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PFNA (375-95-1)


2,408 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Micellization of lithium perfluoroheptanoate and its aggregation on poly(ethylene glycol) oligomers in water

Authors: Gianni, P; Bernazzani, L; Carosi, R; Mollica, V (2007) Langmuir 23:8752-8759. HERO ID: 3859620

[Less] The interaction of lithium perfluoroheptanoate (LiPFHep) with poly(ethylene glycol) (PEG) of different . . . [More] The interaction of lithium perfluoroheptanoate (LiPFHep) with poly(ethylene glycol) (PEG) of different molecular weights (300 < MW < 20 000 Da) was investigated in water at 298.15 and 308.15 K by the isothermal titration calorimetry (ITC). Density and sound velocity measurements were also performed at 288.15, 298.15, and 308.15 K, while viscosity and conductivity data were only collected at 298.15 K. The aggregation process of this surfactant on the PEG polymeric chain was found to be very similar to the process exhibited by the two homologous perfluorooctanoate and perfluorononanoate. Viscosity and ITC data indicated that the formation of polymer-surfactant complexes between PEG and LiPFHep also leads to a conformational change in the polymer. The aggregation of micelles of the lithium perfluoro surfactants on the PEG polymeric chain is characterized by a comparable thermodynamic stability, which results from a balance of enthalpy and entropy contributions, which both increase with the length of the surfactant hydrophobic chain.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Some properties of lysozyme--lithium perfluorononanoate complexes

Authors: Ciurleo, A; Cinelli, S; Guidi, M; Bonincontro, A; Onori, G; Mesa, CL (2007) Biomacromolecules 8:399-405. HERO ID: 3860127

[Less] Mixtures containing lysozyme, LYSO, and a fully fluorinated surfactant, lithium perfluorononanoate, . . . [More] Mixtures containing lysozyme, LYSO, and a fully fluorinated surfactant, lithium perfluorononanoate, LiPFN, were investigated in a wide range of concentrations and mole ratios. To ensure consistency to the data, a comparison was made, when possible, with the more conventional SDS as surfactant. Molecular solutions, precipitates, and micellar phases have been observed. The region of existence for each phase depends on the LiPFN/LYSO mole ratios, r, and was determined by different experimental methods. Optical absorbance, CD, 19F NMR, viscosity, electrical conductivity, and dielectric relaxation methods were used. Some methods give information on the protein conformation, others on the state of the surfactant or on the collective system properties, respectively. Addition of LiPFN gives rise to a solution, a poly phase dispersion (at low surfactant to protein ratios) and to a micelle-mediated redissolution of the precipitates. Concomitant to the above macroscopic properties, peculiar effects in the state of LYSO are observed. Low amounts of surfactant reduce significantly the amount of alpha-helix in favor of the beta-sheet conformation of the protein. The former is almost completely regained once micelle-assisted redissolution of the complex occurs. The tertiary structure of the protein, conversely, is lost at low surfactant content and never recovered. Such evidence suggests the occurrence of a molten globule conformation for LYSO in micellar media.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Adsorption kinetics in binary surfactant mixtures studied with external reflection FTIR spectroscopy

Authors: Day, JPR; Campbell, RA; Russell, OP; Bain, CD (2007) HERO ID: 3860186

[Less] The adsorption kinetics of mixtures of soluble surfactants at the air-water interface was studied on . . . [More] The adsorption kinetics of mixtures of soluble surfactants at the air-water interface was studied on an overflowing cylinder. Vibrational spectra of the adsorbed monolayers were acquired by external reflection Fourier transform infrared spectroscopy, and target factor analysis was used to determine the compositions of mixed monolayers. Laser Doppler velocimetry was employed to measure the surface expansion rates, and hence the effective surface age, which was in the range 0.1-1 s. Three surfactant mixtures with different interactions were investigated. Blends of the cationic hydrocarbon surfactant hexadecyl trimethylammonium bromide (CTAB) and the nonionic hydrocarbon surfactant octaethylene glycol monodecyl ether (C10E8) were found to mix ideally in the monolayer over a wide range of subsurface compositions. Combinations of C10E8 and the anionic fluorosurfactant ammonium perfluorononanoate (APFN) exhibited nonideal mixing that could be described with regular solution theory. APFN adsorbed to the interface at a rate limited by monomer diffusion but the adsorption of C10E8 appeared to be under kinetic control. The adsorption behavior of the cationic-anionic mixture of CTAB and APFN was dominated by the interaction of the oppositely charged headgroups. Either side of equimolar bulk composition only the species in excess was found to adsorb, which is rationalized by the presence of aggregates in the bulk that act as a sink for free monomer. Prior evidence in the literature suggests these aggregates may be vesicles. At equimolar compositions both species were found to coadsorb; this unexpected result may be explained by adsorption of vesicles to the uncharged interface. A semiquantitative model based on the interaction between the electrical double layers of the oppositely charged monolayer and vesicle explains the absence of adsorption of vesicles away from equimolar compositions. The combination of the overflowing cylinder, to generate a steadily expanding surface with well-defined hydrodynamics, and FTIR spectroscopy, to quantify the composition of the adsorbed monolayer, can be used to study a broad range of mixed inonolayers at the air-water interface under nonequilibrium conditions.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

