Food Analytical Methods
·
2021
·Vol. 14
·期 4
·797-804
·
IF 3.366
Zhang Liqun,Wu Leyi,Wu Pinggu
Pollution of foods with chloropropanol fatty acid esters is a growing international food safety issue, especially contamination with 3-monochloropropane-1, 2-diol (3-MCPD) esters. Traditional GC/MS method using phenylboronic acid (PBA) as a derivatization reagent has been proven to be high selective. However, the disadvantage of this method is that excessive amounts of phenylboronic acid causes the formation of triphenylboroxin that may lead to instrument fouling and reduces the sensitivity of this 3-MCPD detection method. The objective of this study was to optimize a solid phase extraction method after the phenylboronic acid derivatization to illimate the triphenylboroxin formed form excess PBA treatment, and to provide an instrument-friendlier GC-MS method for the detection of 3-MCPD in camellia oil. Different solid phase extraction methods were compared, and (n-propyl)ethylenediamine (PSA) column was selected for its selective in the absorption of fatty acid of ethylenediamine-N-propyl (PSA). Good linearity for 3-MCPD esters detection was found within the concentration range of 0.2 to 10 mg/kg ( r 2 = 0.9992). The limits of detection (LOD) and the limits of quantification (LOQ) were 0.05 mg/kg and 0.10 mg/kg, respectively. The average recoveries of 3-MCPD esters spiked at 0.25 mg/kg, 1 mg/kg, and 5 mg/kg in pressed camellia oil ranged from 98.83 to 108.79% with a relative standard deviation less than 10%. When this method was applied to the detection of 3-MCPD esters in commercially available camellia oil samples, high amounts of 3-MCPD were present in refined camellia oil samples: the mean content was 1.33 mg/kg, ranging from < 0.034 to 5.47 mg/kg.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Xiaomei Qin,Yapei Chen,Shihao Yang,Xiaoyun Qin,Jianbo Zhao,Wenjun Fang
Measurements on densities, viscosities, and refractive indices at atmospheric pressure for binary mixtures of 1,3-dimethyladamantane (1,3-DMA), 1,3,5-trimethyladamantane (1,3,5-TMA), and 1-ethyladamantane (1-EA) with n-nonane or n-undecane are carried out over the whole composition range at temperatures T = 293.15–343.15 K and atmospheric pressure. The excess molar volume (VmE), deviation in viscosity (Δη), deviation in refractive index (ΔnD), and deviation in molar refraction (ΔR) for the six mixtures are calculated and then fitted to the Redlich–Kister polynomial. The VmE values are all negative over the entire range of mole fractions and decrease with increasing temperature for the six binary systems. The absolute values of Δη for the mixtures decrease obviously with increasing temperature. The ΔnD values with the volume fraction for the six systems are all positive over the entire composition range. Density, viscosities, and refractive index of the six systems are correlated by the Jouyban–Acree model. The experimental results could be useful for the development of high-energy-density hydrocarbon fuels.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Baihui Chi,Jingyi Zou,Haixia Pan,Xianliang Yi,Yang Liu,Xuwang Zhang,Zhiqiang Zhao,Jingjing Zhan,Hao Zhou
The challenge posed by the chemical stability of N,N-dimethylformamide (DMF) renders its biological treatment a complex endeavor. Despite the isolation and characterization of numerous DMF-degrading bacterial strains, their limited adaptability to diverse environments has resulted in suboptimal efficacy in the treatment of actual DMF-containing wastewater. This research aims to address this predicament by employing a “top-down” approach to engineer a synthetic bacterial community termed DMF syn . The mineralization of 0.5 % (v/v) DMF (∼4725 mg L −1 ) was efficiently carried out by DMF syn within 4 days. Notably, robust DMF degradation capabilities across a broad spectrum of environmental conditions were observed. In scenarios where N,N-dimethylacetamide (DMAC) and N-methylpyrrolidone (NMP) coexisted with DMF, degradation followed a sequential pattern: NMP > DMAC > DMF. Through 16S rRNA gene sequencing, and metagenomic analysis, potential functional genes and species responsible for DMF degradation were unveiled. The active DMF degraders in DMF syn , including Paracoccus aminovorans bin8, Hyphomicrobium sulfonivorans bin2, Hyphomicrobium zavarzinii bin0, Paracoccus zhejiangensis bin23, and Aquamicrobium lusatiens e bin4, were substantiated by metaproteomic analysis. Furthermore, another DMF-mineralizing bacterium Aminobacter niigataensis DMFA1 was isolated from DMF syn . Molecular dynamics simulations indicated that the preference for DMAC over DMF at the community level is dictated by the substrate specificity of DMFases from Sphingosinicella microcystinivorans bin6. By harnessing a multi-omics approach, conducting pure culture studies, and employing molecular simulations, an intricate mechanism governing DMF degradation and substrate preference within the DMF syn was elucidated.
