Page 408 - Multidimensional Chromatography

400 Multidimensional Chromatography

Figure 14.21 GC chromatogram of the dibenzothiophenes fraction of a heavy gas-oil sam-
ple. Peak identification is as follows: 1, dibenzothiophene; 2, 4-methyldibenzothiophene; 3, 2-
methyldibenzothiophene; 4, 3-methyldibenzothiophene; 5, 4,6-dibenzothiophene; 6, other
C 2 -dibenzothiophenes, 7, C 3 -dibenzothiophenes; 8, C 4 - and higher dibenzothiophenes.

Phillips and Xu have presented two-dimensional (2D) chromatograms of
kerosines, separated with different stationary phase combinations, in many thou-
sands of components (37). Frysinger et al. have separate benzene–toluene–ethyl
benzene–xylenes (BTEX) and total aromatics in gasolines by using GC
GC
(38). These authors also analysed marine diesel fuel with GC
GC, connected to
a quadrupole mass spectrometer for identification purposes, although the scan
speed of the spectrometer was not quite suited for the fast second-dimension peaks
(39). GC
GC was used as an excellent tool for identifing oil spill sources by
Gaines et al. (40). