全氟辛烷
多溴联苯醚
环境化学
化学
分配系数
微粒
蒸汽压
污染物
室内空气
挥发性有机化合物
持久性有机污染物
环境科学
磺酸盐
环境工程
色谱法
有机化学
钠
作者
Mahiba Shoeib,Tom Harner,Michael G. Ikonomou,Kurunthachalam Kannan
摘要
Perfluoroalkyls (PFAs) and polybrominated diphenyl ethers (PBDEs) are two classes of emerging persistent organic pollutants (POPs) that are widely used in domestic and workplace products. These compounds also occur in remote locations such as the Arctic where they are accumulated in the food chain. This study makes connections between indoor sources of these chemicals and the potential and mode for their transport in air. In the case of the PFAs, three perfluoralkyl sulfonamides (PFASs) were investigatedN-methyl perfluorooctane sulfonamidoethanol (MeFOSE), N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE), and N-methyl perfluorooctane sulfonamidethylacrylate (MeFOSEA). These are believed to act as precursors that eventually degrade to perfluorooctane sulfonate (PFOS), which is detected in samples from remote regions. High-volume samples were collected for indoor and outdoor air to investigate the source signature and strength. Mean indoor air concentrations (pg/m3) were 2590 (MeFOSE), 770 (EtFOSE), and 630 (∑PBDE). The ratios of concentration between indoor and outdoor air were 110 for MeFOSE, 85 for EtFOSE, and 15 for ∑PBDE. The gas and particle phases were collected separately to investigate the partitioning characteristics of these chemicals. Measured particulate percentages were compared to predicted values determined using models based on the octanol−air partition coefficient (KOA) and supercooled liquid vapor pressure ( ); these models were previously developed for nonpolar, hydrophobic chemicals. To make this comparison for the three PFASs, it was necessary to measure their KOA and vapor pressure. KOA values were measured as a function of temperature (0 to +20 °C). Values of log KOA at 20 °C were 7.70, 7.78, and 7.87 for MeFOSE, EtFOSE, and MeFOSEA, respectively. Partitioning to octanol increased at colder temperatures, and the enthalpies associated with octanol−air transfer (ΔHOA, kJ/mol) were 68−73 and consistent with previous measurements for nonpolar hydrophobic chemicals. Solid-phase vapor pressures ( ) were measured at room temperature (23 °C) by the gas saturation method. Values of (Pa) were 4.0 × 10-4, 1.7 × 10-3, and 4.1 × 10-4, respectively. These were converted to for describing particle−gas exchange. Both the -based model and the KOA model worked well for the PBDEs but were not valid for the PFASs, greatly underpredicting particulate percentages. These results suggest that existing KOA- and -based models of partitioning will need to be recalibrated for PFASs.
科研通智能强力驱动
Strongly Powered by AbleSci AI