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ACS Catalysis
·
2023
·
IF 12.9
Yun Wang,Mengting Chen,Kaiyue Zhang,Haimei Wu,Jiale Wang,Yuran Cheng,Yingxin Liu,Zuojun Wei
Highly efficient transformation of renewable biomass and its derivatives into high-value-added chemicals and biofuels over non-noble-metal catalysts is attractive but challenging. Herein, we developed non-noble CoNi alloy nanoparticles confined in N-doped porous carbon (CoNi@NC) via simple pyrolysis of the metal–organic framework (MOF) precursor at 900 °C under an inert atmosphere. The as-obtained CoNi@NC catalyst exhibited higher performance than monometallic Co@NC and Ni@NC catalysts in the reductive amination of levulinic acid (LA) with benzylamine to N-benzyl-5-methyl-2-pyrrolidinone (BMP) under mild conditions of 130 °C and 3 MPa H2 for 6 h, achieving a full conversion of LA and a ≥ 99% yield of BMP. Detailed characterizations substantiated that multifunctional support and the significant synergistic effect between Co and Ni markedly enhanced the catalytic performance. Furthermore, CoNi@NC manifested outstanding recyclability (reusable 20 cycles without loss of activity), which was attributed to the well-dispersed CoNi alloy nanoparticles confined in the N-doped porous carbon and the anchoring of N species to metal nanoparticles. Additionally, the resultant CoNi@NC catalyst can be successfully applied in the one-pot transformation of LA/esters with amines/nitroarenes/nitriles to the corresponding N-substituted pyrrolidones, as well as the reductive amination of other carbonyl compounds with benzylamine to form N-heterocyclic compounds. Moreover, CoNi@NC enabled us to catalyze the continuous reductive amination of LA with amines in a trickle-bed reactor, which is a more promising, efficient, highly atomically economic, and green synthetic methodology, and exhibited excellent stability during the reaction over 36 h.
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RSC Advances
·
2016
·Vol. 6
·期 42
·35952-35965
·
IF 3.289
Qian Gan,Chun-Lian Zhang,Bing-Feng Wang,Ya-Hong Xiong,Yin-Lian Fu,Zong-Wan Mao,Xue-Yi Le
Two novel mononuclear mixed ligand copper(II) complexes, [Cu(Gly-L-val)(HPB)(H2O)]·ClO4·1.5H2O (1) and [Cu(Gly-L-val)(PBT)(H2O)]·ClO4 (2) (Gly-L-val = glycyl-L-valine, HPB = 2-(2′-pyridyl)benzimidazole, PBT = 2-(2′-pyridyl)benzothiazole), have been synthesized and characterized using various analytical and spectroscopic methods. The interactions of the complexes with DNA have been explored by viscometry, thermal denaturation, cyclic voltammetry (CV), agarose gel electrophoresis and spectroscopic means (UV absorption, circular dichroism (CD) and fluorimetry), as well as molecular docking techniques. These studies confirmed the mode of the complexes bound to calf thymus DNA (CT-DNA) through insertion with certain affinity (Kb = 3.211 × 105 M−1 for 1 and 4.734 × 104 M−1 for 2). In the fluorimetric experiments of thermodynamics (KSV = 1.145 × 104 M−1 for 1 and 2.634 × 103 M−1 for 2), the changes in enthalpy (ΔH > 0), entropy (ΔS > 0) and Gibbs free energy (ΔG < 0) in the interactions between the complexes with DNA suggested that the process occurred spontaneously through hydrophobic interactions. The complexes displayed oxidative cleavage of pBR322 plasmid DNA in the presence of ascorbic acid, probably induced by ˙OH as a reactive oxygen species. Furthermore, the molecular docking technique was applied to ascertain the mode of action for the complexes towards DNA. Moreover, superoxide dismutase (SOD) activity studies were performed using the photoreduction of nitroblue tetrazolium (NBT) under a non-enzymatic system and the antioxidant activities of 1 and 2 determined with IC50 values of 0.337 and 0.146 μM, respectively. The cytotoxicity of the Cu(II) complexes against A549, HeLa, PC-3 tumor cell lines and NIH3T3 (non-tumor cell line) was studied by an MTT assay and it was found that 1 exhibited better cytotoxicity against A549 and PC-3 than 2 and the widely used drug cisplatin.
