Page 427 - Multidimensional Chromatography

Forensic and Toxicological Applications 419

Figure 15.7 (continued)

separation is performed on a non-polar DB-5 (5% phenyl polydimethylsiloxane)
column, while and the second separation is camed out on a more polar DB-225
(50% cyanopropylphenyl methyl polysiloxane) column, which allows highly selec-
tive separation of the aromatic components. This presents an excellent example of
target compound analysis from a very complex matrix. Note that the individual tar-
gets which are not resolved in the first dimension are mostly well resolved in the sec-
ond. This is also an excellent example of the use of multiple heart-cuts within a
single analytical run, opening up the possibility of performing numerous analyses
with a single injection.
Multiple cryogenic traps between the pre-column and the analytical column were
developed in 1993 by Ragunathan et al. (23). These authors found that a multiple
trap configuration provided the necessary resolution and automated sampling for
simultaneous GC/IR and GC/MS determination of very complex mixtures. A