Abstract  Perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) have been detected globally in wildlife and humans. Data from a gene array indicate that PFOA decreases organic anion transporting polypeptides (Oatps) in liver. Na(+)-taurocholate cotransporting polypeptide (Ntcp) and Oatp1a1, 1a4, and 1b2 are major transporters responsible for uptake of bile acids (BAs) and other organic compounds into liver. The purpose of the present study was to determine the effects of two perfluorinated fatty acids, PFOA and PFDA, on mRNA and protein expression of hepatic uptake transporters Oatps and Ntcp, and to determine the underlying regulatory mechanisms by using peroxisome proliferator-activated receptor alpha (PPAR-alpha), constitutive androstane receptor, pregnane-X receptor, NF-E2-related factor 2, and farnesoid X receptor-null mouse models. After 2 days following a single i.p. administration, PFOA did not alter serum BA concentrations, but PFDA increased serum BA concentrations 300%. Furthermore, PFOA decreased mRNA and protein expression of Oatp1a1, 1a4, and 1b2, but not Ntcp in mouse liver. In contrast, PFDA decreased mRNA and protein expression of all four transporters, and decreased the mRNA expression in a dose-dependent manner, with the decrease of Oatp1a4 occurring at lower doses than the other three transporters. Multiple mechanisms are likely involved in the down-regulation of mouse Oatps and Ntcp by PFDA. By using the various transcription factor-null mice, PPAR-alpha was shown to play a central role in the down-regulation of Oatp1a1, 1a4, 1b2, and Ntcp by PFDA. The current studies provide important insight into understanding the mechanisms by which PFDA regulate the expression of hepatic uptake transporters. In conclusion, PFOA and PFDA decrease mouse liver uptake transporters primarily via activation of PPAR-alpha.

Abstract  Macrophage activation contributes to adverse effects produced by a number of hepatotoxic compounds. Transcriptional profiles elicited by two macrophage activators, LPS and zymosan A, were compared to those produced by 100 paradigm compounds (mostly hepatotoxicants) using cDNA microarrays. Several hepatotoxicants previously reported to activate liver macrophages produced transcriptional responses similar to LPS and zymosan, and these were used to construct a gene signature profile for macrophage activators in the liver. Measurement of cytokine mRNAs in the same liver samples by RT-PCR independently confirmed that these compounds are associated with macrophage activation. In addition to expected effects on acute phase proteins and metabolic pathways that are regulated by LPS and inflammation, a strong induction was observed for many endoplasmic reticulum-associated stress/chaperone proteins. Additionally, many genes in our macrophage activator signature profile were well-characterized PPARalpha-induced genes which were repressed by macrophage activators. A shared gene signature profile for peroxisome proliferators was determined using a training set of clofibrate, WY 14643, diethylhexylphthalate, diisononylphthalate, perfluorodecanoic acid, perfluoroheptanoic acid, and perfluorooctanoic acid. The signature profile included macrophage activator-induced genes that were repressed by peroxisome proliferators. NSAIDs comprised an interesting pharmacological class in that some compounds, notably diflunisal, co-clustered with peroxisome proliferators whereas several others co-clustered with macrophage activators, possibly due to endotoxin exposure secondary to their adverse effects on the gastrointestinal system. While much of these data confirmed findings from the literature, the transcriptional patterns detected using this toxicogenomics approach showed relationships between genes and biological pathways requiring complex analysis to be discerned.

Abstract  The biodegradability of several potential endocrine disrupting compounds, namely 4-n-nonylphenol (4-n-NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), bisphenol A (BPA), triclosan (TCS), di-(2-ethylhexyl)-phthalate (DEHP), perfluorooctanoate (PFOA) and perfluorononanoate (PFNA) was evaluated in this study, using OECD method 301F (manometric respirometry test) and activated sludge as inoculum. According to the results, 4-n-NP and BPA meet the strict definition of ready biodegradability and they are not expected to be persistent during the activated sludge process. Partial biodegradation was observed for DEHP (58.7+/-5.7%, n=3), TCS (52.1+/-8.5%, n=3) and NP1EO (25.9+/-8.1%, n=3), indicating their possible biodegradation in wastewater treatment systems, while no biodegradation was observed for NP2EO, PFOA and PFNA. Experiments in the co-presence of a readily biodegradable compound showed the absence of co-metabolic phenomena during 4-n-NP, BPA and TCS biodegradation. Using first order kinetics to describe biodegradation of the target compounds, half-lives of 4.3+/-0.6, 1.3+/-0.2, 1.8+/-0.5, 6.9+/-2.6 days were calculated for 4-n-NP, BPA, TCS and DEHP, respectively. Toxicity tests using marine bacterium Vibrio fischeri showed that biodegradation of 4-n-NP, NP1EO, BPA and TCS is a simultaneous detoxification process, while possible abiotic or biotic transformations of NP2EO, DEHP, PFOA and PFNA during respirometric test resulted to significant increase of their toxicities.

