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Sökning: L773:0045 6535 OR L773:1879 1298 > Yamashita Nobuyoshi

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1.
  • Ahrens, Lutz, et al. (författare)
  • Distribution of polyfluoroalkyl compounds in water, suspended particulate matter and sediment from Tokyo Bay, Japan
  • 2010
  • Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 79:3, s. 266-272
  • Tidskriftsartikel (refereegranskat)abstract
    • This study examined the environmental behaviour and fate of polyfluoroalkyl compounds (PFCs) found in water, suspended particulate matter (SPM) and sediment. The sampling of the sediment was performed at two stations from Tokyo Bay, Japan, in 2008. In addition, a depth profile of seawater was collected at three water layers from both sampling stations. The ∑PFC concentrations ranged from 16.7 to 42.3 ng L-1 in the water column, from 6.4 to 15.1 ng g-1 dry weight (dw) in the SPM fraction and from 0.29 to 0.36 dw in surface sediment. The distribution of PFCs was found to depend on their physicochemical characteristics. While short-chain perfluoroalkyl carboxylic acids (PFCAs) (C < 7) were exclusively detected in the dissolved phase, longer-chain PFCAs (C ≥ 7), perfluoroalkyl sulfonates (PFSAs), ethylperfluorooctane sulfonamidoacetic acid (EtFOSAA), and perfluorooctane sulfonamide (PFOSA) appeared to bind more strongly to particles. Results showed that the sorption of PFCs on SPM increases by 0.52-0.75 log units for each additional CF2 moiety and that the sorption of PFSAs was 0.71-0.76 log units higher compared to the PFCA analogs. In addition, the sorption of PFCs was influenced by the organic carbon content. These data are essential for modelling the transport and environmental fate of PFCs.
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2.
  • Ahrens, Lutz, et al. (författare)
  • Partitioning of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) between water and sediment
  • 2011
  • Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 85:5, s. 731-737
  • Tidskriftsartikel (refereegranskat)abstract
    • Laboratory partitioning experiments were conducted to elucidate the sorption behaviour and partitioning of perfluoroalkyl compounds (PFCs). Three different sediment types were used and separately spiked with perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) at low environmentally realistic concentrations. PFOA, PFOS and PFOSA were mainly distributed in the dissolved phase at low suspended solid concentrations, indicating their long-range transport potential in the marine environment. In all cases, the equilibrium isotherms were linear and the organic carbon normalised partition coefficients (K OC) decreased in the following order: PFOSA (log K OC=4.1±0.35cm 3g -1)>PFOS (3.7±0.56cm 3g -1)>PFOA (2.4±0.12cm 3g -1). The level of organic content had a significant influence on the partitioning. For the sediment with negligible organic content the density of the sediment became the most important factor influencing the partitioning. Ultimately, data on the partitioning of PFCs between aqueous media and suspended solids are essential for modelling their transport and environmental fate.
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3.
  • Guruge, Keerthi S., et al. (författare)
  • Fluorinated alkyl compounds including long chain carboxylic acids in wild bird livers from Japan
  • 2011
  • Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 83:3, s. 379-384
  • Tidskriftsartikel (refereegranskat)abstract
    • A wide range of fluorinated alkyl compounds (FACs) has been reported in wildlife in various locations in the world. However, such information regarding Japanese wildlife is rarely found. In the present study, we investigated the occurrence of 21 FACs, including perfluorinated alkyl sulfonates (PFASs), perfluorinated carboxylates (PFCAs), and fluorotelomer acids, in the livers of 10 wild bird species from two regions in northern Japan. To avoid interferences, FACs were quantified by a recently developed method using acetonitrile and solid-phase extraction followed by an ion exchange HPLC column separation. Apart from perfluorooctane sulfonate (PFOS), which was found at the highest levels of all the compounds detected, several long chain perfluorinated carboxylates (PFCAs) from C8 to C16, particularly perfluorotetradecanoic acid (PFTeDA) and perfluorohexadecanoic acid (PFHxDA), were detected for the first time. Additionally, 7:3 FTCA, a fluorotelomer acid, was also detected in most swan livers from Miyagi prefecture and all the birds from Tochigi prefecture. However, none of the sulfonamides and unsaturated telomer acids were detected in any species. Swans seem to be the least exposed wild birds to FACs among the investigated birds, signifying that feeding habits may reflect FAC accumulation in wild birds. The highest total concentration of detected FACs was 405ngg-1wet wt., which was found in a Japanese sparrowhawk, indicating that the top predatory wild birds can accumulate several long chain carboxylic acids. However, the current FAC concentrations found in livers may suggest that these compounds alone would not cause a severe toxic effect in these species.
