ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 19
·19409-19416
·
IF 2.76
Peng Guilong,He Qiang,Lu Ying,Mmereki Daniel,Zhong Zhihui
A simple method based on dispersive solid-phase extraction (DSPE) and dispersive liquid–liquid microextraction method based on solidification of floating organic droplets (DLLME-SFO) was developed for the extraction of chlorpyrifos (CP), chlorpyrifos-methyl (CPM), and their main degradation product 3,5,6-trichloro-2-pyridinol (TCP) in tomato and cucumber samples. The determination was carried out by high performance liquid chromatography with ultraviolet detection (HPLC-UV). In the DSPE-DLLME-SFO, the analytes were first extracted with acetone. The clean-up of the extract by DSPE was carried out by directly adding activated carbon sorbent into the extract solution, followed by shaking and filtration. Under the optimum conditions, the proposed method was sensitive and showed a good linearity within a range of 2–500 ng/g, with the correlation coefficients ( r ) varying from 0.9991 to 0.9996. The enrichment factors ranged from 127 to 138. The limit of detections (LODs) were in the range of 0.12–0.68 ng/g, and the relative standard deviations (RSDs) for 50 ng/g of each analytes in tomato samples were in the range of 3.25–6.26 % ( n = 5). The proposed method was successfully applied for the extraction and determination of the mentioned analytes residues in tomato and cucumber samples, and satisfactory results were obtained.
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高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2016
·Vol. 32
·期 4
·630-633
·
IF 1.086
Zhu Jian,Jin Zhimin
After being hydrolyzed into corresponding hydrosoluble carboxylate by 1,1,3,3,-tetramethylguanidine (TMG), camptothecin was extracted via the aqueous two-phase systems composed of ionic liquid 1,1,3,3-tetramethylguanidinium(TMGM) carboxylate and K 2 CO 3 , and was regenerated at the final by dilute aqueous hydrochloric acid. Among the ionic liquids, TMGM benzoate showed the best effect, TMGM formate the worst, this results were consistent with the liposolubilities of different carboxylic acid components in the ionic liquids. Through two-step extraction of TMGM benzoate ionic liquid/K 2 CO 3 aqueous two-phase at a favorable condition, camptothecin was obtained in a purity of 98.3% and a total yield of 85.1%, from the crude camptothecin extract with a purity of 14.2%.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2016
·Vol. 32
·期 4
·586-593
·
IF 1.086
Zhang Guofu,Zhang Guihua,Lei Jie,Li Shasha,Xu Shengjun,Ding Chengrong,Shan Shang
A facile, practical and scalable catalyst system for alcohols ammoxidation into nitriles is developed using amino acid as ligand, oxygen as terminal oxidant and copper iodide(CuI) as catalyst. The catalyst system shows excellent functional groups compatibility for a wide range of testing substrates, even the substrates bearing oxidation-sensitive groups such as MeS—, alkenyl and —NH 2 can also work well. In addition, the protocol is readily scaled up to more than 20 g and the product can be obtained just through filtration or distillation without conventional column chromatography.
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MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 9
·2547-2553
·
IF 4.831
Qu Fei,Sun Zhe,Liu Dongya,Zhao Xianen,You Jinmao
The authors describe dual-emission carbon nanodots containing blue emitters (BE; peak emission at 385nm under 315 nm excitation) and yellow emitters (YE; peak emission at 530 nm under 365nm excitation), and how they can be applied to direct and indirect determination of tetracyclines (TCs). The direct detection scheme is based on the finding that tetracycline (TET), oxytetracycline, chlortetracycline and doxycycline quench the two emissions of the carbon dots. While direct determination is rapid and convenient, it cannot differentiate between TCs. The indirect detection scheme, in contrast, is based on the finding that Al (III) ions enhance the fluorescence of the YE in the carbon dots, and that they cause a blue shift in emission. It is, however, known that TET forms a strong complex with Al (III), and this can inhibit the interaction between Al (III) and the YE, so that the fluorescence of YE is not enhanced and blue-shifted by Al (III) in the presence of TET. This finding is exploited in a fluorescence turn-on/off assay for TET that can distinguish TET from other TCs. The linear range of indirect determination for TET extends from 1 nM to 30 μM, and the limit of detection is 0.52 nM. The indirect method was successfully applied to the determination of TET in spiked milk, fish and pork, and recoveries ranged from 91.7 to 102 %.
High concentrations of tetracyclines quench the dual (blue and green) emission of carbon dots. Additionally, based on the fluorescence enhancement of yellow emitters by Al 3+ , an indirect turn-on/off detection of tetracycline is established with high selectivity and sensitivity.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 11
·11541-11547
·
IF 1.798
Liu Hongdong,Hu Zhongli,Ruan Haibo,Hu Rong,Su Yongyao,Zhang Lei,Zhang Jin
Owing to the high reversible capacity, low-cost, natural abundance and environmental friendliness, manganese dioxide (MnO 2 ) is recognized as one of the most appropriate and promising anode materials. In this work, nanostructured MnO 2 anode materials have been achieved via a hydrothermal method. The crystal structure, morphology and specific surface area of as-prepared MnO 2 are characterized by XRD, SEM and BET techniques. As anode materials for lithium-ion batteries, MnO 2 samples show high initial discharge capacity and relatively excellent cyclic performance. The electrochemical performance of MnO 2 samples is related to crystal structure and surface morphology. Monoclinic structure, it is similar to graphene, which is more convenient for the fast ionic transportation into the bulk of the electrode materials. And porous structure, which can accommodate volume expansion, shorten the electron and lithium ion diffusion pathway and provide a large number of electrochemical reactive sites for lithium ion insertion and extraction during cycling.