Abstract  Concentrations of 12 perfluorinated compounds (PFCs) were measured in 21 representive water, sediment and soil samples from Guanting Reservoir and vicinity. Perfluorooctanoic acid (PFOA) was the predominant PFCs with concentrations of 0.55-2.3 ng/L, <LOQ to 0.68 ng/g dw and <LOQ to 2.8 ng/g dw in water, sediment and soil, respectively. Perfluorododecanoic acid (PFDoA) was frequently detected in solid matrices, with concentrations of <LOQ to 0.18 ng/g dw in sediment and 0.13-0.26 ng/g dw in soil. PFCs were detected in all environmental matrices sampled, but concentrations found throughout the watershed were less than those reported from other locations.

Abstract  The concentrations of four perfluorinated sulfonate acids (PFSAs) and 10 perfluorinated carboxylate acids (PFCAs) were measured in water and sediment samples from Liao River and Taihu Lake, China. In the water samples from Taihu Lake, PFOA and PFOS were the most detected perfluorinated compounds (PFCs); in Liao River, PFHxS was the predominant PFC followed by PFOA, while PFOS was only detected in two of the samples. This suggests that different PFC products are used in the two regions. PFOS and PFOA in both watersheds are at similar level as in the rivers of Japan, but significantly lower than in Great Lakes. The contributions of PFOS and long chain PFCAs in sediments were much higher than in water samples of both watersheds, indicating preferential partition of these PFCs in sediment. The concentrations of PFOS and PFOA were three orders of magnitude of lower than that of polycyclic aromatic hydrocarbons in the same sediments. The average sediment-water partition coefficients (log K(oc)) of PFHxS, PFOS and PFOA were determined to be 2.16, 2.88 and 2.28 respectively.

Abstract  PURPOSE: Due to their high water solubilities and mobilities, persistent, polar perfluorinated compounds (PFCs) such as perfluorinated carboxylates and sulfonates are likely to end up in the oceans. In part 1 of this study, their distribution in North and Baltic Sea water is reported, being of special interest because these seas are surrounded by highly industrialized countries with high population densities.

METHODS: A combination of solid-phase extraction and liquid chromatography coupled with tandem mass spectrometry was used after optimisation to determine nine PFCs with chain lengths of C(4) to C(10) in water samples at ultra-trace levels.

RESULTS: The observed concentration distribution and gradients were explained by oceanographic mixing processes and currents. The big rivers were identified as major input sources. At the mouth of the river Elbe, concentrations of 9 ng/L were observed for perfluorooctanoate (PFOA), and 8 ng/L for perfluorooctylsulfonate (PFOS); all other PFC concentrations ranged from 0.6 to 1.7 ng/L. At coastal stations, concentrations decreased to 3.8 ng/L (PFOA) and 1.8 ng/L (PFOS), dropping to 0.13 and 0.09 ng/L, respectively, towards the open sea. Along the Dutch coast, high perfluorobutylsulfonate concentrations (3.9 ng/L) were observed as regional characteristics. In the Baltic Sea, fairly even PFC distributions with low gradients were observed. Again, PFOA and PFOS were the major compounds (up to 1.1 and 0.9 ng/L).

CONCLUSION: The results underline the necessity to include PFCs in marine monitoring programs. Water was found to be a good matrix for monitoring environmental levels, sources, and transport pathways of PFCs.

