反相液相色谱中同族化合物作用指数的预测

基于气相色谱与液相色谱的内在联系，首次讨论了用气相色谱保留值预测两元冲洗体系反相液相色谱作用指数的方法，该方法经文献数据验证，其预测结果达到了实验精度，这为扩大反相液相色谱的作用指数库提供了一个实用的方法。     

采用反相液相色谱作用指数进行已知保留值定性的研究

本文从理论上提出了采用反相液相色谱作用指数进行已知保留值定性的方法,该方法是建立在反相液相色谱保留值基本方程Ink′=a+cC_B的基础上,通过建立各类样品标准的a,c指数库来实现保留值的预测,从而达到定性的目的,在定性过程中利用了参数a,c之间的线性关系以及双柱之间的a-a线性关系,在此基础上给出了一些典型的实例来验证这种定性方法的正确性。     

反相高效液相色谱分离黄酮类化合物的研究

根据18种黄酮类化合物在C_3、C_(18)和CN三种固定相上的梯度洗脱反相高效液相色谱分离的研究,建立了一种连续快速分离植物提取物中黄酮类化合物的方法。此法可在55 min内完成一个样品的分离及柱平衡。最佳波长和温度分别是280nm和35℃。     

反相液相色谱保留值的预测模式

液相色谱保留值的预测一直是色谱领域里研究最为活跃的领域之一,寻找一种以最少系数求算和预测色谱保留值是色谱工作者的长期研究的目标,但目前,仍没有真正的预测方法。我们在液相色谱保留值基本方程的基础上,曾对不同C_(18)的担体上的保留规律进行过研究,并从中引入了溶质lnk′=A C·C_B BlnC_B (1)作用指数的概念,作用指数即为方程(1)中的参数C(参数B在反相色谱中忽略),CB为二元冲洗剂中强冲洗组分的浓度。本文从溶质的作用指数出发来探讨反相液相色谱保留值的预测模式。     

咪唑键合硅胶液相色谱固定相的反相色谱行为

采用嫁接法制备了一种新型高效液相色谱固定相.考察了固定相的液相色谱保留行为,发现该键合相具有很强的阴离子交换作用,还同时存在反相疏水作用.利用其疏水作用,可以对一些简单的有机化合物进行分离.     

液相色谱手性柱的温度效应

使用脲衍生型手性色谱柱作正相色谱,在不同温度下拆分３,５－二硝基苯甲酰氨基酸丁酯对映体。结果表明,柱温在－６℃至４０℃间变化时,ｌｎｋ＇与１／Ｔ以及ｌｎα与１／Ｔ皆呈直线关系。随着柱温的下降,相对保留值α上升,但部分化合物的Ｒｓ－Ｔ曲线在低温时出现转折。     

反相液相色谱中温度对蛋白分子构象变化的新表征

液相色谱中溶质计量置换保留模型的Ｚ值可用来对反相高效液相色谱中热变蛋白的分子构象进行表片。发现在异丙醇－甲酸４４％（Ｖ／Ｖ）－水体系为流动相对完全变性蛋白的Ｚ值随温度升高而降低。且Ｚ值与绝对温度例数（１／Ｔ）成正比，因此蛋白分子构象变化可用Ｚ对１／Ｔ作图所得两条直线的斜率差值来表征，差值愈大，蛋白分子构象变化愈甚。该两直线的交点即为蛋白分子构象的突变温度。与通常采用的１ｇＫ＇对１／Ｔ的作图相比，用     

Enthalpies Estimation of Formation of Monosubstituted Alkanes by Interaction Potential Index

The interaction potential index IPI(X) of 16 kinds of substituents X (X=OH, SH, NH₂, Br, Cl, I, NO₂, CN, CHO, COOH, CH₃, CH=CH₂, C≡CH, Ph, COCH₃, COOCH₃) were proposed, which are derived from the experimental enthalpies of formation Δ_fH^?(g) values of monosubstituted straight-chain alkanes. Based on the IPI(X) and polarizability effect index, a simple and effective model was constructed to estimate the Δ_fH^?(g) values of monosubstituted alkanes RX (including the branched derivatives). The present model takes into account not only the contributions of the alkyl R and the substituent X, but also the contribution of the interaction between R and X. Its stability and prediction ability was confirmed by the results of leave-one-out method. Compared with previous reported studies, the obtained equation can be used to estimate enthalpies of formation for much more kinds of monosubstituted alkanes with less parameters. Thus, it is recommended for the calculation of the Δ_fH^?(g) for the RX.     

Retention behavior of basic compounds on alkylphosphonate-modified magnesia-zirconia composite stationary phase in RPHPLC

Summary The chromatographic properties of an alkylphosphonate-modified magnesia-zirconia composite stationary phase have been investigated by reversed-phase high-performance liquid chromatography with basic compounds as probes. The influence of organic modifier composition and mobile phase pH was studied. The new stationary phase, similar to a silica-based reversed-phase stationary phase, has hydrophobic properties, but greater pH stability. Use of the phase results in more symmetric peaks for basic compounds. A possible mechanism of retention of basic solutes on the new stationary phase is discussed. The chromatographic behavior of the basic solutes depends mainly on hydrophobic interactions between the solutes and the hydrophobic moiety of the stationary phase. Br?nsted acidic and basic sites on the surface of the new stationary phase play an important role in the retention of ionized solutes by ion-exchange interaction. Promising separations of some basic compounds have been achieved by use of methanolic TRIS buffer, pH 10.0, as the mobile phase.     

