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  • 1.
    Chen, Chang-Er L.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. South China Normal University, China.
    Löfstrand, Karin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Adolfsson-Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    MacLeod, Matthew
    Deriving in Vivo Bioconcentration Factors of a Mixture of Fragrance Ingredients Using a Single Dietary Exposure and Internal Benchmarking2018In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 9, p. 5227-5235Article in journal (Refereed)
    Abstract [en]

    Chemicals in mixtures that are hydrophobic with Log K-OW > 4 are potentially bioaccumulative. Here, we evaluate an abbreviated and benchmarked in vivo BCF measurement methodology by exposing rainbow trout to a mixture of eight test chemicals found in fragrance substances and three benchmark chemicals (musk xylene (MX), hexachlorobenzene (HCB) and PCB52) via a single contaminated feeding event followed by a 28-day depuration period. Concentrations of HCB and PCB52 in fish did not decline significantly (their apparent depuration rate constants, k(T), were close to zero), whereas k(T) for MX was 0.022 d(-1). The test chemicals were eliminated much more rapidly than the benchmark chemicals (k(T) > 0.117 d(-1)). The bioconcentration factors (BCFA) for the test chemicals were in the range of 273 L kg(-1) (8-cyclohexadecen-1-one (globanone)) to 1183 L kg(-1) (alpha-pinene); the benchmarked BCFs (BCFG) calculated relative to HCB ranged from 238 L kg(-1) (globanone) to 1147 L kg(-1) (alpha-pinene). BCFG were not significantly different from BCFA but had smaller standard errors. BCFs derived here agreed well with values previously measured using the OECD 305 test protocol. We conclude that it will be feasible to derive BCFs of chemicals in mixtures using a single dietary exposure and chemical benchmarking.

  • 2.
    Chen, Changer Long
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Löfstrand, Karin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Adolfsson-Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Determination of fragrance ingredients in fish by ultrasound-assisted extraction followed by purge & trap2017In: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 9, no 15, p. 2237-2245Article in journal (Refereed)
    Abstract [en]

    Fragrance materials are widely used in household and personal care products in applications that can lead to emissions into the aquatic environment. Assessing the potential of fragrance materials to bioaccumulate in fish in in vivo laboratory studies requires a reliable analytical method for determining the concentrations of chemical substances in fish tissue. Here, we present an analytical method for simultaneously measuring a group of model chemicals that are representative of chemicals found in fragrance materials in rainbow trout. This method involves ultrasound-assisted extraction (UAE) followed by enrichment of the fragrance ingredients using a purge & trap system. Nine fragrance ingredients including semi-volatile and volatile compounds were selected as model substances for method development. Homogenised whole rainbow trout subsamples were spiked with these nine model fragrance ingredients, hexachlorobenzene (HCB) and 2,2',5,5'-tetrachlorobiphenyl (PCB52). The targeted chemicals were extracted from the fish tissue using acetonitrile in an ultrasonic bath; after solvent exchange to hexane, they were extracted into the gas phase by heating the samples and purging with nitrogen and trapped on a solid-phase extraction (SPE) cartridge. Finally, these chemicals were eluted with hexane from the SPE column and analysed using gas chromatography-mass spectrometry (GC-MS). The proposed method has been evaluated for blanks, spiked recoveries and precision, which are all acceptable. We believe that the method presented here is generally applicable for analysis of acid-sensitive volatile and semi-volatile organic chemicals in fish and provides the basis to conduct in vivo bioaccumulation studies of fragrance materials.

  • 3. Ge, Linke
    et al.
    Dong, Qianqian
    Halsall, Crispin
    Chen, Chang-Er L.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Li, Jun
    Wang, Degao
    Zhang, Peng
    Yao, Ziwei
    Aqueous multivariate phototransformation kinetics of dissociated tetracycline: implications for the photochemical fate in surface waters2018In: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 25, no 16, p. 15726-15732Article in journal (Refereed)
    Abstract [en]