Abstract  Perfluorinated alkylated substances (PFAS) are of global interest due to their occurrence and persistency in the environment. This study includes surface waters and sediments for the analysis of eleven PFAS. The PFAS studied can be grouped in perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFS) and perfluoroalkyl sulfonamides (PFSA). The two most important compounds are perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS). These two substances showed the most significant values for surface water samples with maximum concentrations of 21 ng l(-1) for PFOA and 37 ng l(-1) for PFOS. Sediment samples from seven Austrian lakes and the river Danube were studied. Whereas PFSA and PFS were not detected in any sediment sample PFCAs were detected in most of the lake samples in concentrations up to 1.7 microg kg(-1) dry wt. PFOA, perfluorohexanoic acid (PFHxA) and perfluoroheptanoic acid (PFHpA) were detected in all Danube river sediment samples in concentrations varying from 0.1 up to 5.1 microg kg(-1) dry wt. For the various sampling points the proportional mass flows deriving from wastewater discharges were calculated. Whereas only up to 10% of the average flow is discharged wastewater up to more than 50% of the PFAS mass flows in the rivers can be attributed to wastewater discharges. Besides wastewater different other pathways as emissions from point sources, further degradation of precursor products, runoff from contaminated sites or surface runoff as well as dry and wet deposition have to be considered as relevant sources for PFAS contamination in surface waters.

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  Perfluorochemicals (PFCs) are the subject of increasingly intense environmental research. Despite their detection both in biota and in aqueous systems, little attention has been paid to the possible presence of this class of compounds in solid environmental matrixes. The limited available data indicate that some PFCs such as perfluorooctane sulfonate (PFOS) may strongly sorb to solids, and sewage sludge is widely suspected as a major sink of PFCs entering municipal waste streams. A quantitative analytical method was developed that consists of liquid solvent extraction of the analytes from sediments and sludge, cleanup via solid-phase extraction, and injection of the extracts with internal standards into a high-performance liquid chromatography (HPLC) system coupled to a tandem mass spectrometer (LC/MS/MS). The limits of detections of the method were analyte and matrix dependent, but ranged from 0.7 to 2.2 ng/g and 0.041 to 0.246 ng/g (dry weight) for sludge and sediment, respectively. A demonstration of the method was performed by conducting a limited survey of domestic sludge and sediments. The concentration of PFCs in domestic sludge ranged from 5 to 152 ng/g for total perfluorocarboxylates and 55 to 3370 ng/g for total perfluoroalkyl sulfonyl-based chemicals. Data from a survey of San Francisco Bay Area sediments suggest widespread occurrence of PFCs in sediments at the low ng/g to sub-ng/g level. Furthermore, substances that may be transformed to PFOS, such as 2-(N-ethylperfluorooctanesulfonamido) acetic acid (N-EtFOSAA) and 2-(N-methylperfluorooctanesulfonamido) acetic acid (N-MeFOSAA), are present in both sediments and sludge at levels often exceeding PFOS.

Abstract  Perfluoroalkyl substances (PFASs) can interfere with male reproductive function, but evidence in humans is limited. Six hundred four fertile men (199 from Greenland, 197 from Poland and 208 from Ukraine) were enrolled in the study. We measured four PFASs in serum (PFOS, PFOA, PFNA and PFHxS) and concurrent DNA damage in spermatozoa by sperm chromatin structure assay (SCSA) and in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, apoptotic markers in semen (Fas-receptor and Bcl-xL), and reproductive hormones in serum. No association between PFASs and SCSA, apoptotic markers or reproductive hormones emerged. We observed a slight increase in SHBG and TUNEL-positivity with increased PFOA exposure in men from Greenland. Thus, consistent evidence that PFAS exposure interferes with sperm DNA fragmentation, apoptosis or reproductive hormones was not found.

