ELECTROCHIMICA ACTA
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2017
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IF 4.798
Siqi Liu,Xiezhen Zhou,Weiqing Han,Jiansheng Li,Xiuyun Sun,Jinyou Shen,Lianjun Wang
Flutriafol is one of the widely used triazole fungicides in global pesticides market, and its degradation mechanisms are important to develop powerful technologies to remove it. Insight into the kinetics and mechanisms of · OH-mediated mineralization of flutriafol have been obtained using quantum chemical calculation and electrochemical experiment methods. The complete · OH-mediated degradation pathway of flutriafol was proposed by density functional theory (DFT) simulation and the potential energy surface was mapped out for possible reactions. On the basis of DFT calculations, the optimal · OH-mediated mineralization mechanism of flutriafol was revealed, and a series of intermediates were observed accumulated in the degradation process, most significance among which were (2-fluorophenyl) (4-fluorophenyl)-Methanone, phenol , dihydroxybenzenes, benzoquinones , muconic acids , maleic acids , oxalic acids and formic acid . To give deeper insight into the · OH-mediated reaction mechanism, the electrostatic potential (ESP) and average local ionization energy (ALIE) analysis were conducted for o-benzoquinone and p-benzoquinone. The proposed mechanism was further validated by electrochemical experiments at TiO 2 -NTs/SnO 2 -Sb/PbO 2 anode. The main intermediates were identified and quantified by experimental method, indicating that the proposed · OH-mediated degradation mechanism derived from DFT calculations was feasible. These detailed findings could be instrumental for a comprehensive understanding of the · OH-mediated mineralization mechanism of flutriafol and the similar contaminants.
研究领域:
环境科学
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化学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2024
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IF 3.8
Fujun Li,Peihao Cheng,Xinghai Li,Yun Zou,Shengyang Tao
Bromination reactions involving bromine monomers tend to be polybrominated, resulting in poor product selectivity and subsequent separation difficulties. This proposal outlines a multistep cascade for continuous flow synthesis involving photobromination and debromination. The process comprises five units: bromine generation, photobromination, quenching, water/oil separation, and photodebromination. A full-process continuous and efficient synthesis of the trifluorostrolibin intermediate (E)-Methyl-2-(2-broMoMethylphenyl)-2-MethoxyiMinoacetate (MBPA) was achieved. This process converts the byproduct (E)-Methyl-2-(2-dibroMoMethylphenyl)-2-MethoxyiMinoacetate into the target product MBPA. At a total residence time of 12.9 min, the conversion of (E)-Methy-2-(methoxyimino)-2-(o-toly) acetate reached 99.0%, and the total yield of MBPA reached 94.2%. Machine learning and quantum chemical calculations enhance the comprehension of photodebromination mechanisms. Simultaneously, through comprehensive simulations involving sensitivity and scenario analyses, the optimization of photon utilization emerged as a pivotal factor for improving the overall applicability of the production process. This method of synthesizing halogenated products is anticipated to play a crucial role in pharmaceuticals or pesticides.
研究领域:
有机化学
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农药合成
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制药工程
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产品关联
DOI
高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
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2019
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IF 2.87
Jiejun Xi,Jian Shao,Yuan Wang,Xiaoqin Wang,Hui Yang,Xinwei Zhang,Dongmei Xiong
Triflumizole is one of imidazole fungicides that works by inhibiting ergosterol biosynthesis , and is widely used for the control of powdery mildew and scabs on various fruits and crops. Triflumizole residue has been frequently detected in soil and aquatic ecosystems . While many studies have focused on its toxic effect on terrestrial and aquatic animals, little attention has been paid to aquatic algae, the primary producers of aquatic environments . Therefore, we evaluated the acute (96 h) toxicity effects of triflumizole on the freshwater algae Chlorella vulgaris , by examining growth, cell morphology, photosynthesis , and oxidative stress . The results showed that the 96 h median inhibition concentration (96 h-EC 50 ) was 0.82 mg / L (95% confidential interval 0.70–0.98 mg/L).The growth of algal cells was conspicuously inhibited by triflumizole exposure, and the cell surfaces appeared to be shrunkThe chlorophyll content (including Chl-a, Chl-b and T-Chl) dramatically decreased at triflumizole concentrations of 0.2 and 1.0 mg/L. In addition, the transcript abundance of photosynthesis-related genes ( psa B, psb C and rbc L) showed obvious decreases in above treatments after 96 h of exposure to triflumizole. Moreover, the algal growth inhibition was accompanied by an increase in intracellular reactive oxygen species and malondialdehyde content, as well as increased activity of antioxidant enzymes such as superoxide dismutase and peroxidase , indicating oxidative stress and lipid peroxidation . Our findings reveal that triflumizole has potential toxicity to the primary producers (freshwater algae) in aquatic ecosystems.