High-resolution atmospheric modeling of fluorotelomer alcohols and perfluorocarboxylic acids in the North American troposphere

Authors: Yarwood, G; Kemball-Cook, S; Keinath, M; Waterland, RL; Korzeniowski, SH; Buck, RC; Russell, MH; Washburn, ST (2007) Environmental Science and Technology 41:5758-5762. HERO ID: 623716

[Less] A high spatial and temporal resolution atmospheric model is used to evaluate the potential contribution . . . [More] A high spatial and temporal resolution atmospheric model is used to evaluate the potential contribution of fluorotelomer alcohol (FTOH) and perfluorocarboxylate (PFCA) emissions associated with the manufacture, use, and disposal of DuPont fluorotelomer-based products in North America to air concentrations of FTOH, perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) in North America and the Canadian Arctic. A bottom-up emission inventory for PFCAs and FTOHs was developed from sales and product composition data. A detailed FTOH atmospheric degradation mechanism was developed to simulate FTOH degradation to PFCAs and model atmospheric transport of PFCAs and FTOHs. Modelled PFCA yields from FTOH degradation agree with experimental smog-chamber results supporting the degradation mechanism used. Estimated PFCA and FTOH air concentrations and PFCA deposition fluxes are compared to monitoring data and previous global modelling. Predicted FTOH air concentrations are generally in agreement with available monitoring data. Overall emissions from the global fluorotelomer industry are estimated to contribute approximately 1-2% of the PFCAs in North American rainfall, consistent with previous global emissions estimates. Emission calculations and modelling results indicate that atmospheric inputs of PFCAs in North America from fluorotelomer-based products will decline by an order of magnitude in the near future as a result of current industry commitments to reduce manufacturing emissions and lower the residual fluorotelomer alcohol raw material and trace PFCA product content.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Perfluorinated acids in Arctic snow: new evidence for atmospheric formation

Authors: Young, CJ; Furdui, VI; Franklin, J; Koerner, RM; Muir, DC; Mabury, SA (2007) Environmental Science and Technology 41:3455-3461. HERO ID: 1228502

[Less] Perfluorinated acids (PFAs) are ubiquitously found in water and biota, including remote regions such . . . [More] Perfluorinated acids (PFAs) are ubiquitously found in water and biota, including remote regions such as the High Arctic. Under environmental conditions, PFAs exist mainly as anions and are not expected to be subject to long-range atmospheric transport in the gas phase. Fluorinated telomer alcohols (FTOHs) are volatile and can be atmospherically oxidized to form perfluorocarboxylic acids. Analogously, fluorosulfamido alcohols can be oxidized to form perfluorooctane sulfonate (PFOS). High Arctic ice caps experience contamination solely from atmospheric sources. By examining concentrations of PFAs in ice cap samples, it is possible to determine atmospheric fluxes to the Arctic. Ice samples were collected from high Arctic ice caps in the spring of 2005 and 2006. Samples were concentrated using solid-phase extraction and analyzed by LC-MS-MS. PFAs were observed in all samples, dating from 1996 to 2005. Concentrations were in the low-mid pg L(-1) range and exhibited seasonality, with maximum concentrations in the spring-summer. The presence of perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA) on the ice cap was indicative of atmospheric oxidation as a source. Ratios of PFAs to sodium concentrations were highly variable, signifying PFA concentrations on the ice cap were unrelated to marine chemistry. Fluxes of the PFAs were estimated to the area north of 65 degrees N for the 2005 season, which ranged from 114 to 587 kg year(-1) for perfluorooctanoic acid (PFOA), 73 to 860 kg year(-1) for perfluorononanoic acid (PFNA), 16 to 84 kg year(-1) for PFDA, 26 to 62 kg year(-1) for PFUnA, and 18 to 48 kg year(-1) for PFOS. The PFOA and PFNA fluxes agreed with FTOH modeling estimations. A decrease in PFOS concentrations through time was observed, suggesting a fast response to changes in production. These data suggest that atmospheric oxidation of volatile precursors is a primary source of PFAs to the Arctic.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Polyfluoroalkyl chemicals in the US population: Data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and comparisons with NHANES 1999-2000

Authors: Calafat, AM; Wong, LY; Kuklenyik, Z; Reidy, JA; Needham, LL (2007) Environmental Health Perspectives 115:1596-1602. HERO ID: 1290899

[Less] Background: Polyfluoroalkyl chemicals (PFCs) have been used since the 1950s in numerous commercial applications. . . . [More] Background: Polyfluoroalkyl chemicals (PFCs) have been used since the 1950s in numerous commercial applications. Exposure of the general U.S. population to PFCs is widespread. Since 2002, the manufacturing practices for PFCs in the United States have changed considerably.

