JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2018
·
IF 2.441
Qiong Lou,Jun Wen,Yuanying Jiang,Jinghua Huang,Guorong Fan,Fenyun Song
A reliable liquid chromatography/tandem mass (LC-MS/MS) method was developed for quantitation of 3′, 4′-dimethoxy flavonol-3-β- d -glucopyranoside (DF3G) in rat plasma using pantoprazole as the internal standard. An Agilent C18 column (100 mm × 3 mm, 3.5 μm) was performed for chromatographic separation with the mobile phase composed of methanol-water (containing formic acid) at a flow rate of 0.4 mL/min. A triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source in positive ion mode was applied to quantitative analysis by multiple reacting monitoring (MRM). The MRM precursor-product ion transition of DF3G and Pantoprazole (IS) were m / z 461.1 → 299.2 and 383.9 → 200.2, respectively. Calibration curves were recovered in a concentration range of 1–500 ng/mL for plasma with a limit of lower quantification (LLOQ) of 1 ng/mL. The intra-day and inter-day precision were not >10%. The accuracy of DF3G ranged from −10% to 0.53% in quality control (QC) samples at three concentrations. DF3G was not degraded during the analysis and the storage period. All the data were validated in accordance with the FDA bioanalytical method validation guideline. The LC-MS/MS method was successfully employed in the pharmacokinetic study of the DF3G after oral administration and intravenous injection in rats.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2012
·
IF 2.905
Xiaohua Zhu,Qifang Jiao,Chuyi Zhang,Xiaoxi Zuo,Xin Xiao,Yong Liang,Junmin Nan
The graphene and 5-[ o -(4-Bromine amyloxy) phenyl]-10,15,20-triphenylporphrin ( o -BrPETPP) composite (GR- o -BrPETPP) film is prepared on the glassy carbon electrode (GCE) with graphene oxide (GO) modifier through a consecutive cyclic voltammetry process, and then its electrocatalytic oxidation to indirubin is investigated. The as-prepared GR- o -BrPETPP film exhibits wrinkling paper-like structure and lower electron transfer resistance. In comparison with the o -BrPETPP/GCE and GCE, the GR- o -BrPETPP film electrode prepared for five cycles indicates an excellent electrocatalytic oxidation activity toward indirubin with about 2.2 and 13.3 times higher current response, respectively. In addition, in the 0.1 mol L −1 acetate buffer solution (pH = 4.6), the film electrode displays a linear relationship between the oxidation current and the indirubin concentration in the range from 5.0 × 10 −7 mol L −1 to 2.4 × 10 −5 mol L −1 , and presents a detection limit of 1.0 × 10 −7 mol L −1 ( S / N = 3) by differential pulse voltammetry (DPV) with 220 s accumulation. Especially, this film electrode also shows a comparative sensitivity with high-performance liquid chromatography (HPLC) for the determination of the indirubin extractive of herbal medicines, showing its practical prospect in the electrochemical determination of indirubin.
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Food Analytical Methods
·
2016
·Vol. 10
·期 1
·111-117
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IF 2.167
Liu Qi,Wang Li,Hu Jie,Miao Yanni,Wu Zixue,Li Jianrong
A rapid and sensitive analytical method for the determination of main organic acids in wines was developed by capillary electrophoresis (CE) with indirect UV detection. Separation parameters including the pH of electrolyte, chromophore, and its concentration were optimized. The results showed that the optimal electrolyte for the separation of organic acids consisted of 10 mmol L −1 2, 4-dihydroxybenzoic acid (DHBA) at pH 3.6 containing 0.4 mmol L −1 cetyltrimethlammonium bromide (CTAB). DHBA as chromphore was selected based on the close mobility to the analyte and relatively large molar extinction coefficient. The method showed good linearity with limits of detection (LOD), ranging from 0.5 to 7.5 mg L −1 . The relative standard deviation (RSD) of interday precisions for the peak area and the migration time were less than 7.2 and 0.8 %, respectively. The recoveries of the analyte in Chinese rice wine sample were between 90.3 and 106.9 % with RSD ranging from 1.4 to 8.9 %. The method was successfully applied to the commercial rice wine and beer samples with dilution and filtration.
