Foods
·
2023
·Vol. 12
·期 15
·2875
·
IF 5.2
Yibo Dong,Xiaolong Yao,Wanping Zhang,Xiaomao Wu
3,4-dichloroaniline (3,4-DCA) and 3,5-dichloroaniline (3,5-DCA) are, respectively, the primary metabolites deriving from the breakdown of phenylurea herbicides and dicarboximide fungicides in both soils and plants, whose residues in vegetable products have a heightened concern considering their higher health risks to humans and greater toxicity than the parent compounds in the environment. In this study, a sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous determination of 3,4-DCA and 3,5-DCA residues in chive products based on the optimization of HPLC-MS/MS chromatographic and mass-spectrometric conditions using the standard substances and the modified QuEChERS preparation technique. The preparation efficiency of 3,4-DCA and 3,5-DCA from chive samples showed that acetonitrile was the best extractant. The combination of the purification agent graphite carbon black + primary secondary amine and the eluting agent acetonitrile + toluene (4:1,v/v) had a satisfactory purification effect. The linear correlation coefficients (R2) were more than 0.996 with the six concentration range of 0.001–1.000 mg/L for 3,4-DCA and 3,5-DCA. The limit of detection and limit of quantitation of this method was 0.6 and 2.0 µg/kg for 3,4-DCA, as well as 1.0 and 3.0 µg/kg for 3,5-DCA, respectively. The matrix effect range of 3,4-DCA and 3,5-DCA in chive tissues was from −9.0% to −2.6% and from −4.4% to 2.3%, respectively. The fortified recovery of 3,4-DCA and 3,5-DCA in chive samples at four spiked levels of 0.001–1.000 mg/kg was 75.3–86.0% and 78.2–98.1%, with the relative standard deviation of 2.1–8.5% and 1.4–11.9%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.6, 2.0, and 1.0, 3.03 for 4-DCA and 3,5-DCA, respectively. This study highlights that the analytical method established here can efficiently and sensitively detect residues of 3,4-DCA and 3,5-DCA residues for monitoring chive products. The method was successfully applied to 60 batches of actual vegetable samples from different regions.Keywords:3,4-dichloroaniline;3,5-dichloroaniline;simultaneous determination;UPLC-MS/MS;chive
研究领域:
分析化学
·
食品安全
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADSORPTION SCIENCE & TECHNOLOGY
·
2013
·
IF 0.559
Ping Yu,Qilong Sun,Jianming Pan,Zhenjiang Tan,Jiangdong Dai,Yongsheng Yan,Feng Cheng
Poly(styrene–divinylbenzene)/Fe3O4 (Fe3O4@St–DVB) magnetic porous polymer microspheres based on suspension polymerization were prepared for adsorption of 2, 4-dichlorophenol (2, 4-DCP) and 2, 6-dichlorophenol (2, 6-DCP) from aqueous solution. The as-prepared product was characterized by Fourier transform infrared spectroscopy, Raman, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis and elemental analysis. The results showed that the composite material has both porous and magnetic characteristics, which aid in faster separation and increase in adsorption capacity. The adsorption performance of the Fe3O4@(St–DVB) magnetic porous microspheres was manifested by batch mode adsorption experiments with respect to pH, initial concentration, contact time and temperature. The adsorbent was found to be sensitive to changes in pH, and the adsorption capacity of 2, 4-DCP is higher than that of 2, 6-DCP. The kinetics experimental data fitted well with the pseudo-second-order model, as three steps belonged to the pseudo-second-order adsorption process. The adsorption isotherms were also described by the Langmuir and Freundlich isotherm models, respectively. It was found that the Langmuir isotherm model fitted the equilibrium data superior to the Freundlich model. Thermodynamic parameters were calculated by the Gibbs free energy function, confirming that adsorption process was spontaneous and endothermic. In addition, the reusability performance of the Fe3O4@(St–DVB) magnetic porous microspheres was demonstrated by four repeated cycles.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Progress in Natural Science-Materials International
·
2024
·
IF 4.8
Mengxia Ma,Zhaoyang Li,Xu Yan,Yanli Mao,Chaohai Wang,Haiyan Kang,Qun Yan,Jieqiang Zhou,Zhongxian Song,Dandan Pang
Magnetic flower-like α-Fe 2 O 3 @N–C particles were synthesized by hydrothermal self-assembly method and oxygen-limited carbonisation in a glycerol and ethanol solution system using glucose as the carbon source, iron nitrate as the magnetic source and particle skeleton and urea as the nitrogen source. Four hydrothermal temperatures of 120 °C, 140 °C, 160 °C and 180 °C were used to modulate the adsorbent structure. Hydrothermal temperature of 140 °C, solution pH = 7, and a dosage of 0.06 g are the optimum conditions. The adsorption capacity of 2,4-dichlorophenol (2,4-DCP) onto MC-2 was determined as 108.556 mg g −1 at 25 °C. Experiments show that the adsorbents all fitted well to the Langmuir isothermal adsorption model and the quasi-secondary kinetic model, and the adsorption behaviour was dominated by monolayer chemisorption . The adsorption process was heat absorbing and spontaneous. Raman and XRD analysis showed that the adsorbent had a stable α-Fe 2 O 3 skeleton and carbon layers. FTIR and XPS analysis showed that the adsorbent had hydrogen bonding , electrostatic interaction and π-π bonding to 2,4-dichlorophenol.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
