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超临界流体色谱法分离生育酚同系物   总被引:10,自引:0,他引:10  
蒋崇文  杨亦文  任其龙  吴平东 《分析化学》2003,31(11):1337-1340
用超临界流体色谱法进行了生育酚异构体的分离研究。在实验温度303.15K~343.15K和压力14~22MPa范围内,考察了ODS柱上温度、压力和密度与容量因子和选择性的关系,得到了生育酚在超临界色谱中的最佳分离条件:温度为343.15K,压力为20MPa,CO2流量750mL/min。  相似文献   

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本文在作者提出的反相液相色谱中同系物保留值与常沸点的交点规律基础上,推导出系物保留值与流动相组成的交点规律,用大量实验数据作了检验。并用新交点方程式,由化合物在一个流动相组成下的保留值,预测该化合物在任一流动相组成下的保留值,对14组同系物在5种色谱柱上5类流动相下的验算结果表明,721个数据点的绝对平均误差为2.8%。  相似文献   

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超临界流体色谱中热力学参数最佳化和动力学最佳化同等重要。溶质的保留行为和物质对的分离受柱固定相和流动相各种参数的影响。在本研究中,使用纯CO_2作为流动相,饱和烃、芳烃、以及它们的硝基取代物作为溶质,对上述影响进行了系统地考察。结果发现影响物质对分离的(以分离系数,α,表示)最主要因素是流体的密度。而温度的影响并不明显。柱固定相的性质也有一定程度的影响。在柱固定相相同的情况下,改变操作参数,溶质峰的洗馏顺序可能出现倒置。表明在超临界流体色谱中流动相溶解能力的重要作用。实验结果为了解和优化超临界流体色谱热力学参数提供了依据。  相似文献   

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许峰  梁鑫淼  林炳承  苏凡 《色谱》1999,17(2):128-130
基于土壤淋溶柱色谱符合logk'-ψ的线性保留方程,在同系物(正构烷基苯、甲基苯)和氯代苯中,同类溶质与固定相(土壤)和淋洗剂(甲醇-水)有相似的作用方式,所以溶质保留值(logk')与淋洗剂有机调节剂浓度间存在浓度交点,与沸点间存在沸点交点规律,并用实验进行了验证。  相似文献   

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王彦  张静  耿信笃 《色谱》1999,17(4):326-331
以波相色谱中溶质计量置换统一保留模型(SDM-R)的二参数、三参数和四参数方程为基础,研究了在预测同系物保留值时实验点与预测方程参数间的匹配关系。用两个实验点,分别以二、三和四参数方程对反相色谱中同系物保留值进行预测,发现预测值与实验值基本相符,但以二参数方程预测结果为最佳。又与其它保留方程的预测结果进行了比较,证实了上述结论。当实验点数增加到4~5个时,多参数方程预测同系物的准确度增加,且明显高于二参数方程。同时还讨论了方程中各参数与同系物碳数间的线性关系,发现二参数方程中的参数遵循同系物变化规律。  相似文献   

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本文在 Martire 等人以平均场晶格模型处理超临界流体色谱(SFC)保留值方法的基础上,提出修正函数的假设,结合实验数据确定了修正函数的具体表达式为△′=(0.01605+0.02387n_■)ρ~3_■/T,-(0.01382+0.02055n_■)ρ~4_■/T_■。经过修正后的保留值方程可在较大密度范围内(ρ_■:0.705~1.632)定量描述正构烷烃在非极性柱上,超临界流体 CO_2中的保留值变化规律。  相似文献   

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Capillary Electrochromatography is a kind of micro-separation techniques newly developed in resent years. It is of both high selectivity of HPLC and high efficiency of capillary electrophoresis. This subject is being studied widely now. However, still many imperative problems need to be explored in the respect of retention rule. In this paper,based on the retention rule in RP-HPLC, the intersection point rule for the retention of homologues and the volume fraction of the organic modifier in the mobile phase in the reversed-phase capillary electrochromatography (RP-CEC) was derived, and was testified by a lot of experimental data.  相似文献   

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填充柱超临界流体色谱系统中的溶剂效应   总被引:2,自引:0,他引:2  
陆峰  刘荔荔  吴玉田 《色谱》2000,18(2):155-157
 考察了填充柱超临界流体色谱法 (SFC)中的样品溶剂及连续进样等因素对化合物保留行为变化的影响规律。以超临界 CO2 或含低体积分数甲醇的 CO2 为流动相时 ,氨基柱上组分的保留时间随着样品溶剂的极性增大而增大 ,而溶剂对 C1 8柱上组分的保留时间影响不大 ;在 C1 8柱上 ,溶剂对连续进样的后续效应不强 ;而在氨基柱上 ,甲醇溶液的后续效应比丙酮、氯仿溶液的后续效应强。当甲醇的体积分数大于 1 .0 %时 ,溶剂的效应明显减弱。这种变化规律对填充柱 SFC的合理进样并获得重现性良好的色谱数据具有实际意义。  相似文献   

