Chromatographic theory liquid -

It was known from gas chromatographic theory that efficiency could be improved if the particle size of the stationary phase materials used in lc could be reduced. High performance liquid chromatography developed steadily during the late 1960s as these high efficiency materials were produced, and as improvements in instrumentation allowed the full potential of these materials to be realised. As hplc has developed, the particle size of the stationary phase used has... 

Enhanced-Fluidity Liquid s Properties and Chromatographic Theory. .. 435... 

The review is organized in the following sections. The chromatographic theory relevant to EFLC and HT-HPLC is first described. Next a detailed description of the physicochemical properties of EEL mixtures is included. This is followed by a survey of the scope of liquid chromatography (LC) techniques that are presently using the attributes of EELs. Finally, a discussion of future applications of EF-HPLC is included. 

ENHANCED-FLUIDITY LIQUID S PROPERTIES AND CHROMATOGRAPHIC THEORY... 

The process of analyte retention in high-performance liquid chromatography (HPLC) involves many different aspects of molecular behavior and interactions in condensed media in a dynamic interfacial system. Molecular diffusion in the eluent flow with complex flow dynamics in a bimodal porous space is only one of many complex processes responsible for broadening of the chromatographic zone. Dynamic transfer of the analyte molecules between mobile phase and adsorbent surface in the presence of secondary equilibria effects is also only part of the processes responsible for the analyte retention on the column. These processes just outline a complex picture that chromatographic theory should be able to describe. 

With developments in technology it was possible to apply chromatographic theory to the development of column liquid chromatography and... 

In the late 1960s, emphasis was placed in developing LC as a complementary technique to GLC. In the early 1970s, the evolution and application of chromatographic theory, coupled with the technical improvements and advancements made in instrumentation and separation media, resulted in the development of HPLC and later capillary gas and liquid chromatography. ... 

In the last few years, interest has renewed in closed-column LC because of new instrumentation, new column packings, and a better understanding of chromatographic theory. High-performance liquid chromatography (HPLC) is rapidly becoming as widely used as gas chromatography and is often the preferred technique for the rapid separation of nonvolatile or thermally unstable samples. 

Optimization might be defined as the process directed towards obtaining the best analysis condition [1], The first paper wherein an experimental optimization technique was applied to chromatographic separation appeared around 1970, for gas chromatography (GC) separations. However, even at that time it was still common practice to use chromatographic theory to direct the steps in the optimization procedure. It wasn t until the late 1970s that pure experimental optimization methods were applied to liquid chromatographic separation problems. 

The basic principles of fast-atom bombardment (FAB) and liquid-phase secondary ion mass spectrometry (LSIMS) are discussed only briefly here because a fuller description appears in Chapter 4. This chapter focuses on the use of FAB/LSIMS as part of an interface between a liquid chromatograph (LC) and a mass spectrometer (MS), although some theory is presented. 

The development of micellar liquid chromatography and accumulation of numerous experimental data have given rise to the theory of chromatographic retention and optimization methods of mobile phase composition. This task has had some problems because the presence of micelles in mobile phase and its modification by organic solvent provides a great variety of solutes interactions. 

The initial concentration distribution is therefore simply translated at the velocity of the liquid steady flow and full equilibrium between the liquid and its matrix require that the amount of element transported by the concentration wave is constant. In more realistic cases, either the flow is non-steady due to abrupt changes in fluid advection rate or porosity, or solid-liquid equilibrium is not achieved. These cases may lead to non-linear terms in the chromatographic equation (9.4.35) and unstable behavior. The rather complicated theory of these processes is beyond the scope of the present book. 

Houston, R. H., Univ. California Radiation Lab. Rept. 3817 (1958). A Theory for Industrial Gas-Liquid Chromatographic Columns. ... 

Several studies attempted to relate the partition coefficient P of a solute in a liquid chromatographic or a gas chromatographic system with the composition of the two phases, one of which has a varying composition [19-23]. Tijssen et al. [24] and Schoenmakers [25] derived a relation between the partition coefficient and a binary mobile phase in reversed-phase HPLC from the solubility parameter theory of Hildebrand et al. [26]. Similarly, a relation can be derived for liquid-liquid extraction with extraction liquids composed of three components ... 

The gas chromatographic technique is explained on the basis of a physical process with correlations to distillation,liquid-liquid extraction, countercurrent distribution, and other separation techniques to give the reader a better appreciation of the basic process of chromatography. Explanation of fundamentals is followed by chapters on columns and column selection, theory and use of detectors, instrumentation necessary for a gas chromatographic system, techniques used for qualitative and quantitative analyses, and data reduction and readout. Subsequent chapters cover specialized areas in which gas chromatographic literature is more scattered and data collection and evaluation are more important. 

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