共查询到19条相似文献,搜索用时 46 毫秒
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合成了PM和PA两个系列甲基丙烯酸甲酯或丙烯酸甲酯与二乙烯苯的多孔聚合物,测定了它们的物理、化学性能和气相色谱性能,并评价其极性。通过实例说明它们对各种混合物的分离情况;保留时间较短,柱温较低,选择性较高,性能优于PorapakT或其它极性相近的商品聚合物固定相。 相似文献
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通过比保留体积对数值与绝对温度倒数的直线关系,水和甲醇标准曲线的正截距、氘交换以及吸附系数和溶解系数的测定,证明至少对我们的聚合物固定相来说。表面吸附对保留值是决定性的因素。 相似文献
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研究了五种有机聚合物固定相的色谱性能.选择在170℃柱温下测定其极性常数,并以下式计算各种填料的极性常数:X′=Ix-653,Y′=Iy-590,Z′=Iz-627,U′=Iu-652,S′=Is-699.式中Ix、Iy、Iz、Iu、Is分别为柱温170℃测得的5种表征物质的保留指数,同时以实验验证了该方法的有效性和实用性.还测定了这些固定相在高纯氮气和空气中的热分析(TG、DTA)曲线,研究了DTA曲线产生峰值的原因,指出了其上限使用温度.扩展了此类固定相的应用范围.此外,还对保留值与柱温的关系进行了研究. 相似文献
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聚硅氧烷键合的离子液体用作高温气相色谱固定相的研究 总被引:1,自引:0,他引:1
合成了阴离子为二(三氟甲基磺酸酰)亚胺(NTf-2)的新型聚硅氧烷键合离子液体 ([PSOMIm][NTf2]),并采用静态涂渍法,制备了毛细管气相色谱柱.该固定相具有良好的热稳定性.热重测试显示,温度高于380 ℃后,[PSOMIm][NTf2]开始缓慢分解.色谱性能评价显示,此固定相对多种异构体和同系物均具有良好的分离选择性和高的热稳定性.对Grob试剂的分离结果表明,各种组分均能在柱上得到良好的分离且峰的对称性很好.此新型聚合物离子液体在高温气相色谱固定相的研究和应用方面具有较大的潜力. 相似文献
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《Analytical letters》2012,45(16):2721-2731
In the present work a novel strategy for improving and/or tuning the selectivity of gas chromatographic (GC) separation by combining three different stationary phases (SPs) without premixing was introduced. A fused silica fiber coated with polydimethylsiloxane (SE30) and another coated with cyanopropylphenylmethylpolysiloxane (OV1701) were serially inserted into an 8-m polyethylene glycol 20 M (PEG20M) capillary column to form a GC annular column with ternary SP, abbreviating as SE30-OV1701-CF/PEG20M-CC. The separation capability of this ternary SP annular column was compared with a SE30-coated fiber-in-PEG20M-coated capillary annular column and a PEG20M-coated open tubular column by a test mixture of 19 organic compounds. Among these three columns, SE30-OV1701-CF/PEG20M-CC produced the best separation when the SE30-coated fiber and OV1701-coated fiber was 3 and 5 m, respectively. Selectivity can be easily tuned by changing the length of the SP-coated fibers in the ternary SP annular column. The proposed ternary SP annular column shows additional tunability, thus making it a promising tool for separation of organic solvents that are often used in the manufacturing process of pharmaceutical formulations and lacquer thinners. 相似文献
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用一种新合成的套索冠醚N,N′-双(乙酰苄胺)-二氮杂-18-冠-6作为固定相,涂渍在弹性石英毛细管内,测其柱效、惰性、热稳定性、平均极性及选择性等性质。实验表明,它具有良好的色谱性能,中等极性,分离选择性高,适用于对醇、卤代烃、芳香烃等各类异构体的分离,并从分子结构和热力学参数等探讨了保留机理。 相似文献
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ItisgenerallyknownthatadditivityofmixedstationaryphasesinGCcanbeencoun-tered.Ourinvestigationshaveshowntheexistenceofsynergisticeffectintheside-chaincrownetherpolysiloxaneandperethylatedo-CDmixedstationaryphase,'resorcareneandcyclodextrinmixedstationaryphase,'aswellasinthemixedstationaryphasecon-sistingofheptakis(2,3,6-tri-o-pentyl)-o-CandAgNO3orT1NO,.'Ininorganicchemis-try,synergisticeffectshavebeenstudiedwidelyinextraction.'Theeffectsalsoexistintheextractionoforganiccompounds'andincapill… 相似文献
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A rigid spherical giant-pore poly (glycidyl methacrylate-co-ethylene dimethacrylate) matrix has been prepared by radical suspension–polymerization
on the basis of a novel porogenic mode using superfine particles of calcium carbonate as a solid porogen. Scanning electron
microscopy reveals that the bead has pores as large as 10 μm. The hydrodynamic properties show that this polymeric material
has good strength and a low back pressure of 1.0 MPa at a flow velocity of 3,000 cm h−1. After being modified to be an anion-exchange material, high dynamic binding capacity of plasmid DNA of above 1,000 μg plasmid
per mL of bed by a column of this material, could be obtained comparing to the 150 μg plasmid per mL of bed with a Q-Sepharose
FF column at the same flow rate. Large-scale preparative plasmid separations (2–20 mL) from cell lysate were investigated.
A 75% yield and 94.9% purity of SC plasmid DNA were obtained by a 20 mL column of giant-pore beads at a flow rate of 600 cm h−1. 相似文献
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Volker Schurig 《Angewandte Chemie (International ed. in English)》1984,23(10):747-765
If a stationary phase A employed in gas chromatography possesses a chemical affinity for substance B, which is to be separated, then the retention behavior is not only determined by the normal physical equilibrium between the gas and liquid phases but also by the chemical equilibrium A + B ? AB. If A and B are chiral and A is present in optically active form while B is a racemic mixture, then it is possible to achieve a gas chromatographic enantiomer resolution without the isolation of diastereomers: the energetically different diastereomeric associates AR BR and AR BS are formed rapidly and reversibly. This enantiospecific resolution principle was first demonstrated in 1966 by the quantitative resolution of racemic amino acid derivatives on optically active peptide phases in analogy to the well-known stereospecificity of enzymes. The anchoring of the chiral resolving agent to thermally stable polysiloxanes together with the employment of high resolution capillary columns and the use of appropriate derivatization strategies has led to the development of enantiomer resolution into a routine modern method for many classes of substances. The demonstration of enantiospecificity in the gas chromatographic separation process is of fundamental interest, and its systematic study can result in a significant contribution to the understanding of the molecular mechanism of “chiral recognition”. The gas chromatographic separation of enantiomers has also proven to be an accurate and sensitive method for the determination of the enantiomeric composition of natural products and products of enantioselective transformations (asymmetric syntheses, “chiral pool” transformations, kinetic resolutions, biomimetic reactions) and for the quantification of racemization, e.g. in the synthesis and hydrolysis of peptides. In any research program devoted to the phenomenon of chirality, the gas chromatographic separation of the enantiomers of volatile compounds constitutes an indispensable modern instrumental technique. 相似文献