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本文介绍了3,3'-(苯亚甲基)双吲哚的制备和柱层析分离实验的原理和操作步骤。该实验具有以下特点:(1)反应时间短,30min左右便可完成;(2)产物为粉红色,在进行硅胶板层析和层析柱时比较直观,适合于学生的实验教学;(3)反应物、催化剂和产物的极性相差很大,容易进行柱层析分离产物。该实验特别适合于综合性大学和地方高等师范院校化学和相关本科专业的"有机化学实验"或"综合化学实验"进行开设。 相似文献
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本文介绍了3,3’-(苯亚甲基)双吲哚的制备和柱层析分离实验的原理和操作步骤。该实验具有以下特点:(1)反应时间短,30min左右便可完成;(2)产物为粉红色,在进行硅胶板层析和层析柱时比较直观,适合于学生的实验教学;(3)反应物、催化剂和产物的极性相差很大,容易进行柱层析分离产物。该实验特别适合于综合性大学和地方高等师范院校化学和相关本科专业的"有机化学实验"或"综合化学实验"进行开设。 相似文献
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设计了一个综合性化学实验——生物质的液化转化及其产物的分离分析。实验内容包括生物质(麦秆)的醇解液化;气/液/固产物的收集与分离,以及用气相色谱仪、气相质谱联用仪、红外光谱仪和热重分析仪等对产物成分与结构的检测与表征;液体产物(生物油)的萃取与柱层析分离,以提取苯乙酮、2,6-二甲氧基苯酚等高附加值化学品。该实验从社会能源现状出发,使学生的理论知识与实际应用相结合,可以激发学生对于新能源化学的兴趣;实验中涉及到多种分离纯化手段的运用和产物分析仪器的使用,提高了学生基本实验技能、动手操作能力和数据处理能力;同时鼓励学生进行知识拓展,进行创新方案设计。 相似文献
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本文经过匀浆、聚乙二醇分级沉淀和DEAE-Sephadex A-50柱层析分离步骤,进一步用蓝色三嗪染料琼脂糖柱层析分离,得到了电泳均一的鸡肝果糖-6-磷酸-2-激酶(EC2.7.2.105)。该酶的性质为:(1)对果糖-6-磷酸的底物饱和曲线为双曲线型,无机磷降低果糖-6-磷酸的Km,而不影响V_(max);(2)对底物ATP的结合具有负协同性,Hill系数为0.56;(3)受低浓度Mg~(2+)的激活,但受高浓度Mg~(2+)的抑制,在EDTA存在下不表现活力;(4)在30℃内较稳定,高于40℃下易失活;(5)在pH7—9范围内活性比较平稳,pH高于9.0时,活性上升,而在大于9.5后,活性很快下降;(6)对胰蛋白酶较敏感,但ATP对其有显著的保护作用。 相似文献
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以苯肼与乙酰乙酸乙酯为起始原料,经过6步反应制得新型1,5-苯并硫氮杂衍生物。采用重结晶或柱层析等操作对中间产物及目标产物进行分离提纯,并通过IR、MS及~1HNMR对目标化合物结构进行表征。通过该系统性的训练,可培养学生的综合实验能力、独立科研能力及综合创新能力。 相似文献
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The complexation of technetium with humic acid is usually done by a reduction of pertechnetate by Sn2+ ions. A Tc-HA complex can be scavenged in a Sn-HA complex, if tin is present as reductant. The main aim of the study was a preparation of the Tc-HA complex without impurities of Sn ions or other metal reductant, which was performed by a ligand exchange with hexakis(thiourea-S)technetium(III) under nitrogen atmosphere at pH 5.5. The [Tc(tu)6]3+ complex was prepared from TcO4
- in acidic solution with thiourea as a reductant. Presence of the Tc-HA complex and other technetium species was determined by gel chromatography, paper chromatography and dialysis. Yield of Tc-HA complex was about 80% and reaction mixture contains about 20% of technetium dioxide, which is a side product of ligand-exchange. 相似文献
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《Green Chemistry Letters and Reviews》2013,6(3):251-254
Abstract An efficient synthesis of 1,3-bis(1,4,7-triazacyclonon-1-yl)-2-hydroxypropane is described. In contrast to earlier procedures, an improved synthetic strategy led to the selection of suitable reagents and conditions that afforded the title compound in excellent overall yield with improved process efficiency and scalability. Moreover, the mildness and synthetic efficiency of the chosen conditions were particularly well-suited for the large-scale synthesis of the title compound, which is in increasing demand for a variety of applications, including the preparation of stationary phases for immobilized metal-ion affinity chromatography of recombinant proteins. 相似文献
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P. Tkac R. Kopunec S. Skraskova 《Journal of Radioanalytical and Nuclear Chemistry》2003,258(2):215-220
