SEPARATION AND PURIFICATION TECHNOLOGY
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2021
·
IF 7.312
Yaxing Han,Ji Chen,Yuefeng Deng,Tianchi Liu,Hailian Li,Deqian Li
The current separation technique of ion-adsorption high yttrium (Y) rare earth ore (high-yttrium ore) using 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) and naphthenic acid (NA) has been confronted with low separation efficiency and high acid consumption. This is a consequence of the low selectivity and the difficulty of complete stripping of heavy rare earths (HREEs). Therefore, an innovative separation technique of high-yttrium ore was proposed. The leachate of high-yttrium ore was firstly divided into Erbium (Er) / Thulium (Tm) groups with P507-isooctanol followed by separating Y (III) from the high Y-enrichment of Er (III) group with sec -octylphenoxy acetic acid (CA12)-tri- n -butyl phosphate (TBP). The basic thermodynamics experiments and cascade extraction simulations were conducted to verify the feasibility of this technology. The results show that P507-15vol% isooctanol is superior to P507 in both stripping ability and separation selectivity of HREEs. The first cascade extraction for Er (III) / Tm (III) grouping with P507-15vol% isooctanol was simulated successfully, reducing acid consumption but obtaining high purity products. In theory, the second cascade extraction simulation designed for separating Y (III) with CA12-TBP could not only improve the separation ability between Y (III) and light rare earths (LREEs) but also shorten the extraction stages and reduce the production costs. All these results revealed that this two-step separation process probably provided a promising application prospect for separating high-yttrium ore.
研究领域:
冶金工程
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稀土化学
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分离科学与技术
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资源加工工程
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湿法冶金
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萃取分离
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DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2015
·Vol. 94
·期 3
·424-429
·
IF 1.231
Xia Gui,Ying Ding,Zhi Yun
An integrated approach was developed for preparing epoxy fatty acid methyl esters (EFAMEs) from cottonseed using a two-phase solvent extraction (TPSE) process followed by sequential base-catalyzed transesterification and epoxidation reactions. The TPSE process was performed to achieve simultaneous production of high-quality crude cottonseed oil and nontoxic cottonseed meal. The base-catalyzed transesterification of the cottonseed oil proceeded smoothly at 30 °C over 2 h to provide a high yield of fatty acid methyl esters (FAMEs). Subsequent epoxidation of the unsaturated FAMEs using petroleum ether as a non-polar solvent, H 3 PO 4 as a catalyst, 0.3 g/g H 2 O 2 as an oxygen donor, and HCOOH as an oxygen carrier gave the corresponding EFAMEs with a conversion to oxirane of 0.85 g/g. The order of effectiveness of catalysts was found to be H 3 PO 4 > TiO 2 > H 2 SO 4 > strong-acid cation exchange resin. The bio-based integrated process and new methods for the preparation of modified EFAMEs show great promise for comprehensive development and commercial applications of cottonseed with fewer steps and lower cost.
研究领域:
应用化学
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油脂化学
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生物基材料
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绿色化工
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天然产物转化
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DOI
高影响因子
Food Analytical Methods
·
2015
·Vol. 9
·期 7
·2026-2035
·
IF 1.956
Du Jiaojiao,Gao Ruixia,Mu Hui
Phthalates represent a potential risk for humans, since they are ubiquitous environmental contaminants. Efficient extraction and purification procedures are demanded for the detection of low concentration levels of phthalates. In this work, a novel type of molecularly imprinted polymers coated onto the surface of vinyl functionalized multi-walled carbon nanotubes was synthesized and coupled with gas chromatography–mass spectrometry (GC/MS) for the selective separation and determination of dioctyl phthalate (DOP) in beverage samples. The morphology, structure property, and thermostability of the resultant polymers were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The adsorption properties of the prepared polymers were investigated by equilibrium rebinding and competitive experiments. The resultant imprinted nanomaterials exhibited high capacity and favorable selectivity. In addition, the feasibility of the developed method using the obtained imprinted polymers as a solid-phase sorbent coupled with GC/MS for the selective isolation and determination of DOP in different beverage samples was demonstrated. Under optimal conditions, the limit of detection of the proposed method for DOP was 2.3 ng L −1 . DOP spiked at three levels of concentration in beverage samples was extracted and determined through the application of the present method, with recoveries ranging from 88.6 to 93.0 % with relative standard deviations less than 5.6 %.
