Taniyasu S.,Japan National Institute of Advanced Industrial Science and Technology |
Kannan K.,New York State Department of Health |
Wu Q.,New York State Department of Health |
Kwok K.Y.,City University of Hong Kong |
And 8 more authors.
Analytica Chimica Acta
The ISO 25101 (International Organization for Standardization, Geneva) describes a new international standard method for the determination of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) in unfiltered samples of drinking and surface waters. The method is based on the extraction of target analytes by solid phase extraction, solvent elution, and determination by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). For the determination of the performance of this method, more than 20 laboratories from 9 different countries participated in an inter-laboratory trial in 2006. In addition, inter-laboratory trials were conducted in 2008 and 2009 for the analysis of perfluoroalkylsubstances (PFASs), including PFOS and PFOA, in water samples by following the protocols of Japanese Industrial Standard (JIS). Overall, the repeatability coefficients of variation (i.e., within-laboratory precision) for PFOS and PFOA in all water samples were between 3 and 11%, showing a adequate precision of the ISO and JIS methods. The reproducibility coefficients of variation (i.e., between-laboratory precision) were found to vary within a range of 7-31% for surface water and 20-40% for wastewater. The recoveries of PFOS and PFOA, as a measure of accuracy, varied from 84 to 100% for surface water and from 84 to 100% for wastewater among the samples with acceptable criteria for internal standards recovery. The determined concentrations of PFASs in samples compared well with the " true" values. The results of the inter-laboratory trial confirmed that the analytical methods are robust and reliable and can be used as a standard method for the analysis of target compounds in water samples. © 2013 Elsevier B.V. Source
Takazawa Y.,Japan National Institute of Environmental Studies |
Takasuga T.,Shimadzu Techno Research Inc. |
Doi K.,Chiyoda Corporation |
Saito M.,Chiyoda Corporation |
Shibata Y.,Japan National Institute of Environmental Studies
Hexachlorocyclohexanes (HCHs), chlordanes (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) in air-mass outflows from East Asia were recorded monthly from April 2009 to March 2014 at Cape Hedo in Japan. These organochlorine pesticides (OCPs) were collected by a high volume air sampler equipped with a quartz fiber filter, a polyurethane foam plug, and activated carbon fiber and analyzed by using a gas chromatograph-high resolution mass spectrometer. The overall (and geometric mean ± SD) concentration over the period was 4.9-43 pg m-3 (15 ± 7.8 pg m-3) in HCHs (sum of α-/β-/γ-/δ-HCH), 1.5-83 pg m-3 (8.8 ± 11 pg m-3) in CHLs (sum of cis-/trans-chlordane, cis-/trans-nonachlor, and oxychlordane), and 0.71-16 pg m-3 (2.5 ± 2.0 pg m-3) in DDTs (sum of o,p'-/p,p'-DDD, o,p'-/p,p'-DDE, and o,p'-/p,p'-DDT). Clear seasonal changes, i.e. higher in summer and lower in winter, were observed in HCHs and CHLs, suggesting the dominant effect of temperature-dependence, secondary sources in these OCPs. DDT concentration as well as the ratio of (o,p'-DDT + p,p'-DDT) to total DDTs, on the other hand, showed clear a declining trend during the five year sampling period, suggesting the decrease of input of newly produced DDTs in the regional environment by reflecting recent activities in the East Asian region to eliminate production and use of DDTs under the Stockholm Convention. © 2016 Elsevier Ltd. Source
Cao Y.,Kyoto University |
Harada K.H.,Kyoto University |
Liu W.,Kyoto University |
Liu W.,Shenyang University |
And 10 more authors.
Short-chain chlorinated paraffins (SCCPs) are emerging persistent organic pollutants. It has been found that dietary intakes of SCCPs in China have recently increased and are now higher than in Japan and Korea. The contribution of cooking oil to dietary exposure to SCCPs in China was evaluated by analyzing SCCPs in cooking oil, raw seeds used to produce cooking oil, and fried confectionery products collected in China in 2010 and 2012. Detectable amounts of SCCP homologs were found in 48 out of the 49 cooking oil samples analyzed, and the SCCP concentrations varied widely, from <9 to 7500ngg-1. Estimated dietary intakes of total SCCPs in cooking oil ranged from <0.78 to 38μgd-1. The estimated dietary intake of SCCPs was relatively high (mean 14.8μgd-1) for residents of Beijing. Fried confectionery was found to contain SCCP concentrations of 11-1000ngg-1. Cooking oil might therefore be one of the sources of SCCPs to Chinese diets. SCCPs were also detected in raw seeds used to produce cooking oil, but the concentrations varied widely. The SCCP homolog patterns in the raw seed and cooking oil samples were different, implying that the seeds used to produce the oil (and therefore the soil on which the seeds were produced) were unlikely to be the sources of SCCPs in cooking oil. Further investigations are needed to determine the routes through which cooking oil becomes contaminated with SCCPs during the production and processing of the oil. © 2015 Elsevier Ltd. Source
Ide Y.,Japan International Center for Materials Nanoarchitectonics |
Ide Y.,Waseda University |
Nagao K.,Waseda University |
Saito K.,Waseda University |
And 6 more authors.
Physical Chemistry Chemical Physics
The activity of Au nanoparticle-loaded P25 TiO2 (Au/P25) plasmonic photocatalysts, evaluated by the oxidative decomposition of formic acid in water under visible light irradiation, was enhanced up to 3 times by simply mixing Au/P25 with photocatalytically inactive h-BN nanosheets as a result of electron transfer from photoexcited Au/TiO2 to the h-BN nanosheets and retardation of the charge recombination. © the Owner Societies 2016. Source
Araoka F.,Tokyo Institute of Technology |
Masuko S.,Tokyo Institute of Technology |
Kogure A.,Shimadzu Techno Research Inc. |
Miyajima D.,University of Tokyo |
And 2 more authors.
The self-organization of ferroelectric columnar liquid crystals (FCLCs) is demonstrated. Columnar order is spontaneously formed in thin films made by the wet-process due to its liquid crystallinity. Electric-field application results in high optical quality and uniform spontaneous polarization. Such good processability and controllability of the wet-processed FCLC films provide us with potential organic ferroelectric materials for device applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source