研究领域:
环境毒理学
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水生生态学
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植物学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2022
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IF 5.304
Honglin Qin,Yuan Tao,Ruiting Niu,Bingyan Han,Lizhen Qiao
In this work, magnetic flower-like and fluorine-doped nickel oxide composites Fe 3 O 4 @SiO 2 @F/NiO were prepared and applied for the magnetic solid-phase extraction (MSPE) of five imidazole fungicides. The obtained materials were characterized by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller analysis to verify the successful synthesis. The effect of some experimental parameters on the extraction efficiency were explored to optimize the MSPE conditions, including the adsorbent dosage, ultrasonic time, salt concentration, sample solution pH, elution solvent type and volume. Then, method validation was performed under the optimal conditions in combination with high-performance liquid chromatography-ultraviolet detection. The determination coefficients ranged from 0.9956 to 0.9991, and the limits of detection and limits of quantification for the imidazole fungicides were 0.1–3 μg·L −1 and 0.3–10 μg·L −1 , respectively. Moreover, the intra-day and inter-day precisions were evaluated in three different concentrations with relative standard deviations in the range of 1.34 %-13.31 % and 4.96 %-13.92 %. At last, the proposed MSPE method was used to enrich and determine imidazole fungicides in tap water, milk and green tea samples, and the spiked recoveries were in the range of 77.93 %-119.38 %, demonstrating the potential of the method in the determination of imidazole fungicides from real samples.
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产品关联
DOI
高影响因子
Surfaces and Interfaces
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2021
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IF 4.837
Xiao-Ting Zhen,Ya-Ling Yu,Min-Zhen Shi,Si-Chen Zhu,Tian-Ci Yan,Zi-Xuan Yue,Yu-Xin Gu,Hui Zheng,Jun Cao
The Hawthorn kernel activated carbon (HKAC), acquired from food waste (hawthorn kernel) by a two-step method including carbonization operation and thermally activating potassium hydroxide process, was prepared. Morphological integrity and crystalline state of the HKAC were characterized by scanning electron microscopye and X-ray diffraction. Structural feature of the HKAC was investigated by the Brunauer–Emmett–Teller method, Fourier transform infrared spectroscopy , Raman spectroscopy together with zeta potential . The HKAC contained a specific surface area of 1269.92 m 2 /g and pore volume of 0.67 cm 3 /g. The optimized adsorption conditions were to use HKAC with a carbonization temperature of 550 °C were at a concentration of 0.6 g/L for adsorption in a solution with a temperature of 60 °C and a pH of 6.0. The kinetic studies proved that the pseudo-second-order model fitted experimental data best with the high correlation coefficient values of 0.9968–0.9993. Besides, experimental results revealed that Langmuir isotherm model gave the best fit among the studied isotherm models with a maximum adsorption capacity of 100.00 mg/g, the experimental results revealed that the Langmuir isotherm model was more consistent than the Freundlich isotherm model with a maximum adsorption capacity of 100.00 mg/g, and the adsorption of fungicides onto HKAC was endothermic spontaneous process. Moreover, it was confirmed in tap water and Dendrobium that the removal rate of the six fungicides remained at 86.3% to 96.2% after five cycles of HKAC even in a complex matrix. The aforesaid satisfying experimental results proved that HKAC was a cost-effective and green adsorbent for removing water and plant contaminated by fungicides.
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产品关联
DOI
高影响因子
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