| 1. |
- Zhou, Jie, et al.
(författare)
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Copper nanoparticle-decorated nitrogen-doped carbon nanosheets for electrochemical determination of paraquat
- 2023
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Ingår i: Microchimica Acta. - : Springer. - 0026-3672 .- 1436-5073. ; 190:7
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Tidskriftsartikel (refereegranskat)abstract
- A new strategy to prepare copper (Cu) nanoparticles anchored in nitrogen-doped carbon nanosheets (Cu@CN) has been designed and the nanomaterial applied to the determination of paraquat (PQ). The nanocomposite materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and several other techniques. We found that the Cu nanoparticles are uniformly distributed on the carbon materials, providing abundant active sites for electrochemical detection. The electrochemical behavior of the Cu@CN-based PQ sensor was investigated by square-wave voltammetry (SWV). Cu@CN exhibited excellent electrochemical activity and PQ detection performance. The Cu@CN-modified glassy carbon electrode (Cu@CN/GCE) exhibited excellent stability, favorable sensitivity, and high selectivity under optimized conditions (enrichment voltage −0.1 V and enrichment time 400 s) of the SWV test. The detection range reached 0.50 nM to 12.00 μM, and the limit of detection was 0.43 nM with high sensitivity of 18 μA·μM−1·cm−2. The detection limit is 9 times better than that of the high-performance liquid chromatography method. The Cu@CN electrochemical sensor demonstrated excellent sensitivity and selectivity also in environmental water and fruit samples enabling its use in practical, rapid trace-level detection of PQ in environmental samples. Graphical abstract: [Figure not available: see fulltext.].
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| 2. |
- Fu, Jianjie, et al.
(författare)
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Spatial distribution of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs) in an e-waste dismantling region in Southeast China : use of apple snail (Ampullariidae) as a bioindicator
- 2011
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 82:5, s. 648-655
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Tidskriftsartikel (refereegranskat)abstract
- Fengjiang is a large e-waste dismantling site located in southeast China. In this paper, apple snail and soil samples were collected from this e-waste dismantling site and 25 vicinal towns to investigate the contamination status, spatial distributions and congener patterns of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs). Total PCB concentrations in apple snails (3.78-1812ngg(-1) dry weight (dw)) were significant higher than that in soil samples (0.48-90.1ngg(-1) dw). PBDE (excluding BDE 209) concentrations in apple snail and soil samples ranged from 0.09 to 27.7ngg(-1) dw and 0.06 to 31.2ngg(-1) dw, respectively. Concentrations of PCBs and PBDEs in snails and soils correlated negatively with the distance from Fengjiang. Both the concentrations and profiles of the pollutants were significantly correlated (p<0.05) between the snail and soil samples, indicating the suitability of apple snail as a reliable bioindicator for PCBs and PBDEs contamination in this region. Relatively high concentrations of PCBs and PBDEs at locations far from e-waste dismantling sites implied that these pollutants have been transported to surrounding regions.
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| 3. |
- Zeng, Lixi, et al.
(författare)
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Distribution of short chain chlorinated paraffins in marine sediments of the East China Sea : influencing factors, transport and implications
- 2012
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 46:18, s. 9898-9906
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Tidskriftsartikel (refereegranskat)abstract
- Short chain chlorinated paraffins (SCCPs) are high production volume chemicals in China and found to be widely present in the environment. In this study, fifty-one surface sediments and two sediment cores were collected from the East China Sea to study their occurrence, distribution patterns and potential transport in the marginal sea. SCCPs were found in all surface sediments and ranged from 5.8 to 64.8 ng/g (dry weight, d.w.) with an average value of 25.9 ng/g d.w. A general decreasing trend with distance from the coast was observed, but the highest value was found in a distal mud area far away from the land. The C10 homologue was the most predominant carbon chain group, followed by C11, C12, and C13 homologue groups. Significant linear relationship was found between total organic carbon (TOC) and total SCCP concentrations (R(2) = 0.51, p < 0.05). Spatial distributions and correlation analysis indicated that TOC, riverine input, ocean current, and atmospheric deposition played an important role in controlling SCCP accumulation in marine sediments. Vertical profiles of sediment cores showed that SCCP concentrations decreased from surface to the depth of 36 cm, and then slightly increased again with depth, which showed a significant positive correlation with TOC and chlorine contents (Cl%). The results suggest that SCCPs are being regionally or globally distributed by long-range atmospheric or ocean current transport.
