JOURNAL OF HAZARDOUS MATERIALS
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2018
·
IF 6.434
Jiafeng Ding,Gaoyuan Long,Yang Luo,Runze Sun,Mengxia Chen,Yajun Li,Yanfang Zhou,Xinhua Xu,Weirong Zhao
Polychlorinated dibenzo- p -dioxins (PCDDs), as a group of notorious anthropogenic environmental toxicants, are arguably ubiquitous in nature. In this study, we investigated the photocatalytic reductive dechlorination of 2-chlorodibenzo- p -dioxin (2-CDD) over Pd/g-C 3 N 4 catalysts under UV–vis irradiation. The g-C 3 N 4 and a series of Pd/g-C 3 N 4 catalysts were prepared by thermal polymerization and mechanical mixing-illumination method and characterized by XRD, TEM, BET, SEM and UV–vis DRS analyses. Among all the samples, the Pd/g-C 3 N 4 (5 wt%) yielded the optimal dechlorination activity with a total 2-CDD conversion of 54% within 4 h, and 76% of those converted 2-CDD were evolved to dibenzo- p -dioxin (DD). The kinetics of dechlorination could be described as pseudo-first-order decay model (R 2 > 0.84). Corresponding rate constants (k) increased from 0.052 to 0.17 h −1 with Pd contents up to 5 wt% and decreased to 0.13 h −1 with a 10 wt% of Pd. The enhanced activities originated from the surface plasmonic resonance (SPR) effect of Pd nanoparticles and the formation of Schottky barrier between Pd and g-C 3 N 4 , which extend the spectrum responsive range and suppress the charge recombination of g-C 3 N 4 . This is the first report on the photocatalytic reductive removal of PCDDs and may provide a new approach for PCDDs pollution control.
研究领域:
环境科学
·
化学工程
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DOI
高影响因子
Journal of Food Measurement and Characterization
·
2023
·Vol. 18
·期 3
·1734-1739
·
IF 3.4
Hao Lingchuan,Xu Wenxue,Wu Minghuo
Proanthocyanidins (PCs), known as natural antioxidants capable of scavenging free radicals, are rich in blueberry as oligomeric proanthocyanidins (OPCs). Aim to efficiently determine the total PCs in blueberry, a simple method of dispersive solid phase extraction (DSPE) followed by UV–Vis spectrophotometry detection was developed, in which C18-bonded silica microspheres were used as absorbent to purify the targets, and vanillin–HCl was applied for chromogenic reaction. After systematic optimization of DSPE conditions, reliable determination of total PCs was achieved. Though the sensitivity of this method was not comparable to those based on high performance liquid chromatography or mass spectrometry, it was simple and reliable for the analysis of PCs-rich fruits. With this method, impacts of storage conditions including time and temperature, as well as the freshness on total PCs concentration in blueberry were investigated. The results revealed that with the increase of storage time or temperature, the total PCs decreased accordingly. Meanwhile, the highest concentration of total PAs was found in the freshest blueberries stored at a low temperature of 4 °C, which supported that the low temperature was favorable for blueberry storage, showing the practical significance for the storage of PCs-rich fruits.
研究领域:
食品科学
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分析化学
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DOI
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 11
·1500-1507
·
IF 2.378
Sha Sha Li,Bo Yin,Hong Lin Zhai,Shao Hua Lu,Jia Ying Mi
Although UV-Vis spectroscopy has been applied in many fields, it still encounters some challenges in multi-component mixture analysis due to severe spectral overlapping and different interferences. In this paper, a Tchebichef curve moment (TM) approach has been developed and proposed for the quantitative analysis of five skin-whitening agents in several cosmetic products with different substrates based on conventional UV-Vis determination for the first time. First, the TMs were calculated from the raw UV-Vis spectra of mixed standard samples, and employed to establish linear quantitative models by stepwise regression. Then, the obtained models were applied to the analysis of real samples. The leave-one-out correlation coefficients (Rloo-cv) of the established models were more than 0.9948 within the linear ranges. The proposed approach was evaluated using intra- and inter-day precision (less than 5.98%) and recovery (ranging from 88.3 ± 2.8% to 109.2 ± 2.3%). The LODs and LOQs were less than 0.13 mg L−1 and 0.45 mg L−1, respectively. Compared with the classical methods, the proposed approach is not only more accurate, reliable and robust in the quality control analysis of cosmetic products, but also can extend effectively the application of conventional UV-Vis determination.