Objectives: We aimed to assess exposure to perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and eight other PFCs in a representative 2003–2004 sample of the general U.S. population ≥ 12 years of age and to determine whether serum concentrations have changed since the 1999–2000 National Health and Nutrition Examination Survey (NHANES).

Methods: By using automated solid-phase extraction coupled to isotope dilution–high-performance liquid chromatography–tandem mass spectrometry, we analyzed 2,094 serum samples collected from NHANES 2003–2004 participants.

Results: We detected PFOS, PFOA, PFHxS, and PFNA in > 98% of the samples. Concentrations differed by race/ethnicity and sex. Geometric mean concentrations were significantly lower (approximately 32% for PFOS, 25% for PFOA, 10% for PFHxS) and higher (100%, PFNA) than the concentrations reported in NHANES 1999–2000 (p < 0.001).

Conclusions: In the general U.S. population in 2003–2004, PFOS, PFOA, PFHxS, and PFNA serum concentrations were measurable in each demographic population group studied. Geometric mean concentrations of PFOS, PFOA, and PFHxS in 2003–2004 were lower than in 1999–2000. The apparent reductions in concentrations of PFOS, PFOA, and PFHxS most likely are related to discontinuation in 2002 of industrial production by electrochemical fluorination of PFOS and related perfluorooctanesulfonyl fluoride compounds.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Rapid response of Arctic ringed seals to changes in perfluoroalkyl production

Authors: Butt, CM; Muir, DC; Stirling, I; Kwan, M; Mabury, SA (2007) Environmental Science and Technology 41:42-49. HERO ID: 2903129

[Less] Temporal trends in perfluoroalkyl compounds (PFCs) were investigated in liver samples from two ringed . . . [More] Temporal trends in perfluoroalkyl compounds (PFCs) were investigated in liver samples from two ringed seal (Phoca hispida) populations in the Canadian Arctic, Arviat (Western Hudson Bay) (1992, 1998, 2004, 2005) and Resolute Bay (Lancaster Sound) (1972, 1993, 2000, 2004, 2005). PFCs analyzed included C7-C15 perfluorinated carboxylates (PFCAs) and their suspected precursors, the 8:2 and 10:2 fluorotelomer saturated and unsaturated carboxylates (FTCAs, FTUCAs), C4, C6, C8, C10 sulfonates, and perfluorooctane sulfonamide (PFOSA). Liver samples were homogenized, liquid-liquid extracted with methyl tert-butyl ether, cleaned up using hexafluoropropanol, and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). C9-C15 PFCAs showed statistically significant increasing concentrations during 1992-2005 and during 1993-2005 at Arviat and Resolute Bay, respectively. Doubling times ranged from 19.4 to 15.8 years for perfluorododecanoate (PFDoA) to 10.0-7.7 years for perfluorononanoate (PFNA) at Arviat and Resolute Bay but were shorter when excluding the 2005 samples. Conversely, perfluorooctane sulfonate (PFOS) and PFOSA concentrations showed maximum concentrations during 1998 and 2000 at Arviat and Resolute Bay, with statistically significant decreases from 2000 to 2005. In the case of Arviat, two consecutive decreases were measured from 1998 to 2003 and from 2003 to 2005. PFOS disappearance half-lives for seals at Arviat and Resolute Bay were 3.2 and 4.6 years. These results indicate that the ringed seals and their food web are rapidly responding to the phase out of perfluorooctane sulfonyl fluoride based compounds by 3M in 2001. Further, the relatively short doubling times of the PFCAs and PFOS disappearance half-lives support the hypothesis of atmospheric transport as the main transport mechanism of PFCs to the arctic environment.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Determination of perfluorinated compounds in wastewater and river water samples by mixed hemimicelle-based solid-phase extraction before liquid chromatography-electrospray tandem mass spectrometry detection

Authors: Zhao, X; Li, J; Shi, Y; Cai, Y; Mou, S; Jiang, G (2007) Journal of Chromatography A 1154:52-59. HERO ID: 3858309

