Octanol-air partition coefficients (K OA ) for five fluorotelomer alcohols (4:2 FTOH, 6:2 FTOH, 8:2 FTOH, 10:2 FTOH, and for the first time 12:2 FTOH) were determined over a temperature range from (5 to 40) °C using a modified generator column method. Octanol-saturated air at a fixed temperature was blown over a column filled with glass spheres which were coated with an FTOH solution. FTOHs partitioning to the gas phase were collected on a trap filled with XAD-2 and eluted with acetone afterward. The concentrations of FTOH were measured by GC-MS using positive chemical ionization. The K OA values were calculated as the ratio of the FTOH concentrations in the octanol to the FTOH concentrations in the air. Values of log K OA at 25 °C ranged from 4.5 (4:2 FTOH) to 6.2 (12:2 FTOH). The calculated internal energies of phase change (∆U OA ) ranged from 42.8 kJ • mol -1 (12:2 FTOH) to 61.1 kJ • mol -1 (4:2 FTOH). The combined uncertainty of the method applied ranged from 8.3 % (4:2 FTOH) to 10.5 % (10:2 FTOH). The expanded uncertainty (P ) 95 %) ranged from 18.7 % (4:2 FTOH) to 38.7 % (10:2 FTOH), respectively.

As ombrotrophic peat bogs receive only atmospheric input of contaminants, they have been identified as suitable natural archives for investigating historical depositions of airborne pollutants. To elucidate their suitability for determining the historical atmospheric contamination with perfluoroalkyl substances (PFAS), two peat cores were sampled at Mer Bleue, a bog located close to Ottawa, Canada. Peat cores were segmented, dried, and analyzed in duplicate for 25 PFASs (5 perfluororalkyl sulfonates (PFSAs), 13 perfluoroalkyl carboxylates (PFCAs), 7 perfluororalkyl sulfonamido substances). Peat samples were extracted by ultrasonication, cleaned up using a QuEChERS method, and PFASs were measured by HPLC-MS/MS. Twelve PFCAs and PFSAs were detected regularly in peat samples with perfluorooctane sulfonate (85-655 ng kg(-1)), perfluorooctanoate (150-390 ng kg(-1)), and perfluorononanoate (45-320 ng kg(-1)) at highest concentrations. Because of post depositional relocation processes within the peat cores, true or unbiased deposition fluxes (i.e., not affected by post depositional changes) could not be calculated. Apparent or biased deposition rates (i.e., affected by post depositional changes) were lower than measured/calculated deposition rates for similar urban or near-urban sites. Compared to PFAS production, PFAS concentration and deposition maxima were shifted about 30 years toward the past and some analytes were detected even in the oldest segments from the beginning of the 20th century. This was attributed to PFAS mobility in the peat profile. Considerable differences were observed between both peat cores and different PFASs. Overall, this study demonstrates that ombrotrophic bogs are not suited natural archives to provide authentic and reliable temporal trend data of historical atmospheric PFAS deposition.

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Multimedia fate and transport models are used to evaluate the long range transport potential (LRTP) of organic pollutants, often by calculating their characteristic travel distance (CTD). We calculated the CTD of several polycyclic aromatic hydrocarbons (PAHs) and metals using two models: the OECD P OV & LRTP Screening Tool (The Tool), and ELPOS. The absolute CTDs of PAHs estimated with the two models agree reasonably well for predominantly particle-bound congeners, while discrepancies are observed for more volatile congeners. We test the performance of the models by comparing the relative ranking of CTDs with the one of experimentally determined travel distances (ETDs). ETDs were estimated from historical deposition rates of pollutants to peat bogs in Eastern Canada. CTDs and ETDs of PAHs indicate a low LRTP. To eliminate the high influence on specific model assumptions and to emphasize the difference between the travel distances of single PAHs, ETDs and CTDs were analyzed relative to the travel distances of particle-bound compounds. The ETDs determined for PAHs, Cu, and Zn ranged from 173 to 321 km with relative uncertainties between 26% and 46%. The ETDs of two metals were shorter than OPEN ACCESSAtmosphere 2014, 5 325 those of the PAHs. For particle-bound PAHs the relative ETDs and CTDs were similar, while they differed for Chrysene.

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