色谱法中的谱带和色谱峰

对色谱法中的谱带作了具体的定义。详细论述了谱带与色谱峰之间的关系,指出分析谱带是研究色谱现象的基础。色谱法中的色谱峰并不局限于色谱图中的色谱峰,只要是组分的分析谱带,都可以形成一个色谱峰与之相对应。     

Extracolumn band broadening in capillary liquid chromatography

A commercially available capillary LC instrument was modified to investigate and control the contribution of different instrument components on extracolumn band broadening. Quantitative estimations of dispersion induced by several equipmental parts were carried out. Injection parameters could be optimized to achieve the theoretical value of 12 for a profile factor describing a rectangular sample profile. Additionally, an additive injector flow channel dependent dispersion effect was found. A practical approach for minimizing instrumental effects in capillary LC is suggested. The results were compared with those obtained with an HPLC instrument designed for conventional size columns.     

烟碱的色谱测定

总结了近十多年来色谱法(GC、GC-MS、HPLC和SFC等)测定烟碱的情况，归纳整理了国内外主要杂志报道的有关色谱分析烟草、卷烟及其烟气、空气、农药、鼠脑、唾液、头发、血液、尿等中烟碱的方法，并对色谱分析烟碱的主要方法及其发展前景进行了评述。     

基于分离粒子随机扩散理论的色谱模拟

为了对扩散分子的轨迹实施动态追踪与模拟, 深入理解分子扩散对色谱动力学的影响, 本文利用微尺度受限空间随机行走的模拟方法对色谱填充柱中的分子扩散过程进行了模拟. 重点考察了固定相的填充率、固定相的形状和柱长对色谱动力学行为的影响. 模拟结果表明短柱和大填充率具有较高的柱效; 在相同的密堆排列下, 固定相形状对分子扩散过程影响微弱; 待分离粒子的运动表现出微尺度空间限域的扩散特征, 但粒子的流动行为会随外部压力的增大而增加. 本论文提出的模拟方法对于发展高效能色谱, 开发新型分离技术等具有参考意义.     

色谱研究最新进展

色谱作为一种强大的分离分析手段,为推动生物医学和人类健康、环境监测与保护、食品安全与质检等领域的发展提供着解决问题的关键技术。最近几年来,我国色谱学科经历了全面快速发展,取得了令人瞩目的成绩,研究水平和国际地位得到巨大提升,色谱相关SCI论文发表数量居世界第一位。色谱应用领域也在不断扩大,尤其在蛋白质组学、代谢组学等新兴领域,以及药物、环境、食品分析等传统领域发挥越来越重要的作用。本文对近年来色谱学科(重点是我国色谱学科)在色谱技术、色谱填料和色谱柱、样品前处理方法、应用领域等方面的进展情况进行介绍。共引用109篇参考文献。     

用热解吸色谱进行生油岩的评价

采用吸附丝采样，热解吸色谱分析轻烃，研究岩芯性质对色谱峰形、正构烷烃分布的影响。通过吸附烃丰度和轻烃单体组成特征对生油岩进行评价。     

铜催化的端基炔偶联反应的研究进展

综述了近年来应用于端基炔偶联反应的均相、多相铜基催化剂的研究进展,包括Cu(I)、Cu(II)以及CuNPs催化剂。阐述了各催化剂催化端基炔偶联反应的最优条件,从催化剂的寿命、底物适用性等方面比较了各催化剂的性能,以及各类催化剂的可能反应机理。通过比较可得,负载型Cu(II)多相催化剂稳定且制备过程简单易行,反应条件温和、效率高,将可能成为端基炔偶联反应今后发展的主要趋势。     

塔板理论流出曲线的统计特征

直接从原始塔板理论的级数形式色谱流出曲线表达式出发,得到了流出曲线一级原点矩及二,三级中心矩的数学表达式,并依此讨论了色谱峰的形状特征及各种因素对峰形的影响规律.本文结果直接证实原始塔板理论曲线为不对称分布,描述峰型不对称性的偏态系数与塔片数及容量因子有关,且随容量因子的增大逐渐变小.当塔片数很大时,容量因子不很小的组分流出曲线有相似的对称性.     

Rapid Analysis of Fluorine in Geological Samples with Ion Chromatographic Detection

Abstract

A method is described for the analysis of fluorine in geological samples involving the decomposition of the sample with phosphoric acid and the measurement of the fluoride ion concentration using an ion chromatograph. The detection limit is below 5 g F in the original sample. Multiple analyses of NBS-91 Opal Glass yielded a relative standard deviation of less than 2.5%. In excess of 30 samples can be analyzed in an 8 hour day. Potential interference from high carbon containing samples, such as oil shales, is discussed.     