一些液相色谱文献中反射式折光检测器基本方程的错误

指出了一些液相色谱文献中对反射式折光检测器基本方程的错误表示,并推导出了正确公式。     

High Temperature Interaction Chromatography of Olefin Copolymers

Summary: The synthesis and characterization of polyolefins continues to be one of the most important areas for academic and industrial polymer research. One consequence of the development of new “tailor-made” polyolefins is the need for new and improved analytical techniques for the analysis of polyolefins with respect to molar mass and chemical composition distribution. The present article briefly reviews different new and relevant chromatographic techniques for polyolefin analysis. For the fast analysis of the chemical composition distribution of polyolefins a new high-temperature gradient high-performance liquid chromatography (HPLC) system has been introduced. The efficiency of this system for the separation of various olefin copolymers is demonstrated. The correlation between elution volume and chemical composition can be accessed by on-line coupling of high temperature HPLC with FTIR spectroscopy. For the elucidation of the chemical composition as a function of molar mass high-temperature size exclusion chromatography and ¹H-NMR spectroscopy can be coupled. It is shown that the on-line NMR analysis of chromatographic fractions yields information on microstructure and chemical composition in addition to molar mass distribution.     

取代硼酸与羟乙基胺化合物间的相互作用研究

取代硼酸与顺式二羟基化合物间的可逆的共价相互作用为糖蛋白和糖等重要生物分子的识别和分离提供了独特的亲和作用.为了获得良好的选择性,以β-激动剂与β-阻断剂这两类典型的羟乙基胺化合物为研究对象,利用核磁共振和高效液相色谱研究了它们与苯硼酸间的相互作用.研究结果表明,在高pH值条件下,羟乙基胺化合物与苯硼酸间存在强亲和作用,而在低pH值条件下,该亲和作用变弱甚至消失.这种pH值调控的相互作用表观上与顺式二羟基和苯硼酸间的硼亲和作用很相似.但是,与硼亲和作用机理不同,质子化溶剂的存在能加强这种相互作用,而非质子化溶剂的存在会破坏相互作用.本研究为深入认识硼亲和作用和获得可靠的应用提供了新依据,同时也为利用取代硼酸和羟乙基胺化合物之间的相互作用奠定了基础.     

高温二维液相色谱系统的构建及其评价

在二维液相色谱中, 第二维的分离速度是制约其发展的重要因素. 升高色谱柱温度可以有效降低流动相粘度, 加快溶质在两相间的传质速率, 有效加快分析速度. 以离子交换色谱法(WAX)为第一维分离模式和反相色谱法(RP)为第二维分离模式, 十通阀和两个捕集柱为接口, 通过将第二维色谱柱温度升高到80 ℃和提高流量到3 mL/min, 构建了高温WAX/RP二维液相色谱系统. 以4种标准蛋白的酶解物为样品评价系统的分离性能, 第一维共有33个馏分被捕集并导入到第二维分析, 高温二维液相色谱系统识别出187个色谱峰.     

RPHPLC as a tool for determining the congenericity of a set of 2,4-dihydroxythiobenzanilide derivatives

Summary During the chemometric analysis of 2,4-dihydroxythiobenzanilides by of RPHPLC, four of the derivatives were observed to have unexpectelly high lipophilicity. These substances also behaved abnormally as mobile phase pH was increased. The high hydrophobicity and the lack of dissociation of these substances result from the formation of additional internal hydrogen-bond. Lack of congenericity was also observed in biological investigations—the 2-hydroxy-4-nitro derivative behaved as a typical outlier during analysis of quantitative structure-activity relationships (QSAR). Chromatographic investigations can, therefore, be used to reveal lack of congenericity in series of bioactive analogues; this can be important in studies of QSAR and quantitative structure-retention relationships.     

反相高效液相色谱法测定毛竹叶中总黄酮

用反相高效液相色谱法,RP－C8柱为固定相,甲醇－水－冰乙酸（40＋60＋2）为流动相,以芦丁为参照物外标法定量,辅以二极管阵列检测技术,测定了毛竹叶中总黄酮的含量,并与光度法作了比较。     

AcQ·Tag~(TM)法测定鱼粉水解液中的氨基酸

１前言鱼粉是动物性蛋白质饲料,过去鱼粉中氨基酸测定大多采用氨基酸分析仪以离子交换树酯分离,柱后衍生测定。但氨基酸分析仪价格昂贵,分析时间长。近年来,柱前衍生高效液相色谱法测定氨基酸的技术因其具有衍生步骤简单,速度快,剩余试剂不干扰测定等优点,而有逐渐...     

由气相色谱程序升温数据计算恒温保留指数

提出了一种由程序升温数据推算恒温保留指数的计算方法,采用实验数据关联死时间和温度的关系,引入等效温度作为间接变量进行最优化。应用于Ｃ＿５～Ｃ＿９正构烷烃和Ｃ＿６烯烃的数据表明该法适应性强、精确度高,推算的恒温保留指数可作为定性依据。