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EUROPEAN POLYMER JOURNAL
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2016
·
IF 3.485
Quan Yuan,Guo-Hua Sun,Ke-Fei Han,Jing-Hua Yu,Hong Zhu,Zhong-Ming Wang
A series of copolymers, which can also be regarded as ABPBIs containing phenoxyl in the main chain, were synthesized by copolymerization of two kinds of self-polycondensation monomers: 3,4-diaminobenzoic acid (DABA) and 4-(3,4-diamino-phenoxy)-benzoic acid (DPBA). The phenoxyl-containing ABPBIs exhibit better processability and acid stability than original ABPBI, despite their affinities towards acid decrease with the addition of phenoxyl moieties. By adjusting the phenoxyl content of the polymer, we made a tradeoff between acid doping levels and proton conductivity, with mechanical properties. The optimal polymer therein, PO-AB-50 (50 M percentages of DPBA in total monomers), exhibits considerable proton conductivity (53.47 mS/cm at 160 °C) and tensile strength (1.9 MPa) after doped with phosphoric acid. In addition, the oxidation stability, water uptake and swell ratio properties of the polymers were also improved with the introduction of phenoxyl moieties.
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DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 45
·15836-15847
·
IF 4.029
Liguang Dou,Yanna Wang,Yangguang Li,Hui Zhang
A series of novel hierarchical nanocomposite catalysts xCu@Cu2O/MgAlO-rGO were fabricated by calcination of CuxMg3−xAl-LDH/rGO precursors (LDH: layered double hydroxide, rGO: reduced graphene oxide, and x = 0.5, 1.0, and 1.5), obtained by a facile citric acid-assisted coprecipitation route, under a N2 flow upon in situ self-reduction of lattice atomic-dispersed Cu2+ by rGO. Systematic characterization reveals highly dispersed core–shell-like Cu@Cu2O nanoparticles near the border between vertically interconnected mixed oxide MgAlO nanoplates and rGO layers. All the obtained catalysts show extraordinary catalytic performances for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at room temperature. The 1.0Cu@Cu2O/MgAlO-rGO shows the highest activity for complete conversion of 4-NP with an apparent rate constant (kapp) of 55.3 × 10−3 s−1, a normalized rate constant (knor) of 14 497 s−1 g−1 on an active Cu content, and an unprecedented recycling stability for 25 successive cycles, which are superior to those of the recently reported Cu- and Co-based metal nanoparticles and even compared favourably with those of the most active noble metal catalysts. The superior activity of 1.0Cu@Cu2O/MgAlO-rGO can be attributed to the highly dispersed core–shell-like Cu@Cu2O nanoparticles and the greatly enhanced four-phase synergistic effect among Cu, Cu2O, MgAlO and rGO upon calcination. Moreover, 1.0Cu@Cu2O/MgAlO-rGO shows an excellent efficiency in the fixed bed system for the treatment of simulated industrial effluents containing nitrophenols and organic dyes. The present cost-effective, highly efficient and reusable non-noble metal nanocatalyst would open a new pathway for future water remediation.
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TALANTA
·
2017
·
IF 4.162
Xiaofang Ma,Yali Wu,Samrat Devaramani,Caizhong Zhang,Qixia Niu,Mahgoub Ibrahim Shinger,Wenqi Li,Duoliang Shan,Xiaoquan Lu
The GO-COOH/AuNPs/ZnAPTPP nanocomposites were constructed using zinc monoamino porphyrin (ZnAPTPP) through π–π conjugation with carboxylated graphene oxide (GO-COOH) loaded with Au nanoparticles (AuNPs). Prepared materials were characterized by 1 H NMR spectra, UV–vis absorption spectroscopy and electrochemical impedance spectroscopy . ITO electrode surface was modified with the prepared nanocomposites showed a good photocurrent response when the bias potential, −0.1 V was applied. Nanocomposites modified ITO electrode exhibited good photo-response to the 4-nitrophenol (4-NP). ZnAPTPP were excited from HOMO to LUMO under light irradiation , the photoexcited electrons injected into the conduction band of GO-COOH, and then transferred to AuNPs further to the ITO. The presence of GO-COOH and AuNPs improved the separation of photogenerated charges due to their synergetic effect and excellent conductivity. Externally added 4-NP scavenges the photogenerated holes i.e. it acts as a sacrificial electron donor thereby it enhances the photocurrent of the system. Based on this interaction, a novel method for photoelectrochemical detection of 4-NP was developed with a linear range from 0.1 to 15 nmol/L (r = 0.996) and detection limit of 0.04 nmol/L (S/N = 3). Proposed method is simple and sensitive and this was successfully applied for the quantification 4-NP in river water sample matrices.