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4.
  • Horii, Yuichi, et al. (författare)
  • Novel evidence for natural formation of dioxins in ball clay
  • 2008
  • Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 70:7, s. 1280-1289
  • Tidskriftsartikel (refereegranskat)abstract
    • Elevated concentrations of dioxins in ancient ball clay from the Mississippi Embayment suggest natural formation of dioxins in the environment. Evidence for such natural formation in ball clay derives from unique congener profiles in undisturbed ancient clay deposits and from the lack of other anthropogenic contaminants. Here we present novel evidence of natural formation of dioxins based on congener-specific carbon isotopic analysis of octachlorodibenzo-p-dioxin (OCDD) in ball clays from the USA and Japan. The analyses were performed using a combination of double-column high performance liquid chromatography clean-up and two-dimensional gas chromatography-isotope ratio mass spectrometry. Elevated concentrations of OCDD found in ball clays from the USA and Japan were isotopically distinguished from the anthropogenic source materials (fly ash and pentachlorophenol) and environmental samples (sediment and soil). The isotopic signatures and the occurrence of OCDD in ancient ball clays deposited in the Tertiary Era provide evidence for the in situ formation of dioxins.
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5.
  • Li, Xuemei, et al. (författare)
  • Accumulation of perfluorinated compounds in captive Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) in China
  • 2008
  • Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 73:10, s. 1649-1653
  • Tidskriftsartikel (refereegranskat)abstract
    • The accumulation of perfluorinated compounds (PFCs) in the sera of captive wildlife species Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) from Harbin Wildlife Park, Heilongjiang Province, in China were analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Perfluorooctanesulfonate (PFOS) was the predominant contaminant with a mean serum concentration of 1.18 ng mL-1 in tigers and 2.69 ng mL-1 in lions. Perfluorononanoic acid (PFNA) was the second most prevalent contaminant in both species. The composition profiles of the tested PFCs differed between tigers and lions, and the percentages of perfluorooctanoic acid (PFOA) were greater in lions than in tigers, indicating different exposures and/or metabolic capabilities between the two species. Assessments of the risk of PFC contamination to the two species were obtained by comparing measured concentrations to points of departure or toxicity reference values (TRVs). Results suggest no risk of PFOS exposure or toxicity for the two species.
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6.
  • Taniyasu, Sachi, et al. (författare)
  • Quality assurance and quality control of solid phase extraction for PFAS in water and novel analytical techniques for PFAS analysis
  • 2022
  • Ingår i: Chemosphere. - : Pergamon Press. - 0045-6535 .- 1879-1298. ; 288
  • Tidskriftsartikel (refereegranskat)abstract
    • An inter-laboratory trial (ILT) has been performed to validate ISO 21675 method for the measurement of per-and polyfluoroalkyl substances (PFAS) in water samples using solid phase extraction method and high-performance liquid chromatography-tandem mass spectrometry. A total of twenty-seven laboratories from eleven countries (Belgium: 1, Canada: 2, China: 2, France: 1, Germany: 3, Italy: 2, Japan: 6, Netherlands: 2, South Korea: 1, Sweden: 4, and USA: 3) participated in the ILT. Results of the homogeneity of ILT water samples showed that the repeatability tended to increase from short-chain to long-chain of PFAS. Results of stability of PFAS in Milli-Q water stored at 5 ± 3 °C ranged from 75% to 121% including those ultra-short-chain compounds, except for N-MeFOSA (44%), N-EtFOSA (44%), and 8:2 FTOH (30%) at 168 days. As for stability of PFAS in environmental waters, they were in acceptable range (between 70 and 125%) for most of PFAS, except for 8:2 FTUCA in the river water, seawater, and wastewater, and 8:2 FTSA and 8:2 FTOH in wastewater. Based on the performance data (reproducibility (CVR): <40%, recoveries (η): 70-125%) of the ILT, current ISO 21675 is validated for up to 30 PFAS depending on water type. Novel analytical techniques namely "In-Situ Solid Phase Extraction" and the "Purge and Trap Extraction" were developed and explored to measure volatile PFAS. Preliminary results showed acceptable recoveries for volatile PFAS such as fluorotelomer alcohols and iodides in spiked MilliQ water.