研究领域:
分析化学
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化妆品科学
·
光谱学
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产品关联
DOI
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2018
·
IF 2.831
Lan Luo,Congcong Gu,Mingxian Li,Xiangyuan Zheng,Feng Zheng
4-Nitrobenzaldehyde is the synthetic raw material and an important photodegradation product of chloramphenicol . With a structural “alert” of human genotoxic potential and reported mutagenicity, this compound should be controlled in drug substances as a potential genotoxic impurity. However, current analysis methods require complex pre-treatment processes and/or lack sufficient specificity and sensitivity. Nitrophenylhydrazine is a common carbonyl derivatization reagent used to determine the residual aromatic aldehydes in drug samples. In the present study, we report an unexpected advantage of 3-nitrophenylhydrazine hydrochloride as a derivatization reagent in the derivatization high-performance liquid chromatography-ultraviolet detection method to determine 4-nitrobenzaldehyde in chloramphenicol samples. Compared with other nitro-substituted phenylhydrazines , 3-nitrophenylhydrazine hydrochloride can minimize drug matrix and derivatization reagent interferences, since the maximum absorption wavelength of its derivative is significantly red-shifted to 397 nm. The derivatization conditions have been optimized in terms of reaction efficiency, including reaction temperature, time, and diluting solvent, through a design of experiments. As a result, after reaction with 500 μg mL −1 of 3-nitrophenylhydrazine hydrochloride in acetonitrile-water (70:30, v/v) at 60 °C for 30 min, the developed HPLC method could be used to determine 4-nitrobenzaldehyde with a limit of detection of 0.009 μg mL −1 . The method was then validated and applied for the determination of residual 4-nitrobenzaldehyde in chloramphenicol and its eye-drop samples.
研究领域:
药物分析
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毒理学
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制药工程
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产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2024
·
IF 2.7
hui shi,Yuntong Liu,Chu Qiu,Chunyu Wang,Zhimin Zhang,Meijun Lu,Bo Wang,Yuan Tian,Daqian Song,Ziwei Zhang
Alkaline phosphatase (ALP) is an indispensable hydrolase in living organisms and the abnormality of ALP activity is correlated with a variety of diseases. To explore ALP activity is important for clinical diagnosis and biomedical research to understand its physiological function. In this study, a dual-mode biosensing platform was constructed based on Cu-based metal-organic framework (Cu-MOFs) for electron spin resonance (ESR) and ultraviolet-visible (UV-vis) sensing of ALP. Cu-MOFs, as peroxidase mimic, catalyzed the decomposition of hydrogen peroxide (H2O2) and the generation of reactive oxygen species (ROS) which could oxidize ABTS into ABTS•+ with good ESR and UV-vis signals. Pyrophosphate ion (PPi) with high affinity to Cu2+ in Cu-MOFs could suppress the peroxidase-like activity of Cu-MOFs, and ALP could hydrolyze PPi, resulting in the recover of Cu-MOFs catalytic activity. Thus, a quantitative dual-mode method for detection of ALP activity was established with good linearity in the range of 0-42 U L-1 and limits of detection as low as 0.386 and 0.523 U L-1 respectively for ESR and UV-vis detection. Benefiting from its high sensitivity and excellent selectivity, this method was applied for ALP detection in human serum and satisfactory recoveries were achieved. The off-on dual-mode sensing platform is more reliable than the single-mode sensor and shows merits like simple operation and cost-friendliness, making it have great potential in the diagnosis of ALP-related diseases.
研究领域:
生物化学
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分析化学
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生物医学工程
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临床诊断
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产品关联
DOI
PubMed
高影响因子
CHEMICAL PAPERS
·
2022
·Vol. 77
·期 3
·1631-1644
·
IF 2.146
Zuo Xiong Jun,Liu Jinhui,Gu Feng Long
A new method of how to use high concentrations of UV–Vis absorbable components in mobile phases for ion chromatographic separation of anions with indirect photometric detection (IPD) was developed. The UV–Vis absorption curves, the signal strengths at selected wavelengths, and the response ranges at different wavelengths of three organic salts, sodium benzoate, sodium 4-nitrobenzoate and sodium 3,5-dinitrobenzoate were detected using a photodiode array detector. Mobile phases containing these three organic salts at concentrations as high as 20 mM were used for ion chromatographic separations of inorganic anions, such as F − , Cl − , NO 2 − , Br − , NO 3 − , and SO 4 2− . Separation characteristics detected at different wavelengths such as, the baseline stability, signal to noise levels shown as detection limits, linearity, etc., were investigated. It is found that the best wavelength used for IPD may not be the maximum or near the maximum absorption wavelength, but definitely not the non-absorptive wavelength of the eluent. Therefore, the best wavelength should be optimized. With the optimized wavelength at 385 nm, anions of sub-nanomoles were able to be quantitatively detected, and a good linear relationship with a correlation coefficients, ( r > 0.9998), within the sample ranges from 0.5 to 200 ng was available. By using the optimized wavelength, the threshold of the detector will no longer be a strict restriction factor of using high concentrations of UV–Vis absorbable components. Consequently, columns with different ion exchange capacities can be used for separations with IPD. Furthermore, because the separation system can be fast re-equilibrated after sample injection using high concentrations of monovalent ion eluent, the separation efficiency can be highly improved. This method is promising for developing mobile phases for other chromatographic separations with IPD.
