共查询到20条相似文献,搜索用时 15 毫秒
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F.P. McCandless 《Journal of membrane science》1984,19(1):101-113
A comparison is made of separation factors commonly used to characterize separations in single-entry barrier-permeation stages. These include the overall, heads, tails and Sandell's separation factors together with Rony's extent of separation. Equations are developed which show how the various separation indexes are related to stage cut, recovery and loss terms, and to each other. Calculations were made to compare the various separation indexes to determine which are suitable to characterize the “goodness” of separation in ideal countercurrent, cross-flow, cocurrent, and perfect mixed permeation stages. When compared at the same stage cut all of the separation indexes can be used as a qualitative measure of separation. However, only Rony's extent of separation appears to be generally applicable when comparing separations that are based on different stage cuts, or product stream rates. In all cases the extent of separation index gives a qualitative, and presumably a quantitative, measure of the goodness of separation. 相似文献
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微流控芯片毛细管电泳在蛋白质分离分析中的应用研究进展 总被引:1,自引:1,他引:0
重点介绍了近年来国内外在微流控芯片毛细管电泳法用于蛋白质分离分析方面的研究进展。按照分离模式的不同,综述了各种应用于蛋白质分离的微流控芯片毛细管电泳系统,讨论了抑制芯片中的蛋白吸附的各种方法,并展望了芯片毛细管电泳系统在蛋白质分离领域的发展前景。引用文献47篇。 相似文献
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在现有支撑液膜分离技术的理论研究基础上,探索合适的液膜分离体系,研究了Pb(Ⅱ)在PC-88A-煤油-HCl分散支撑液膜体系中的传输行为;考察了料液pH值、膜溶液与解析剂体积比、解析相中HCl浓度以及Pb(Ⅱ)的起始浓度对Pb(Ⅱ)传输的影响。 结果表明,以HCl为解析剂,料液相pH=5.25、膜溶液与解析剂体积比为160∶40、解析相中HCl浓度为5.00 mol/L时,该分散支撑液膜体系对金属Pb(Ⅱ)具有良好的传输作用。 在选取的最佳传输条件下,料液相中Pb(Ⅱ)的初始浓度为3.00×10-4 mol/L时,传输190 min,传输率可达88.9%,而传统支撑液膜只有72.3%。 分散支撑液膜不仅具有较高的传输效率,而且膜体系稳定,膜的使用寿命长。 相似文献
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E. W. Becker K. Bier W. Bier R. Schütte D. Seidel 《Angewandte Chemie (International ed. in English)》1967,6(6):507-518
The separation nozzle process is based on the partial spatial separation of components of different mass in an expanding supersonic jet stream. The process is of especial interest for the separation of uranium isotopes. Details of a systematic experimental determination of the most favorable operating conditions for such a separation are given and the construction and testing of a closed circulation system, the basic unit of a ten membered pilot cascade separator for uranium isotope separation, is described. The optimum values of the specific cost factors obtained experimentally for the separation nozzle process are compared with the corresponding values estimated for the gaseous diffusion process. 相似文献
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超临界流体色谱法分离手性药物 总被引:11,自引:2,他引:9
对超临界流体色谱技术(SFC)在手性药物分离方面的研究与应用状况做了评述,对超临界流体色谱手性分离的分离方式、操作条件及影响因素作了介绍。 相似文献
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分子筛材料在小分子吸附分离中的应用 总被引:1,自引:0,他引:1
吸附分离技术与工艺在工业上具有重要意义. 常见的吸附剂包括沸石分子筛、 金属有机框架材料、 活性炭等材料. 分子筛具有比表面积大、 稳定性高、 生产成本低等优势, 可以满足吸附分离技术中高效、 节能和环保的需求, 是一种非常有应用前景的小分子混合物分离吸附剂. 本文综合评述了吸附分离领域中常用的吸附剂材料的特点和吸附分离机理与评价方法, 总结了分子筛在空气分离、 烃类分离、 二氧化碳吸附、 芳香硫化物脱除、 一氧化碳吸附、 氮氧化物吸附、 氢气储存吸附及氢同位素分离等领域的应用, 并对基于分子筛膜的小分子混合物分离现状进行了介绍. 此外, 本文还系统分析了分子筛对不同混合物的吸附分离性能与其拓扑结构、 骨架组成及改性方法之间的关系, 并对未来的研究前景进行了展望. 相似文献
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Blumberg LM 《Journal of chromatography. A》2011,1218(32):5375-5385
Earlier introduced metrics of separation performance are described in a systematic way. After providing the definitions of the metrics suitable for a broad variety of applications, the study focuses on static analyses (isothermal GC, isocratic LC, etc.) and their general separation performance. Statistically expected number of resolved (adequately separated) single-component peaks is treated as the ultimate metric of general separation performance of chromatographic analysis. That number depends on the peak capacity of the analysis and the number of components in a test mixture. The peak capacity, in turn, depends on the separation capacity of a column and the lowest separation required by the data-analysis system for resolving poorly separated peaks. The separation capacity is a special case of a broader metric of the separation measure which is a function of column efficiency, solute separability, and the level of the solute interaction with a column stationary phase. The formulae for theoretical prediction of all these metrics for arbitrary pairs of peaks in static analyses are derived. To provide a better insight into the basic metrics of the separation performance, additional metrics such as the solute discrimination (relative difference in solute velocities), utilization of separability (solute discrimination per unit of their separability), specific separation (the separation per unit of separability), and others are defined and found for static analyses. 相似文献
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Synchronized cyclic capillary electrophoresis using channels arranged in a triangle and low voltages
A Manz L Bousse A Chow T B Metha A Kopf-Sill J W Parce 《Fresenius' Journal of Analytical Chemistry》2001,371(2):195-201