研究领域:
分析化学
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环境毒理学
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食品安全
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分子识别
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材料科学
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色谱分析
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DOI
高影响因子
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
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2019
·
IF 1.267
Yue Yang,Zihui Liu,Hao Chen,Shengqing Li
A simple and fast method of low-density solvent based dispersive liquid-liquid microextraction (LDS-DLLME) followed by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed for the speciation analysis of organoarsenic and inorganic arsenic in water samples. The low-density solvent (octanol) was given as the organic phase and injected into the aqueous sample (donor phase) with methanol as the disperser. With As (V), As (III), p-APAA, 4-HPAA, ROX and PAA as target species, factors of LDS-DLLME including pH value, anionic carriers, elution conditions and extractant, were studied in detail. Besides, volumes of solvents were further optimised by response surface methodology. Under the optimal conditions, the limits of detection for four phenylarsenics and arsenate were in the range of 0.001–0.039 μg L−1. The relative standard deviations (RSDs) were 3.6–9.4% and the enrichment factors varied from 6.2 to 70.8. The proposed method of LDS-DLLME-HPLC-ICP-MS was satisfactorily applied to the determination of six arsenic compounds in water samples with recoveries of 81.8–111.7% for the spiked lake water samples.
研究领域:
环境科学
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分析化学
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2014
·
IF 3.583
Haiyun Zhai,Jiangmei Li,Zuanguang Chen,Zihao Su,Zhenping Liu,Xiao Yu
A simple glass/PDMS microfluidic chip for on-line sample pretreatment and contactless conductivity detection, which consisted of a 0.17 mm-thick glass cover and a PDMS substrate embedded with an SPE monolithic column, was presented in this paper. Using this integrated microchip system, sample extraction, injection, separation and detection were automatically performed in sequence. A sample of auramine O was concentrated by molecularly imprinted SPE (MISPE), eluted to sample reservoir, and injected by electromigration into separation channel for electrophoresis separation and contactless conductivity detection, with the calculated detection limit (S/N = 3) being 2.5 μg mL − 1 . The monolithic column was utilized to quantitatively extract auramine O , yielding an on-line enrichment factor of about 12. The microchip system is reliable and applicable to the analysis of auramine O in food sample.
研究领域:
分析化学
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微流控技术
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食品安全
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分子印迹技术
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电泳学
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生物医学工程
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DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2016
·
IF 3.847
Yong-gang Wang,Guang-ce Jiang,Sheng-juan Zhang,Hai-yong Zhang,Xiong-chao Lin,Xin Huang,Mao-hong Fan
The selectivity of organic solvent extraction for separating non-aromatic hydrocarbons, aromatic hydrocarbons and polar components in low-temperature coal tar was enhanced by applying the Hansen Solubility Parameters theory. The relationship between solubility parameter “distance” ( R a ) and solubility was obtained by turbidimetric titration, thus allowing an approximate comparison of dissolving properties between different solvents and the typical model compound (solute). A modified dissolving model in terms of the Hansen solubility sphere was established in order to select the extraction solvent. In practice, the low-temperature coal tar was successfully divided into three parts (i.e., enriching non-aromatic hydrocarbons, aromatic hydrocarbons and polar components) by a three-step extraction-precipitation process at 298 K and 1 atm. Experimental results demonstrated a high correlation with the estimation made by the ellipsoidal model. The mass percentage of non-aromatic hydrocarbons, aromatic hydrocarbons and polar components in their separation products were all ca. 90 wt.%. The mass percentages of the three products in total feedstock were around 12%, 46% and 36%, respectively. The mass loss during the entire separation process was from 4.5% to 6.0%.