研究领域:
分析化学
·
色谱技术
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2012
·Vol. 1
·期 7
·2558-2566
·
IF 0
Essy Kouadio Fodjo,Da-Wei Li,Niamien Paulin Marius,Trokourey Albert,Yi-Tao Long
AgxMoyOz (Ag/α-MoO3, Ag/h-MoO3, Ag/β-MoO3, Ag2Mo2O7, and Ag2MoO4) nanomaterials are synthesized at relatively low temperature (80 °C) and with a short hydrothermal treatment time (3 h) using glucose (Glc) as a catalyst. Contrary to previous studies, it is possible to synthesize one of the AgxMoyOz binaries at 80 °C by altering the pH of the reaction media in the presence of glucose. In addition, further experiments indicate that Ag/h-MoO3, Ag2Mo2O7 and Ag/β-MoO3 can be converted to Ag/α-MoO3 which can also be synthesized from a reaction involving ammonium heptamolybdate tetrahydrate and AgNO3 at room temperature using cysteamine in both methods. Characterization with UV-Vis, XRD and Raman spectroscopy reveals high purity of as-synthesized product. These synthesized products are finally used to fabricate SERS substrates by coating a silicon wafer with a mixture of silver nanoparticles (Ag NPs) and AgxMoyOz (Si@Ag/AgxMoyOz). The results show a good sensitivity and stability. In addition, it is also found that the SERS activity of Si@Ag/AgxMoyOz is higher than that of Si@Ag.
研究领域:
材料科学
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纳米技术
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表面增强拉曼光谱
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化学合成
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产品关联
DOI
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 24
·36337-36350
·
IF 5.19
Wang Bing,Cao Qingtong,Li Guomin,Zhang Jian
Given that the biological treatment of antibiotic wastewater can easily induce resistant bacteria, the photocatalytic degradation of antibiotics is considered as a better method for treating antibiotic wastewater. Therefore, the ability to remove Tylosin (TYL) and Tetracycline (TC) in aqueous solution using rare earth element Tb-doped g-C 3 N 4 under simulated natural solar radiation was investigated. A series of rare earth Tb 3+ doped mesoporous g-C 3 N 4 were successfully prepared by nitric acid treatment and Tb(NO 3 ) 3 ·5H 2 O samples showed significantly higher degradation efficiency for TYL and TC than pure g-C 3 N 4 . Leaching toxicity experiments were carried out on the catalyst using chard seeds and demonstrated negligible toxicity of the leachate from the catalyst. The structure, elemental state, optical properties, morphology, and photogenerated carrier separation of the prepared xTCN catalysts were characterized by XRD, XPS, UV–Vis DRS, TEM, and PL. The results show that Tb doping enhanced the photocatalytic activity of the g-C 3 N 4 catalyst by narrowing the band gap while improving the light-trapping ability; The separation and transport rate of photogenerated carriers were significantly increased after Tb doping. Finally, a simple, efficient, and non-polluting Tb-doped carbon nitride photocatalyst is successfully developed in this paper.
研究领域:
环境科学
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材料科学
·
化学
·
光催化
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yi Wen,Zheng Huang,Min Zhao,Longshan Zhao
The discharge of industrial heavy metal wastewater not only leads to environmental pollution, but also harms human health, so it is imperative to control heavy metal pollution. In the current work, a sequence of anatase/brookite TiO 2 @COF with different mass ratios, bi-phase TiO 2 and bare COF were successfully synthesized by simple hydrothermal synthesis. The photocatalytic activity of the prepared catalysts was assessed by reducing Cr(Ⅵ) in model pollutant (K 2 Cr 2 O 7 ). Under the condition of pH = 3, the Cr(Ⅵ) reduction rate of TiO 2 @COF-4 was as high as 99.19% in 30 min. The photocatalytic activity of TiO 2 @COF-4 remained stable in four consecutive cycles, suggesting that it has a potential application prospect for the removal of Cr(Ⅵ) in the actual environment. The morphology and structure of photocatalysts were observed by different techniques (SEM/EDS, HRTEM, BET analysis, XRD, FTIR and XPS). The specific reasons for the enhancement of photocatalytic performance of materials were explored by different methods (PL, UV–vis DRS, Mott-Schottky plots, I-T curves and EIS). Finally, we concluded that the photocatalytic system of TiO 2 @COF-4 may follow the typical direct Z- scheme mechanism. This work provides an effective solution for the water treatment of heavy metal pollution.