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JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Wen Song,Xinyu Xiao,Guanlong Wang,Xiaoli Dong,Xiufang Zhang
Supporting Fe catalysts on N doped carbon (Fe-N-C) renders a promising way towards peroxymonosulfate (PMS) activation for water decontamination , but constructing high-efficiency Fe-N-C remains challenging due to the insufficient understanding of the structure-performance relationship. Herein, the N doped carbon nanotube supported Fe catalysts (Fe-NCNT) were prepared towards PMS activation for organic pollutants removal, in which the Fe-N coordination number and Fe species were tuned through changing the pyrolysis temperature to study their roles in PMS activation. Results showed increasing the pyrolysis temperature converted the Fe-N 4 structure in Fe-NCNT to low-coordinated Fe-N 3 structure and produced Fe nanoparticles (FeNP, encapsulated in carbon). The Fe-NCNT with Fe-N 3 and FeNP exhibited a remarkably high specific activity (0.119 L min −1 m −2 ), which was 1.8 times higher than that of Fe-NCNT with only Fe-N 4 and obviously outperformed those of the state-of-the-art PMS activators. The low-coordinated structure and FeNP promoted the PMS reduction on Fe 2+ of Fe-N x for •OH and SO 4 •− production, which served as major oxidants for pollutants degradation . The experimental results and theoretical calculation corroborated the low-coordinated structure and FeNP jointly enhanced the PMS adsorption and electron density on Fe center, which accelerated electron transfer from Fe center to PMS for radical production.
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DRUG METABOLISM AND DISPOSITION
·
2018
·
IF 3.64
Danyi Lu,Dong Dong,Qian Xie,Zhijie Li,Baojian Wu
UDP-glucuronosyltransferases (UGTs) play an important role in metabolism and detoxification of amine-containing chemicals. However, the disposition mechanisms for amines via UGT metabolism are not fully clear. Here we aim to investigate a potential role of UGT2B10 in N-glucosidation, and to determine the transporters for excretion of N-glucosides. We first established a HEK293 cell line stably overexpressing UGT2B10. Incubation of mianserin or cyclizine with the cells generated one N-glucuronide and one N-glucoside. Chemical inhibition (using specific chemical inhibitor Ko143) and biological inhibition (using specific shRNA) of BCRP resulted in a significant reduction in efflux of N-glucuronide. Similar results were observed when MRP4 was inhibited. Furthermore, inhibition of BCRP led to increased intracellular N-glucoside, whereas inhibition of MRP4 caused no changes in disposition of N-glucosides. The data overall indicated that BCRP not MRP4 was responsible for excretion of N-glucosides, whereas both BCRP and MRP4 contributed to excretion of N-glucuronides. Interestingly, down-regulation of N-glucuronidation led to increased N-glucosidation in the cells, supporting the glucosidation as a potential complementary pathway for conventional glucuronidation. In conclusion, UGT2B10 was for the first time identified as a N-glucosidation enzyme. Generated N-glucosides were excreted primarily by the BCRP transporter.