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7.
  • Yamashita, Nobuyoshi, et al. (författare)
  • Biochar from paddy field : A solution to reduce PFAS pollution in the environment
  • 2024
  • Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 364
  • Tidskriftsartikel (refereegranskat)abstract
    • Generally, activated carbons demonstrated a notable ability to capture long-chain PFAS, but exhibited relatively lower effectiveness for short-chain PFAS. Thirteen commercially available activated carbons in Japan underwent testing for their adsorption capacity of PFAS in water. The activated carbon derived from rice husk, Triporous™-PFAS, exhibited the highest adsorption capacity (over 95%) for PFAS from ultrashort-chain (perfluorocarbon chain: C1 for perfluorocarboxylic acid (PFCA) and C2 for perfluoroalkane sulfonic acid (PFSA)) to long-chain PFAS (C13 for PFCA and C10 for PFSA). An earlier lysimeter study highlighted Andosol, representative soil in Japan, as a potential medium for removing PFAS from irrigation water. Considering cultivating rice on Andosol fields and producing biochar from rice husks and rice straw, a new rice cultivation system is proposed. This system aims to facilitate continuous removal of PFAS from the environment in Asia. Japanese rice cultivation system produces not only rice but also biochar to remove PFAS from water circulation system. The total fluorine content in the tested activated carbon materials ranged from 0.18 to 38 μg g-1 F. Based on the results from background F blank and adsorption capacity, TriporousTM-PFAS-F was shown to be an option to lower the method detection limit for a proposed international standard method for measuring total PFAS.
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8.
  • Yeung, Leo W. Y., 1981-, et al. (författare)
  • A survey of perfluorinated compounds in surface water and biota including dolphins from the Ganges River and in other waterbodies in India
  • 2009
  • Ingår i: Chemosphere. - Oxford, United Kingdom : Elsevier. - 0045-6535 .- 1879-1298. ; 76:1, s. 55-62
  • Tidskriftsartikel (refereegranskat)abstract
    • Despite the reports of the occurrence of perfluorochemicals (PFCs) in industrialized nations, information on PFCs in less industrialized countries is meager. In the present study, concentrations and profiles of PFCs were investigated in surface waters (rivers, lakes, coastal seas and untreated sewage; n = 42) including the Ganges River water, and biota such as shrimp (n = 2), fish (n = 28), and Ganges River dolphin (Platanista gangetica; n = 15). PFOS was the dominant PFC found in most of the samples analyzed including water samples except untreated sewage (water: <0.04–3.91 ng L1; biota: 0.248–27.9 ng g1 ww). Long-chain (C11–C18) perfluorocarboxylates (PFCAs) were not detected in the water samples (<0.2 ng L1), although PFDA (0.061–0.923 ng g1 ww) and PFUnDA (0.072–0.998 ng g1 ww) were found in biological samples The arithmetic mean PFOS concentration found in the liver of Ganges River dolphin was 27.9 ng g1 ww. Bioconcentration and biomagnifications factors of PFCs were estimated in the Ganges River basin food web. The highest concentration of PFOA, 23.1 ng L1, was found in untreated sewage samples. Overall, concentrations of PFCs of water and biological samples from India are lower than the concentrations reported for other countries so far. PFC profiles in Indian waters are dominated by PFOS, followed by PFOA, which is different from the pattern reported for other countries such as Korea, Japan and USA, where PFOA was the predominant compound in waters. The flux estimates for PFOS, PFOA and PFNA from the Ganges River in India to the Bay of Bengal were in the range of several hundreds of kilograms per year.
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