Characterization of Molecular Interactions by Inverse Liquid Chromatographic Method

Inverse chromatography (IC) has been widely applied to characterize surface, interface, and bulk characteristics of technologically important materials. Probe molecules with known properties are injected into an isothermal chromatographic system with the material of interest as     

Characterization of Molecular Interactions by Inverse Liquid Chromatographic Method

Inversechromatography (IC)hasbeenwidelyappliedtocharacterizesurface ,interface ,andbulkcharacteristicsoftechnologicallyimportantmateri als .Probemoleculeswithknownpropertiesarein jectedintoanisothermalchromatographicsystemwiththematerialofinterestasstatio…     

纤维素三苯甲酯的合成及其作为气相色谱固定相的性能研究

本文将超声合成的纤维素三苯甲酯沉积于载体Chromosorb GAW DMCS上,用作气相色谱固定相,探讨了其分离特性,成功地分离了正构醇(C_1～C_6)     

用反相气相色谱法测定端羟基聚丁二烯的溶解度参数

用反相气相色谱法测定了端羟基聚丁二烯(HTPB)在50、60和70℃下的溶解度参数δ_2,经线性外推得到25℃时δ_2=9.13。估计了HTPB与九种溶剂相互作用参数的熵项X_S。     

Characterization of Microporous Aluminas by Inverse Gas Chromatography

Inverse gas chromatography (IGC) is a versatile tool for the characterization of porous solids. IGC at finite dilution has historically been used for isotherm measurements because of fast equilibration times. A combination of IGC with a flash thermodesorption method allows the separation of micropores and outer surface contributions due to different adsorption mechanisms. Whereas the outer surface and the mesopores have a mono-/multilayer sorption mechanism, the micropores are filled according to the "theory of volume filling of micropores" model. Therefore, a higher energy is required for desorption out of micropores than for desorption out of mesopores and from the surface. This difference is used to calculate two separate isotherms respective to each contribution. Four aluminas with different microporosities are investigated to show the benefit of this approach. Copyright 2000 Academic Press.     

Surface Characterization of Sepiolite by Inverse Gas Chromatography

Inverse gas chromatography (IGC) was applied to characterize the surface of sepiolite. The adsorption thermodynamic parameters (the standard enthalpy (ΔH ⁰), entropy (ΔS ⁰) and free energy of adsorption (ΔG ⁰)), the dispersive component of the surface energy (γ _S ^d ), and the acid/base character of sepiolite surface were estimated by using the retention time of different non-polar and polar probes at infinite dilution region. The specific free energy of adsorption (ΔG ^sp ), the specific enthalpy of adsorption (ΔH ^sp ), and the specific entropy of adsorption (ΔS ^sp ) of polar probes on sepiolite were determined. ΔH ^sp were correlated with the donor and modified acceptor numbers of the probes to quantify the acidic K _A and the basic K _D parameters of the sepiolite surface. The values obtained for the parameters K _A and K _D indicated an acidic character for sepiolite surface.     

高温毛细管气相色谱柱的制备及应用

研究了臭氧交联法制备毛细管气相色谱柱的方法,即用镀铝石英毛细管,涂渍ＳＥ３１,经臭氧交联,最高使用温度可达３６０℃。测试的结果表明其柱效高,吸附性小,热稳定性好,适用于烃类、醇类、多环芳烃及二硝基甲苯和三硝基甲苯的分离。     

水滑石焙烧产物-镁铝复合氧化物表面性质的反相气相色谱研究

用共沉淀法制备的镁铝水滑石(Mg/Al物质的量比为3),经一定温度焙烧后,得到“笼”状结构的复合氧化物,并采用反相气相色谱法(IGC)对复合氧化物和混合氧化物(氧化镁和氧化铝)的表面性质进行了研究。实验测得一系列探针分子在复合氧化物和混合氧化物上的保留时间,可计算出其吸附热力学函数(吸附自由能(ΔG^?),吸附焓(ΔH^?),吸附熵(ΔS^?)),表面能色散组分(γ_S^d)及复合氧化物的表面酸碱参数(K_A,K_D),并探讨了探针分子在复合氧化物上的吸附机理。结果表明,探针分子进入复合氧化物的“笼”状结构后,可以减小温度对探针分子吸附过程的影响。此外,计算出复合氧化物的表面酸碱参数K_A=3.21及K_D=21.02,定量地表明镁铝复合氧化物是一种两性偏碱的材料。     

Synthesis of Cellulose Tris (4-Methylbenzoate) as Gas Chromatographic Stationary Phase and its Characterization

Cellulose (MC) is the most accessible optically active polymer. Its benzoate and phenylcarbamate derivatives exhibit a high chiral recognition ability for a variety of racemic compounds as chiral stationary phases (CSPs) for high performance liquid chromatography1-3. However, the application of cellulose derivatives in gas chromatography has seldom been reported except that Zou reported cellulose tribenzoate (CTB) which was used as a stationary phase for gas chromatography 4. Cellulose and…     

气相色谱固定液极性和选择性评价

对非同族化合物溶质在两种固定相上保留值的关系进行了理论推导，并将该方程应用于８９种常见固定相的极性和选择性的评价。固定相的极性可用Ｂ值来评价，而选择性则用Ｂ、Ｔ３＾ａ，Ｃ３β值来评价。用该方程评价固定相具有两个优点，一是基于分子间作用力来评价固定相；二是探针化合物的选择不再受限制。     