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RSC Advances
·
2016
·Vol. 6
·期 64
·58970-58978
·
IF 3.289
Jun Yuan,Heng Li,Yong Gao,Duanguang Yang,Yijiang Liu,Huaming Li,Shaorong Lu
A robust method for the synthesis of well-defined polyurethane-graft-poly(N,N-dimethylacrylamide) (PU-g-PDMA) copolymers with good control over the graft density and the grafted chain length was presented in this study. Firstly, a functional polyurethane (fPU) polymer with lateral trithiocarbonate-based chain transfer agent group was synthesized by the polyaddition reaction of 2,2-bis(hydroxymethyl)butyl 2-(ethylthiocarbonothioylthio)-2-methylpropanoate (BEMP) with hexamethylene diisocyanate (HDI), and the subsequent chain extension reaction with 1,4-butanediol (BDO). The content of the chain-transfer groups in the synthesized fPU could be well tuned by altering the mole ratio of BEMP to HDI during the synthesis of the prepolymer. The produced fPU was then applied as the macro-RAFT agent to mediate the radical polymerization reaction of the N,N-dimethylacrylamide (DMA) monomers that were initiated by azobisisobutyronitrile (AIBN), resulting in well-defined amphiphilic PU-g-PDMA graft copolymers with a known graft density and tunable grafted chain lengths. The structure of the obtained PU-g-PDMA was characterized carefully using FTIR and 1H NMR. The average molecular weight and polydistribution of PU-g-PDMA copolymers were analyzed by GPC. The thermal properties of fPU and PU-g-PDMA copolymers were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The amphiphilic PU-g-PDMA graft copolymers could self assemble into spherical nanoparticles with a core–shell structure in water. The core–shell structured nanoparticles could be applied as emulsifiers for the formation of stabilized toluene-in-water Pickering emulsions, and an extremely low content of emulsifiers (∼0.01%) relative to the total weight of oil and water was required.
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MICROCHIMICA ACTA
·
2014
·Vol. 181
·期 11
·1215-1221
·
IF 3.719
Pan Zhong-Qin,Xie Jing,Liu Xiao-Jun,Bao Ning,Gu Hai-Ying
We report on a new whole cell biosensor for hydrogen peroxide. A chitosan-coated glassy carbon electrode (GCE) was modified with poly(N,N-diethylacrylamide) (PDEA) hydrogel containing human red blood cells (RBCs). The morphology of RBCs in the hydrogel was investigated using scanning electron microscopy (SEM). Fourier transform infrared spectroscopy and SEM were applied to study the association of the PDEA chains and RBCs. Uncompromised bioactivity of native human hemoglobin in the RBCs on the modified GCE was confirmed by cyclic voltammetry. The modified electrode showed a faster electron transfer rate and better electrocatalytic activity in the reduction of H 2 O 2 than previously reported sensors. A linear relationship is found between the response to H 2 O 2 and its concentration in the range from 0.11 μM to 12.7 mM. The detection limit is 55 nM at an SNR of 3. It is assumed that the improvement of the biosensor results from the porosity and conductivity of the PDEA hydrogel.
With the presence of poly(N,N-diethylacrylamide) chains, our novel red blood cells based biosensor displays a fast electron transfer rate and excellent electrocatalytic activity to H 2 O 2 . It responds to H 2 O 2 in the concentration range from 0.11 μM to 12.7 mM, and the detection limit is 55 nM (at an SNR of 3).