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  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  A sensitive method for the quantitative determination of spinosin in rat plasma was developed and validated using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The analytes of interest were extracted from rat plasma samples by methyl tert-butyl ether (MTBE) after acidification with 1.0% acetic acid aqueous solution. Chromatographic separation was achieved on an Agilent Zorbax SB-C(18) (50 mm x 4.6 mm, 5 microm) using a isocratic mobile phase consisting of acetonitrile-water (30:70, v/v) with 1% isopropyl alcohol and 0.01% heptafluorobutyric acid. The flow rate was 0.2 ml/min. The column temperature was maintained at 25 degrees C. Detection was performed on a triple quadrupole tandem mass spectrometer by selected reaction monitoring (SRM) mode via electrospray ionization (ESI). The calibration curve was linear over the range of 1.00-400 ng/ml in rat plasma, with 1.00 ng/ml of the lower limit of quantification (LLOQ). The inter- and intra-day precisions and accuracy for all samples were satisfactory. The validated method was successfully applied for the pharmacokinetic study of spinosin in rat. After oral administration of 20mg/kg spinosin to rats, the main pharmacokinetic parameters of T(max), C(max), T(0.5) and AUC(0-T) were 5.33+/-0.58 h, 132.2+/-10.6 ng/ml, 4.89+/-0.37 h, 1.02+/-0.09 microg h/l, respectively.

Abstract  Perfluorinated compounds (PFCs) are persistent and bioaccumulative organic compounds used as additives in many industrial products. After use, these compounds enter wastewater treatment plants (WWTP) and long-chain PFCs are primarily accumulated in sludge. The aim of this study was to determine the occurrence and behavior of five PFCs in sludge from 15 WWTP from Spain and Germany that receive both urban and industrial wastes. The PFCs studied were perfluorooctanesulfonate (PFOS), perfluorohexanesulfonate (PFHxS), perfluorobutanesulfonate (PFBS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA). One gram of freeze-dried, sieved, and homogenized sludge was extracted using an ultrasonic bath with methanol and glacial acetic acid. After that, the extract was recovered and evaporated to dryness with a TurboVap and then 1 mL of acetonitrile was added and the extract was cleaned up with black carbon. Liquid chromatography coupled to mass spectrometry operated in selected reaction monitoring was used to determine target compounds. Quality parameters are provided for the set of compounds studied. PFCs were detected in all samples. In Spanish sludge, ∑PFC ranged from 0.28 to 5.20 ng/g dry weight (dw) with prevalence of PFOS, while in German sludge, ∑PFC ranged from 20.7 to 38.6 ng/g dw and PFBS was the dominant compound. As a next step, the evolution of PFC concentrations within the sludge treatment steps (primary sludge, anaerobic digested sludge, and centrifuged sludge) was evaluated and differences among levels and patterns were observed and were attributed to the influent water quality and treatment used. Finally, we estimated the amount of PFCs discharged via sludge in order to determine the potential impact to the environment according to different sludge usage practices in the two regions investigated. This manuscript provided an intra-European overview of PFC distribution in sludge. Levels and compound distribution depend on the WWTP sampled. This study demonstrates that PFCs are persistent to sludge treatment and the loads in sludge may pose a future environmental risk, if not controlled.

Abstract  Perfluorinated compounds (PFCs) are widely used in everyday life and one of the main recipients of these compounds is waste water treatment plants (WWTPs). Due to the structure and physicochemical properties of PFCs, these compounds could be redistributed from influent water to sludge. This work reports a new validated protocol for the analysis of 13 perfluorinated acids, 4 perfluorosulfonates and the perfluorooctanesulfonamide. The present work has been focused to develop a sensitive and robust method for the analysis of 18 PFCs in sewage sludge, based on pressurized solvent extraction (PSE) followed by solid phase extraction (SPE) clean-up, analytes separation by liquid chromatography and analysis in a hybrid quadrupole-linear ion trap mass spectrometer (LC-QLiT-MS/MS) working in single reaction monitoring (SRM) mode. The final methodology was validated using a blank sewage sludge fortified at different concentration levels. The method limits of detection were ranging in general from 15 to 79 ng/kg. These values were comparable to the decision limit (CCα) and the detection capability (CCβ), which were 17-1134 ng/kg and 18-1347 ng/kg, respectively. The percentage of recovery was from 79 to 111% in the most cases at different spiked levels. Finally, the repeatability of the method was in the range 4% (PFOS and PFOA) to 25% (RSD %). In order to evaluate the applicability of the method, 5 sludge samples were analyzed. The results showed that the 18 PFCs were present in all samples. However, the concentrations for most of them were below the limits of quantification. The compound present at higher concentrations was perfluorooctanesulfonate (PFOS), which was in concentrations from 53.0 to 121.1 μg/kg. The other PFCs were at concentrations between 0.3 and 30.3 μg/kg.

