Displacement chromatography preparative technique

Displacement chromatography was named and introduced by Tiselius [1] who demonstrated its utility in both preparative and analytical applications. Tiselius explored separations of many different biological substances including amino acids and peptides [2,3]. The technique was also used... 

Displacement chromatography offers an alternative to elution chromatography for preparative-scale separations under nonlinear conditions [10,66,82,83]. It has found limited success for the purification of biopolymers by reversed-phase [10,83,84] and ion-exchange chromatography [85-88], but is not widely used for the purification of small molecules [89-91]. It has the potential for greater use, but remains a minor technique compared with elution chromatography. 

This nonlinear multicomponent separation technique is eminently suitable for preparative/process scale applications. In displacement chromatography, the competition... 

Displacement chromatography has an enormous potential as a preparative bioseparation technique. In many situations from the mg to the kg scale and beyond the displacement chromatography may theoretically be the most practical, the most economic and the most efficient approach to a given separation problem. However, in order to exploit the full potential of displacement chromatography, suitable displacer/stationary phase systems must become available. This chapter is intended as an introduction to our current understanding of the requirements for systematic displacer design. 

Chromatography Chromatography is a sorptive separation technique that allows multicomponent separations in both gas and Hquid phase. As a preparative tool, it is often used as a displacement-purge process, although many applications employ an inert-displacement mode, especially for use in analysis. General characteristics and operating modes are discussed in a separate part of this section. 

New developments in chiral chromatography (more universal, easily available, stable, tailor-designed CSPs) and technology (recycling, displacement and especially, SMB) makes chromatography a valuable alternative to classical techniques for the preparation of pure enantiomers. 

The frontal technique (Section 2.1.3) does not lend itself to many analytical applications because of the overlap of the bands and the requirement of a large amount of sample. However, it may be used to study phase equilibria (isotherms) and for preparative separations. (Many of the industrial chromatographic techniques use frontal analysis.) Displacement development (Section 2.1.4) has applications for analytical liquid chromatography (LC). (For instance, it may be used as an initial concentrating step in GC for trace analysis.) This technique may also be used in preparative work. The outstanding disadvantage of both of these techniques... 

Figure 8.2 shows, schematically, the simplest possible VLE experiment. A liquid sample of the mixture of interest is placed in an Erlenmeyer flask and heated to a boil. The boiling continues until the vapor has displaced all the air from the flask. This means that the liquid composition will no longer be equal to that originally prepared, because the vapor leaving the system does not have the same composition as the liquid. When we are sure that all the air is gone, we measure the temperature and take samples of liquid and vapor, which we analyze (by any of several laboratory techniques, e.g., chromatography). 

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