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JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Chunyu Liu,Xingchen Zhao,Liqiong Guo,Qilin Yu,Weifei Zhang,Zijuan Peng,Yan Gao,Xiaoyun Gong,Penghui Li,Hui Jiao,Tao Zhou,Qinghe Zhang,Shanjun Song,Guibin Jiang
With increasing concerns about N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) and 6PPD-quinone (6PPD-Q), relevant environmental investigations and toxicological research have sprung up in recent years. However, limited information could be found for human body burden assessment. This work collected and analyzed 200 samples consisting of paired urine and plasma samples from participants (50 male and 50 female) in Tianjin, China. Low detection frequencies (DF, <15 %) were found except for urinary 6PPD-Q (86 %), which suggested the poor residue tendency of 6PPD and 6PPD-Q in blood. The low DFs also lead to no substantial association between two chemicals. Data analysis based on urinary 6PPD-Q showed a significant difference between males and females ( p < 0.05). No significant correlation was found for other demographic factors (Body Mass Index (BMI), age, drinking, and smoking). The mean values of daily excretion (ng/kg bw/day) calculated using urinary 6PPD-Q for females and males were 7.381 ng/kg bw/day (female) and 3.360 ng/kg bw/day (male), and apparently female suffered higher daily exposure. Further analysis with daily excretion and ALT (alanine aminotransferase)/TSH (thyroid stimulating hormone)/ blood cell analysis indicators found a potential correlation with 6PPD-Q daily excretion and liver/immune functions. Considering this preliminary assessment, systematic research targeting the potential organs at relevant concentrations is required.
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DYES AND PIGMENTS
·
2024
·
IF 4.1
Xiang Long,Hongxiang Liu,Jing Hu,Shaogui Wu
Herein, we report a facile one-step solvothermal synthesis of nitrogen and sulfur co-doped fluorescent carbon dots (N,S-CDs) using benzoic acid as the carbon source and sulfonamide as the doping agent. The synthesized N,S-CDs exhibit stable photoluminescence with an impressive fluorescence quantum yield of 16.8 %. These N,S-CDs maintain their luminescent properties under various challenging conditions, including high salt concentrations, elevated temperatures, UV radiation exposure, acidic or alkaline environments, long-term storage, and different solvents. Notably, the photoluminescence of N,S-CDs is excitation-wavelength dependent, with emission wavelengths tunable from 470 nm to 585 nm. Furthermore, the N,S-CDs display distinct fluorescent hues in aqueous and ethanolic media, presenting a novel dual-switch anti-counterfeiting ink system. Leveraging the sensitivity of N,S-CDs to gentamicin, we have developed a facile and rapid detection method for this antibiotic, which has been successfully applied to the analysis of authentic milk samples. This research contributes a novel and efficient protocol for the fabrication of high-performance carbon dots, thereby expanding their potential applications in food analysis and anti-counterfeiting technologies.
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DALTON TRANSACTIONS
·
2016
·Vol. 45
·期 47
·19062-19071
·
IF 4.177
Guang-Ning Liu,Ke Li,Qing-Shun Fan,Hui Sun,Xin-Yu Li,Xiao-Nan Han,Yu Li,Zhen-Wei Zhang,Cuncheng Li
Solvothermal reactions of AgI with the vulcanization accelerator 2,2′-dibenzothiazolyl disulfide and hydroiodic acid in alcohols afford two hybrid iodoargentates with one-dimensional structures, namely (Et2mbt)[Ag2I3] (1, Hmbt = 2-mercaptobenzothiazole) and {(Hmbt)[AgI]}n (2). The syntheses of both 1 and 2 involve unprecedented multiple in situ reactions. Specifically, a simultaneous disulfide bond cleavage, N and S donor atoms bialkylation, and self-assembly reaction lead to 1 that contains a discrete N,S-biethylated cation (Et2mbt)+ and a rare inorganic (Ag2I3)− anionic chain, while a simultaneous disulfide bond cleavage, N-protonation and self-assembly reaction affords 2 which features zwitterionic Hmbt molecules coordinating with the opposite side Ag atoms of a neutral inorganic (AgI)n chain via forming Ag–S coordination bonds. The simultaneous alkylation on a thiazolyl-N donor and a thiol-S donor atom for a thiazolyl-based heterocycle using inexpensive alcohols and haloids under solvothermal conditions instead of traditional two-step organic synthesis was found for the first time. The two compounds have band gaps of 2.95 eV for 1, and 2.78 eV for 2 exhibiting an observed blue shift compared with bulk AgI. Also, 1 and 2 can be used as effective heterogeneous photocatalysts for methyl orange dye treatment under UV light irradiation.
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