Quantitation of guanidine derivatives as representative persistent and mobile organic compounds in water: method development2023 · 記述言語： 英語 掲載種別： 研究論文（学術雑誌） 出版者・発行元： Analytical and Bioanalytical Chemistry Persistent and mobile organic compounds (PMOCs) are highly soluble in water, thereby posing a threat to water resource quality. Currently, there are no methods that can accurately quantify guanidine derivative PMOCs, other than 1,3-diphenylguanidine (DPG) and cyanoguanidine (CG), in aqueous media. In this study, we developed a quantitation method that combines solid-phase extraction and liquid chromatography (LC)-tandem mass spectrometry to detect seven guanidine derivatives in aquatic environments and applied it to environmental water samples. Five LC columns were examined, and among them, a hydrophilic interaction liquid chromatography column was chosen owing to its suitable instrument detection limit and retention factor. Method precision was assessed using seven replicate analyses of river water. The corresponding analyte recoveries ranged from 73 to 137% (coefficient of variation = 2.1–5.8%). DPG and CG were detected in ultrapure water samples at levels up to 0.69 and 150 ng L−1, respectively; DPG and CG levels up to 44 and 2600 ng L−1, respectively, were detected in lake water, river water, sewage effluent, and tap water sampled in Western Japan. This is the first reported detection of DPG in the surface water of Japan, revealing that DPG and CG are ubiquitous compounds in aquatic environments. Moreover, this is the first study to detect 1-(o-tolyl)biguanide and N,N′′′-1,6-hexanediylbis(N′-cyanoguanidine) in water. This study provides a foundation for further research on the distribution, fate, and emission source of these pollutants, which is critical to maintain high water quality and to determine regulatory limits for these pollutants. Graphical Abstract: [Figure not available: see fulltext.]. DOI： 10.1007/s00216-023-04613-x Scopus その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85148937129&origin=inward
Hexabromocyclododecane in riverine and estuarine sediments from Osaka, Japan: spatial distribution and concentration variability within identical samples2020 · 記述言語： 英語 掲載種別： 研究論文（学術雑誌） 出版者・発行元： Environmental Science and Pollution Research In this study, hexabromocyclododecane (HBCD) in riverine and estuarine sediments was investigated in Osaka, Japan. The mean total HBCD concentration detected in sediments ranged from < 0.50 to 130 ng g dry weight. This exceeded the ubiquitous HBCD contamination level found globally but was lower than that in areas affected by point sources, such as textile industries and expanded polystyrene plants. Sewage effluent was one of the suspected point sources of HBCD in the study area. The HBCD concentrations in sediments were highly dependent on certain factors, such as the location of the sampling site (proximity to possible emission sources), sediment properties (silt or sand), and organic substance content. The range of the diastereomer composition of α- and γ-HBCD was wider than that in other studies. Repeatability tests (n = 3) were conducted for all samples to assess the variability in the HBCD concentrations within identical sediment samples. Some variations were observed in the HBCD concentrations and diastereomer compositions within the repeatability test results at some sampling sites; nevertheless, the same samples were extracted and analyzed in triplicate. The bromine contents of the extracts of these samples were analyzed by X-ray fluorescence, and the results agreed well with those estimated from the LC-MS/MS results. From these results, it was confirmed that several sediment samples contained heterogeneously distributed HBCD. The risk characterization ratios (predicted environmental concentration/predicted no-effect concentration) of sites with high HBCD concentrations ranged from 0.1 to 1; thus, further information is required, and the sediment HBCD levels in this region should be continuously studied. −1 DOI： 10.1007/s11356-020-09856-0 Scopus その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85087363345&origin=inward