Synchronized cyclic capillary electrophoresis (SCCE) makes use of a closed loop separation channel by which the same sample can be separated during many cycles. This enables the repeated use of the same voltage for separations such that a high total voltage, and thus high efficiency, is obtained for the synchronized components. This can be accomplished by using any type of polygon geometry for the separation channel; and calculations of the available field and number of connections needed for polygons from 3 to 5 sides are presented. Triangular designs have the advantage of using the lowest number of wells. Such designs are described, with two additional features compared to that of earlier work: 1. voltage connections that are much shallower than the separation channel, to reduce losses and dispersion at the intersections; and 2. corners that are narrower than the separation channels to reduce dispersion in the turns. Experimental data is presented for the separation of a mixture of amino acids, and for a DNA separation in a polymeric sieving matrix. The DNA separation is most sensitive to the corner dispersion problem, which reduces the observed efficiency for that separation. 相似文献
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乙烯,作为石油化工行业的龙头原料,其高效回收分离具有重要的战略意义。离子液体作为一种结构可调控的新型绿色溶剂,在乙烯的回收分离中展现出巨大的应用前景。本文总结了近年来离子液体在乙烯/乙烷和乙烯/乙炔分离方面的研究进展,从溶剂吸收、膜吸收和与多孔材料相结合的吸附分离法等角度展开,系统地阐述了常规离子液体、功能化离子液体、聚离子液体等纯组分体系及多组分体系在不同分离方法中的研究现状,展望了离子液体在乙烯回收分离方面的应用前景和发展趋势。 相似文献
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Separation of enantiomers has become a well-established technique in many fields of science over the last decade. Unfortunately, even though there are a large number of chiral stationary phases able to perform enantiomeric separation, there is still a great deal of trial and error in developing a method for the separation of enantiomers. Thin-layer chromatography is a very versatile technique, which has brought much advancement in various fields of science. The simplicity of the technique makes it amenable for separation of enantiomers. This paper will present a review of the literature concerning separation of enantiomers. Because of the process of trial and error present in developing a chiral separation method, this paper also presents the mechanism underlying each form of separation. Thus, the methods are presented according to the main mechanism governing the particular separation. 相似文献
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This paper presents the use of a physical model and numerical simulation in the investigation of traveling electric fields on capillary electrophoresis (CE) chips. The principal material transport mechanisms of electrokinetic migration, ionic concentration, fluid flow, and diffusion are all taken into consideration. Traditionally, the high electric field strength required for the separation of biological samples by microfluidic devices has involved the application of high external voltages. In contrast, this study presents a proposal for samples separation by means of a moving electric field within a low voltage-driven CE chip. Under this proposal, the separation channel is partitioned into a series of smaller separation zones by means of electrode pairs. This paper considers two different electrode configurations, namely arranged along a single side of the separation channel, and arranged on two sides of the separation channel. The quality of the separation achieved with these two configurations is then compared with the traditional straight separation channel approach. The results confirm that the proposed method is successful in maintaining an adequate field strength for separation purposes in a low-voltage driven CE chip. Furthermore, it is determined that the best separation results are obtained using electrodes arranged along both sides of the separation channel. 相似文献
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V. Koprda 《Journal of Radioanalytical and Nuclear Chemistry》1974,21(1):211-216
A quantitative separation scheme for 15 radionuclides is presented. The scheme is based on group separation by means of anion-exchange
resins using mixed solvent systems and subsequent separation of the groups into individual components by means of change of
both eluting agent and resin type. The optimum working conditions for separation are established. Separation procedures are
of good reproducibility and practically quantitative. 相似文献
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《Journal of separation science》2018,41(15):3163-3169
Repeated separation is a valuable method in counter current chromatography, especially on a preparative scale. It can greatly reduce the separation time and the consumption of solvent. In this study, an overlapping repeated separation method was developed. Meanwhile, this method was used to separate steviol glycosides and compared with conventional repeated separation method. The results show that both methods are effective ways for countercurrent chromatography to prepare compounds but the overlapping repeated separation method requires fewer time and solvent than the conventional repeated separation method. So this novel repeated separation method has enormous potential for a preparative separation of target compounds and is very useful for the high‐throughput purification of natural products. 相似文献
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M. Hahn C. Voigt H. H. Rüttinger H. Matschiner 《Fresenius' Journal of Analytical Chemistry》1992,344(7-8):311-315
Summary The coupling is described of coulometric separation methods with an ion exchange separation step. Various methods of enrichment and separation are described using the analysis of nitrogen compounds, such as ammonia, urea and nitrite, as examples. A microcomputer controls the separation step and regulates the coulometric determination. Quantitative separations are achieved in all cases, so that the advantage of coulometric titration, as a precise absolute determination method, is retained. 相似文献