The preparation of technetium-99m-humic complex without presence of any metal reductant was studied. For the preparation of Tc-HA complex by ligand substitution hexakis(thiourea-S)technetium(III) complex was used as a precursor. Ligand exchanging reaction was studied with two different humate/thiourea concentration ratios. After mixing of [99mTc(tu)6]3+ complex with natrium humate under a nitrogen atmosphere a formation of technetium humate wasobserved. The determination of reaction products was performed by combination of gel and paper chromatography. Reaction yields are dependent on humate/thiourea concentration ratio and reaction time. Tc-HA complex was obtained with the highest yield of 62%. Reaction mixture also contains a technetium dioxide as a side product of exchanging reaction and other technetium species, which are also discussed. Oxidation state of technetium in prepared Tc-HA complex is apparently unchanged. 相似文献
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F. R. Abou-Shakra A. B. Sage J. Castro-Perez J. K. Nicholson J. C. Lindon G. B. Scarfe I. D. Wilson 《Chromatographia》2002,56(1):S9-S18
Summary The paper describes the role and tasks of environmental analysis and monitoring. It emphasises the leading role played by
gas chromatography, especially when coupled with suitable sample preparation. This is demonstrated by some literature evidence
and mainly by the author's original work on the design of sample preparation apparatus and development of GC-based methods
of determination of a wide variety of organic pollutants in environmental samples. A typical example is the physical speciation
of PAHs and PCBs in river environment with the use of a home-made filtration vessel coupled with SPE cartridges to prepare
samples for GC-MS analysis; thin layer head space with self-generation of aqueous concentrate to prepare humane urine samples
for DAI (direct aqueous injection)-GC-ECD analysis for the content of volatile chloro-organic compounds; studies on capillary
denuders in sampling organic air pollutants; passive dosimeters in indoor air quality measurements; design and application
of thermal desorbers for the introduction of analytes into GC columns and modification of a speciation analyser for organometalic
environmental pollutants.
Presented at Balaton Symposium '01 on High-Performance Separation Methods, Siófok, Hungary, September 2–4, 2001 相似文献
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Purification and identification of PEGlated hemoglobin, a potential blood substitute, by chromatography and capillary electrophoresis 总被引:2,自引:0,他引:2
Summary Bovine hemoglobin (Hb) has been chemically modified, by reaction of its lysine residues with the active ester of poly(ethylene
glycol) (PEG,M
w=5000), to produce a potential blood substitute for human therapy. Covalent attachment of PEG chain to the protein produced
a heterogeneous mixture of Hb from the mixture. This paper describes the use of cation-exchange chromatography (IEC), in flow-through
mode, and size-exclusion chromatography (SEC) for purification of the PEG-Hb mixture. The highly modified Hb flowed through
the IEC column in the loading buffer without adsorption by the chromatographic medium. SEC was then used for further purification.
