FOOD CHEMISTRY
·
2013
·
IF 3.334
Huabin Xing,Xiao Zhang,Qiwei Yang,Ruiyang Liu,Zongbi Bao,Baogen Su,Yiwen Yang,Qilong Ren
Long chain unsaturated fatty acids (LCUFAs) are important food components and dietary supplements due to their beneficial health effects. The key process to produce high-purity LCUFAs is to separate long chain fatty acids (LCFAs) with different degrees of unsaturation and chain lengths. This process faces great challenge because of similar physico-chemical properties of fatty acids concerned. In this work, fractional extraction is proposed to separate LCFAs, using eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), conjugated linoleic acids (CLAs), oleic acid (OA) and stearic acid (SA) as model LCFAs. COSMO-RS calculations were performed for fast extractant screening and exploring the potential separation mechanism. Satisfactory distribution coefficients and high selectivities were obtained in extraction equilibrium experiments. Simulation and experimental validation of fractional extraction were performed, and high purity and high yield of CLAs were obtained. EPA and DHA could be separated thoroughly from OA, though they could not be separated each other.
研究领域:
食品科学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biofuels Bioproducts & Biorefining-Biofpr
·
2023
·Vol. 17
·期 3
·592-601
·
IF 3.9
Liangliang Zhang,Man Xu,Qinhao Guan,Jianchun Jiang,Kang Sun,Emmanuel Manirafasha
Tannin is a chemical compound found in plants such as tea, with yellow or brown as a characteristic color. Tannin is present in any plant species’ wood, stems, barks, leaves, roots, and fruits. However, the tannin contents in those plants are not the same and plants rich in tannin are the most used raw material for industrial-level tannin extraction, such as chestnut. The central purpose of this article was to identify the tannin content of vegetables. In this study, tannins were extracted from 72 plants in China. The contents and purities of tannins, non-tannins and insoluble substances in those studied plants were determined. A gravimetric approach, using hider powder as a precipitate to bind tannins, has been developed to quantify total tannins in plants. The results showed that high contents of tannins (>20%) were found in Pltycarya strobilacea fruit, Quercus acutissima shell, Quercus variabilis shell, Acacia mearnsii bark, Albizia kalkora bark, Camellia oleifera wood, Rosa cymosa root, Rosa laevigata root, Rhus chinensis gallnut, Bruguiera sexangular bark, Kandelia candel bark, Ceriops tagal bark, Lumnitzera racemose bark and Dioscorea cirrhosa tuber. The purity of tannins was more than 70% in some plants: Larix gmelimi bark, Causuarina equisetifolia bark, P. strobilacea fruit, Castanopsis tibetana wood, Quercus aliena shell, Quercus chenii shell and bark, A. mearnsii bark, A. kalkora bark, Bruguiera gymnorrhiza bark, C. tagal bark, K. candel bark and D. cirrhosa tubers . These plants are excellent resources for vegetable tannins in China. © 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd.
研究领域:
植物化学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
Waste and Biomass Valorization
·
2023
·
IF 3.2
Li Zhi-jian,Wang Wei,Jiang Long-jin,Chang Zhi-dong,Ma Xi-ping,Luo Xin
In order to extend the duration of the electrolyte solution in which copper granules recovered from waste printed circuit board are refined through electrolysis to obtain copper foil with high purity and which is contaminated by the accumulation of metallic impurities along with the refinery of waste printed circuit board, the leaching and electrowinning processes are used to pretreat the copper granules. The effects of impurities of copper granules as well as H 2 SO 4 mole ratio, leaching temperature, liquid-solid ratio, and operation time on the removing efficiencies of Zn, Sn, Fe and Al, were studied. The results showed that more than 95% of impurities can be removed when the mole ratio of impurities to H 2 SO 4 was 1:4, the temperature was 70 °C, the liquid-solid ratio was 20 mL/g, along with the leaching time of 180 min. After 1440 min electrolysis of the pretreated granules with the electric current density of 40 mA/cm 2 , the purity of refined copper foil maintained at 99% in contrast with 95% which copper granules are without pretreatment. The maximal concentration of the accumulated ions of impurities is less than 60 mg/L, which suggests that sulfuric acidic pretreatment is a promising approach to increase the duration of the electrolyte solution.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2023
·
IF 3.5
Guang Yang,Hengwei Yan,Zhanwei Liu,Wenhui Ma,Shenghui Guo,Yonghui Yang
In this study, aluminothermic reduction and molten salt electrolysis were combined to prepare titanium powder. In this combined method, titanium dioxide was first deoxidized to produce titanium–aluminum alloy through an aluminothermic reduction reaction, and then the titanium–aluminum alloy was separated through chloride molten salt electrolysis to generate titanium powder. The obtained titanium powder, titanium aluminum alloy and slag was analyzed using several techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. A mass ratio of 2:3 of titanium dioxide and aluminum was suitable for the production of titanium–aluminum alloys. A large amount of alumina generated through the aluminothermic reduction reaction was separated into slag phases using cryolite. Then, the phases were electrolyzed into aluminum and cryolite, which were reused as raw materials. The final titanium–aluminum alloy product was electrolyzed in a chloride molten salt system to separate titanium and aluminum and produce titanium powder. Therefore, the combination of thermal reduction and molten salt electrolysis is efficient and has great potential for producing high-purity titanium powder.