Abstract  In the frame of the development of a novel HPLC-ELSD (evaporative light scattering detection) method for the determination of the aminoglycoside antibiotic neomycin sulfate, the influence of mobile phase composition and peak broadening on ELSD response was evaluated. ELSD response was enhanced by: (a) increase of mobile phase volatility (solvents examined: water, acetonitrile, methanol and acetone), (b) increase of molecular mass of ion-pairing species [acidic reagents tested: formic, acetic, trifluoroacetic, trichloroacetic and heptafluorobutyric acid (HFBA)], and (c) decrease of peak width and asymmetry obtained by controlling the concentration of the ion-pairing acidic reagent (HFBA). Utilizing a Waters ODS-2 C18 Spherisorb column, evaporation temperature of 45 degrees C and nitrogen pressure of 3.5 bar, the optimized mobile phase was water-acetone (50:50), containing 11.6 mM HFBA, in an isocratic mode at a rate of 1.0 ml/min. Neomycin was eluted at 4.9 min, with asymmetry factor 1.3. Logarithmic calibration curve was obtained from 2 to 50 microg/ml (r > 0.9997). Limit of detection (LOD) was 0.6 microg/ml and R.S.D. = 1.7% (n = 3, 3.3 microg/ml). In raw materials, the simultaneous determination of sulfate (LOD = 3 microg/ml, R.S.D. = 1.7%, r> 0.9998) and of minor impurities was feasible. The developed method was also applied for the determination of neomycin in pharmaceutical formulations (powder, aerosol and cream) without any interference from excipients (recovery from spiked samples ranged from 99 to 102%) and a %R.S.D. of <2.1 (n = 3). The HPLC-ELSD method was also found applicable in the determination of neomycin in animal feeds (LOQ=0.2%) without any interference from the feed matrices.

Abstract  Increasing speciation demands in clinical chemistry, toxicology and nutrition have made the determination of the total elements in a sample inadequate; the amount of an element and the chemical forms in which it is present need to be known. Inductively coupled plasma mass spectrometry (ICP-MS) was used after high-performance liquid chromatographic (HPLC) separation, as was electrospray ionization mass spectrometry (ESI-MS). The effect of variation of the number of carbon atoms in perfluorinated carboxylic acids used as ion-pairing agents for the separation of selenium compounds was examined. Trifluoroacetic acid (0.1%), pentafluoropropanoic acid (0.1%) or heptafluorobutanoic acid (0.1%; HFBA) were alternatively used as additives to methanol-water (1:99, v/v) solutions as mobile phases. Reversed-phase HPLC-ICP-MS with 0.1% HFBA in the mobile phase allowed more than 20 selenium compounds to be separated in 70 min in an isocratic elution mode; the separation of natural selenium-enriched sample extracts was examined and explained. The pH of the 0.1% HFBA solution was modified with hydrochloric acid or ammonia and the pH of the sample extracts before injection was modified in order to overcome unwanted double peak formation in the chromatograms of sample extracts. Oxidations of standard gamma-glutamyl-Se-methylselenocysteine and Se-methylselenocysteine were carried out using 30% H2O2 solution and identifications of selenium-containing oxidation products were made using HPLC-ICP-MS and HPLC-ESI-MS. The principal organic oxidation product in both cases was methaneseleninic acid (MeSeO2H).

Abstract  CONTEXT: Perfluorocarbons (PFC) are man-made chemicals used in numerous household products. They have a long half-life in humans and complex animal toxicity, and accumulating evidence points toward associations with multiple human health endpoints.

OBJECTIVE: Our objective was to investigate whether PFC are associated with endocrine disruption in women.

DESIGN: Cross-sectional analyses were made between quintiles of serum PFC, serum estradiol, and menopause onset.

SETTING: The C8 Health Project, with cohort of 69,030 adults and children, was conducted due to PFC contamination of drinking water from six water districts in two states.

PARTICIPANTS: Participants included 25,957 women aged 18-65 yr.