研究领域:
能源化学
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煤化工
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分离科学
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物理化学
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应用化学
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材料化学
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过程工程
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DOI
高影响因子
CHROMATOGRAPHIA
·
2018
·Vol. 82
·期 3
·683-693
·
IF 1.401
Shen Chen,Wu Tong,Zang Xiaohuan
In this work, a zeolitic imidazolate framework-based graphene oxide composite (ZIF-8@GO) was prepared and used as the adsorbent in hollow fiber stir bar sorptive extraction. The stir bar was constructed of a small section of hollow fiber filled with 5 mg ZIF-8@GO and a thin stainless wire of 1.5 cm long in its lumen, and used to extract the trace levels of phthalate esters from children’s food samples prior to gas chromatography–mass spectrometric detection. The ZIF-8@GO showed a high adsorption efficiency for the compounds containing aromatic rings. The main experimental parameters that can impact the extraction efficiency including extraction temperature, extraction time, stirring rate, sample salinity, and desorption conditions were investigated. Under the optimized conditions, the limits of detection (LODs) for the five phthalate esters (diethyl phthalate, dipropyl phthalate, diisobutyl phthalate, butylbenzyl phthalate, and di(2-ethylhexyl) phthalate) were 0.15–0.6 µg L −1 for CiCi beverage and pear juice samples, and 0.75–2.2 µg kg −1 for jam samples. The limits of quantitation (LOQs) were 0.5–2.0 µg L −1 for CiCi beverage and pear juice samples, and 2.5–7.5 µg kg −1 for jam samples. Wide linear ranges of 0.5–500.0 µg L −1 and 2.5–2000 µg kg −1 were obtained for CiCi beverage, pear juice samples and jam samples, respectively, with good repeatability (RSD < 11%) and high method recoveries (72%–100%). The lifetime test results showed that the ZIF-8@GO-based hollow fiber stir bar can be reused for 120 extraction cycles without a significant loss of extraction efficiency, indicating its high durability and stability. The established method was applied successfully for the determination of the phthalate esters (PAEs) in children’s food samples. Graphical abstract
研究领域:
分析化学
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食品安全
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环境毒理学
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暴露科学
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食品化学
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污染物检测
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2016
·
IF 2.822
Fang Long,Jing Wang,Zhaohui Zhang,Liang Yan
A novel magnetic molecularly imprinted electrochemical sensor (MMIP-sensor) combined with magnetic molecularly imprinted solid-phase extraction (MMISPE) was constructed for rapid and sensitive detection of tetrabromobisphenol S (TBBPS) in water samples. The magnetic molecularly imprinted polymer based on magnetic graphene/multi-walled carbon nanotubes hybrid composite (MMIP/Gr-MWCNTs) was prepared as MMISPE sorbet to separate and enrich TBBPS from complex system. Adsorption results showed that the MMIP/Gr-MWCNTs possessed excellent selective adsorption toward TBBPS with a maximum adsorption capacity of 17.83 mg g − 1 . The magnetic imprinted sensor based on the magnetic Gr-MWCNTs composite modified electrode was prepared by electropolymerization of dopamine monomer . The high sensitivity of the MMIP-sensor was attributed to the large specific surface area and excellent electrical conductivity of the magnetic Gr-MWCNTs composites. The detection limit of the MIP-sensor toward TBBPS was calculated as 2.1 × 10 − 11 mol L − 1 (S/N = 3). Under the optimum conditions, the MISPE-MMIP-sensor combination system provided 10–12 fold preconcentration than that of MMIP-sensor alone determination. The MISPE-MMIP-sensor was successfully used for detection of TBBPS in drinking water , rain water , lake water and tap water with recoveries of 88.4–98.8%.
研究领域:
分析化学
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环境监测
·
电化学传感
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分子印迹技术
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水处理
·
污染物检测
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）