Abstract  Semivolatile fluorinated organic compounds (FOCs) were measured in archived air sample extracts collected from Hedo Station Observatory (HSO) on Okinawa, Japan and Mount Bachelor Observatory (MBO), Oregon U.S. during the springs of 2004 (MBO and HSO) and 2006 (MBO). Fluorotelomer alcohols (FTOHs) were measured in both Asian and western U.S. air masses, though western U.S. air masses had significantly higher concentrations. Concentrations of fluorotelomer olefins in Asian air masses and 8:2 fluorotelomer acrylate in U.S. air masses were reported for the first time. N-ethyl perfluorooctane sulfonamide, N-methyl perfluorooctane sulfonamido ethanol, and N-ethyl perfluorooctane sulfonamido ethanol were also measured in Asian and western U.S. air masses but less frequently than FTOHs. The atmospheric sources and fate of FTOHs were investigated by estimating their atmospheric residence times, calculating FTOH concentration ratios, investigating FTOH correlations with nonfluorinated semivolatile organic compound concentrations, and determining air mass back trajectories. Estimated atmospheric residence times for 6:2 FTOH, 8:2 FTOH, and 10:2 FTOH were 50, 80, and 70 d, respectively, and the average concentration ratio of 6:2 FTOH to 8:2 FTOH to 10:2 FTOH at MBO in 2006 was 1.0 to 5.0 to 2.5. The relative order of these atmospheric residence times may explain the observed enhancement of 8:2 FTOH and 10:2 FTOH (relative to 6:2 FTOH) at MBO compared to North American indoor air (FTOH average ratio of 1.0 to 2.0 to 1.0). FTOH concentrations in western U.S. air masses were positively correlated (p < 0.05) with gas-phase polycyclic aromatic hydrocarbon and polychlorinated biphenyl concentrations and negatively correlated (p < 0.05) with agricultural pesticide concentrations. In comparison to western U.S. air masses, trans-Pacific air masses did not contain elevated concentrations of these compounds, whereas lower boundary layer air masses that passed over urban areas of the western U.S. did. This suggests that semivolatile FOCs are emitted from urban areas in the western U.S.

Abstract  A new, fast and simple sampling method using commercially available Isolute ENV+ solid-phase extraction (SPE) cartridges for the enrichment of neutral, volatile polyfluorinated alkyl substances (PFAS) was developed and applied to selected air samples. The SPE cartridges showed good retention capacity for the target analytes, and most of the investigated compounds could be quantified in 20m(3) indoor air. Employing the developed method, it was shown that high levels of selected fluorotelomer alcohols (FTOHs) and N-alkyl fluorooctane sulfonamides/-ethanols (FOSAs/FOSEs) evaporated from a paraglider. Furthermore, the new method was compared to the 'classical' approach using glass-fibre filters (GFFs) and XAD-2 resin sandwiched between polyurethane foam plugs (PUF/XAD/PUF) to investigate environmental air concentrations in metropolitan Hamburg. Due to the high counter pressure of SPE cartridges, only low-volume air sampling was feasible. Therefore, the trace levels of FOSAs/FOSEs occurring in environmental air could only be quantified occasionally in the samples enriched on SPE cartridges. However, quantitative analysis of the higher concentrated 6:2 FTOH, 8:2 FTOH and 10:2 FTOH was possible in all low-volume environmental air samples. Finally, the determination of ionic PFAS, including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), bound to airborne particles in the air samples from Hamburg is described.

Abstract  BACKGROUND, AIM, AND SCOPE: As possible precursors of PFOA, fluorotelomer alcohols are a class of highly fluorinated and volatile compounds. Although they are widespread in the environment, little toxicity data is available. The present study focused on testing the population growth impairment potential of FTOH. Moreover, certain efforts were made to find the possible effect mechanism of these compounds.

MATERIALS AND METHODS: The growth inhibition test was made both in an open system (96-well microplates) and in a closed system (closed flasks). In addition, cells were stained with acridine orange and observed under fluorescence microscopy at 488 nm. Furthermore, direct membrane damage was checked by measuring LDH leakage.

RESULTS: For 8:2 FTOH and 10:2 FTOH, no growth inhibition was found in either of the systems. In contrast, 4:2 FTOH interfered with population growth in the closed system (EC(50) = 276.1 mg/L), whereas, 6:2 FTOH had an influence on population growth both in the closed system (EC(50) = 64.3 mg/L) and in the open system. Macronucleus destruction was observed with 6:2 FTOH. No direct membrane damage was detectable.

DISCUSSION: With a closed system, 4:2 and 6:2 FTOH were found to be capable of impairing population growth. However, this potential was to a certain extent underestimated. With the help of the air-water distribution coefficient, the real EC(50) was estimated within the interval [203.2, 276.1] mg/L and [14.7, 64.3] mg/L for 4:2 and 6:2 FTOH, respectively. Some evidence, such as the absence of direct membrane or macronucleus damage, indicate that certain FTOH could likely cause apoptosis. But the exact effect mechanism could not be determined on the basis of the present results.