研究领域:
材料科学
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冶金工程
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2023
·
IF 8.1
Cong Li,Xiaofeng Yang,Yongkui Li,Yu Chen,Xiaodong Pan,Yongping Xie,Xingyu Liu,Suqin Li
Hematite tailings (HTs) are rich in silica and are used as replacements for fine aggregates in the preparation of construction materials. However, there is scope for a more effective utilization of the valuable elements present in HTs. In this paper, a process for preparing high-purity SiO 2 using HTs procured from Ansteel (China) is proposed. HTs were treated using the superconducting high-gradient magnetic separation (S-HGMS) technology, where the silica as part of the nonmagnetic fraction was obtained in the form of a high-silica concentrate, which was then subjected to mixed-acid leaching to dissolve impurities to achieve refined purification. The optimum process conditions for S-HGMS were determined, and the response surface methodology was applied to optimize the process parameters of the mixed-acid leaching process. The process indicators of the mixed-acid leaching step included the leaching time, leaching temperature, and molar ratio of the mixed acids. The optimum process conditions for S-HGMS were as follows: the magnetic strength-to-velocity ratio in the weak magnetic separation stage was set to 0.034 T·s/m whereas it was maintained at 0.076 T·s/m in the strong magnetic separation stage; the pulp concentration was 40 g/L, the pulp velocity was 500 mL/min, and the dispersant concentration was 1 mg/g. Under these conditions, the high-silica pulp was processed. The corresponding SiO 2 grade increased from 71.788 % to 95.260 %, and its recovery and yield reached 56.330 % and 42.450 %, respectively. The SiO 2 content in the sample increased from 95.260 % to 99.961 %. Further, the mechanisms of the S-HGMS and mixed-acid leaching were revealed. The proposed process is environmentally friendly and operationally inexpensive. It can reduce the amount of HTs by 42.450 %, and the obtained high-purity silica product has high economic value and good industrialization prospects.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Xianjiang Li,Wei Zhang,Shukun Zhou,Xiao Li,Mengling Tu,Yunxiao Zhu,Qinghe Zhang,Hongmei Li
Thiamethoxam (TMX) belongs to the second-generation neonicotinoid pesticide, which is among the most common residual in food commodities. To guarantee accurate quantification and traceability of results in food samples, certified reference materials (CRMs) are indispensable benchmark. TMX was characterized and its purity value was assessed by two independent measurement methods including mass balance (MB) and quantitative nuclear magnetic resonance spectroscopy (qNMR). Its mass fraction was 997.0 mg/g and 991.7 mg/g in MB and qNMR, respectively. Eventually, a purity of 994 mg/g with standard uncertainty of 3 mg/g ( k = 2) was assigned to TMX.