MAIN OUTCOME MEASURES: Serum estradiol levels and onset of menopause were assessed. The survey was the result of a class action suit, and survey designers (an independent corporation) had no a priori hypotheses. All hypotheses have been formulated by other investigators after data collection.

RESULTS: After excluding women who reported hysterectomy and adjusting for age within the group, smoking, alcohol consumption, body mass index, and exercise, the odds of having experienced menopause were significantly higher in the highest quintile relative to the lowest quintile of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in the perimenopausal [PFOS odds = 1.4, confidence interval (CI) = 1.1-1.8; PFOA odds =1.4, CI = 1.1-1.8] and menopausal age groups (PFOS odds = 2.1, CI=1.6-2.8; PFOA odds = 1.7, CI = 1.3-2.3). After appropriate exclusions and adjustment for covariates, there was a significant inverse association between PFOS and estradiol in perimenopausal (β = -3.65; P < 0.0001) and menopausal age groups (β = -0.83; P = 0.007) but not between PFOA and estradiol.

CONCLUSIONS: These data suggest that PFC are associated with endocrine disruption in women and that further research on mechanisms is warranted.

Abstract  11β-Hydroxysteroid dehydrogenase 2 (11β-HSD2) regulates active glucocorticoid access to glucocorticoid and mineralocorticoid receptors by metabolizing it to an inactive form. Perfluoroalkylated substances (PFASs) are man-made polyfluorinated compounds that are widely used and persistent in the environment. We tested the inhibitory potencies of four PFASs including perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexanesulfonate (PFHxS) and perfluorobutane sulfonate (PFBS) on human and rat 11β-HSD2. PFOS was a potent inhibitor of both human (IC(50)=48 nM) and rat (IC(50)=293 nM) 11β-HSD2 activities. The potencies for the inhibition of human and rat 11β-HSD2 activities were PFOS>PFOA>PFHxS>PFBS. PFASs showed competitive inhibition of both human and rat 11β-HSD2 activities. This observation indicates that PFOS is a potent endocrine disruptor for glucocorticoid metabolism. Article from the Special issue on Targeted Inhibitors.

Abstract  Monodisperse gold clusters have been prepared on surfaces in different charge states through soft landing of mass-selected ions. Ligand-stabilized gold clusters were prepared in methanol solution by reduction of chloro(triphenylphosphine)gold(I) with borane tert-butylamine complex in the presence of 1,3-bis(diphenylphosphino)propane. Electrospray ionization was used to introduce the clusters into the gas phase, and mass selection was employed to isolate a single ionic cluster species (Au(11)L(5)(3+), L = 1,3-bis(diphenylphosphino)propane), which was delivered to surfaces at well-controlled kinetic energies. Using in situ time-of-flight secondary ion mass spectrometry (TOF-SIMS), it is demonstrated that the Au(11)L(5)(3+) cluster retains its 3+ charge state when soft landed onto the surface of a 1H,1H,2H,2H-perfluorodecanethiol self-assembled monolayer (FSAM) on gold. In contrast, when deposited onto 16-mercaptohexadecanoic acid (COOH-SAM) and 1-dodecanethiol (HSAM) surfaces on gold, the clusters exhibit larger relative abundances of the 2+ and 1+ charge states, respectively. The kinetics of charge reduction on the FSAM and HSAM surfaces are investigated using in situ Fourier transform ion cyclotron resonance (FT-ICR) SIMS. It is shown that an extremely slow interfacial charge reduction occurs on the FSAM surface while an almost instantaneous neutralization takes place on the surface of the HSAM. Our results demonstrate that the size and charge state of small gold clusters on surfaces, both of which exert a dramatic influence on their chemical and physical properties, may be tuned through soft landing of mass-selected ions onto carefully selected substrates.