CONCLUSIONS: Comparing the results from the two test systems, tests in a closed system are more reliable for testing these volatile compounds with Tetrahymena thermophila than in an open system.

RECOMMENDATIONS AND PERSPECTIVES: The present study has highlighted several future research directions. For ecotoxicological risk assessment of FTOH, their distribution and environmental fate should be determined. To understand the effect mechanism, more tests could be conducted to test whether apoptosis is caused. Finally, in order to standardize test procedure in a closed system, more compounds should be investigated in the closed system to clarify the sensitivity of the test procedures.

Abstract  Chemical modification of wood was investigated using blocked isocyanates prepared from reaction of 4,4'-diphenylmethane diisocyanate (MDI) with I equivalent of 2-perfluorohexyl ethanol followed by addition of 1.1 equivalent of methyl ethyl ketoxime (MEKO). Thermal dissociation of the urethane linkage bearing a methyl ethyl ketoxime group allows generation of free isocyanate which reacts with alcohols like cyclohexanol or benzyl alcohol. The reaction was then extended to the hydroxyl groups of wood in order to bind perfluoroalkyl chains. Reaction was first studied on wood meal before grafting on blocks. Such modified blocks possess improved dimensional stability compared to untreated ones. Contact angle measurements were also performed. sigma values obtained for modified blocks were greater and did not decrease with time compared to those obtained with unmodified blocks. (C) 2000 Elsevier Science S.A. All rights reserved.

Abstract  We demonstrate the formation of mixed monolayers derived from a microwave-assisted reaction of alcohols with silicon oxide surfaces in order to tune their surface oleophobicity. This simple, rapid method provides an opportunity to precisely tune the constituents of the monolayers. As a demonstration, we sought fluorinated alcohols and aliphatic alcohols as reagents to form monolayers from two distinct constituents for tuning the surface oleophobicity. The first aspect of this study sought to identify a fluorinated alcohol that formed monolayers with a relatively high surface coverage. It was determined that 1H,1H,2H,2H-perfluoro-1-octanol yielded high quality monolayers with a water contact angle (WCA) value of ∼110° and contact angle values of ∼80° with toluene and hexadecane exhibiting both an excellent hydrophobicity and oleophobicity. Tuning of the oleophobicity of the modified silicon oxide surfaces was achieved by controlling the molar ratio of 1H,1H,2H,2H-perfluoro-1-octanol within the reaction mixtures. Surface oleophobicity progressively decreased with a decrease in the fluorinated alcohol content while the monolayers maintained their hydrophobicity with WCA values of ∼110°. The simple and reliable approach to preparing monolayers of a tuned composition that is described in this article can be utilized to control the fluorocarbon content of the hydrophobic monolayers on silicon oxide surfaces.

Abstract  Two quantitative methods using high-performance liquid chromatography (HPLC) combined with triple quadrupole tandem mass spectrometry (MS/MS) were developed to determine perfluoroalkyl and polyfluoroalkyl substances (PFASs) in aqueous samples. The first HPLC-MS/MS method was applied to 47 PFASs of 12 different substance classes with acidic characteristics such as perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs), as well as precursor substances and biotransformation intermediates (e.g., unsaturated fluorotelomer carboxylic acids). In addition, 25 (13)C-, (18)O-, and (2)H-labeled PFASs were used as internal standards in this method. The second HPLC-MS/MS method was applied to fluorotelomer alcohols (FTOHs) and perfluorooctane sulfonamidoethanols as these compounds have physicochemical properties different from those of the previous ones. Accuracy between 82% and 110% and a standard deviation in the range from 2% to 22% depending on the substances were determined during the evaluation of repeatability and precision. The method quantification limit after solid-phase extraction ranged from 0.3 to 199 ng/L depending on the analyte and matrix. The HPLC-MS/MS methods developed were suitable for the determination of PFASs in aqueous samples (e.g., wastewater treatment plant effluents or influents after solid-phase extraction). These methods will be helpful in monitoring campaigns to evaluate the relevance of precursor substances as indirect sources of perfluorinated substances in the environment. In one exemplary application in an industrial wastewater treatment plant, FTOHs were found to be the major substance class in the influent; in particular, 6:2-FTOH was the predominant compound in the industrial samples and accounted for 74% of the total PFAS concentration. The increase in the concentration of the transformation products of FTOHs in the corresponding effluent, such as fluorotelomer carboxylic acids, unsaturated fluorotelomer carboxylic acids, n:3 polyfluorinated saturated carboxylic acids (n indicates the number of nonfluorinated carbon atoms), and PFCAs, indicated biotransformation of FTOHs or their derivatives during wastewater treatment. However, only 33 mol% of the total amount of PFASs present in the influent was quantified in the corresponding effluent. Graphical abstract Method development of an HPLC-MS/MS multi-method for the determination of PFASs in aqueos samples.