研究领域:
食品科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Furong Jia,Yun Li,Hongfei Guo,Xueqing Chen,Jilin Cao
Currently, comprehensive utilization technology of seawater bittern faces several challenges, including low resource utilization efficiency, limited value of magnesium salt products, and high energy consumption. This study proposes an innovative approach to prepare high-purity MgO. This process begins with the reaction of brine with a mixed alkaline solution of NaOH-Na 2 CO 3 to synthesize basic magnesium carbonate (4MgCO 3 ·Mg(OH) 2 ·4 H 2 O). Subsequently, 4MgCO 3 ·Mg(OH) 2 ·4 H 2 O is transformed into a high-purity Mg(OH) 2 structure through the hydrothermal conversion method. Finally, high-purity MgO is obtained by calcining magnesium hydroxide. The effects of mixed alkali precipitation and hydrothermal reaction conditions on the structure, morphology, and purity of intermediate products and MgO are systematically investigated. The optimal conditions for preparing high-purity MgO are determined as follows: the molar ratio of Mg 2 + :CO 3 2− :OH − in seawater bittern to the NaOH-Na 2 CO 3 mixed alkali is 5:4.7:2, at a reaction temperature of 60 °C, stirring speed of 200 rpm, stirring time of 10 min, and reaction time of 35 min. Under these conditions, spherical 4MgCO 3 ·Mg(OH) 2 ·4 H 2 O is initially obtained. Subsequently, the 4MgCO 3 ·Mg(OH) 2 ·4 H 2 O underwent hydrothermal treatment at a solid-to-liquid ratio of 8:100 and a temperature of 120 °C. Polyethylene glycol (PEG) is added as a surfactant at 3 wt % of the solid content of 4MgCO 3 ·Mg(OH) 2 ·4 H 2 O, along with 5 g of NaOH (accounting for 62.5 wt %), for 2 h. This process yielded high-purity Mg(OH) 2 with a thin flake morphology. Finally, the high-purity Mg(OH) 2 is calcined at 500 °C for 4 h, resulting in cubic crystal nano-MgO with a purity of 99.8 % and an average particle size of approximately 30 nm.
研究领域:
材料科学
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化学工程
·
无机合成
·
纳米技术
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资源利用
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Yulin Zhai,Guoli Li,Kai Peng,Zhaosong Ge,Weibing Zhang,Duxin Li
The resolving power of multiple dimensional liquid chromatography (mD-LC) is multiplicative as it adds dimensions. However, the issue in creating a preparative mD-LC system is that the higher the dimensionality, the more complicated the system configuration. Thus, we presented a new configuration of preparative mD-LC using one set of LC modules and trapping array-based multiple heart-cut interfaces. A preparative two-dimensional liquid chromatography (2D-LC) separation of herbal medicine formulation produced 40 compounds with a purity of >90%. During the separation process, the interface stores the fractions and allocates positions for the fractions from a different dimension; LC draws the fraction from the interface, makes nD separation, and sends isolated fractions to the interface. By repeating this process, we achieved variable dimensionality of LC separations. We also presented a preparative 3D-LC separation of herbal medicines to validate the principle of “less configuration and more dimensionality”. Thus, we can explore the higher dimensional preparative separations. The developed preparative mD-LC displayed exceptional power in the isolation of various compounds and has great potential in the application of natural products.
研究领域:
分析化学
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天然产物化学
✓ 已验证
DOI
高影响因子
BIOTECHNOLOGY LETTERS
·
2019
·Vol. 41
·期 6
·789-799
·
IF 2.154
Wang Xiuwen,Cheng Yang,Jin Qingzhe,Wei Wei,Wang Xingguo
Objectives To investigate the lipase-catalyzed synthesis of high purity sn -1/3 and sn -2 monoacylglycerols (1/3-MAG and 2-MAG) of different fatty acids (FAs). Results The 1/3-MAGs of three FAs (16:0, 17:0, 16:1) were synthesized using lipase-catalyzed esterification of glycerol with FAs. The 2-MAGs were obtained from the ethanolysis of synthetic triacylglycerols using sn -1,3 regiospecific lipase. The effects of lipase types, substrate ratio, temperature, reaction time and lipase load on the MAG conversion were studied. Under the optimal conditions, high purities (96.74%, 95.44%, 92.96%) with acceptable isolated yields (51.00%, 54.28%, 46.00%) were obtained for 1/3-16:0-MAG, 1/3-17:0-MAG, and 1/3-16:1-MAG, respectively. For 2-16:0-MAG, 2-17:0-MAG, and 2-16:1-MAG, the purities were 92.64, 95.04, and 96.48%, with isolated yields of 50.64, 52.16, and 26.12%, respectively. The molecular structures of the synthetic compounds were confirmed by 1 H NMR, and MS and the melting points were characterized by DSC. Conclusions High purity MAG isomers can be synthesized via lipase-catalyzed reactions to be building blocks for production of functional lipids, the melting points of which are largely governed by the hydrophobic interactions among the alkanyl chains.
