[Perfluorinated Compounds in Snow from Downtown Hangzhou, China].
Snow samples were collected from the snow event on January 20-22, 2016 from 11 sites in downtown Hangzhou to explore the occurrence of sixteen perfluorinated compounds (PFCs) in the atmosphere. All samples were prepared by solid-phase extraction with Oasis WAX cartridges and analyzed using ultra performance liquid chromatography interfaced with tandem mass spectrometry (UPLC-MS/MS). The results showed that seven medium- and short-chain PFCs including C4 and C8 perfluorinated sulfonates (PFSAs) and C4-C6, C8, and C9 perfluorinated carboxylic acids (PFCAs) were detected in the snow samples. Total PFC concentrations ranged from 2.85 to 35.1 ng·L-1, whereas perfluorooctanoic acid (PFOA) dominated, with ranges of 2.15-23.0 ng·L-1, and perfluorooctane sulfonate (PFOS) was detected at lower levels, ranging from 0 to 0.46 ng·L-1. As compared to the results from other studies, the PFOA concentrations of the study region were at mid-level and the PFOS concentrations were relatively low. The spatial distribution of PFCs varied, and the pollutant concentrations of the snow samples from the sampling sites located in the urban areas were higher than those in the rural areas. The greatest total PFC concentrations were detected in Fuyang, whereas the lowest concentrations were detected in Jiande and Chun'an. In this study, the high concentrations of PFCs dominated by PFOA that were measured in the Hangzhou snow samples emphasize the importance of atmospheric wet deposition as one of the sources of PFC contamination in this ecological system and should be addressed. The occurrence of PFCs in the air, indicated by their presence in the snow, suggests that the atmospheric environment may be an important contributor in human and ecological exposure to PFCs by local residents.