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| 4. |
- Zeng, Lixi, et al.
(författare)
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Spatial distributions and deposition chronology of short chain chlorinated paraffins in marine sediments across the Chinese Bohai and Yellow Seas
- 2013
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 47:20, s. 11449-11456
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Tidskriftsartikel (refereegranskat)abstract
- As the most complex halogenated contaminants, short chain chlorinated paraffins (SCCPs) are scarcely reported in marine environments. In this work, a total of 117 surficial sediment (0-3 cm) samples and two sediment cores were collected from the Chinese Bohai and Yellow Seas to systematically study the spatial and temporal trends of SCCPs at a large scale in the Chinese marine environment. Total SCCP concentrations in the surficial sediments were in the range of 14.5-85.2 ng g(-1) (dry weight, d.w.) with an average level of 38.4 ng g(-1) d.w. Spatial distribution showed a decreasing trend with the distance from the coast to the open waters. Compositional pattern analysis suggested that C10 was the most predominant homologue group, followed by C11, C12, and C13 homologue groups. The concentrations of total SCCPs in sediment cores ranged from 11.6 to 94.7 ng g(-1) d.w. for YS1 and from 14.7 to 195.6 ng g(-1) d.w. for YS2, with sharp rise from the early 1950s to present based on (210)Pb dating technique. The historical records in cores correspond well to the production and usage changes of CPs in China. Multivariate regression statistics indicate TOC, latitude and longitude are the major factors influencing surficial SCCP levels in the Chinese East Seas by combining analysis with the data from the East China Sea (R(2) = 0.332, p < 0.01). These findings indicated that the sources of SCCPs were mainly from river outflows via ocean current and partly from atmospheric depositions by East Asian monsoon in the sampling areas.
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| 5. |
- Zhao, Zongshan, et al.
(författare)
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Source and migration of short-chain chlorinated paraffins in the coastal East China Sea using multiproxies of marine organic geochemistry
- 2013
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 47:10, s. 5013-5022
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Tidskriftsartikel (refereegranskat)abstract
- Multiple proxies of terrestrial organic matters (TOM) were introduced to study the migration behaviors of short-chain chlorinated paraffins (SCCPs) in the coastal East China Sea (ECS). The contents of SCCPs in the surface sediment collected from Changjiang (Yangtze) River Delta (CRD) and along the Zhejiang-Fujian coastline ranged from 9.0 to 37.2 ng/g (dry weight, d.w.), displaying a "band-style" distribution trend. Spatial distribution patterns of SCCP congeners presented an increasing trend seaward and southward along the coastline for shorter carbon length (C₁₀ + C₁₁) and lower chlorinated (Cl₅ + Cl₆ + Cl₇) congeners, suggesting a spreading tendency seaward and southward from the CRD and the north of the inner shelf. The significant relationship between ΣSCCPs and total organic carbons (TOC) (r(2) = 0.402, p < 0.05) indicated that the migration of SCCPs in sediments was markedly affected by TOC. The spatial patterns of the TOM proxies of TOC δ(13)C, the contents of ΣC₂₇ + C₂₉ + C₃₁ n-alkanes, terrestrial marine biomarker ratio (TMBR), and terrestrial TOC (T-TOC) were all similar to that of ΣSCCPs. Linear relationships between SCCP contents and both the contents of ΣC₂₇ + C₂₉ + C₃₁ n-alkanes (r(2) = 0.537, p < 0.05) and T-TOC (r(2) = 0.495, p < 0.05) were also observed. The consistence demonstrated that a major portion of sedimentary SCCPs in the coastal ECS should be from the river input of Changjiang River and deposited in the CRD and along the inner shelf of the ECS, but only a minor fraction was transported to the offshore areas.
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