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RSC Advances
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2015
·Vol. 5
·期 91
·74977-74985
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IF 3.84
Xin Xiao,Shunheng Tu,Chunxia Zheng,Huan Zhong,Xiaoxi Zuo,Junmin Nan
Large-scale synthesis of nanosized β-Bi2O3 is a significant challenge due to its metastable state. A facile L-asparagine-assisted reflux–calcination route was successfully developed for the large-scale preparation of β-Bi2O3 micro/nanostructures under mild conditions (low temperature, atmospheric pressure, and wide temperature windows). The composition, phase structure, morphology, surface area, and photoabsorption properties of as-synthesized β-Bi2O3 and its precursor were systematically characterized. The phase transformation conditions and possible formation mechanism of flower-like β-Bi2O3 were discussed. It is found that with a simple reflux process under atmospheric pressure at 100 °C, uniform monodisperse bismuth–asparagine complex microspheres with average diameters of ∼500 nm were produced and flower-like β-Bi2O3 micro/nanostructures were then conveniently obtained after precursor calcination at temperatures ranging from 340 °C to 420 °C. A surface CO32− coordination effect introduced from L-asparagine explained the formation of stabilized β-Bi2O3 at low temperatures (up to 420 °C). The as-synthesized β-Bi2O3 shows excellent photocatalytic activity toward the degradation of 4-phenylphenol under visible-light irradiation, which is 3.7 and 21.4 times faster than the removal rates of β-Bi2O3 nanospheres and a commercial β-Bi2O3, respectively, and allows for the elimination of 93.2% total organic carbon after 60 min of irradiation. In addition, the photogenerated reactive species were identified by radical scavenger experiments and electron paramagnetic resonance spectroscopy, and a possible visible-light-induced photocatalytic mechanism was then proposed.
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EUROPEAN POLYMER JOURNAL
·
2014
·
IF 3.242
Bolin Li,Xiaolin Lu,Yonghao Ma,Zhan Chen
A novel thermo- and pH-responsive poly(acrylic acid) (PAA)/poly(4-vinylpyridine) (P4VP) aqueous material with an upper critical solution temperature (UCST) was developed in this study. It was found that the formation of the aqueous complex material was caused by the deprotonation of pyridinium groups of P4VP molecules and consequent hydrogen bonding formation between pyridine and carboxylic groups. This aqueous material exhibited significant reversible transition behaviors between the turbid colloidal and transparent solution states upon altering the pH and temperature values. Furthermore, the correlation between the solution pH and the upper critical solution temperature (UCST) enables us to design responsive aqueous materials with a broadly adjustable transition temperature range.
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Food Analytical Methods
·
2013
·Vol. 7
·期 7
·1381-1386
·
IF 1.969
Ma Xiaoxing,Wang Juntao,Wu Qiuhua,Wang Chun,Wang Zhi
A new analytical method by graphene-reinforced hollow fiber liquid-phase microextraction combined with high-performance liquid chromatography fluorescence detection was developed for the determination of bisphenol A and 4- tert -butylphenol in bottled juices. Several important experimental parameters were studied to get optimal extraction conditions for the analytes. Under the optimized conditions, the method showed a good performance having a linear response in the range from 0.05 to 10.0 ng mL −1 with the correlation coefficients ( r ) of 0.9965–0.9994 and limits of detection of 0.01 ng mL −1 . The relative standard deviations were in the range from 6.4 to 7.2 % at the spiked concentration of 1.0 ng mL −1 . The method combines the high-adsorption capacity of graphene and the excellent clean-up performance of hollow fiber liquid-phase microextraction and has been successfully applied to the analysis of the analytes in bottled juice samples.
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JOURNAL OF MEMBRANE SCIENCE
·
2017
·
IF 6.035
Ruijun Zhang,Shuili Yu,Wenxin Shi,Wei Wang,Xiaoying Wang,Zhiqiang Zhang,Li Li,Bing Zhang,Xian Bao
In order to integrate the advantages of polyamide thin film composite (TFC) nanofiltration (NF) membranes and that of polyester TFC NF membranes, a novel polyesteramide (PEA) TFC NF membrane was prepared by interfacial polymerization between serinol and trimesoyl chloride (TMC) and catalyzed by 4-dimethylaminopyridine (DMAP) on a flat-sheet polyethersulfone (PES) substrate membrane. The membrane performance was maximized by optimizing different preparation parameters. The reaction process was divided into four basic patterns. X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy confirmed the membrane had a partially cross-linked active layer that contained ester bonds, amide bonds and residual hydroxyl groups. Morphology analysis showed the surface of the PEA-TFC-NF membrane was grainy, which was different from the typical polyamide membranes. The contact angle and zeta potential measurements confirmed the PEA-TFC-NF membrane was highly hydrophilic and negatively charged across the entire pH range tested. The optimized PEA-TFC-NF membrane had a MWCO of 474 Da and water permeability of 6.0 L m −2 h −1 bar −1 at 0.5 MPa and 25 °C. The membrane salt rejections followed the order of Na 2 SO 4 > MgSO 4 > NaCl > MgCl 2 , which were 96.27%, 83.92%, 58.68% and 28.76%, respectively. Moreover, the PEA-TFC-NF membrane displayed good antifouling ability.