Communications Biology
·
2024
·Vol. 7
·期 1
·1-14
·
IF 5.2
Tan Chao,Li Suxin,Song Jia,Zheng Xianfu,Zheng Hao,Xu Weichang,Wan Cui,Zhang Tan,Bian Qiang,Men Shuzhen
Auxins and their analogs are widely used to promote root growth, flower and fruit development, and yield in crops. The action characteristics and application scope of various auxins are different. To overcome the limitations of existing auxins, expand the scope of applications, and reduce side effects, it is necessary to screen new auxin analogs. Here, we identified 3,4-dichlorophenylacetic acid (Dcaa) as having auxin-like activity and acting through the auxin signaling pathway in plants. At the physiological level, Dcaa promotes the elongation of oat coleoptile segments, the generation of adventitious roots, and the growth of crop roots. At the molecular level, Dcaa induces the expression of auxin-responsive genes and acts through auxin receptors. Molecular docking results showed that Dcaa can bind to auxin receptors, among which TIR1 has the highest binding activity. Application of Dcaa at the root tip of the DR5:GUS auxin-responsive reporter induces GUS expression in the root hair zone, which requires the PIN2 auxin efflux carrier. Dcaa also inhibits the endocytosis of PIN proteins like other auxins. These results provide a basis for the application of Dcaa in agricultural practices.
研究领域:
植物学
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分子生物学
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农业科学
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产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2017
·Vol. 148
·期 1
·23-29
·
IF 2.799
Li Jinlin,Guan Weisheng,Yan Xu,Wu Ziyang,Shi Weidong
Abstract In this paper, LaFeO 3 nanoparticles were used as a visible light photocatalyst for efficient removal of 2,4-dichlorophenoxyacetic acid (2,4-D) with the assist of ozone. The pseudo-first-order kinetic rate constants of degrading 2,4-D removal in 60-PO/Vis in 1 h was 5.72 times as great as the sum of that when using LFO/O 2 /Vis and 60-Oz/Vis at the best concentration of ozone (60 mL/min). This improvement was attributed to the efficient synergistic effect between photocatalysis and ozonation triggered by LaFeO 3 . In PO/Vis, ozone facilitates the photo-generated electrons trapping and improves separation efficiency of photo-generated charges, which enhanced the yield of hydroxyl radical, so as to the degradation efficiency of organic pollutants. In addition, the effects of ozone concentrations on the photocatalytic ozonation processes were also studied. Moreover, we demonstrated the high stability and reusability of LaFeO 3 photocatalyst in photocatalytic ozonation process by circle experiment. Graphical Abstract Schematic illustration of the reaction mechanism of enhanced photocatalytic ozonation of 2,4-D by LaFeO 3 under visible light.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2018
·
IF 6.434
Zimo Lou,Yizhou Li,Jiasheng Zhou,Kunlun Yang,Yuanli Liu,Shams Ali Baig,Xinhua Xu
Titanium carbide (TiC) with excellent electrical conductivity, chemical and thermal stabilities has been recognized as one of the most promising electrocatalysts. A novel cathode, titanium carbide doped palladium/nickel foam (TiC-Pd/Ni foam), was synthesized via electroless deposition to improve the performance of Pd/Ni foam in electrocatlytic hydrodechlorination (ECH). TiC can be co-precipitated onto the surface of cathode during galvanic replacement reaction between Pd(II) solution and Ni foam. Both constant potential and constant current tests proved that TiC-Pd/Ni foam cathode performed remarkably higher activity for 2,4-dichlorobenzoic acid (2,4-DCBA) than Pd/Ni foam cathode, owing to the excellent conductivity of TiC and enhanced water dissociation over TiC-Pd/Ni foam cathode. Under the optimized reaction conditions of –0.85 V ( vs Ag/AgCl), electrolyte of 10 mM and initial pH of 4, 99.8% of aqueous 2,4-DCBA (0.2 mM) was removed within 90 min. The removal process of the aqueous 2,4-DCBA obeyed first-order decay kinetic model. Over 86.3% of 2,4-DCBA can still be removed by TiC-Pd/Ni foam cathode in the fifth consecutive run within 120 min, which was much higher than that of Pd/Ni foam cathode (37.5%). Consequently, TiC-Pd/Ni foam cathode was a promising design for enhanced ECH activity and reduced operation cost.