Abstract  2,3,4,5,6-Pentafluorobiphenyl (PFBi) was modified by the nucleophilic substitution of one fluorine using a series of 0-, S- and N-nucleophiles, viz, alkaline salts of 2,2,2-trifluoro-ethanol, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctanol, 1,2:3,4-di-O-isopropylidenexylitol, allylsulfane, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctane-1-thiol, 3-aminopropan-1-ol (7), and tert-butyl N-(3-aminopropyl)carbamate (8). All the substitutions took place exclusively at the position para to the phenyl group. (3-Amino-propyl)amino derivative of PFBi (15) was further modified at the terminal amino group by acylation or fluoroalkylation. The reaction of 8 was applied to meso-5,10,15,20-tetrakis-(pentafluorophenyl)porphyrin (20) to afford tris- (21) and tetrakis-substituted (22) products with complete para-regioselectivity. Theoretical studies of the reaction pathways of PFBi with ammonia, microsolvated lithium fluoride or lithium hydroxide revealed that no Meisenheimer-type intermediates are formed in the course of the simulated reactions: instead, tetrahedral S(N)2 mechanism was found. Significant regioselectivity of the nucleophilic aromatic substitution, leading to 4-substituted products, was predicted based on relative transition state energies in agreement with the observed experimental results. (C) 2010 Elsevier BM. All rights reserved.

Abstract  Copper(I)-accelerated Huisgen-Meldal dipolar cycloaddition reactions between polyfluoroalkyl azides and propargyl ethers of n-octanol and of triethyleneglycol monomethyl ether exhibited variation in yield of 1,2,3-triazol-4-ylmethyl ethers. Microwave acceleration, and in situ generation of the azides, provided improvements in yield and efficiency. In contrast, very good yields of equivalent fluorous triazoles were obtained from a range of n-alkyl azides with propargyl ethers of perfluorohexylethanol and of perfluoroheptylmethanol through conventional copper(I)-promoted reactions. Together, the resulting substances with systematic variations in polyfluoroalkyl and alkyl substituent length and position of substitution, and degree of oxygen content, make up small libraries of hybrid fluorous 1,2,3-triazol-4-ylmethyl ethers as candidates for study as hydrophilic fluorous surfactants. In addition, a pilot sample of di(1,2,3-triazol-4-ylmethyl) ethers with 1'-octyl-1-polyfluoroalkyl-substituents and 1'-nonyl-1-perfluorooctylethyl substituents were synthesised for the first time in an effort to develop more functional, fluorous surfactants. (C) 2011 Elsevier B.V. All rights reserved.

Abstract  The study reviews the current state of knowledge regarding the biotransformation of fluorotelomer-based compounds, with a focus on compounds that ultimately degrade to form perfluoroalkyl carboxylates (PFCAs). Most metabolism studies have been performed with either microbial systems or rats and mice, and comparatively few studies have used fish models. Furthermore, biotransformation studies thus far have predominately used the 8:2 fluorotelomer alcohol (FTOH) as the substrate. However, there have been an increasing number of studies investigating 6:2 FTOH biotransformation as a result of industry's transition to shorter-chain fluorotelomer chemistry. Studies with the 8:2 FTOH metabolism universally show the formation of perfluorooctanoate (PFOA) and, to a smaller fraction, perfluorononanoate (PFNA) and lower-chain-length PFCAs. In general, the overall yield of PFOA is low, presumably because of the multiple branches in the biotransformation pathways, including conjugation reactions in animal systems. There have been a few studies of non-FTOH biotransformation, which include polyfluoroalkyl phosphates (PAPs), 8:2 fluorotelomer acrylate (8:2 FTAC), and fluorotelomer carboxylates (FTCAs, FTUCAs). The PAPs compounds and 8:2 FTAC were shown to be direct precursors to FTOHs and thus follow similar degradation pathways.

Abstract  The interfacial tensions of the hexane solution of fluorooctanols (1,1,2,2-tetrahydrotridecafluorooctanol, TFC8OH, and 1,1-dihydropentadecafluorooctanol, DFC8OH) against water were measured as a function of temperature and molality under atmospheric pressure. By drawing the interfacial pressure a vs mean area per adsorbed molecule A curves, it was concluded that the adsorbed film of TFC8OH exhibits a first-order phase transition between the gaseous and expanded states and that of DFC8OH shows the two types of phase transitions from the gaseous to the expanded state and from the expanded to the condensed one at the hexane/water interface. The comparison of the pi vs A curve between TFC8OH and DFC8OH shows that the intermolecular interaction is enhanced by the substitution of fluorine for hydrogen on the beta -carbon of TFC8OH. Furthermore, the difference in the transition pressure between DFC8OH and TFC10-OH (1,1,2,2-tetrahydroheptadecafluorodecanol) is explained by the differences in London dispersion force between hydrophobic chains and the dipole moment of their hydroxyl group. The partial molar entropy (s) over bar (H)(s) - s(s)(O) and energy (u) over bar (H)(s) - u(s)(O) changes of adsorption were evaluated and compared to those of TFC10OH. The (s) over bar (H)(s) - s(s)(O) value is negative and therefore alcohol molecules have smaller entropy at the interface than in the solution, which is attributable to the orientation of the molecules at the interface. The phase transition from the expanded to the condensed state in the adsorbed TFC10OH film causes larger decrease in partial molar entropy than that in the DFC8OH one. This may arise from the larger partial molar entropy of TFC10OH molecules due to the larger entropy of mixing of longer fluorocarbon chain with hexane in the expanded state and the smaller entropy of TFC10OH due to the stronger attractive interaction in the condensed state than that of DFC8OH molecules. The (u) over bar (H)(s) - u(s)(O) value is less negative for DFC8OH than for TFC10OH and therefore the energetical stabilization of DFC8OH accompanied by the adsorption from the solution is less than that of TFC10OH. Furthermore, it was concluded that the DFC8OH molecules are stabilized by forming the condensed film at the interface because of the strong molecular interaction between them, and the TFC8OH molecules form mainly tetramers in the hexane solution to lower the energetical state of the system.

