Page 99 - Multidimensional Chromatography

Orthogonal GC–GC 91

Figure 4.9 The peaks produced in the second dimension (see Figure 4.8) can be plotted as a
contour shape in the retention or separation space, with characteristic retentions in each
dimension. It can be seen that such peaks are now well resolved.

simultaneously; the usual post-run simple method reports are no longer simple since
we have multiple peaks reported in the analytical results of a chromatogram for
every single peak in a sample and recombining these back to the one component for
purposes of quantitation are required; even retention is not an easy property to
define because it will relate to the modulation period in addition to the first-column
retention. These are, however, challenges which clever programming and familiarity
with chromatogram interpretation will resolve in time. At present, the state-of-the-
art of GC GC appears to be in its qualitative capabilities. Selected highly com-
plex samples have been reported in the GC GC experiment, chiefly in the
petroleum area–few other samples can be as complex as these–and the general
consensus is that GC GC has revealed complexity that has never before been
realized, even though it may have been suspected. Not only have the samples been