研究领域:
环境科学
·
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2015
·
IF 2.037
Xian Lu,Yisheng Shao,Naiyun Gao,Lei Ding
The study investigated the performance of 2,4-D adsorption on MIEX resin. The different temperatures affecting the adsorption performance were specifically evaluated. Equilibrium data followed the Freundlich and Langmuir isotherm model for all investigated temperatures (283 K to 333 K). The Langmuir model was slightly better than the Freundlich model at a lower temperature (283 K); however, with the increase of temperature the Freundlich model could well describe the isotherm data. The solute coefficient of distribution (Kd) could be better used to estimate the thermodynamic parameters compared with the Langmuir equilibrium constant (KL). The thermodynamic parameters (ΔH0, ΔS0, and ΔG0) showed that the adsorption of 2,4-D was feasible, endothermic, and spontaneous at 283 K to 313 K. The activation energy (Ea, 47.70 kJ·mol–1) determined by using the rate constant k2 of pseudo-second order model (the suitable kinetic model) and the mean free energy value (Efe, 6.0348 kJ·mol–1) evaluated by using the Dubinin–Radushkevich (D–R) model indicated that chemical ion-exchange was the predominant mechanism of 2,4-D adsorption. The calculated film diffusion coefficient value (Df) suggested film diffusion was the kinetic rate-limiting step. The adsorbent displayed excellent reusability with 0.1 mol·kg–1 NaCl as the regeneration agent.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Li Xiao,Hanbin Shan,Yi Wu
Epichlorohydrin-modified chitosan-Schiff base composite (CS/24Cl/ECH) prepared via the one-pot reaction as characterized by Fourier transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), Differential scanning calorimetry (DSC) and Scanning electron microscope (SEM). Its removal ability of Pb(II) ions from aqueous solution was investigated. The adsorption of Pb(II) ions carried out at different initial pH, dose of CS/24-Cl/ECH, contact time and co-existing ions. The maximum adsorption capacity of Pb(II) ions was 170 mg/g. Finally, based on the absorption results, the adsorption of Pb(II) ions was fitted by single-layer Langmuir isotherm model and the pseudo-second-order (PSO) kinetics model. The absorption mechanism of Pb(II) ions was controlled by chemical coordination Pb(II) ions with the active sites on the surface of CS/24Cl/ECH composite. Also, CS/24Cl/ECH showed excellent recyclable efficiency up to 5 cycle and potential sorbent for other heavy metal ions.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2024
·
IF 3.5
Xiaoyu Chu,Xinrui Wang,Shuo Tian,Yongkuo Zhao,Shikai Liu,Hong Yan,Yan Shang
Modulating the photogenerated electrons of CeO2 to activate O2 and efficiently photocatalytic degradation of chlorophenols is a highly desired goal. Herein, we have successfully fabricated FePc/CeO2 heterojunction through H-bond induced assembly. The photocatalytic degradation of 2, 4-DCP by the amount-optimized FePc/CeO2 nanocomposite was improved by 3 times compared with pure CeO2. By means of electron paramagnetic resonance (EPR) and single wavelength photocurrent spectroscopy, it is confirmed that the excellent photocatalytic performance is mainly attributed to the formation of Z-scheme heterojunction, which promotes charge separation and transfer, and the introduction of FePc broadens the visible light absorption range of heterojunction. Moreover, O2 temperature-programmed-desorbed curves and electrochemical O2 reduction measurements results demonstrate that the single Fe-N4(II) site in FePc is more conducive to promoting O2 activation than that of other metal phthalocyanines. Based on in situ FT-IR and liquid chromatography-tandem mass spectrometry (LC-MS), a possible reaction pathway of 2, 4-DCP degradation was proposed. This study provides a novel strategy to prepare CeO2 based Z-scheme heterojunctions with abundant monoatomic sites for pollutant degradation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Hai Chen,Zhonglei Zhang,Mingbao Feng,Wei Liu,Wenjing Wang,Qi Yang,Yuanan Hu