研究领域:
食品科学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Lei Yanhua,Zhang Anlin,Li Dongdong,Li Feng,Sun Huapeng,Deng Bin
A series of newly synthesized red-emitting phosphors, La 3 Ga 5 SnO 14 :Eu 3+ , were produced through high-temperature solid-state synthesis methods. The phase purity, particle morphology and optical properties were systematically investigated in this work. The prepared fluorescent material has high phase purity. La 3 Ga 5 SnO 14 :Eu 3+ has a strong red emission peak at 612 nm at the excitation at 268 nm, which is caused by the radiative transitions of electrons ( 5 D 0 → 7 F 2 ). The optimal doping concentration of Eu 3+ was observed to be 30 mol% in this series of La 3 Ga 5 SnO 14 :Eu 3+ . The mechanism of concentration quenching was determined to be dipole-quadrupole interaction. The chromaticity coordinates of La 3 Ga 5 SnO 14 :30 mol%Eu 3+ were (0.648, 0.352) with a corresponding high color purity of 100%. The thermal stability of the phosphor was also characterized. The luminous intensity could be sustained at 54% at 480 K. The quantum efficiency of the La 3 Ga 5 SnO 14 :30 mol%Eu 3+ phosphor is 64.4%. The exhaustive findings from this study form the basis for advocating the application of these phosphors in light-emitting devices.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yiang Du,Chong Wang,Wenjun Liu,Tuo Yan,Jiaxuan Li,Bing Wang,Yingde Wang
Boron nitride (BN) has excellent high temperature resistance, thermal conductivity , strong insulation, and wave-transparent properties. Spherical BN is an essential filler in polymer matrix composites due to good particle mobility and high filler content. In this paper, we present a large-scale preparation for BN microspheres with uniform particle size distribution in the range of 1.0–2.8 μm via solvothermal method at low cost and high yield (∼90%), which is two orders of magnitude lower than the diameter of the spherical BN prepared by other methods. BN microspheres can achieve good crystallinity (>70%) and high purity (>99.9%) at 800 °C. The temperature resistance study showed that the BN microspheres could maintain the dense particle morphology at 1200 °C. In addition, the prepared BN microspheres have good dielectric and thermal conductivity properties (dielectric constant ∼3.4, dielectric loss ∼2.0 × 10 −3 , and thermal conductivity of 9.8 W m −1 K −1 ), which show great potential in the field of wave-transparent and thermal conductive composites. The synthesis process of BN microspheres proposed in this study provides a new idea for the preparation of ceramic micro or nano materials by polymer-derived ceramics.
研究领域:
材料科学
·
陶瓷材料
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2020
·
IF 4.142
Xuesong Jiang,Jian Chen,Mengnan Wei,Feifei Li,Boyuan Ban,Jingwei Li
The purity of quartz particles obtained by crushing the same quartz is different. Poly (propylene glycol) bis (2-aminopropyl ether) (PEA) was used to separate quartz sand particles of different purity by flotation . Through flotation experiments combined with XRD , ICP , FT-IR, and XPS , the collection performance and adsorption principle were studied. Froth flotation results demonstrate that particles with higher purity can be more readily floated. Batch flotation results indicate that the first froth product (F1) has the highest purity and its removal rates of Al, K and Na reached 84.6%, 80.7% and 84.1%. The total impurity content (Al, K, Na) of F1 (448 ppmw), F2 (579 ppmw) and F3 (972 ppmw) is lower than the Feed (2717.4 ppmw) and their mass proportion is greater than 25%. XPS analyses confirm that the impurities are mainly enriched on the fracture surface. Consequently, the crushing-classification mechanism and the PEA adsorption model have been proposed.
研究领域:
矿物加工工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）