手性选择剂在色谱分析中的应用

本文综述近年来在光学异构体分离领域中所涉及的主要技术,如高效液相色谱、电色谱、气相色谱及其他色谱法中所使用的常见手性选择性。它们包括环糊精、冠醚、抗菌素、蛋白质、多糖、氨基酸、表面活性剂和分子模板高聚物及其相关的衍生物。     

色谱柱分离过程弛豫理论——流出曲线的动力学本质

在分析型线性色谱中,流出曲线一般表现为拖尾的形式,这种现象可以采用多种机理加以解释。模仿动力学弛豫理论的假设条件,认为溶质在柱过程中的迁移以跃迁形式完成,得到了浓度分布曲线的数学表达式。分别探讨跃迁次数、两相间跃迁速率及溶质在流动相中的轴向跃迁对峰形的影响,进一步说明了色谱流出曲线的动力学本质     

坛紫菜中R-藻红蛋白的色谱纯化及性质研究

从坛紫菜(Porphyrahaitanensis)藻胆蛋白粗提液中分离纯化R 藻红蛋白(R phycoerythrin,R PE),经过两次不同柱长规格的自制羟基磷灰石柱层析和一次DEAE SepharoseFastFlow离子交换层析,获得了较高纯度的R PE(A565nm A280nm>5.3);测定了R PE的紫外可见吸收光谱和荧光光谱,R PE的吸收峰在565和498nm,在540nm有一吸收肩,荧光发射峰在573nm;用SDS PAGE测定组成R PE各亚基的相对分子质量,α β亚基约为18～20kDa,γ亚基约为35kDa;对R PE在不同的pH和温度环境协同影响下的荧光稳定性进行了研究,摸索了R PE的长期有效保存的方法并探讨了(NH4)2SO4的保护机理。     

On the statistical independence of various column contributions to band broadening. Part 3: Independent treatment of longitudinal diffusion in the plate model

It is shown theorectically that the classical formula for calculating the theoretical plate number from squared first central moment, t , and second central moment, σ², according to n _theor = t /σ² is valid only when the capacity ratio, k approaches infinity. The general relation between the classical experimental HETP value, H = L/nm _theor, and the underlying true theoretical plate height, ΔL, is found to be when (σ′)² is the total column contribution to band broadening, L is the column length, D _m is the average diffusion coefficient of the sample component in the mobile phase, D _s is its value in the stationary phase, and u is the average linear velocity of the mobile phase. The mobile phase displacement, as well as the mass exchange process, is assumed to be continuous, but the application of the plate concept conditions leads to a mass balance equation that can be interpreted as belonging to a modified discontinuous plate model. The contributions 2D _m/u and k 2 D _s/u from longitudinal sample diffusion in the mobile and stationary phases, respectively, are consistent with the assumption that the processes are statistically independent, although the common solution technique of the differential equations does not take full account of this independence.     

Thermal effects and band spreading in capillary electro-separation

Summary Four Capillary Electroseparation methods are distinguished. All have an ultimate efficiency limited only by axial diffusion and are in principle capable of achieving 10⁶ plates in <1 hour.The main limitation to performance arises from Ohmic heating of the electrolyte. While forced convection at 10ms^–1 is recommended to keep tubes cool, the parabolic temperature profile within the electrolyte limits the tube bore which can be used. A simple limiting expression is derived: (d_c/m)³ (E/kV m^–1)³ (c/mol dm^–3) <3.3×10⁹.Values of constants underlined     

Chromatographic sample collection from two-phase (gas+liquid) flows

A particularly challenging sample presentation in analytical chemistry is a flowing stream that consists of both a gas and liquid phase, combined with the common situation in which a reliable analysis is needed for both phases, separately. In these cases, the vapor and liquid must be physically separated (without change to either), before the individual phases can be collected and analyzed. It is not possible to analyze two-phase flows otherwise. Although the two phases are at equilibrium, it is imperative that no liquid contaminate the vapor, and no vapor be entrained in the liquid at a given temperature and pressure. In this paper, we describe a simple on-line device that can individually separate and collect the vapor and liquid phases of a two-phase flow. The apparatus, which we call P(2)SC, uses an adaptation of the branch point separator, with vapor collection done downstream in a metal bellows. The liquid collection is done in a length of Teflon tube. The separated vapor and liquid phases are then easily transferred into any desired analytical instrument with a syringe, although any sample introduction method, such as a valve, could be used as well. We discuss the application of this device with a stream of thermally stressed rocket kerosene.     

戊二醛合成体系气相色谱分析

本文给出了环戊烯合成戊二醛体系的气相色谱分析方法，色谱柱为硅烷化担体载１０％ＰＥＧ－２０Ｍ固定液，氢火焰检测器，列出了标准曲线和检测条件，变异系数均〈１．５％，相对误差±２．０％以内，该定量分析快速，简便，准确。     

Gas Chromatographic Analysis of Phenolic Compounds from Lignin

Abstract

This paper describes the separation and identification of phenolics derived from lignin, a major component of wood, by gas chromatography (G.C.) using a Tenax GC column.