Abstract  Degradation of fluorotelomer alcohols (FTOHs) was recognized as an additional source of perfluorocarboxylic acids (PFCAs). Quantification of FTOHs and their degradation products can help shed light on the sources and fates of PFCAs in the environment. In this study, an analytical method was developed for the determination of 6:2 and 8:2 FTOHs, and their degradation products of poly- and perfluorinated acids, including fluorotelomer saturated and unsaturated carboxylic acids (FTCAs and FTUCAs), secondary polyfluorinated alcohols and PFCAs in biosolids-amended soils and plants using ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The extract efficiencies of different methods including ethyl acetate and methanol (MeOH) for FTOHs and acetonitrile, MeOH, methyl tert-butyl ether (MTBE), NaOH-MeOH and NaOH-MTBE for poly- and perfluorinated acids were tested. The results showed that 6:2 and 8:2 FTOHs and their degradation products could be simultaneously and satisfactorily extracted by MeOH, cleaned up by Envi-Carb graphitized carbon and solid phase extraction, respectively, and determined by UPLC-MS/MS separately. NaOH in the extractant caused the conversion of 6:2 FTCA and 8:2 FTCA into the corresponding FTUCAs. The selected methods have matrix recoveries ranged from 52% to 102%, and detection limits of 0.01-0.46ng/g dry weight for FTOHs and their degradation products in soil and plant. The optimized method was applied successfully to quantify FTOHs and their degradation products in two biosolids-amended soils and plants. The total concentrations of FTOHs in the soils were 44.1±5.8 and 82.6±7.1ng/g, and in plants tissues 3.58±0.25 and 8.33±0.66ng/g. The total concentrations of poly- and perfluorinated acids in the soils were 168.0±13.2 and 349.6±11.2ng/g, and in plants tissues 78.0±6.4 and 75.5±5.3ng/g.

Abstract  Saturated and unsaturated fluorotelomer carboxylic acids have been identified as intermediates in the degradation of fluorotelomer alcohols to perfluorinated carboxylic acids (PFCAs). Although surface waters are the likely environmental sink for telomer acids, no fate or toxicity data exist for this matrix. We assessed the acute toxicity of the 4:2, 6:2, 8:2, and 10:2 saturated (FTCA) and unsaturated (FTUCA) fluorotelomer carboxylic acids to Daphnia magna, Chironomus tentans, and Lemna gibba. In general, toxicity increased with increasing fluorocarbon (FC) chain length, particularly for telomer acids of > or =8 FCs. In addition, the FTCAs were generally more toxic than the corresponding FTUCAs. Acute EC50s ranged from 0.025 mg/L (0.04 micromol/L) for D. magna (10:2 FTCA, immobility) to 63 mg/L (167 micromol/L) for C. tentans (6:2 FTCA, growth). While chain-length trends observed in the current study agree with those previously reported for PFCAs, the toxicity thresholds generated here are up to 10,000 times smaller. Our data provide the first evidence that PFCA precursors are more toxic than the PFCAs themselves.

Abstract  6:2 Fluorotelomer alcohol (6:2 FTOH) was evaluated for potential developmental and reproductive toxicity. 6:2 FTOH was administered by oral gavage to Sprague-Dawley rats as a suspension in 0.5% aqueous methylcellulose at dosages of 5, 25, 125, or 250 mg/kg/day. The developmental toxicity study was performed in accordance with the Organization for Economic Development (OECD) Test Guideline 414, and the one-generation reproductive toxicity study was performed in accordance with the OECD Test Guideline 415. For the developmental toxicity study, adverse maternal toxicity observed at 250 mg/kg/day included reductions in body weight parameters and food consumption. Evidence of developmental toxicity was limited to increases in skeletal variations (ossification delays in the skull and rib alterations) at 250 mg/kg/day. There were no adverse maternal or developmental effects observed at 5, 25, or 125 mg/kg/day and there were no effects on reproductive outcome or quantitative litter data at any dose level. For the one-generation reproduction toxicity study, systemic parental and developmental toxicity were observed at 125 and 250 mg/kg/day. At 250 mg/kg/day, there was increased mortality among male and female parental rats, effects on body weight parameters, food consumption, and clinical signs, and there were effects on offspring survival indices and body weights. At 125 mg/kg/day, there was an increase in mortality in parental males only, and parental toxicity was limited to effects on body weight gain, food consumption (lactation), and clinical signs. Uterine weights were decreased at 125 and 250 mg/kg/day, although there were no corroborative histopathological changes. At 125 mg/kg/day, pup mortality was increased on lactation day 1, and body weights of the offspring were decreased during the second half of lactation. There was no evidence of either parental or developmental toxicity at 5 or 25mg/kg/day, and there were no effects on reproductive outcome at any dose level. Based on these data, 6:2 FTOH is not a selective reproductive or developmental toxicant at dosages that induce clear maternal/parental toxicity. Therefore, 6:2 FTOH would not be classified for reproductive/developmental toxicity under the United Nations' Globally Harmonized System of Classification and Labeling of Chemicals.