[Less] A comparative study on the use of cetyltrimethylammonium bromide (CTAB)-coated silica and sodium dodecyl . . . [More] A comparative study on the use of cetyltrimethylammonium bromide (CTAB)-coated silica and sodium dodecyl sulphate (SDS)-coated alumina mixed hemimicelles-based solid-phase extraction (SPE) for the pre-concentration of six perfluorinated compounds (PFCs) in environmental water samples was presented. The six analytes heptafluorobutyric acid (HFBA), perfluoroheptanic acid (PFHeA), perfluorooctanic acid (PFOA), perfluorooctanic sulfonic (PFOS), perfluorononanic acid (PFNA) and perfluorodecanic acid (PFDeA) were quantitatively retained on both sorbent materials. The cationic surfactant (CTAB adsorbed onto silica) was more appropriate for SPE of PFCs. The main factors affecting adsolubilization of PFCs including the amount of surfactant, pH of solution, sample loading volume and desorption were investigated and optimized. Concentration factor of 500 were achieved by SPE of 500 mL of several environmental water samples. The method detection limits obtained for HFBA, PFHeA, PFOA, PFOS, PFNA and PFDeA were 0.10, 0.28, 0.07, 0.20, 0.10 and 0.05 ng/L, respectively. The relative standard deviation of recoveries ranged from 2 to 8%, which indicated good method precision.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Perfluorinated compounds in the Cape Fear Drainage Basin in North Carolina

Authors: Nakayama, S; Strynar, MJ; Helfant, L; Egeghy, P; Ye, X; Lindstrom, AB (2007) Environmental Science and Technology 41:5271-5276. HERO ID: 2901973

[Less] Concern over perfluorinated organic compounds (PFCs), e.g., perfluorooctane sulfonate (PFOS) and perfluorooctanoic . . . [More] Concern over perfluorinated organic compounds (PFCs), e.g., perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), is due to a number of recent studies which show that the PFCs are persistent, bioaccumulative, and toxic in animals. Despite sustained interest in this topic, little information is available concerning the environmental distributions of the compounds. In this study, a new method was developed for the analysis of 10 target PFCs and its performance was examined in a systematic evaluation of surface water in the Cape Fear River Basin in North Carolina. One hundred samples from 80 different locations were collected during the spring of 2006. Detectable levels of the target PFCs were found in all samples, and were comparable to values reported previously, with maximum PFOS at 132 ng/L, PFOA at 287 ng/L, perfluorononanoic acid (C9) at 194 ng/L, and perfluoroheptanoic acid (C7) at 329 ng/L. In general, the lowest concentrations of the PFCs were found in the smallest tributaries while the highest levels were found in middle reaches of the Drainage Basin. Variability of PFC concentrations suggests a series of source inputs throughout the Basin. Seventeen sample sites (22%) had PFOS concentrations greater than 43 ng/L, a conservative safe water concentration estimated to be protective of avian life. In addition, a total of 26 sites (32%) had PFOA concentrations above 40 ng/L.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

In vitro metabolism of 8-2 fluorotelomer alcohol: interspecies comparisons and metabolic pathway refinement

Authors: Nabb, DL; Szostek, B; Himmelstein, MW; Mawn, MP; Gargas, ML; Sweeney, LM; Stadler, JC; Buck, RC; Fasano, WJ (2007) Toxicological Sciences 100:333-344. HERO ID: 3857402

[Less] The detection of perfluorinated organic compounds in the environment has generated interest in their . . . [More] The detection of perfluorinated organic compounds in the environment has generated interest in their biological fate. 8-2 Fluorotelomer alcohol (8-2 FTOH, C(7)F(15)CF(2)CH(2)CH(2)OH), a raw material used in the manufacture of fluorotelomer-based products, has been identified in the environment and has been implicated as a potential source for perfluorooctanoic acid (PFOA) in the environment. In this study, the in vitro metabolism of [3-(14)C] 8-2 FTOH and selected acid metabolites by rat, mouse, trout, and human hepatocytes and by rat, mouse, and human liver microsomes and cytosol were investigated. Clearance rates of 8-2 FTOH in hepatocytes indicated rat > mouse > human >/= trout. A number of metabolites not previously reported were identified, adding further understanding to the pathway for 8-2 FTOH metabolism. Neither perfluorooctanoate nor perfluorononanoate was detected from incubations with human microsomes. To further elucidate the steps in the metabolic pathway, hepatocytes were incubated with 8-2 fluorotelomer acid, 8-2 fluorotelomer unsaturated acid, 7-3 acid, 7-3 unsaturated acid, and 7-2 secondary fluorotelomer alcohol. Shorter chain perfluorinated acids were only observed in hepatocyte and microsome incubations of the 8-2 acids but not from the 7-3 acids. Overall, the results indicate that 8-2 FTOH is extensively metabolized in rats and mice and to a lesser extent in humans and trout. Metabolism of 8-2 FTOH to perfluorinated acids was extremely small and likely mediated by enzymes in the microsomal fraction. These results suggest that human exposure to 8-2 FTOH is not expected to be a significant source of PFOA or any other perfluorocarboxylic acids.