- Two-dimensional chromatography
Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages. This is done is by injecting the eluent from the first column onto a second column. Typically the second column will provide a different separation mechanism, so that bands which are poorly resolved from the first column may be completely separated in the second column. (For instance, a C18 column may be followed by a phenyl column.) Alternately, the two columns might run at different temperatures. The second stage of the separation must be run much faster than the first, since there is still only a single detector.
Two-dimensional separations can be carried out in
gas chromatographyor liquid chromatography. Various different coupling strategies have been developed to "resample" from the first column into the second.
The chief advantage of two-dimensional techniques is that they offer a huge increase in
peak capacity, without requiring extremely efficient separations in either column. (For instance, if the first column offers a peak capacity (k1)of 100 for a 10 minute separation, and the second column offers a peak capacity of 5 (k2) in a 5 second separation, then the combined peak capacity may approach k1 × k1 = 500, with the total separation time still ~ 10 minutes.) 2D separations have been very successfully applied to the analysis of gasoline and other petroleum mixtures, and more recently to protein mixtures.cite journal
author = Jan Blomberg, Peter J. Schoenmakers, Jan Beens, Robert Tijssen
title = Compehensive two-dimensional gas chromatography (GC×GC) and its applicability to the characterization of complex (petrochemical) mixtures
journal = Journal of High Resolution Chromatography
doi = 10.1002/jhrc.1240201005
year = 1997
volume = 20
issue = 10
pages = 539-544] cite journal
title = Comparison of the practical resolving power of one- and two-dimensional high-performance liquid chromatography analysis of metabolomic samples
author = Stoll, D.R., Wang, X., Carr, P.W.
year = 2008
journal = Analytical Chemistry
volume = 80
issue = 1
pages = 268-278
doi = 10.1021/ac701676b] .
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