Abstract  Twenty high-volume air samples were collected during a crossing of the North Atlantic and Canadian Archipelago in July 2005 to investigate air concentrations of fluorotelomer alcohols (FTOHs) and perfluoalkyl sulfonamido ethanols (PFASs). These commercial chemicals are widely used as surface treatments and are believed to be precursors for perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS) that accumulate in humans and biota, including those from remote arctic regions. The highest concentrations (sum of gas- and particle-phase) of FTOHs were for 8:2 FTOH (perfluoroctyl ethanol) (5.8-26 pg/m(3)), followed by 10:2 FTOH (perfluorodecyl ethanol) (1.9-17 pg/ m(3)) and 6:2 FTOH (perfluorohexyl ethanol) [BDL (below detection limit) to 6.0 pg/m(3)]. For the PFASs, MeFOSE (N-methyl perfluorooctane sulfonamido ethanol) was dominant and ranged from 2.6 to 31 pg/m(3); EtFOSE (N-ethyl perfluorooctane sulfonamido ethanol) ranged from BDL to 8.9 pg/m(3) and MeFOSEA (N-methyl perfluorooctane sulfonamide ethylacrylate) was BDL in all samples. Air parcel back-trajectories showed that the sampled air was largely representative of the arctic air mass. Air concentrations of target compounds were of the same order of magnitude as reported air concentrations in source regions. For instance, the mean 8:2 FTOH concentration was only a factor of about 3 lower than for three urban samples that were collected in Toronto for comparison. These findings confirm model results that predictthe efficient, long-range atmospheric transport and widespread distribution of FTOHs and related compounds in the arctic region. Mean particulate percentages for FTOHs and PFASs in the cruise samples (mean temperature, 5+/-4 degrees C) were BDL for 6:2 FTOH, 23% for 8:2 FTOH, 15% for 10:2 FTOH, 32% for MeFOSE, and 22% for EtFOSE. Further, the partitioning to particles for MeFOSE and EtFOSE was significantly correlated with inverse absolute temperature, whereas the FTOHs did not show this trend. The Toronto samples (mean temperature, -1+/-1 degree C) showed similar particulate percentages for MeFOSE and EtFOSE; however, the FTOHs were substantially less particle-bound. Although the mechanism for this partitioning is not understood, the results do indicate the need to better account for particle phase transport when modeling the atmospheric fate of these chemicals.

Abstract  The quantitative measurement of individual cells and their characteristics by means of flow cytometry is already for many years of great value for clinical studies. However, its potential as a tool in (eco)toxicology has only recently been discovered. Analysis of cell cycle kinetics with DNA-staining dyes can offer a valuable alternative to detect effects of chemicals on cell proliferation, an important endpoint in screening estrogen-like properties of chemicals. In the present study, flow cytometric cell cycle analysis in growth arrested MCF-7 cells exposed to five xenoestrogens correspond well with cell proliferation results of the conventionally used E-screen assay. Moreover, re-induction of proliferation in MCF-7 cells, indicated by the percentage of cells in S(ynthesis)-phase, is most pronounced after 24 h exposure, thus allowing a faster screening of xenoestrogens. This flow cytometric proliferation assay confirms that the estrogenic activity of structurally analogous parabens is mediated by the estrogen receptor pathway and is proportional to the alkyl chain length. Moreover, the ER-mediated mode of action of two fluorotelomer alcohols (6:2 FTOH and 8:2 FTOH), recently reported as xenoestrogenic, could be elucidated. These results support the potential of flow cytometric cell cycle kinetics as a screening assay for estrogen-like properties of chemicals.

Abstract  Levels of perfluorinated carboxylates (PFCAs) in different environmental and biological compartments have been known for some time, but the routes of exposure still remain unclear. The opinions are divergent whether the exposure to general populations occurs mainly indirect through precursor compounds or direct via PFCAs. Previous results showed elevated blood levels of PFCAs in ski wax technicians compared to a general population. The objective of this follow-up study was to determine concentrations of PFCAs, perfluorosulfonates (PFSAs), and fluorotelomer alcohols (FTOHs), precursor compounds that are known to degrade to PFCAs, in air collected in the breathing zone of ski wax technicians during work. We collected air samples by using ISOLUTE ENV+ cartridges connected to portable air pumps with an air flow of 2.0 L min(-1). PFCAs C5-C11 and PFSAs C4, C6, C8, and C10 were analyzed using LC-MS/MS and FTOHs 6:2, 8:2, and 10:2 with GC-MS/MS. The results show daily inhalation exposure of 8:2 FTOH in μg/m(3) air which is up to 800 times higher than levels of PFOA with individual levels ranging between 830-255000 ng/m(3) air. This suggests internal exposure of PFOA through biotransformation of 8:2 FTOH to PFOA and PFNA in humans.

