Per- and poly-fluoroalkyl substances (PFASs) in the urban, industrial, and background atmosphere of Northeastern China coast around the Bohai Sea: Occurrence, partitioning, and seasonal variation

Distribution and dry deposition of alternative and legacy perfluoroalkyl and polyfluoroalkyl substances in the air above the Bohai and Yellow Seas, China

“…TFA was an ionizable homologue (pK a = 0.23) mainly distributed in the gas phase. The particle phase fraction φ values of TFA varied over a large range from 0 to 100% (mean 27% ± 32%), which was consistent with coastal cities and one inland city in China (Hu et al, 2013;Yao et al, 2016Yao et al, , 2017a. The factors that influence TFA distribution were complex.…”

“…The pretreatment of the samples has been described elsewhere (Wang et al, 2014b;Yao et al, 2017a). Briefly, the air columns were Soxhlet-extracted by DCM for 24 h after being spiked with 10 ng (0.5 ng μL −1 , 20 μL) IS and were then switched to methanol for another 24 h to collect possible residue.…”

“…The ratio of PFOA to PFNA was over 100, and direct release was considered the main source (Chen et al, 2017b). i-PFASs in coastal and marine surface waters could transport to air as aerosols and then undergo long-range atmospheric transport, which was identified as the direct source (Ahrens et al, 2011b;Prevedouros et al, 2006;Yao et al, 2017b). The significantly lower ratios of PFOA to PFNA in air compared to coastal water suggested the moderate contribution of direct sources.…”

“…The Kp values increased with the increasing relative humidity in the air, which suggested the strong partitioning potential of the particle phase in marine atmospheres (Arp et al, 2008). However, fewer studies in marine air than land and coastal city air have been conducted (Ahrens et al, 2012;Shoeib et al, 2004;Yao et al, 2017b). The dry deposition was an important path for PFAS transport from air to surface water, while the estimation of fluxes based on field investigation have been rare.…”

Nontarget Discovery of Per- and Polyfluoroalkyl Substances in Atmospheric Particulate Matter and Gaseous Phase Using Cryogenic Air Sampler

“…Some studies have reported the distribution of PFASs in the particle and gaseous phase of the atmosphere, − indicating that the concentration of PFASs in the global atmosphere is increasing year after year, and that ionizable PFASs show stronger affinity to atmospheric particulate matter than do neutral PFASs. , However, the existing studies only focus on legacy PFASs such as perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFSAs), fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamides (FOSAs), and perfluorooctane sulfonamidoethanols (FOSEs) without studying the distribution of novel PFASs in air, especially the gaseous phase of air. Furthermore, traditional air samplers primarily use adsorbent materials such as polyurethane foam (PUF) for specific pollutants, which can only guarantee the absorption performance of the target PFASs. − It is difficult to collect pollutants effectively from high-humidity air using PUF .…”