    Antibiotics are ubiquitous pollutants in aquatic systems and can exist as different dissociated species depending on the water pH. New knowledge of their multivariate photochemical behavior (i.e., the photobehavior of different ionized forms) is needed to improve our understanding on the fate and possible remediation of these pharmaceuticals in surface and waste waters. In this study, the photochemical degradation of aqueous tetracycline (TC) and its dissociated forms (TCH20, TCH-, and TC2-) was investigated. Simulated sunlight experiments and matrix calculations indicated that the three dissociated species had dissimilar photolytic kinetics and photo-oxidation reactivities. TC2- photo-degraded the fastest due to apparent photolysis with a kinetic constant of 0.938 +/- 0.021 min(-1), followed by TCH- (0.020 +/- 0.005 min(-1)) and TCH20 (0.012 +/- 0.001 min(-1)), whereas Tar was found to be the most highly reactive toward center dot OH (105.78 +/- 3.40 M(-1 )s(-1)), and TC2- reacted the fastest with O-1(2) (344.96 +/- 45.07 M-1 s(-1)). Water with relatively high pH (e.g., similar to 8-9) favors the dissociated forms of TCH- and TC2- which are most susceptible to photochemical loss processes compared to neutral TC. The calculated corresponding environmental half-lives (t(1/2,E) ) in sunlit surface waters ranged from 0.05 h for pH = 9 in midsummer to 3.68 h for pH = 6 in midwinter at 45 degrees N latitude. The moms was dominated by apparent photolysis (especially in summer, 62-91%), followed by O-1(2) and center dot OH oxidation. Adjusting the pH to slightly alkaline conditions prior to UV or solar UV light treatment may be an effective way of enhancing the photochemical removal of TC from contaminated water.

  • 4. Hu, Li-Xin
    et al.
    Olaitan, Olatunde James
    Li, Zhe
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Yang, Yuan-Yuan
    Chimezie, Anyakora
    Adepoju-Bello, Aderonke Ayinke
    Ying, Guang-Guo
    Chen, Chang-Er
    Stockholm University, Faculty of Science, Department of Environmental Science. South China Normal University, China.
    What is in Nigerian waters? Target and non-target screening analysis for organic chemicals2021In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 284, article id 131546Article in journal (Refereed)
    Abstract [en]

    Emerging organic contaminants (e.g., active pharmaceutical ingredients and personal care products ingredients) are ubiquitous in the environment and potentially harmful to ecosystems, have gained increasing public attention worldwide. Nevertheless, there is a scarcity of data on these contaminants in Africa. In this study, various types of water samples (wastewater, surface water and tap water) collected from Lagos, Nigeria were analyzed for these chemicals by both target and non-target analysis on an UHPLC-Orbitrap-MS/MS. In total, 109 compounds were identified by non-target screening using the online database mzCloud. Level 1 identification confidence was achieved for 13 compounds for which reference standards were available and level 2 was achieved for the rest. In the quantitative analysis, 18 of 38 target compounds were detected, including the parent compounds and their metabolites. Acetaminophen, sulfamethoxazole, acesulfame, and caffeine were detected in all samples with their highest concentrations at 8000, 5300, 16, and 7700 μg/L in wastewater, 140000, 3300, 7.7, and 12000 μg/L in surface water, and 66, 62, 0.17 and 1000 μg/L in tap water, respectively. The occurrence of psychoactive substances, anticancer treatments, antiretrovirals, antihypertensives, antidiabetics and their metabolites were reported in Nigeria for the first time. These results indicate poor wastewater treatment and management in Nigeria, and provide a preliminary profile of organic contaminants occurring in Nigerian waters. The findings from this study urge more future research on chemical pollution in the aquatic environments in Nigeria.

  • 5.
    Kierkegaard, Amelie
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Chen, Chang'er
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. South China Normal University, China.
    Armitage, James M.
    Arnot, Jon A.
    Droge, Steven
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Tissue Distribution of Several Series of Cationic Surfactants in Rainbow Trout (Oncorhynchus mykiss) Following Exposure via Water2020In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 54, no 7, p. 4190-4199Article in journal (Refereed)
    Abstract [en]

    Bioaccumulation assessment is important for cationic surfactants in light of their use in a wide variety of consumer products and industrial processes. Because they sorb strongly to natural surfaces and to cell membranes, their bioaccumulation behavior is expected to differ from other classes of chemicals. Divided over two mixtures, we exposed rainbow trout to water containing 10 alkyl amines and 2 quaternary alkylammonium surfactants for 7 days, analyzed different fish tissues for surfactant residues, and calculated the tissues' contribution to fish body burden. Mucus, skin, gills, liver, and muscle each contributed at least 10% of body burden for the majority of the test chemicals. This indicates that both sorption to external surfaces and systemic uptake contribute to bioaccumulation. In contrast to the analogue alkylamine bases, the permanently charged quaternary ammonium compounds accumulated mostly in the gills and were nearly absent in internal tissues, indicating that systemic uptake of the charged form of cationic surfactants is very slow. Muscle-blood distribution coefficients were close to 1 for all alkyl amines, whereas liver-blood distribution coefficients ranged from 13 to 90, suggesting that the dominant considerations for sorption in liver are different from those in blood and muscle. The significant fraction of body burden on external surfaces can have consequences for bioaccumulation assessment.

