Three-dimensional chromatography

Other groups have also used EC and CE to perform non-comprehensive multidimensional separations (15, 16). A three-dimensional separation was performed by Stromqvist in 1994, where size exclusion chromatography (SEC), reverse-phase HPLC, and CZE were used in an off-line manner to separate peptides (17). The most useful information gained from all of these non-comprehensive studies was knowledge of the orthogonality and compatibility of EC and CE. 

THREE-DIMENSIONAL SIZE EXCLUSION CHROMATOGRAPHY-REVERSE PHASE LIQUID CHROMATOGRAPHY-CAPILLARY ZONE ELECTROPHORESIS... 

Figure 9.10 Three-dimensional representation of the data volume of a tryptic digest of ovalbumin. Series of planar slices through the data volume produce stacks of disks in order to show peaks. Reprinted from Analytical Chemistry, 67, A. W. Moore Jr and J. W. Jorgenson, Comprehensive three-dimensional separation of peptides using size exclusion chromatogra-phy/reversed phase liquid chromatography/optically gated capillary zone electrophoresis, pp. 3456-3463, copyright 1995, with permission from the American Chemical Society.

A. W. Moore, Jr and J. W. Jorgenson, Comprehensive three-dimensional separation of peptides using size exclusion chromatography/reversed phase liquid chromatography/ optically gated capillary zone electrophoresis . Anal. Chem. 67 3456-3463 (1995). 

In this chapter, we will discuss the present status of CHIRBASE and describe the various ways in which two (2D) or three-dimensional (3D) chemical structure queries can be built and submitted to the searching system. In particular, the ability of this information system to locate and display neighboring compounds in which specified molecular fragments or partial structures are attached is one of the most important features because this is precisely the type of query that chemists are inclined to express and interpret the answers. Another aspect of the project has been concerned with the interdisciplinary use of CHIRBASE. We have attempted to produce a series of interactive tools that are designed to help the specialists or novices from different fields who have no particular expertise in chiral chromatography or in searching a chemical database. 

Successive separation steps, e.g. in two-dimensional chromatography (two-dimensional thin-layer chromatography) that result in three-dimensional signal functions y = f(ziyz2)y as schematically shown in Fig. 3.4(v). 

FIGURE 1.3 Three-dimensional representation of a tryptic digest of ovalbumin. The three-dimensional separation consists of size-exclusion chromatography (first dimension), reversed-phase LC (second dimension), and capillary electrophoresis (third dimension). From Moore and Jorgenson, (1995) with permission of the American Chemical Society. 

Most proteins must be folded into a specific three-dimensional conformation to express their specificity and activities, which comphcates the DSP [212]. Researchers in the area of RME of proteins/enzymes have reafized this and directed more efforts in developing novel and imaginative techniques in RME as well as coupling the existing techniques such as chromatography, electrophoresis, and membrane extractions with RME. Such promising techniques developed in the recent past have been discussed in this section. Apart from these techniques, use of novel surfactants in the RME and surfactant based separation processes (e.g., cloud-point extraction) are also considered. 

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