Abstract  Perfluorochemicals (PFCs) are emerging persistent organic pollutants (POPs) and are widely present in the environment, wildlife and humans. Recently, reports have suggested that PFCs may have endocrine-disrupting activities. In the present study, we have developed a non-competitive enzyme-linked immunosorbent assay (ELISA) method to investigate estrogenic activities of selected PFCs using vitellogenin (VTG) induction in primary cultured hepatocytes of freshwater male tilapia (Oreochromis niloticus). Cultured hepatocytes were exposed to various concentrations of perfluorooctanyl sulfonate (PFOS), pentadecafluorooctanoic acid (PFOA), 1H, 1H, 2H, 2H-nonafluoro-1-hexanol (4:2 FTOH), 1H, 1H, 2H, 2H-perfluorooctanol (6:2 FTOH) and 1H, 1H, 2H, 2H-perfluoro-1-decanol (8:2 FTOH) for 48 h, while 17beta-estradiol (E2) and 4-nonylphenol (4-NP) were used as positive controls. A dose-dependent induction of VTG was observed in E2-, 4-NP-, PFOS-, PFOA- and 6:2 FTOH-treated cells, whereas VTG levels remained unchanged in the 4:2 FTOH and 8:2 FTOH exposure groups at the concentrations tested. The estimated 48-h EC(50) values for E2, 4-NP, PFOS, PFOA and 6:2 FTOH were 4.7 x 10(-7), 7.1 x 10(-6), 1.5 x 10(-5), 2.9 x 10(-5) and 2.8 x 10(-5)M, respectively. In the time-course study, significant VTG induction took place at 24 h (E2), 6 h (4-NP), 48 h (PFOS), 48 h (PFOA), 72 h (4:2 FTOH), 12 h (6:2 FTOH), 72 h (8:2 FTOH), and increased further after 96 h of exposure. Co-exposure to binary mixtures of individual PFCs and E2 for 48 h significantly inhibited E2-induced hepatocellular VTG production in a dose-dependent manner except for 4:2 FTOH. The estimated 48-h IC(50) (concentration of a compound that elicits 50% inhibition of maximally E2-induced VTG) values for PFOS, PFOA, 6:2 FTOH and 8:2 FTOH were 3.1 x 10(-7), 5.1 x 10(-7), 1.1 x 10(-6) and 7.5 x 10(-7)M, respectively. In order to further investigate the estrogenic mechanism of PFCs, the hepatocytes were co-exposed to binary mixtures of individual chemicals (E2, 4-NP, PFOS, PFOA and 6:2 FTOH) and the known estrogen receptor inhibitor tamoxifen for 48 h; tamoxifen significantly inhibited the ability of these chemicals to stimulate vitellogenesis. The overall results demonstrated that PFOS, PFOA and FTOHs have estrogenic activities and that exposure to a combination of E2 and PFCs produced anti-estrogenic effects. The results of the estrogen receptor inhibition assay further suggested that the estrogenic effect of PFCs may be mediated by the estrogen receptor pathway in primary cultured tilapia hepatocytes.

Abstract  The aerobic biodegradation of [1,2-(14)C] 6:2 FTOH [F(CF(2))(6)(14)CH(2)(14)CH(2)OH] in a flow-through soil incubation system is described. Soil samples dosed with [1,2-(14)C] 6:2 FTOH were analyzed by liquid scintillation counting, LC/ARC (liquid chromatography/accurate radioisotope counting), LC/MS/MS, and thermal combustion to account for 6:2 FTOH and its transformation products over 84 d. Half of the [1,2-(14)C] 6:2 FTOH disappeared from soil in 1.3 d, undergoing simultaneous microbial degradation and partitioning of volatile transformation product(s) and the 6:2 FTOH precursor into the air phase. The overall (14)C (radioactivity) mass balance in live and sterile treatments was 77-87% over 84-d incubation. In the live test system, 36% of total (14)C dosed was captured in the airflow (headspace), 25% as soil-bound residues recovered via thermal combustion, and 16% as soil extractable. After 84 d, [(14)C] 5:2 sFTOH [F(CF(2))(5)CH(OH)(14)CH(3)] was the dominant transformation product with 16% molar yield and primarily detected in the airflow. The airflow also contained [1,2-(14)C] 6:2 FTOH and (14)CO(2) at 14% and 6% of total (14)C dosed, respectively. The other significant stable transformation products, all detected in soil, were 5:3 acid [F(CF(2))(5)CH(2)CH(2)COOH, 12%], PFHxA [F(CF(2))(5)COOH, 4.5%] and PFPeA [F(CF(2))(4)COOH, 4.2%]. Soil-bound residues as well as conjugates between fluorinated transformation products and dissolved soil components were only observed in the live test system and absent in the sterile soil, suggesting that such binding and complexation are microbially or enzymatically driven processes. At day 84, 5:3 acid is postulated to be the major transformation product in soil-bound residues, which may not be available for further biodegradation in soil environment.

