Compounds perfluorinated

PFCs have been manufactured since 1940s. Because of their properties, these compounds are employed in a wide variety of industrial and consumer products. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) have been two of the most used and studied PFCs, but due to their resistance to degradation, widespread in the environment, bioaccumulation and toxicological properties, these two compounds are limited in use and production practically worldwide. However, 

PFCs have been detected in environmental and biological samples being widespread around the world including water, soils and sediments, human samples, and even in remote areas such as the Arctic (atmosphere [34], Arctic Ocean [35], biological samples [36, 37] and few reviews have been published [38, 39]) or Antarctic (biological samples as penguins or seals [40, 41]). 

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The absolute viscosities of the perfluorinated inert Hquids are higher than the analogous hydrocarbons but the kinematic viscosities are lower due to the higher density of the perfluorinated compounds. The viscosity index, ie, the change in viscosity with temperature, is generally higher for the perfluorinated Hquids than for hydrocarbons. 

Direct Fluorination. This is a more recently developed method for the synthesis of perfluorinated compounds. In this process, fluorine gas is passed through a solution or suspension of the reactant in a nonreactive solvent such as trichlorotrifluoroethane (CFC-113). Sodium fluoride may also be present in the reaction medium to remove the coproduct hydrogen fluoride. There has been enormous interest in this area since the early 1980s resulting in numerous journal pubHcations and patents (7—9) (see Fluorine compounds, organic-direct fluorination). Direct fluorination is especially useful for the preparation of perfluoroethers. 

Perfluorinated compounds are also potentially useful as inert reaction media, particularly when one of the reactants is gaseous. The high solubiHty of oxygen and carbon dioxide in perfluorinated Hquids has allowed their use as blood substitutes (41) and as oxygenation media for biotechnology (42). One product, Fluosol DA (43) (Green Cross Corp.), has been commercialized, and there is an abundant patent art in this area (see Blood, artificial). 

Extensive secondary literature coverage of fluonne NMR data is available for articles published through 1981 Massive amounts of fluonne data were comptled in penodic reviews in Annual Reports on NMR Spectroscopy [2, 3, 4, 5, 6, 7, 8, 9] and in two volumes of Progress in NMR Spectroscopy [10, 11] Books wntten by Dungan and Van Wazer [12] and Moonev [13], both published in 1970, are still widely referenced today The majonty of %-NMR data compiled were from highly fluormated and perfluorinated compounds... 

The molecular ion is usually not observed in the mass spectra of aliphatic fluorinated compounds (>ethane). Common losses are F. HF, or CF3. Frequently observed ions lie at m/zs 31 (CF), 50 (CF2). and 69 (CF3). If mass 69 is intense, a CF3 group is present. The presence of a small m/z 51 peak indicates the presence of carbon, hydrogen, and fluorine. If a m/z 51 peak is intense, then CHF is present. The absence of m/z 51 and/or m/z 47 (without chlorine) suggests a perfluorinated compound. 

Organophosphate flame retardants and plasticisers Perfluorinated compounds Pharmaceuticals and personal care products Polar pesticides and their degradation/transformation products Surfactants and their metabolites... 

Stoebe T, Mach P, Grantz S, Huang CC (1996) Phys Rev E 53 1662. In this work the surface tension of the free standing films of some perfluorinated compounds has been measured. The intermediate value of the surface tension (=14 dyn/cm) between that of pure close-packed CF3 and CH3 groups indicates that the surface of the film consist of nearly equal proportions of these fragments... 

Sometimes for some very potent pollutants analytical methodologies provide limits of detection (LODs) higher than the concentrations that cause effects, as derived from ecotoxicological studies. Therefore efforts in the field of analytical chemistry (see Sect. 2) are focused on making available the necessary analytical capabilities to detect pollutants at the required low levels found in the environment. This was the case of pharmaceuticals, illicit drugs, perfluorinated compounds (PFCs), sunscreens/UV filters, etc. few years ago. However, this list is likely to increase with new family candidates. 

Llorca M, Farre M, Pico Y, Barcelo D (2011) Analysis of perfluorinated compounds in sewage sludge by pressurized solvent extraction followed by liquid chromatography-mass spectrometry. J Chromatogr A 1218(30) 4840 1846... 

Wille K, Vanden Bussche J, Noppe H, De Wulf E, Van Caeter P, Janssen CR, De Brabander HF, Vanhaecke L (2010) A validated analytical method for the determination of perfluorinated compounds in surface-, sea- and sewagewater using liquid chromatography coupled to time-of-flight mass spectrometry. J Chromatogr A 1217(43) 6616-6622... 

The second example focuses on qualitative evaluation of cancerogenic potential of some perfluorinated compounds using both QSARs models and an in vitro cell transformation assay. 

Table 2 Selected perfluorinated compounds (PFCs) for the QSARs analysis... 

The evaluation for aquatic toxicity on daphnids and fish is reported in Tables 12 and 13. Bold values indicate that compounds are out of the model applicability domain (ECOSAR) or that the prediction is not reliable. ECOSAR and ToxSuite are able to predict all the selected compounds while T.E.S.T. fails in prediction for the daphnia toxicity of perfluorinated compounds (PFOS and PFOA). Tables 12 and 13 include also a limited number of experimental results provided by the model training dataset (some data are extracted from USEPA Ecotox database). Predicted results are in agreement for five compounds only (2, 3, 5, 13 and 14) for both endpoints while the predictions for the other compounds are highly variable. 

Fromme H, Tittlemier SA, Volkel W, Wilhelm M, Twardella D (2009) Perfluorinated compounds-exposure assessment for the general population in Western countries. Int J Hyg Environ Health 212(3) 239-270... 

Perfluorinated compounds PFOA, PFNA, PFDA, PFUnA, PFOS, 4 2, 6 2, 8 2, 10 2 diPAP... 

Perfluorinated compounds PFHxS, PFOS, PFOA, New York State (2005) PFOA = 18-241 [148]... 

Semeena VS, Lammel G (2005) Significance of the grasshopper effect on the atmospheric distribution of persistent organic substances. Geophysical Research Letters 32 Senthilkumar K, Ohi E, Sajwan K, Takasuga T, Kannan K (2007) Perfluorinated compounds in river water, river sediment, market fish, and wildlife samples from japan. Bull of Environ Contain Toxicol 79 427 131... 

Apart from of investigating the concentration of priority pollutants to assess the temporal and geographic trends as it has been done in the Ebro river basin until nowadays, the SCARCE project pretends to evaluate the consequences of the climate change in the water quality as well as predicting new environmental risks derived from water scarcity. This will be done by determining the presence of new priority (i.e. perfluorinated compounds) and emerging toxicants in Mediterranean river ecosystems in the Iberian Peninsula. In a subsequent step, the effects of chemical and environmental stressors on the biota will be assessed by combining field and experimental studies. The effects of multiple stressors will be addressed from a multi-biomarker perspective [27]. 

Table 3.1 Selected data for some perfluorinated compounds...

Industrial organic pollutants Perfluorinated compounds (PFCs), polybrominated diphenylethers (PBDEs), new pesticides, and nanomaterials. 

Keywords Biotoxins, Coccidiostats, Food contaminants, LC-MS/MS, Nanomaterials antibiotics, Perfluorinated compounds. Pesticides, Polybrominated diphenylethers... 

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