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从分子微观参数预测反相色谱保留值方程系数   总被引:7,自引:1,他引:7  
戴朝政 《色谱》1995,13(2):75-79
在考虑氢键作用能随流动相组成改变的情况下,重新推导了液相色谱保留值方程,进而得到液相色谱保留值方程系数与分子微观参数之间的关系。在分子母体结构相同条件下,提出采用五个系数预测反相色谱保留值的方法,并用文献数据给予验证。  相似文献   

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MicroemulsioneIectrokineticchromatography(MEEKC)isonekindofelectrokineticchromatography(EKC),whoseseparationprincipIeisbasedonthedifferentpartitionofsolutesbetweenthepseudostationaryphaseandthesurroundingaqueousphase.Usingmicroemulsionsolutionasthepseudostationaryphase,MEEKCshowsahighsolubilizationcapacityandseparationefficiency"'.Inthiswork,theretentionbehaviorsofalkylbenzenesinbothanionicandcationicsurfactantMEEKCsystemswereinvestigated.Theeffectsofco-surfactantandsurfactantonseparat…  相似文献   

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Carbohydrate purification remains problematic due to the intrinsic diversity of structural isomers present in nature. Although liquid chromatography-based techniques are suitable for analyzing or preparing most glycan structures acquired either from natural sources or through chemical or enzymatic synthesis, the separation of regioisomers or linkage isomers with a clear resolution remains challenging. Herein, a carbon dioxide supercritical fluid chromatography (SFC) method was devised to resolve 18 human milk glycosides: oligomers (disaccharides to hexasaccharides), fucosylated regioisomers (lacto-N-fucopentaose I, III, and V; lacto-N-neofucopentaose V; lacto-N-difucohexaose III; blood group H1 antigen; and TF-LNnT), and connectivity isomers (lacto-N-tetraose/lacto-N-neotetraose and para-lacto-N-hexaose/para-lacto-N-neohexaose/type-1 hexasaccharide). The analysis of these glycosides represents a major limitation associated with conventional carbohydrate analysis. The unprecedented resolution achieved by the SFC method indicates the suitability of this key technology for revealing complex human milk glycomes.  相似文献   

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超临界流体色谱在生物工程中应用的新进展   总被引:4,自引:0,他引:4  
超临界流体色谱(SFC)是高效液相色谱(HPLC)和气相色谱(GC)的重要补充技术。用SFC可以分离多数不能用GC分离的低挥发性物质。与传统的HPLC相比,SFC的分离速度更快、效率更高。本文综述了SFC在生物分子分离分析方面应用的新进展。引用文献74篇。  相似文献   

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In consideration of the adsorption of solvent, diluent and solute molecules on the surface of a stationaryphase, a new equation for solute retention in liquid chromatography is presented. This equation includesthree parameters: the displacement equilibrium constant (Ksd) between the solvent and diluent molecules onthe surface of the stationary phase, the total number(N) of the solvent and diluent molecules released fromthe stationary phase after one solute molecule being adsorbed, and the parameter (I) related to the thermody-namic equilibrium constant for the solute adsorption on the stationary phase. Over the whole concentrationrange of the solvent in the mobile phase, the experimental retention data can be well described by this equa-tion, parameters K~, N and I can be obtained by the regression analysis of the experimental retention data,and consequently the number of the solvent and the diluent molecules displaced by one solute molecule fromthe stationary phase can also be derived at different solvent concentrations in the mobile phase,  相似文献   

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《Analytical letters》2012,45(9):2009-2024
Abstract

Adding additional components to supercritical carbon dioxide in supercritical fluid chromatography can extend or significantly alter the fluid solvating properties. Polar samples which are difficult to be analyzed with pure supercritical CO2 because of their high polarity can be separated by adding polar modifiers to supercritical CO2. In this paper, a new mixing device using a teflon high capacity filter for adding polar modifiers to carbon dioxide mobile phase is introduced. This new mixing device could keep the amount of modifier in the mobile phase constant for a much longer time than a saturator column. The amount of water or methanol dissolved in supercritical CO2 was measured by amperometric microsensor which is made of thin film of perfluorosulfonate ionomer(PFSI).  相似文献   

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研究指出,反相液相色谱中同系物的容量因子对数lnk'与常沸点的直线关系在不同流动相组成下有一共同交点,此交点规律可用如下交点方程描述: lnk'-lnk_0'=B_1(t_b-t_b~0) 利用最优化求极值法求出九组同系物在三种色谱柱上四类流动相的交点常数。按交点方程预测同系物中所有成员的容量因子,488个数据点的绝对平均误差为2.4%。  相似文献   

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反相液相色谱中同系物保留过程中的等焓点   总被引:2,自引:0,他引:2  
张维平  郭鸿  耿信笃 《分析化学》2000,28(4):480-485
依据液相色谱中溶质计量置换保留模型,从理论上分别推导了出在反相高效订色谱(RPLC)中同系物端基和重复结构单元对Z(1mol溶剂化溶质被固定相吸附时,在其接触表面释放出溶剂的摩尔总数)与绝对温度倒数间的线性关系式。也从分子结构参数推荐导出了同系物端基对总变的贡献△H,和同系物非端基(或键长)对总焓变的贡献△HsNc的表达式。从而建立了等焓点的坐标方程,阐明了等点的纵坐标相是溶质在等点处的变为零,等  相似文献   

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