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June 17 - 23, 2006, 29th International Symposium on High Performance Liquid Phase Separations & Related Techniques (HPLC) 2006, San Francisco, CA, USA
Resolution of Complex Separations Through Chemometric Analysis of Hyphenated Chromatographic Information
Michael McBrien, Eduard Kolovanov, Vadim Tashlitsky, Andrey Vazhentsev, Mark Bayliss, Vitaly Lashin
Abstract
Two dimensional chromatography has been applied to the problem of complex separations for more than 20 years. The primary benefit of the many forms of 2D chromatography has been the ability to utilize multiple selectivities independently, resulting in resolving power unattainable in 1D separations. A great deal of attention has been paid to the concept of the theoretical resolving power of multidimensional chromatography. Applications of chromatography with greater dimensionality than two have rarely been reported, for many reasons, including theoretical and practical issues.
Recently, chemometric techniques for chromatographic peak matching across multiple chromatographic runs have created the opportunity to exploit complementary retention mechanisms using conventional instrumentation. Hyphenated detection techniques (i.e., LC/UV/MS) have been shown to be effective in tracking chromatographic peaks in the same sample across different chromatograms when used in conjunction with chemometric techniques such as Mutual Automated Peak matching (MAP)1. When these chromatograms have been collected under orthogonal chromatographic conditions, 2 components that co-elute under one system have an excellent chance of being at least partially resolved from each under the second system. The components in fact, can show zero resolution in any of the individual runs and still be "virtually resolved", provided that in at least one experiment, coelution with the exact same component does not occur. Obviously the chances of this coelution occurring decrease considerably with each additional experiment, provided that the new experiment can be expected to display markedly different chromatographic behavior. The number of "dimensions" that can be applied to the problem is limited only by the sample size, and the number of orthogonal condition sets that can be conceived.
The benefits of this approach, called n-Dimensional MAP Chromatography (NDMC) over conventional multidimensional chromatography are clear; standard instrumentation can be used, and the data collected is considerably smaller than for conventional multidimensional chromatography, while still containing spectral information for each component. This paper will discuss the application of NDMC to various samples, discussing practical limitations to the peak matching algorithm, and the extraction of spectral and quantitative data.
Download the presentation in MS PowerPoint (1.22 Mb ZIP file) or Adobe Acrobat format (743 Kb PDF file).
Relevant Products: MS Manager, ChromManager, Method Development Suite, AutoChrom, LC Simulator
Relevant Solution: Impurity Detection
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