In this study, mackinawite (FeS) was prepared and used as the heterogeneous catalyst to activate persulfate (PS) for 2,4-dichlorophenoxyacetic acid (2,4-D) degradation, and impact factors including initial pH, PS concentration, FeS dosage, reaction temperature and inorganic anions (Cl − , NO 3 − , and HCO 3 − ), were investigated. The results showed that 2,4-D could be efficiently degraded and mineralized by FeS/PS system. Acidic pH would accelerate 2,4-D degradation, whereas neutral and alkaline conditions showed negative effects. The degradation efficiency of 2,4-D was improved with increasing FeS dosage, PS concentration and reaction temperature. Furthermore, inorganic anions exerted different effects on 2,4-D degradation. The quenching experiments indicated that though both sulfate radicals (SO 4 − ) and hydroxyl radicals (HO ) were responsible for 2,4-D degradation, HO played a more important role. Based on the quenching tests and electron paramagnetic resonance (EPR) analysis, the possible mechanism of 2,4-D oxidation in FeS/PS system was proposed. Additionally, the reusability tests revealed that, although FeS had a short time of deactivation after first use, it still maintained satisfactory catalytic activity in five consecutive 2,4-D degradation experiments. The transformation intermediates were identified by a gas chromatography mass spectrometry (GC–MS), and the possible reaction pathways were proposed based on the measured results. The method of activating PS with FeS may offer great benefits for the application of iron-containing mineral in remediation of herbicide-contaminated water.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Xiaoxue Pan,Junyan Wei,Mengting Zou,Jing Chen,Ruijuan Qu,Zunyao Wang
We systemically investigated the transformation behavior of 2,4-dichlorophenol (24-DCP) in seven different reaction systems including KMnO 4 , heat/PS, O 3 , UV, Fenton, NaClO and K 2 FeO 4 treatment. The results revealed that complete removal of 24-DCP could be reached in minutes, especially for Fe(VI), KMnO 4 , NaClO, Fenton and O 3 system. A total of 41 products were identified by LC-MS, and 10 of them were validated using commercial and self-synthesized standards. Hydroxyl substitution and coupling reactions were commonly observed in the studied systems. Meanwhile, extra routes such as sulfate substitution, (de)chlorination and direct oxidation were also involved for certain oxidation methods. Comparisons showed that a high degree of chlorination (>90%) occurred for NaClO system, while coupling products accounted for ~45% of the removed 24-DCP under PS oxidation. Moreover, low mineralization degree together with high aquatic toxicity was attributed to the occurrence of coupling reaction, which was possibly related to the redox potential of the main oxidative species. Considering the low abundance of coupling products and the gentle reaction condition, UV irradiation is a better option for 24-DCP removal in water and wastewaters. These findings can deepen our understanding on the transformation process of 24-DCP and provide some useful information for the environmental elimination of substituted phenols.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2019
·
IF 3.556
Kaiyuan Zheng,Yuqiao Song,Xu Wang,Xin Li,Xuhui Mao,Dihua Wang
Herein, with the exploitation of iron and nickel electrodes, the 2,4-dichlorophenol (2,4-DCP) dechlorinating processes at the anode and cathode, respectively, were separately studied via various electrochemical techniques (e.g., Tafel polarization, linear polarization , electrochemical impedance spectroscopy). With this in mind, Ni/Fe nanoparticles were prepared by chemical solution deposition, and utilized to test the dechlorination activities of 2,4-DCP over a bimetallic system. For the iron anode, the results showed that higher 2,4-DCP concentration and solution acidity aggravated the corrosion within the electrode. The charge transfer resistance ( R ct ) values of the iron electrode were 703, 473, 444, and 437 Ω ∙ cm 2 for the initial 2,4-DCP concentrations of 0, 20, 50, and 80 mg/L, respectively. When the bulk pH of the 2,4-DCP solution varied from 3.0, 5.0 to 7.0, the corresponding R ct values were 315, 376, and 444 Ω ∙ cm 2 , respectively. For the nickel cathode, the reduction current densities on the electrode at − 0.75 V (vs. saturated calomel electrode) were 80, 106, and 111 μA/cm 2 , for initial 2,4-DCP concentrations of 40, 80, and 125 mg/L. The dechlorination experiments demonstrated that when the initial pH of the solution was 7.0, 5.0, and 3.0, the dechlorination percentage of 2,4-DCP by Ni/Fe nanoparticles was 62%, 69%, and 74%, respectively, which was in line with the electrochemical experiments. 10 wt.% Ni loading into Ni/Fe bimetal was affordable and gave a good dechlorination efficiency of 2,4-DCP, and fortunately the Ni/Fe nanoparticles remained comparatively stable in the dechlorination processes at pH 3.0.
研究领域:
环境科学
·
电化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）