反相气相色谱法探究铜镁铝水滑石的表面性质

采用共沉淀法合成了Cu_xMg_3-xAl-LDHs (x＝0～3), 利用FTIR 及IGC 法(反相气相色谱法)对合成的样品进行测试和表征, 并结合计算机模拟的结果来探讨铜镁铝水滑石的表面性质. 结果表明, 随 Cu²⁺含量的增加, 铜镁铝水滑石表面吸附自由能及表面能色散组分增加, 稳定性下降, 这可能由于Cu²⁺本身具有的Jahn-Teller 畸变会很大程度地影响层板的稳定性, 导致含铜水滑石体系的稳定性降低; 随着Cu²⁺含量的增加, 水滑石表面碱性先减小后增大.     

Inverse Gas Chromatographic Study of the Oxidation Stability of Lubricating Base Oils via Solubility Parameter Calculations

 The Flory-Huggins interaction parameter (χ∞1,2) and solubility parameter (δ2) and its hydrogen bonding sensing component (δh) were determined using inverse gas chromatography (IGC). These parameters were successfully used in the probes of chemical changes that occur during the oxidation of naphthenic and paraffinic base oils in a GC column. Changes in χ∞1,2 values reflect the different types of intermolecular interactions (dispersive, polar, hydrogen bonding) of the given lubricating base oil during oxidation. The obtained results showed that δh component of solubility parameter is the most important parameter for probing the oxidative-chemical changes during the oxidation of given lubricating oils.     

用低温气相色谱分析火焰气体

本文采用低温气相色谱法分析了火焰气体的成份和深度，色谱柱固定相为ＰｏｒａｐａｒｋＱ，柱温范围－９９－２５０℃氦气作载气。在所选择的实验条件下，火焰气体中的Ｎ２和Ｏ２有效地得到分离，可迅速精确地分析确定Ｎ２的浓度以及其他成份和浓度。     

Gas Chromatographic Profiling and Screening for Phenols as O-Isobutoxycarbonyl Derivatives in Aqueous Samples

An efficient gas chromatographic method is described for the simultaneous profiling and screening of phenol and substituted 49 phenols including nitrophenols, chlorophenols, alkylphenols, catechol and hydroquinone present in aqueous samples.     

新型含酯基多孔聚合物小球气相色谱固定相

在甲苯和C_9～C_(13)醇混合物作稀释剂存在下,以偶氮二异丁腈作引发剂,用悬浮聚合法由间-苯二甲酸二烯丙酯、二乙烯苯和丙烯腈制备了一系列多孔共聚物,改变单体的摩尔比获得了不同极性的气相色谱柱填料,而共聚物小球的多孔结构主要决定于稀释剂的数量和组成,测定了小球的物理化学性能和气相色谱性能,并用改进的McReynolds极性标度评价其极性,通过实例展示这种色谱固定相的优良选择性。     

四羟乙基己二酰胺类色谱固定相的合成及性能初探

１引言有机物的结构清楚,种类广泛,对有机组份的分离选择性强,很早就有人把它作为色谱固定相。本文合成了四羟乙基己二酰胺及其乙酰基衍生物,并首次将之作为填充柱及毛细管柱色谱固定相,对它们的柱行为进行了测试。实验表明,该有机胺类色谱固定相对于烷基苯类及醇类表现出较好的分离能力。该研究为有机胺类固定相的实际应用做了有益的探索,具有潜在的应用价值。２实验部分２．１四羟乙基己二酰胺的合成将己二酸二甲酯与乙二醇胺按１：２摩尔比加入到一个厚壁的锥形瓶内,加入钛酸四异丙酯作催化剂,放到电磁搅拌器上水浴加热并抽真空…     

Gas Chromatographic Determination of Cinoxacin

A gas Chromatographic method has been established for analysis of Cinoxacin in crystalline powder. The method is based on chemicaI derivatization of Cinoxacin as its methyl ester, and n-octacosane is used as an internal standard. Gas chromatographic analysis was proceeded on a glass column packed with 2% OV-1 on Chromosorb W. Quantitation is feasible by measurements of peak area ratios. The method proves to be simple, rapid and accurate.     

反相气相色谱法研究1,3,5-三氨基-2,4,6-三硝基苯的表面特性

采用反相气相色谱技术(IGC)研究了4种不同粒度的1,3,5-三氨基-2,4,6-三硝基苯(TATB)的表面性质。4种不同粒度的TATB表面自由能的色散分量（γds）随着温度的升高而增加;粒度越大的粒子,其色散自由能上升越快;在较高温度下,粗颗粒TATB显示了更强的色散作用(γds=193.2 mJ/m2,353 K),粒度最小的亚微米TATB显示了最弱的色散作用(γds=64.0 mJ/m2,353 K)。由于制备方法不同和粒子大小的差异,4种TATB的表面酸碱性质显示了明显的差别,细颗粒TATB表面有较强的亲电子特性;而其他3种TATB在极性探针分子的作用下的吸附均表现为吸热吸附,表现出在分子内和分子间具有强烈的相互作用,其Ka和Kb值均为负。