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Journal of Inorganic and Organometallic Polymers and Materials
·
2016
·Vol. 26
·期 5
·1101-1106
·
IF 1.308
Wang Xiaoshuo Wu Pengfei,Lu Siyuan Xu Pengpeng
A new copper coordination polymer, [Cu 2 L 4 (H 2 O) 2 ] n ( 1 ), (HL = 3-(pyridine-2-yl)benzoic acid) has been solvothermally synthesized by using the HL and CuCl 2 ⋅2H 2 O and characterized by IR spectra, elemental analysis, single-crystal and powder X-ray diffractions, and TGA. Compound 1 contains a well-known paddle-wheel unit [Cu 2 (COO) 4 ], which is connected to a three-dimensional supramolecular structure with pcu topology through the hydrogen bond interactions. Compound 1 displays considerable thermal stability and exhibits selective absorption in the visible region, which is shown by thermogravimetric analysis and solid-state UV–Vis diffuse-reflectance spectra, respectively. In addition, compound 1 represents an example of visible light driven photocatalyst based on coordination polymer and shows good degradation ability over Rhodamine B (RhB).
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 19
·19266-19280
·
IF 2.76
Yang Hui,Hu Yuanan,Cheng Hefa
Sorption of 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) on a range of dealuminated zeolites were investigated to understand the mechanism of their sorption on microporous minerals, while the influence of common metal cations, solution pH, and humic acid was also studied. Sorption of chlorophenols was found to increase with the hydrophobicity of the sorbates and that of the microporous minerals, indicating the important role of hydrophobic interactions, while sorption was also stronger in the micropores of narrower sizes because of greater enhancement of the dispersion interactions. The presence of metal cations could enhance chlorophenol sorption due to the additional electrostatic attraction between metal cations exchanged into the mineral micropores and the chlorophenolates, and this effect was apparent on the mineral sorbent with a high density of surface cations (2.62 sites/nm 2 ) in its micropores. Under circum-neutral or acidic conditions, neutral chlorophenol molecules adsorbed into the hydrophobic micropores through displacing the “loosely bound” water molecules, while their sorption was negligible under moderately alkaline conditions due to electrostatic repulsion between the negatively charged zeolite framework and anionic chlorophenolates. The influence of humic acid on sorption of chlorophenols on dealuminated Y zeolites suggests that its molecules did not block the micropores but created a secondary sorption sites by forming a “coating layer” on the external surface of the zeolites. These mechanistic insights could help better understand the interactions of ionizable chlorophenols and metal cations in mineral micropores and guide the selection and design of reusable microporous mineral sorbents for sorptive removal of chlorophenols from aqueous stream.
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高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2016
·Vol. 126
·期 2
·959-967
·
IF 1.781
Shen Chang-shuai,Zhou Cai-rong
The thermal decomposition kinetics of bezafibrate in a nitrogen atmosphere has been investigated by analyzer DTG-60. The thermal behavior of bezafibrate at the different heating rates 4, 8, 12, 16 and 20 °C min −1 displays two-stage decomposition processes among 500–650 K. The activation energy ( E ) and pre-exponential factor ( A ) were calculated to be 128.72 kJ mol −1 and 3.56 × 10 10 min −1 by Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, Doyle, Kissinger and Šatava–Šesták methods for the second-stage decomposition process. The results show that the non-isothermal thermal decomposition mechanism of bezafibrate is classified as three-dimensional diffusion model, and the integral and differential equations are \(g(\alpha ) = [1 - (1 - \alpha )^{1/3} ]^{2}\) and \(f(\alpha ) = \frac{3}{2}\left( {1 - \alpha } \right)^{{{\raise0.7ex\hbox{$2$} \!\mathord{\left/ {\vphantom {2 3}}\right.\kern-0pt} \!\lower0.7ex\hbox{$3$}}}} \left[ {1 - \left( {1 - \alpha } \right)^{{{\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 3}}\right.\kern-0pt} \!\lower0.7ex\hbox{$3$}}}} } \right]^{ - 1}{.}\) The enthalpy (Δ H
≠ ), entropy (Δ S
≠ ) and Gibbs free energy (Δ G
≠ ) were calculated to be 123.74 kJ mol −1 , −91.07 J mol −1 K −1 and 178.29 kJ mol −1 , respectively.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2017
·Vol. 33
·期 6
·876-881
·
IF 1.024
Su Ping,Chen Xiaonan,He Zhangjing,Yang Yi