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JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2024
·
IF 8
Yan Xu
The pursuit of clean energy generation and environmental preservation is of utmost importance for societal progress. However, couple clean energy production and pollution control is still a difficulty. In this study, a novel electrospun composite mat, with nano zero valent iron (Fe 0 , nZVI) encapsulated into polyacrylonitrile (PAN) nanofibers was acted as a catalyst. The activation energy (E a ) for the hydrolysis of NaBH 4 to produce hydrogen is 22 kJ·mol −1 , hydrogen atom utilization efficiency (HGE) of NaBH 4 is 60.80%. Three kinds of organic dyes 4-nitrophenol (4-NP), methylene blue (MB), and Rhodamine B (RhB) were served as the model pollutant, to construct NaBH 4 -organic system for energy production and pollution reduction. The NaBH 4 -organic system demonstrates a collaborative capability to simultaneously remove organic pollutants and generate hydrogen, with a coupling equilibrium point between the two processes. The hydrogen generation rate (HGR) and HGE increased with the concentration of pollutants increased. The degradation of 4-NP, MB, and RhB followed pseudo-first-order kinetics, with RhB degrading dosage 20 and 44 times higher than 4-NP and MB, respectively. H 2 and H· contributed to the organic degradation. nZVI directly participated in the formation H 2 and H·. PAN@Fe 0 possessed good recyclability and moderate cost. The degradation process adhered to the classical surface reaction controlled Langmuir-Hinshelwood (L-H) model. The integration of synergistic production capacity and pollutant degradation aligns well with the principles of green chemistry and sustainable development. This study demonstrates a novel approach to no precursor loss catalysts preparation, efficient production clean H 2 , advanced treatment of dye-containing wastewater, carbon neutral operation of sewage treatment plant.
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Microbiome
·
2025
·Vol. 13
·期 1
·1-26
·
IF 12.7
Li Daojie,Meng Kun,Liu Guohua,Wen Zhiguo,Han Yunsheng,Liu Weiwei,Xu Xin,Song Liye,Cai Hongying,Yang Peilong
Background Fatty liver hemorrhage syndrome (FLHS) has become one of the major factors leading to the death of laying hen in caged egg production. FLHS is commonly associated with lipid peroxidation, hepatocyte injury, decreased antioxidant capacity, and inflammation. However, there are limited evidences regarding the preventive effect of Lactiplantibacillus plantarum on FLHS in laying hens and its mechanisms. Our previous results showed that Lp. plantarum FRT4 alleviated FLHS by regulating lipid metabolism, but did not focus on its antioxidant and anti-inflammatory functions and mechanisms. Therefore, this study aimed to investigate the preventive mechanisms of Lp. plantarum FRT4 in alleviating FLHS, with a focus on its role in antioxidant activity and inflammation regulation. Results Supplementation with Lp. plantarum FRT4 enhanced the levels of T-AOC, T-SOD, and GSH-Px, while reducing the levels of TNF-α, IL-1β, IL-8, and NLRP3 in the liver and ovary of laying hens. Additionally, Lp. plantarum FRT4 upregulated the mRNA expressions of SOD1 , SOD2 , CAT , and GPX1 , downregulated the mRNA expressions of pro-inflammatory factors IL-1β , IL-6 , and NLRP3 , and upregulated the mRNA expressions of anti-inflammatory factors IL-4 and IL-10 . Lp. plantarum FRT4 improved the structure and metabolic functions of gut microbiota, and regulated the relative abundances of dominant phyla (Bacteroidetes, Firmicute, and Proteobacteria) and genera ( Prevotella and Alistipes ). Additionally, it influenced key KEGG pathways, including tryptophan metabolism, amino sugar and nucleotide sugar metabolism, insulin signaling pathway, FoxO signaling pathway. Spearman analysis revealed that the abundance of microbiota at different taxonomic levels was closely related to antioxidant enzymes and inflammatory factors. Furthermore, Lp. plantarum FRT4 modulated the mRNA expressions of related factors in the FoxO / TLR - 4 / NF-κB signaling pathway by regulating gut microbiota. Moreover, the levels of E 2 , FSH, and VTG were significantly increased in the ovary after Lp. plantarum FRT4 intervention. Conclusions Lp. plantarum FRT4 effectively ameliorates FLHS in laying hens. This efficacy is attributed to its antioxidant and anti-inflammatory properties, which are mediated by modulating the structure and function of gut microbiota, and further intervening in the FoxO / TLR - 4 / NF-κB signaling pathway. These actions enhance hepatic and ovarian function and increase estrogen levels.
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危险品化学品经营许可证（带存储）