These two steps were suitable for pilot-scale preparation or for analytical chromatography. The purified product was assessed
by high-performance capillary electrophoresis (HPCE), which was also used to optimize the chromatographic parameters. 相似文献
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In order to assess the environmental risks of a compound it is imperative to have suitable and reliable techniques for its determination in environmental matrices. In this paper, we focused on a method development for the recently introduced online coupling of a field flow fractionation (FFF) system to an Orbitrap-HRMS, that allows the simultaneous size and concentration determination of different aqueous fullerene aggregates and their concentrations in different size fractions. A 0.05% NH4OH solution in water was identified as the best carrier liquid for the analysis of the three different aqueous fullerene suspensions (C60 [60], [6,6]-phenyl-C61 butyric acid methyl ester ([60]PCBM) and [6,6]-(bis)phenyl-C61 butyric acid methyl ester ([60]bisPCBM)). The multi-angle light scattering (MALS) data received after employing the ammonia solution was consistent with both the theory and calibration using well defined Au and latex particles. The LODs obtained using Orbitrap HRMS detection were 0.1 μg L−1 for an injection volume of 100 μL which are significantly better than the LODs obtained by using UV (20 μg L−1) and MALS detectors (5 μg L−1). However, these LODs can be further improved as in theory there is no limit to the amount of sample that can be injected into the FFF. Environmental samples (river and sewage water) were spiked with fullerenes and the fractograms obtained for these samples revealed that the matrix does affect the size of fullerene aggregates. Information on the size distribution can be useful for the risk assessment of these particles. 相似文献
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Chrystelle Bancon‐Montigny Lu Yang Ralph E. Sturgeon Vanessa Colombini Zoltn Mester 《应用有机金属化学》2004,18(2):57-64
Isotopically enriched CH3198HgCl (MeHgCl) has been synthesized from commercially available elemental 198Hg (96% isotopic purity). Elemental mercury is first converted to HgCl2 and subsequently reacted with methylcobalamin to produce MeHgCl. The resulting MeHgCl is isolated from the reaction mixture by successive extractions with toluene and dried over Na2SO4. The product structure was verified using gas chromatography–mass spectrometry (GC–MS) and the isotopic composition was determined by GC–inductively coupled plasma MS. The yield obtained is 99%. The proposed method allows preparation of milligram quantities of MeHgCl in one step, minimizing the cost of this synthesis. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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The preparation of an 8-hydroxyquinoline complex of trivalent gold by the action of oxine upon gold chloride and “monopyridine gold chloride” is described. The absorption spectrum of the complex, which approximated to the composition AuCl2C9H6ON was plotted in the U.V. and visible regions of the spectrum.A partial separation between tri- and tetravalent titanium was obtained using paper chromatography. Absorption curves were obtained for oxine complexes of Ti(III) and Ti(IV) in the visible region of the spectrum. 相似文献
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Maasoumeh Jafarpour Abdolreza Rezaeifard Marzieh Aliabadi 《Helvetica chimica acta》2010,93(3):405-413
An operationally simple and environmentally benign protocol for a highly regio‐ and chemoselective preparation of β‐substituted alcohols by means of ring‐opening reactions of oxiranes with various aliphatic alcohols, H2O, NaN3, and NaCN as nucleophiles in the presence of catalytic amounts of zirconium tetrakis(dodecyl sulfate) as Lewis acid/surfactant‐combined catalysts (LASCs) was developed. The high efficiency of the catalyst was confirmed by the high product yields obtained within desired times and, in particularly by the reusability of the ZrIV complex. 相似文献
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Wolfgang Hiller Stephanie Frey Joachim Strähle Gernot Boche Wolfgang Zarges Klaus Harms Michael Marsch RenéA Wollert Kurt Dehnicke 《欧洲无机化学杂志》1992,125(1):87-92
The Crystal Structures of {Li3(12-crown-4)2[HC(CN)2]3}, {Na(15-crown-5)[HC(CN)2]}, and {NaN(nBu)4[HC(CN)2]2 · THF} The preparation and the crystal structures of the title compounds 1 — 3 are described. 1 forms a polymeric chain structure, in which one of the lithium ions is linked by Li…NCC(H)CN… bridges. The remaining lithium ions form (12-crown-4)Li[NCC(H)CN] units, which are coordinated by one of the nitrogen atoms of the dicyanomethanide ions with the lithium ions of the chain. 2 forms an ion pair, in which the sodium ion is coordinated by the five oxygen atoms of the crown ether molecule and by one nitrogen atom of the dicyanomethanide ion. 3 has a threedimensional network, in which the sodium ions are coordinated in a distorted tetrahedral manner by the nitrogen atoms of the dicyanomethanide ions. In the cavities of the network the tetrabutylammonium ions and the THF molecules are found. 相似文献