Kanamycin is an aminoglycoside antibiotic used increasingly in human and veterinary medicine. However, kanamycin residues in food can cause serious side effects. Here we reported the preparation of polyclonal antibody and the development of an indirect competitive biotin-streptavidin-amplified-based enzyme-linked immunosorbent assay(BA-ELISA) that can sensitively and specifically detect kanamycin residues in milk and honey. The immunogen and coating antigen were synthesized by covalently linking kanamycin to carrier proteins using the carbodiimide method. The anti-kanamycin polyclonal antibodies were obtained from immunized rabbits. The key assay parameters were investigated and optimized. The results show that under optimum conditions, the limit of detection for kanamycin is 0.07 ng/mL and the IC 50 is 6.48 ng/mL. Cross-reactivity values of the antibody with four kanamycin analogues are all <1%. Trace amounts of kanamycin in milk and honey samples can be detected by this novel BA-ELISA method successfully with satisfactory recoveries of 91.0%—103.3%. The developed protocol was also validated against liquid chromatography-mass spectrometry, returning a significant correlation. These results indicate that BA-ELISA is a viable option for monitoring kanamycin residues in milk and honey.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 3
·2525-2536
·
IF 2.019
Huang Feng,Sui Yanwei,Wei Fuxiang,Qi Jiqiu,Meng Qingkun,He Yezeng
NiS x−n grown on the carbon cloth (NiS x−n //CC) were successfully prepared via a facile one-step hydrothermal technique by controlling initial S 2− /Ni 2+ molar ratio n . Serving as a supercapacitor electrode, the specific capacitance of Ni 3 S 4 //CC ( n = 3.0) has been measured to be 1340 F/g at a discharge density of 1 A/g. Also, the Ni 3 S 4 //CC displays an excellent long-time cycling stability (94.5%). Furthermore, the flexible all-solid-state supercapacitor device fabricated based on the Ni 3 S 4 //CC exhibits good supercapacitive performance with maximum power density of 6750 W/kg and superior cycling stability after 5000 continuous cycles (retention rate of cycling around 84.7%). These results indicate that the Ni 3 S 4 //CC is a promising and suitable electrode material for high-performance flexible all-solid-state supercapacitors.
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Biotechnology for Biofuels
·
2017
·Vol. 10
·期 1
·1-16
·
IF 5.203
Jiang Yongguang,Xiao Peng,Shao Qing,Qin Huan,Hu Zhangli,Lei Anping,Wang Jiangxin
Background Microalgae have been demonstrated to be among the most promising phototrophic species for producing renewable biofuels and chemicals. Ethanol and butanol are clean energy sources with good chemical and physical properties as alternatives to gasoline. However, biosynthesis of these two biofuels has not been achieved due to low tolerance of algal cells to ethanol or butanol. Results With an eye to circumventing these problems in the future and engineering the robust alcohol-producing microalgal hosts, we investigated the metabolic responses of the model green alga Chlamydomonas reinhardtii to ethanol and butanol. Using a quantitative proteomics approach with iTRAQ-LC–MS/MS technologies, we detected the levels of 3077 proteins; 827 and 730 of which were differentially regulated by ethanol and butanol, respectively, at three time points. In particular, 41 and 59 proteins were consistently regulated during at least two sampling times. Multiple metabolic processes were affected by ethanol or butanol, and various stress-related proteins, transporters, cytoskeletal proteins, and regulators were induced as the major protection mechanisms against toxicity of the organic solvents. The most highly upregulated butanol response protein was Cre.770 peroxidase. Conclusions The study is the first comprehensive view of the metabolic mechanisms employed by C. reinhardtii to defend against ethanol or butanol toxicity. Moreover, the proteomic analysis provides a resource for investigating potential gene targets for engineering microalgae to achieve efficient biofuel production.
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高影响因子
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2017
·Vol. 243
·期 12
·2265-2273
·
IF 1.664
Wang Xiaobin,Huang Wenqian,Zhao Chunjiang,Wang Qingyan,Liu Chen,Yang Guiyan
Raman hyperspectral imaging technology not only can acquire the image information of the sample; it also contains the Raman spectra information about each pixel. Due to the abundant information that the method provides, it has been applied to detect food safety. This study adopted line-scan Raman hyperspectral technology to quantify benzoyl peroxide (BPO) additive in flour. By analyzing the Raman spectra of BPO and flour, the 999 cm −1 Raman peak was selected for the detection and identification of BPO in flour. Savitzky–Golay filter and adaptive iteratively reweighted penalized least squares (airPLS) methods were used to de-noise and fluorescence correction of the original Raman signals. Binary image was established by 999 cm −1 single-band correction image and threshold segmentation, and this method was used to detect 11 mixture samples with different BPO additive concentrations. The results show that the BPO additives in the mixture samples can be detected, and the detected BPO pixels had a good linear relationship with the concentration of BPO in the mixture samples, correlation coefficient was 0.9902. The above results indicated that the method established in this paper can be applied to non-destructive quantitative detection of BPO additive in flour.
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