Atmospheric concentrations and gas/particle partitioning of neutral poly- and perfluoroalkyl substances in northern German coast

Abstract

Total 58 high volume air samples were collected in Busum, Germany, from August 2011 to October 2012 to investigate air concentrations of 12 per- and polyfluoroalkyl substances (PFASs) and their gas/particle partitioning. The total concentration (vapor plus particle phases) of the 12 PFASs (Sigma PFASs) ranged from 8.6 to 155 pg/m(3) (mean: 41 pg/m(3)) while fluorotelomer alcohols 8:2 (8:2 FTOH) dominated all samples accounting for 61.9% of Sigma PFASs and the next most species were 10:2 FTOH (12.7%). Air mass back trajectory analysis showed that atmospheric PFASs in most samples were from long range atmospheric transport processes and had higher ratios of 8:2 to 6:2 FTOH compared to the data obtained from urban/industrial sources. Small portion of particle PFASs in the atmosphere was observed and the average percent to Sigma PFASs was 2.0%. The particle-associated fractions of different PFASs decreased from perfluorooctane sulfonamidoethanols (FOSEs) (15.5%) to fluorotelomer acrylates (FTAs) (7.6%) to perfluorooctane sulfonamides (FOSAs) (3.1%) and F10Hs (1.8%), indicating the functional group obviously influenced their gas/particle partitioning. For neutral compounds with acid dissociation constant (PKa) > 7.0 (i.e., FTOHs, FOSEs and FOSAs), a significant log-linear relationship was observed between their gas/particle partition coefficients (K-SP) and vapor pressures (p(L)(o)), suggesting the gas/particle partitioning of neutral PFASs agreed with the classical logK(SP)-logp(L)(o) relation. Due to the pK(a) values of 6:2 and 8:2 FTA below the typical environmental pH conditions, they mainly exist as ionic form in aerosols, and the corrected logK(SP) (neutral form) were considerably lower than those of FTOHs, FOSEs and FOSAs with similar vapor pressures. Considering the strong partitioning potential to aqueous phases for ionic PFASs at higher pH values, a need exists to develop a model taking account of the ad/absorption mechanism to the condensed phase of aerosols for ionizable PFASs (e.g., FTAs). (C) 2014 Elsevier Ltd. All rights reserved

Neutral polyfluoroalkyl substances in the atmosphere over the northern South China Sea

“…2 (Ahrens et al, , 2012Cai et al, 2012a;Del Vento et al, 2012;Dreyer and Ebinghaus, 2009;Li et al, 2011;Shoeib et al, 2010;Wang et al, 2014Wang et al, , 2015Xie et al, 2013Xie et al, , 2015. The concentrations of SFTOHs in this study were comparable with those observed in the marine atmosphere, e.g., the Atlantic to the Southern Ocean , the North Sea , the Japan Sea to the Arctic (Cai et al, 2012a) and the Northeast Atlantic Ocean (Shoeib et al, 2010), and lower than those in urban and coastal areas (Ahrens et al, 2012;Dreyer and Ebinghaus, 2009;Li et al, 2011;Wang et al, 2014).…”

“…2b) (Li et al, 2011), and also lower than those reported in other terrestrial areas (Del Vento et al, 2012;Wang et al, 2014). It should be noted that the observed concentrations in this study were even lower than those from the field measurements in other marine atmosphere, such as the North Sea and the Japan Sea to Arctic Ocean (Cai et al, 2012a).…”

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

“…) (Wang et al, 2014d), and most studies (based on reconverted data) across Japan, India, and other places in China using passive samplers (28.0e78.5 pg m À3 ) (Li et al, 2011), but lower than those from Zürich, Switzerland (868 pg m À3 ) (Müller et al, 2012) and Manchester, UK (381e527 pg m À3 ) (Barber et al, 2007). The levels of FTOHs matched those from previous investigation using passive samplers in summer at TJ (117 pg m À3 ) (Yao et al, 2016a), while much higher levels of FOSE/As were reported in this study.…”

“…Half the samples (15 in summer and 14 in winter) from every alternative day were used in this study. Details of high volume air samplers are described elsewhere (Shoeib et al, 2006;Wang et al, 2014d). Briefly, the sampling train comprised a GFF (90 mm diameter) to screen airborne particles and a self-packed PUF-XAD sandwich to trap gas-phase compounds.…”

“…Partitioning between gas and particle phases is an important process that affects the fate of a chemical in the atmosphere. A limited number of field studies have reported the occurrence of neutral PFASs in the particle phase of the atmosphere and their levels were consistently low (Dreyer et al, 2009b;Cai et al, 2012;Müller et al, 2012;Wang et al, 2014d). Nevertheless, FTOHs were able to partition effectively to both organic and mineral surfaces of particulate matter (Arp et al, 2006;Li et al, 2006;Thuens et al, 2008).…”