Abstract  For this study, we developed methods of determining ten perfluorinated chemicals in drinking water, milk, fish, beef, and pig liver using high-flow automated solid-phase extraction (SPE) and ultra-high performance liquid chromatography/tandem mass spectrometry. The analytes were separated on a core-shell Kinetex C18 column. The mobile phase was composed of methanol and 10-mM N-methylmorpholine. Milk was digested with 0.5 N potassium hydroxide in Milli-Q water, and was extracted with an Atlantic HLB disk to perform automated SPE at a flow rate ranged from 70 to 86 mL/min. Drinking water was directly extracted by the SPE. Solid food samples were digested in alkaline methanol and their supernatants were diluted and also processed by SPE. The disks were washed with 40% methanol/60% water and then eluted with 0.1% ammonium hydroxide in methanol. Suppression of signal intensity of most analytes by matrixes was lower than 50%; it was generally lower in fish and drinking water but higher in liver. Most quantitative biases and relative standard deviations were lower than 15%. The limits of detection for most analytes were sub-nanograms per liter for drinking water and sub-nanograms per gram for solid food samples. This method greatly shortened the time and labor needed for digestion, SPE, and liquid chromatography. This method has been applied to analyze 14 types of food samples. Perfluorooctanoic acid was found to be the highest among the analytes (median at 3.2-64 ng/g wet weight), followed by perfluorodecanoic acid (0.7-25 ng/g) and perfluorododecanoic acid (0.6-15 ng/g).

Abstract  Perfluorinated compounds (PFC) in water, sediment, soil, and biota from the coastal industrial area of Tianjin, China, were measured to provide baseline information and to determine possible sources and potential risk to wildlife. Perfluorooctanesulfonate (PFOS) was the predominant PFC with maximum concentrations of 10 ng/L in water, and 4.3, 9.4, and 240 ng/g dw in sediment, soil, and fish, respectively. Perfluorooctanoate (PFOA) concentration in water ranged from 3.0 to 12 ng/L. Perfluoroundecanoate (PFUnA) and Perfluorododecanoate (PFDoA) were detected in solid matrices, respectively, at concentrations of <LOQ to 1.2 ng/g dw and 0.27-0.81 ng/g dw in sediments, and <LOQ to 1.0 ng/g dw and 0.26-0.61 ng/g dw in soils. Concentrations of PFOS, PFUnA, and PFDoA in sediment and soil from this industrialized and urbanized area were greater than those previously reported, while PFOS and PFOA in water and biota were both less than reported threshold concentrations for adverse effects in wildlife.

Abstract  Perfluorinated compounds (PFCs) are man-made fluoro-surfactants that are identified as global pollutants and can pose health risks to humans and wildlife. Two aspects of risk assessment were conducted in this study, including exposure and response. Exposure was estimated by using the concentrations of PFCs in fish and applying standard exposure factors. Among different PFCs, PFOS, PFOA, PFNA, PFDA, PFUdA and PFTrDA were detected. Total concentrations of PFC in fish ranged from 0.27-8.4 ng g(-1) to 0.37-8.7 ng g(-1) respectively in Hong Kong and Xiamen. The calculated hazard ratio (HR) of PFOS for all fish was less than 1.0. However, the HR for mandarin fish in Hong Kong and bighead carp, grass carp and tilapia in Xiamen, had HR values of approximately 0.5, indicating that frequent consumption of these 4 more contaminated fish species might pose an unacceptable risk to human health. Our data support the notion that the released/disposed chemical pollutants into water systems make fish a source of environmental toxicants to humans. The risks and potential effects of PFCs to health of coastal population in the Pearl River Delta are of concern.

Abstract  A total of 21 perfluorinated compounds (PFCs) were quantified in water and biota samples collected from Shenyang in North-east China and the Yangtze River Delta area in East China. The human health risk owing to intake of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) via fish and domestic poultry dietary was evaluated. The total PFC concentration (Sigma PFC) in water samples from the rivers in Shenyang averaged 5.32 ng L(-1), with PFOS and PFOA as the predominant compounds. The urban sewage could be the source of PFOS and perfluorohexane sulfonate (PFHxS) in the surface waters. The total PFCs in water samples from the Yangtze River Delta area ranged from 42.4 to 170 ng L(-1). The highest concentrations of most PFCs were observed in waters from the Shanghai section of the Yangtze River. In the biota samples, PFOS and PFUnDA (perfluoroundecanoic acid) were the most abundant. The acceptable daily intake (ADI) and hazard ratio (HR) values for PFOS and PFOA intake through the diet of fish and poultry in the studied areas were calculated, and showed that the HR values for PFOS and PFOA are all less than 1.0 for both the areas.