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Determination of inorganic anions in ethyl acetate by in-line hollow fiber membrane extraction with ion chromatography 被引量:1
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作者 Zhen Zhen Hu Ying Ying Zhong Yun Chang Fan Yan Zhu 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第12期1498-1501,共4页
In this work, a novel hollow fiber membrane extractor was set up to extract inorganic anions from ethyl acetate using deionized water. Inorganic anions in slightly soluble organic solvents can be determined by the in-... In this work, a novel hollow fiber membrane extractor was set up to extract inorganic anions from ethyl acetate using deionized water. Inorganic anions in slightly soluble organic solvents can be determined by the in-line hollow fiber membrane extractor coupled with ion chromatography at first time. Different aspects of the extraction procedure such as magnetic stirring speed, extraction flow rate and extraction time were optimized to achieve high extraction efficiency and good separation results. Satisfactory linear range, limits of detection and good repeatability were obtained. The procedure was applied to analyze inorganic anions in two commercial ethyl acetate samples. 展开更多
关键词 Inorganic anions Ethyl acetate In-line hollow fiber membrane extraction Ion chromatography
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Transport Behaviour of La^(3+) with Flat-Sheet-Sandwich Supported Liquid Membrane Extraction System
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作者 易涛 严纯华 +5 位作者 李标国 李洁 朱国斌 杜启云 王利生 胡小平 《Journal of Rare Earths》 SCIE EI CAS CSCD 1995年第2期81-84,共4页
This paper suggested a modified model of SLM which could improve its stability.In the model, an organic solution was sandwiched between two layers of supported film,which we called sandwich supported liquid membrane(S... This paper suggested a modified model of SLM which could improve its stability.In the model, an organic solution was sandwiched between two layers of supported film,which we called sandwich supported liquid membrane(SSLM).The transport experiments of La3+ were performed with SSLM containing HEH(EHP)as a carrier. The permeability coefficient (p) of La3+ were measured and some factors affecting the p were investigated. The results showed that if the pH of the feed was below 4.0,the p was increased with increasing in pH. The p was also increased when the strip acidity increases.Inspite of not enough satisfactory reproducibility on test result, the stability of the model was improved. 展开更多
关键词 Liquid membrane extraction LANTHANUM Permeability coefficient HEH(EHP) Flat-Sheet-Sandwich
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Transport Behaviour of La^(3+) with Hollow Fiber Sandwich Liquid Membrane Extraction System
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作者 朱国斌 李洁 +5 位作者 杜启云 王利生 胡小平 严纯华 易涛 李标国 《Journal of Rare Earths》 SCIE EI CAS CSCD 1995年第4期252-256,共5页
The extraction of La ̄(3+) with hollow fiber sandwich liquid membrane was described in present paper. The theoretical equations of mass transport for this system were deduced. The permeability coefficient p of mass tr... The extraction of La ̄(3+) with hollow fiber sandwich liquid membrane was described in present paper. The theoretical equations of mass transport for this system were deduced. The permeability coefficient p of mass transport and its related factors were observed experimentally. The p value was increased with increase of pH in the feed and became constant under the condition of pH over 4. The p value was the highest when the flow rate was at 30 ml/min. The value of the coefficient was lower than that of single hollow fiber supported liquid membrane under the same conditions, but the stability and concentrated capacity of the sandwich membrane was better. 展开更多
关键词 LANTHANUM Liquid membrane extraction Hollow fiber Permeability coefficient HEH ( EHP )
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Study on Transfer and Interfacial Kinetics of Neodymium and Samarium in Membrane Based Extraction
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作者 张凤君 马玖彤 +2 位作者 罗芳 李德谦 吴庸烈 《Journal of Rare Earths》 SCIE EI CAS CSCD 2002年第3期228-230,共3页
Extraction and interfacial kinetics of Nd 3+ and Sm 3+ with HEH/EHP kerosene in a hollow fiber membrane extractor were studied. The results show that the extraction reactions in the hollow fiber membrane e... Extraction and interfacial kinetics of Nd 3+ and Sm 3+ with HEH/EHP kerosene in a hollow fiber membrane extractor were studied. The results show that the extraction reactions in the hollow fiber membrane extractor are the same as those in the liquid liquid extraction, which can be expressed as a quasi first order reaction. The effect of acidity in aqueous phase, concentrations of extractant, Nd 3+ and Sm 3+ on extraction rate were discussed and the corresponding reaction series were obtained. The reaction equations, reaction rate constants and the separation constant were obtained. 展开更多
关键词 rare earths hollow fiber membrane extraction transfer kinetics
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Hollow-Fiber Microporous Membrane Liquid-Liquid Extraction for Determination of Polybrominated Diphenyl Ethers at Trace Levels in Sewage Sludge with Gas Chromatography-Electron Capture Detection
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作者 Azadeh Sharifi Aghili Jan Ake Jonsson 《Journal of Environmental Protection》 2011年第2期198-203,共6页