Abstract  Interest in the environmental fate of fluorotelomer alcohols (FTOHs) has spurred efforts to understand their equilibrium partitioning behavior. Experimentally determined partition coefficients for FTOHs between soil/water and air/water have been reported, but direct measurements of partition coefficients for dissolved organic carbon (DOC)/water (K-doc) and octanol/water(K-ow)have been lacking. Here we measured the partitioning of 8:2 and 6:2 FTOH between one or more types of DOC and water using enhanced solubility or dialysis bag techniques, and also quantified K-ow values for 4:2 to 8:2 FTOH using a batch equilibration method. The range in measured log K-doc values for 8:2 FTOH using the enhanced solubility technique with DOC derived from two soils, two biosolids, and three reference humic acids is 2.00-3.97 with the lowest values obtained for the biosolids and an average across all other DOC sources (biosolid DOC excluded) of 3.54 +/- 0.29. For 6:2 FTOH and Aldrich humic acid, a log Kdoc value of 1.96 +/- 0.45 was measured using the dialysis technique. These average values are similar to 1 to 2 log units lower than previously indirectly estimated Kdoc values. Overall, the affinity for DOC tends to be slightly lower than that for particulate soil organic carbon. Measured log K-ow values for 4:2 (3.30 +/- 0.04), 6:2 (4.54 +/- 0.01), and 8:2 FTOH (5.58 +/- 0.06) were in good agreement with previously reported estimates. Using relationships between experimentally measured partition coefficients and C-atom chain length, we estimated K-doc and K-ow values for shorter and longer chain FTOHs, respectively, that we were unable to measure experimentally.

Abstract  The 6:2 FTOH [F(CF(2))(6)CH(2)CH(2)OH] is a major raw material being used to replace 8:2 FTOH [F(CF(2))(8)CH(2)CH(2)OH] to make FTOH-based products for industrial and consumer applications. A novel aerobic sediment experimental system containing 20 g wet sediment and 30 mL aqueous solution was developed to study 6:2 FTOH biotransformation in river sediment. 6:2 FTOH was dosed into the sediment to follow its biotransformation and to analyze transformation products over 100 d. The primary 6:2 FTOH biotransformation in the aerobic sediment system was rapid (T(1/2)<2d). 5:3 acid [F(CF(2))(5)CH(2)CH(2)COOH] was observed as the predominant polyfluorinated acid on day 100 (22.4 mol%), higher than the sum of perfluoropentanoic acid (10.4 mol%), perfluorohexanoic acid (8.4 mol%), and perfluorobutanoic acid (1.5 mol%). Perfluoroheptanoic acid was not observed during 6:2 FTOH biotransformation. The 5:3 acid can be further degraded to 4:3 acid [F(CF(2))(4)CH(2)CH(2)COOH, 2.7 mol%]. This suggests that microbes in the river sediment selectively degraded 6:2 FTOH more toward 5:3 and 4:3 acids compared with soil. Most of the observed 5:3 acid formed bound residues with sediment organic components and can only be quantitatively recovered by post-treatment with NaOH and ENVI-Carb™ carbon. The 6:2 FTCA [F(CF(2))(6)CH(2)COOH], 6:2 FTUCA [F(CF(2))(5)CF=CHCOOH], 5:2 ketone [F(CF(2))(5)C(O)CH(3)], and 5:2 sFTOH [F(CF(2))(5)CH(OH)CH(3)] were major transient intermediates during 6:2 FTOH biotransformation in the sediment system. These results suggest that if 6:2 FTOH or 6:2 FTOH-based materials were released to the river or marine sediment, poly- and per-fluorinated carboxylates could be produced.

