observed in the recovery yields. The increase in the solvent strength of the methanol—CO2 mixtures greatly increases the recoveries and decreases the total extraction time. Also, an increase in the extraction temperature positively affects the yields. The direct modified SFE and SFE—CO2 experiments give similar extraction yields, and the extractions with the binary mixtures give optimum results.