  • 6. Lammel, Tobias
    et al.
    Wassmur, Britt
    Mackevica, Aiga
    Chen, Chang-Er L.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. South China Normal University, China.
    Sturve, Joachim
    Mixture toxicity effects and uptake of titanium dioxide (TiO2) nanoparticles and 3,3 ',4,4 '-tetrachlorobiphenyl (PCB77) in juvenile brown trout following co-exposure via the diet2019In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 213, article id 105195Article in journal (Refereed)
    Abstract [en]

    Titanium dioxide nanoparticles (n-TiO2) are among the man-made nanomaterials that are predicted to be found at high concentrations in the aquatic environment. There, they likely co-exist with other chemical pollutants. Thus, n-TiO2 and other chemical pollutants can be taken up together or accumulate independently from each other in prey organisms of fish. This can lead to dietary exposure of fish to n-TiO2-chemical pollutant mixtures. In this study, we examine if simultaneous dietary exposure to n-TiO2 and 3,3',4,4'-Tetrachlorobiphenyl (PCB77)-used as a model compound for persistent organic pollutants with dioxin-like properties-can influence the uptake and toxicological response elicited by the respective other substance. Juvenile brown trout (Salmo trutta) were fed custom-made food pellets containing n-TiO2, PCB77 or n-TiO2+PCB77 mixtures for 15 days. Ti and PCB77 concentrations in the liver were measured by ICP-MS and GC-MS, respectively. Besides, n-TiO2 uptake was assessed using TEM. Combination effects on endpoints specific for PCB77 (i.e., cytochrome P450 1A (CYP1A) induction) and endpoints shared by both PCB77 and n-TiO2 (i.e., oxidative stress-related parameters) were measured in intestine and liver using RT-qPCR and enzyme activity assays. The results show that genes encoding for proteins/enzymes essential for tight junction function (zo-1) and ROS elimination (sod-1) were significantly upregulated in the intestine of fish exposed to n-TiO2 and PCB77 mixtures, but not in the single-substance treatments. Besides, n-TiO2 had a potentiating effect on PCB77-induced CYP1A and glutathione reductase (GR) expression/enzyme activity in the liver. This study shows that simultaneous dietary exposure to nanomaterials and traditional environmental pollutants might result in effects that are larger than observed for the substances alone, but that understanding the mechanistic basis of such effects remains challenging.

  • 7. Lin, Zhong
    et al.
    Zhen, Zhen
    Chen, Changer
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Li, Yongtao
    Luo, Chunling
    Zhong, Laiyuan
    Hu, Hanqiao
    Li, Jin
    Zhang, Yueqin
    Liang, Yanqiu
    Yang, Jiewen
    Zhang, Dayi
    Rhizospheric effects on atrazine speciation and degradation in laterite soils of Pennisetum alopecuroides (L.) Spreng2018In: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 25, no 13, p. 12407-12418Article in journal (Refereed)
    Abstract [en]

    Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a worldwide-used herbicide and often detected in agricultural soils and groundwater at concentrations above the permitted limit, because of its high mobility, persistence, and massive application. This study applied pot experiments to investigate the atrazine contents and speciation during the phytoremediation process by Pennisetum alopecuroides (L.) Spreng. in laterite soils. From the change of the total atrazine and bioavailable atrazine measured by diffusive gradients in thin film (DGT), P. alopecuroides significantly improved atrazine degradation efficiency from 15.22 to 51.46%, attributing to the increasing bioavailable atrazine in rhizosphere. Only a small amount of atrazine was taken up by P. alopecuroides root and the acropetal translocation from roots to shoots was limited. The atrazine speciation was significantly different between rhizosphere and non-rhizosphere, attributing to the declining pH and organic matters in rhizosphere. The relationship between pH and soil-bound/humus-fixed atrazine illustrated the pH-dependant release of the atrazine from soils and the competition between humus adsorption and uptake by P. alopecuroides. The present study reveals the important roles of soil pH and organic matters in atrazine speciation and availability in laterite soils, and provides new insights in the rhizospheric effects on effective phytoremediation of atrazine.