Abstract  The polyfluorinated carboxylic acids 5:3 acid (C(5)F(11)CH(2)CH(2)CO(2)H) and 7:3 acid (C(7)F(15)CH(2)CH(2)CO(2)H) are major products from 6:2 FTOH (C(6)F(13)CH(2)CH(2)OH) and 8:2 FTOH (C(8)F(17)CH(2)CH(2)OH) aerobic biotransformation, respectively. The 5:3 and 7:3 acids were dosed into domestic WWTP activated sludge for 90 d to determine their biodegradability. The 7:3 acid aerobic biodegradability was low, only 1.7 mol% conversion to perfluoroheptanoic acid (PFHpA), whereas no transformation was observed previously in soil. In stark contrast, 5:3 acid aerobic biodegradability was enhanced 10 times in activated sludge compared to soil. The 5:3 acid was not activated by acyl CoEnzyme A (CoA) synthetase, a key step required for further α- or ß-oxidation. Instead, 5:3 acid was directly converted to 4:3 acid (C(4)F(9)CH(2)CH(2)CO(2)H, 14.2 mol%) and 3:3 acid (C(3)F(7)CH(2)CH(2)CO(2)H, 0.9 mol%) via "one-carbon removal pathways". The 5:3 acid biotransformation also yielded perfluoropentanoic acid (PFPeA, 5.9 mol%) and perfluorobutanoic acid (PFBA, 0.8 mol%). This is the first report to identify key biotransformation intermediates which demonstrate novel one-carbon removal pathways with sequential removal of CF(2) groups. Identified biotransformation intermediates (10.2 mol% in sum) were 5:3 Uacid, α-OH 5:3 acid, 5:2 acid, and 5:2 Uacid. The 5:2 Uacid and 5:2 acid are novel intermediates identified for the first time which confirm the proposed pathways. In the biodegradation pathways, the genesis of the one carbon removal is CO(2) elimination from α-OH 5:3 acid. These results suggest that there are enzymatic mechanisms available in the environment that can lead to 6:2 FTOH and 5:3 acid mineralization. The dehydrogenation from 5:3 acid to 5:3 Uacid was the rate-limiting enzymatic step for 5:3 acid conversion to 4:3 acid.

Abstract  Activated monomer cationic ring-opening polymerization of ethylene oxide initiated with 1H,1H,2H, 21-l-perfluorooctan-l-ol, using acid exchanged montmorillonite clay called Maghnite-H(+) (Mag-H(+)) as an effective catalyst, was carried out to obtain the corresponding homo-polymers with narrow polydispersity ratios. The molecular weights of the obtained polymers could be controlled with the feed ratio of the monomer and initiator. The effect of amount of catalyst and time on the polymerization yield and viscosity of the polymers were studied. The structure was confirmed by (1)H-NMR and MALDI-TOF-MS. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 3445-3452,2010

Abstract  Fluorotelomer alcohols (FTOHs) are the main precursors of environmentally ubiquitous perfluorinated acids, and determination of FTOHs at low concentrations presents significant challenges. In this study, a new liquid chromatography-electrospray mass spectrometry (LC-ESI-MS) method in conjunction with low-energy collision dissociation tandem mass spectrometry (CID-MS/MS) was developed by employing an optimized derivatization reaction with dansyl chloride (DNS) in acetonitrile under catalysis of 4-(dimethylamino)-pyridine (DMAP). The instrument detection limits (IDLs) of the newly developed method were 0.014, 0.015, 0.014, 0.0075 and 0.0093μg/L for 4:2 FTOH, 6:2 FTOH, 8:2 FTOH, 10:1 FTOH and 10:2 FTOH respectively, which were 7.5-241 times lower than those without derivatizaiton and 57-357 times lower than previous GC/MS method. The method was successfully applied to analyze FTOHs in sediments combined with WAX and silica cartridges cleanup. The overall method recoveries were from 67±6.0% to 83±9.4% with matrix effects of <15%. The limits of quantification for all FTOHs were 0.017-0.060ng/gdry weight (dw). The method was applied to analyze six marine sediment samples from Liaodong Bay, China. All FTOHs except for 10:1 FTOH were detected, and the total concentrations of FTOHs were 0.19-0.52ng/gdw. The developed method provides a new method to sensitively determine FTOHs in environmental matrices.

Abstract  Biotransformation of 6:2 FTOH [F(CF2)6CH2CH2OH] by the white-rot fungus, Phanerochaete chrysosporium, was investigated in laboratory studies. 6:2 FTOH is a raw material increasingly being used to replace products that can lead to long-chain perfluoroalkyl carboxylic acids (PFCAs, ≥ 8 carbons). During a product's life cycle and after final disposal, 6:2 FTOH-derived compounds may be released into the environment and potentially biotransformed. In this study, P. chrysosporium transformed 6:2 FTOH to perfluorocarboxylic acids (PFCAs), polyfluorocarboxylic acids, and transient intermediates within 28 days. 5:3 Acid [F(CF2)5CH2CH2COOH] was the most abundant transformation product, accounting for 32-43 mol % of initially applied 6:2 FTOH in cultures supplemented with lignocellulosic powder, yeast extract, cellulose, and glucose. PFCAs, including perfluoropentanoic (PFPeA) and perfluorohexanoic (PFHxA) acids, accounted for 5.9 mol % after 28-day incubation. Furthermore, four new transformation products as 6:2 FTOH conjugates or 5:3 acid analogues were structurally confirmed. These results demonstrate that P. chrysosporium has the necessary biochemical mechanisms to drive 6:2 FTOH biotransformation pathways toward more degradable polyfluoroalkylcarboxylic acids, such as 5:3 acid, with lower PFCA yields compared to aerobic soil, sludge, and microbial consortia. Since bacteria and fungi appear to contribute differently toward the environmental loading of FTOH-derived PFCAs and polyfluorocarboxylic acids, wood-rotting fungi should be evaluated as potential candidates for the bioremediation of wastewater and groundwater contaminated with fluoroalkyl substances.