A two-phase hollow-fiber (HF) liquid-phase microextraction (LPME) method followed by gas chromatography was developed for quantification of 8 major polybrominated diphenyl ethers at trace level in sewage sludge. In th... A two-phase hollow-fiber (HF) liquid-phase microextraction (LPME) method followed by gas chromatography was developed for quantification of 8 major polybrominated diphenyl ethers at trace level in sewage sludge. In this method the porous polypropylene hollow fibers filled with a few microliters of organic solvent, were immersed in aqueous samples of wet sludge which were spiked with the PBDEs at ng/l level. Parameters such as salt concentration, stirring speed, extraction time and pH were optimized and the optimum extraction conditions were then applied to the determination of PBDEs in sewage sludge from K?llby sewage treatment plant in Lund. The optimized method allowed detection of 5.1 μg kg–1 and 0.43 μg kg–1 of BDE-47 and 183, respectively, in dried sludge. The findings were compatible with the results from recent research on PBDEs level in sewage sludge samples from Sweden. Although BDE-209 was expected to have the highest level, it was not detected. Limit of detection, photodegradation or/and biodegradation of BDE-209 during treatment or experiment are major reasons. Low organic solvent consumption, low sample volume requirement, high preconcentration factor, simplicity without using expensive instrument for extraction and excellent sample clean-up are some important factors that make this sample preparation technique very useful for determination of PBDEs in sludge. 展开更多
关键词 PBDE Gas Chromatography Sewage Sludge membrane extraction LPME
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Transport of yttrium metal ions through fibers supported liquid membrane solvent extraction
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作者 A.G.Gaikwad A.M.Rajput 《Journal of Rare Earths》 SCIE EI CAS CSCD 2010年第1期1-6,共6页
A novel idea of transport of yttrium(Ⅲ) metal ions through fibers supported liquid membrane in two stage processes namely source to membrane and membrane to receiving phase has been proposed.The fibers supported liqu... A novel idea of transport of yttrium(Ⅲ) metal ions through fibers supported liquid membrane in two stage processes namely source to membrane and membrane to receiving phase has been proposed.The fibers supported liquid membrane was impregnated with different concentrations carrier.The experimental variables explored were concentration of yttrium(Ⅲ) ions,pH of source phase,PC-88A concentration in membrane phase,acid concentration in receiving phase and stirring speed.The pre-concentration of yttrium(Ⅲ) ions ... 展开更多
关键词 fibers supported liquid membrane solvent extraction yttrium metal ion CHANNEL extraction STRIPPING PC-88A rare earths
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Study on a novel flat renewal supported liquid membrane with D2EHPA and hydrogen nitrate for neodymium extraction 被引量:4
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作者 PEI Liang WANG Liming YU Guoqiang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第1期63-68,共6页
The Nd(III) extraction in flat renewal supported liquid membrane(FRSLM),with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl) phosphori... The Nd(III) extraction in flat renewal supported liquid membrane(FRSLM),with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl) phosphoric acid(D2EHPA) dissolved in kerosene as the membrane solution,was investigated.The effects of pH in the feed phase,volume ratio of membrane solution to stripping solution,concentra-tion of HNO3 solution and concentration of carrier in the renewal phase on extraction of Nd(III) were also studied,respectively.As a result,the optimum extraction conditions of Nd(III) were obtained when concentration of HNO3 solution was 4.00 mol/L,concentration of D2EHPA was 0.100 mol/L,and volume ratio of membrane solution to stripping solution was 1.00 in the renewal phase,and pH was 4.60 in the feed phase.When initial concentration of Nd(III) was 2.00×10-4 mol/L,the extraction percentage of Nd(III) was up to 92.9% in 75 min. 展开更多
关键词 membrane extraction flat renewal supported liquid membrane di(2-ethylhexyl) phosphoric acid NEODYMIUM extraction flux rare earths
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Biosynthesis of Callose and Cellulose by Detergent Extracts of Tobacco Cell Membranes and Quantification of the Polymers Synthesized in vitro 被引量:2
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作者 Carolina Cifuentes Vincent Bulone Anne Mie C.Emons 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2010年第2期221-233,共13页
The conditions that favor the in vitro synthesis of cellulose from tobacco BY-2 cell extracts were determined. The procedure leading to the highest yield of cellulose consisted of incubating digitonin extracts of memb... The conditions that favor the in vitro synthesis of cellulose from tobacco BY-2 cell extracts were determined. The procedure leading to the highest yield of cellulose consisted of incubating digitonin extracts of membranes from 11-day-old tobacco BY-2 cells in the presence of 1 mM UDP-glucose, 8 mM Ca^2+ and 8 mM Mg^2+. Under these conditions, up to nearly 40% of the polysaccharides synthesized in vitro corresponded to cellulose, the other polymer synthesized being callose. Transmission electron microscopy analysis revealed the occurrence of two types of structures in the synthetic reactions. The first type consisted of small aggregates with a diameter between 3 and 5 nm that associated to form fibrillar strings of a maximum length of 400 nm. These structures were sensitive to the acetic/nitric acid treatment of Updegraff and corresponded to callose. The second type of structures was resistant to the Updegraff reagent and corresponded to straight cellulose microfibrils of 2-3 nm in diameter and 200 nm to up to 5 μm in length. In vitro reactions performed on electron microscopy grids indicated that the minimal rate of microfibril elongation in vitro is 120 nm/min. Measurements of retardance by liquid crystal polarization microscopy as a function of time showed that small groups of microfibrils increased in retardance by up to 0.047 nm/min per pixel, confirming the formation of organized structures. 展开更多
关键词 Biosynthesis of Callose and Cellulose by Detergent Extracts of Tobacco Cell membranes and Quantification of the Polymers Synthesized in vitro
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