研究领域:
环境科学
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材料科学
·
化学工程
·
纳米技术
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Peng Du,Yongjian Xu,Yun Shi,Qinghua Xu,Yang Xu
Bacterial infection has become one of the major threats to human health all over the world, and the development and application of antibacterial materials has drawn great attention. Based on the Schiff-base structure, ZnONPs@ACFs are obtained by loading zinc oxide nanoparticles (ZnONPs) on amino cellulose fibers (ACFs) in-situ through the coordination of amino groups with metal ions. The results of FT-IR, XRD and UV-vis demonstrate that ZnONPs are successfully loaded and uniformly dispersed on ACF surface, and the ACFs maintain intact morphology observed by SEM. Furthermore, the zero-span tensile strength of ZnONPs@ACFs is 66.48 N/cm (ROL: 24.98 N/cm/s) under the optimum conditions, which indicates that ZnONPs@ACFs have a certain strength and can be used to make antibacterial sheet materials via paper-making wet-forming process. Accordingly, the ZnONPs@ACF composites show inhibition zones of 4.95 mm and 1.10 mm against E. coli and S. aureus , respectively. The new cellulose-based antibacterial materials demonstrate potential applications in the field of food packaging and biological medicine etc.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
·
化学工程
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产品关联
DOI
PubMed
高影响因子
Journal of Applied Spectroscopy
·
2023
·Vol. 90
·期 4
·883-892
·
IF 0.7
Shi Ying,Guo Ya-Dan,Mi Yi-Duo,Cheng Jia,Dong Wen,Zhang Gao-Feng,Zeng Yi
The antioxidant activities of flavonoid mixtures can be used to investigate the synergistic antioxidant mechanism of flavonoids. The antioxidant capacities of three flavonoids (quercetin, baicalein, and daidzein) and β-carotene in binary and ternary mixtures with kaempferol were analyzed using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition assay by means of absorption spectroscopy. The results showed that the number of hydroxyl groups and o-hydroxyl groups had a significant effect on the antioxidant activity of the flavonoids, and the mixture of kaempferol, quercetin, and baicalein showed optimal synergistic antioxidant activity. Compared with quercetin and baicalein, kaempferol had the fastest inhibition rate, and multiple prolonged kinetic processes associated with the scavenging of DPPH radicals occurred in mixtures of kaempferol with the other flavonoids and β-carotene. Kaempferol has a potential synergistic antioxidant effect when mixed with daidzein and β-carotene, and the results suggested that this may be due to the regeneration of kaempferol after antioxidation. By means of classic UV-Vis spectroscopy, reaction details of the synergistic antioxidant process of DPPH radical scavenging by flavonoids can be obtained.
研究领域:
食品科学
·
植物化学
·
分析化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2024
·
IF 8
Jialin Liang,Fang Yuan,Ting Liu,Chenguang Qian,Zhangshuo Song,Lijuan Wei,Chunquan Li,Zhiming Sun
Photothermal catalytic oxidation is a promising and sustainable method for the degradation of indoor formaldehyde (HCHO). However, the excessively high surface temperature of existing photothermal catalysts during catalysis hinders the effective adsorption and degradation of formaldehyde under static conditions. Catalyst loading and oxygen vacancies (OVs) modulation are commonly employed strategies to reduce the photothermal catalytic temperature and enhance the efficiency of photothermal catalytic oxidation. In this work, a p-n type CuO/TiO 2 heterojunction is successfully loaded onto diatomite using a wet precipitation method. Under the irradiation of a 300W xenon lamp, the prepared composite material achieved a 100% removal rate of HCHO within 2 h, with a 98% conversion rate to CO 2 , surpassing the performance of both individual photocatalysts and thermocatalysts. Additionally, by adjusting conditions such as light irradiation and temperature, we have demonstrated that this material exhibits synergistic photothermal catalytic properties. Based on HRTEM, XPS, Raman, and EPR analyses, the introduction of diatomite as a catalyst support was shown to effectively increase the number of OVs. Experimental results, along with O 2 -TPD, photoelectrochemical characterization, and radical detection, demonstrate that the presence of OVs enhances the oxidative efficiency of both photocatalysis and thermocatalysis, as well as the UV–Vis-IR photothermal catalytic performance. The ternary composite material generates weak hydroxyl ( • OH) and superoxide ( • O 2 − ) radical under high-temperature with dark conditions, indicating its catalytic oxidation activity under this condition. The increase in temperature and the expansion of the spectral range both enhance the generation of these radicals. In summary, this work demonstrates that the use of diatomite as a support increases the material's specific surface area and OVs content, thereby enhancing adsorption and photothermal catalysis. It elucidates the enhanced catalytic degradation mechanism of this mineral-based photothermal catalyst.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）