Abstract
Semi-volatile organic compounds (SVOCs) are modern chemical substances that are present in large quantities in indoor environments. Understanding the emission of SVOCs from building materials is essential to identify the main sources of indoor SVOCs and to improve indoor air quality. In this study, a reference method employing custom-designed microchambers (630 mL) was optimized by improving the structure of the gas path and adding polytetrafluoroethylene inner coating to the chamber. After optimization, the recoveries of the microchamber method were significantly improved (75.4-96.7%), and the background in the microchamber was greatly reduced (<0.02 μg/h). By using the microchamber method, 33 SVOCs (including two alkanes, one aromatic, one nitrogen compound, and twenty-nine oxygenated compounds) and 32 SVOCs (including seven alkanes, eight aromatics, and seventeen oxygenated compounds) were detected in the emissions of the architectural coating and the PVC flooring samples, respectively. The area-specific emission rates (SER(a)) of total SVOCs emitted from architectural coatings and PVC floorings were in the range of 4.09-1309 μg/m(2)/h) (median: 10.3 μg/m(2)/h) and 0.508-345 μg/m(2)/h (median: 11.9 μg/m(2)/h), respectively. Propanoic acid had the highest SER(a) (3143 μg/m(2)/h) in architectural coatings, while methylbenzene (345 μg/m(2)/h), 2-methylnaphthalene (65.2 μg/m(2)/h), and naphthalene (60.3 μg/m(2)/h) were main SVOCs emitted from PVC floorings. Meanwhile, the average second-stage (adsorbed phase) emission mass of the total SVOCs accounts for 66.3% and 47.3% in architectural coatings and PVC floorings, respectively, suggesting that the SVOCs emitted from building materials have a strong tendency to be absorbed on the surface of the room, e.g., the interior wall, the desk or even the skin.