Collection of airborne fluorinated organics and analysis by gas chromatography/chemical ionization mass spectrometry
ABSTRACT The ubiquitous detection of perfluorooctane sulfonate (PFOS) in humans and animals has produced a need for sensitive and compound-specific analytical methods to determine the environmental distribution of fluorinated organic contaminants. A suite of potential PFOS precursors (sulfonamides) and fluorotelomer alcohols (FTOHs) were separated by gas chromatography and detected by chemical ionization mass spectrometry (GC/CI-MS). Full-scan spectra were collected in both positive and negative chemical ionization (PCI and NCI, respectively) mode to determine retention time windows and fragmentation patterns. In selected ion monitoring (SIM) mode, instrumental detection limits ranged from 0.2 to 20 pg for individual analytes, depending on ionization mode. PCI mode was preferred for routine analysis because of the simple mass spectra produced, typified by the presence of a major molecular ion [M + H]+. High-volume air samplers collected gaseous and particle-bound fluoroorganics on composite media consisting of XAD-2, polyurethane foam (PUF), and quartz-fiber filters. The combined collection efficiency for individual analytes was 87 to 136% in breakthrough experiments. Application of the method to the analysis of ambient air from urban and rural sites confirmed the presence of six novel fluorinated atmospheric contaminants at picogram per meter3 concentrations. Low concentrations of fluoroorganics were consistently detected in blanks (<4 pg m(-3)); however, this did not prevent confirmation or quantification of environmental concentrations.
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ABSTRACT: N-alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire retardants, and anti-corrosion agents, among many other commercial applications. The global distribution and environmental persistence of these compounds has generated considerable interest regarding potential toxic effects. We have previously reported that perfluorooctanesulfonamidoacetate (FOSAA) and N-ethylperfluorooctanesulfonamidoacetate (N-EtFOSAA) induce the mitochondrial permeability transition (MPT) in vitro. In this study we tested the hypothesis that FOSAA and N-EtFOSAA interact with the adenine nucleotide translocator (ANT) resulting in a functional inhibition of the translocator and induction of the MPT. Respiration and membrane potential of freshly isolated liver mitochondria from Sprague-Dawley rats were measured using an oxygen electrode and a tetraphenylphosphonium-selective (TPP(+)) electrode, respectively. Mitochondrial swelling was measured spectrophotometrically. The ANT ligands bongkregkic acid (BKA) and carboxyatractyloside (cATR) inhibited uncoupling of mitochondrial respiration caused by 10 microM N-EtFOSAA, 40 microM FOSAA, and the positive control 8 microM oleic acid. ADP-stimulated respiration and depolarization of mitochondrial membrane potential were inhibited by cATR, FOSAA, N-EtFOSAA, and oleic acid, but not by FCCP. BKA inhibited calcium-dependent mitochondrial swelling induced by FOSAA, N-EtFOSAA, and oleic acid. Seventy-five micromolar ADP also inhibited swelling induced by the test compounds, but cATR induced swelling was not inhibited by ADP. Results of this investigation indicate that N-acetyl perfluorooctane sulfonamides interact directly with the ANT to inhibit ADP translocation and induce the MPT, one or both of which may account for the metabolic dysfunction observed in vivo.Toxicology and Applied Pharmacology 04/2008; 227(2):184-95. DOI:10.1016/j.taap.2007.10.016 · 3.63 Impact Factor
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ABSTRACT: A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/l and <0.01-14 ng/l in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0-260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9-26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions.Chemosphere 09/2007; 68(11):2085-95. DOI:10.1016/j.chemosphere.2007.02.008 · 3.50 Impact Factor
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ABSTRACT: These studies were conducted to investigate the role of dermal exposure to perfluorooctanoic acid (PFOA), a known immunosuppressant, on the hypersensitivity response to ovalbumin (OVA) in a murine model of asthma. PFOA has had widespread use as a carpet and fabric protectant. BALB/c mice were exposed dermally, on the dorsal surface of each ear, to concentrations of PFOA ranging from 0.01 to 1.5% (applied dose 0.25-50 mg/kg) for 4 days. In hypersensitivity studies, mice were also ip injected with 7.5 microg OVA and 2 mg alum on days 1 and 10 and in some studies challenged with 250 microg OVA by pharyngeal aspiration on days 17 and 26. Following exposure to PFOA, an increase in liver weights and a decrease in thymus and spleen weights and cellularities were observed. Similar immunomodulatory trends were demonstrated in mice coadministered PFOA and OVA. Compared to the OVA alone-exposed animals, an increase in total IgE was demonstrated when mice were coexposed to OVA and concentrations of PFOA ranging from 0.75 to 1.5%, while the OVA-specific IgE response peaked with 0.75% PFOA coexposure (p < or = 0.05). OVA-specific airway hyperreactivity was increased in the 1.0% PFOA coexposed group (p < or = 0.05), with an increased pleiotropic cell response characterized by eosinophilia and mucin production, in animals coexposed to concentrations of PFOA up to 1.0%, as compared to the OVA alone-exposed animals. In a murine model, PFOA was demonstrated to be immunotoxic following dermal exposure, with an enhancement of the hypersensitivity response to OVA, suggesting that PFOA exposure may augment the IgE response to environmental allergens.Toxicological Sciences 07/2007; 97(2):375-83. DOI:10.1093/toxsci/kfm053 · 4.48 Impact Factor