  • 8. Peng, Qin
    et al.
    Wang, Mengke
    Cui, Zewei
    Huang, Jie
    Chen, Changer
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Guo, Lu
    Liang, Dongli
    Assessment of bioavailability of selenium in different plant-soil systems by diffusive gradients in thin-films (DGT)2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 225, p. 637-643Article in journal (Refereed)
    Abstract [en]

    Uptake of selenium (Se) by plants largely depend on the availability of Se in soil. Soils and plants were sampled four times within 8 weeks of plant growth in pot experiments using four plant species. Sequential extraction and diffusive gradients in thin-films (DGT) method were employed to measure Se concentrations in potted soils in selenite- or selenate-amended soils. Results showed that DGT-measured Se concentrations (C-DGT-Se) were generally several folds higher for selenate than selenite amended soils, which were obviously affected by the plant species and the duration of their growth. For example, the folds in soil planted with mustard were 1.49-3.47 and those in soils planted with purple cabbage and broccoli, which grew for 3 and 4 weeks after sowing, were 1.06-2.14 and only 0.15-0.62 after 6 weeks of growth. The selenate-amended soil planted with wheat showed an extremely high C-DGT-Se compared with selenite-amended soil, except the last harvest. Furthermore, minimal changes in C-DGT-Se and soluble Se(IV) were found in selenite-amended soils during plant growth, whereas significant changes were observed in selenate-amended soils (p < 0.05). Additionally, Se distribution in various fractions of soil remarkably changed; the soils planted with purple cabbage and broccoli showed the most obvious change followed by wheat and mustard. Soluble Se(VI) and exchangeable Se(VI) were likely the major sources of C-DGT-Se in selenate-amended soils, and soluble Se(IV) was the possible source of C-DCT-Se in selenite-amended soils. In selenate-amended soils, soluble Se(VI) and exchangeable Se(VI) were significantly correlated with Se concentrations in purple cabbage, broccoli, and mustard; in wheat, Se concentration was significantly correlated only with soluble Se(VI) but not with exchangeable Se. C-DGT-Se eventually became positively correlated with Se concentrations accumulated by different plants, indicating that DGT is a feasible method in predicting plant uptake of selenate but not of selenite.

  • 9. Xie, Huaijun
    et al.
    Chen, Jingwen
    Chen, Qining
    Chen, Chang-Er L.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Du, Juan
    Tan, Feng
    Zhou, Chengzhi
    Development and evaluation of diffusive gradients in thin films technique for measuring antibiotics in seawater2018In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 618, p. 1605-1612Article in journal (Refereed)
    Abstract [en]

    As coastal waters in many regions of the world have been polluted by organic micro-pollutants such as antibiotics that can promote the development of resistance genes, it is of importance to monitor the levels of antibiotics in coastal waters. For this purpose, a reliable and robust sampling approach based on diffusive gradients in thin films (DGT) was developed in this study. The DGT measurement can provide a time weighted average concentration of pollutants. A binding material (resin XDA-1) with a high adsorption capacity for antibiotics, which can resist the pH and ionic strength of seawaters, was selected. The DGT sampler exhibited linear accumulation for 20 antibiotics during a 12 h deployment. The antibiotic measurement by the sampler was not affected by pH in the range of 7.3 to 8.9 and ionic strength in the range of 0.5 to 0.8 M. After an 8-hour in situ DGT sampling, 10 antibiotics were detected in Dalian coastal seawaters with the concentrations ranging from 2.6 to 44.8 ngL(-1), which was comparable to the results measured by an active sampling method. This study can be a first attempt to construct DGT sampler for determining antibiotics in seawaters.

  • 10. Xie, Huaijun
    et al.
    Chen, Qining
    Chen, Jingwen
    Chen, Chang-Er L.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. South China Normal University, China.
    Du, Juan
    Investigation and application of diffusive gradients in thin-films technique for measuring endocrine disrupting chemicals in seawaters2018In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 200, p. 351-357Article in journal (Refereed)
    Abstract [en]

    Endocrine disrupting chemicals (EDCs) can be released to coastal waters and affect the endocrine system of marine organisms. To monitor their levels in seawaters, a simple, robust passive sampling method, the diffusive gradients in thin-films (DGT) technique, was developed with XDA-1 resin as a binding agent. Six EDCs (including three estrogens, two pesticides and bisphenol A) were used to assess the performance of the DGT. The XDA-1 binding gel showed adequate ability for adsorbing EDCs in seawaters. The DGT sampler exhibited linear accumulation for the EDCs during a 15-day deployment and diffusion coefficients and sampling rates were calculated. The DGT measurement was independent of pH in the range 7.0-9.0 and ionic strength in the range 0.4-0.8 M. Field applications of this DGT in a coast of Dalian (China) showed comparable results to those from grab sampling. Five EDCs were detected with concentrations ranging from 0.7 to 19.4 ng L-1. This study is a first attempt to apply DGT sampler for determining EDCs in seawaters.

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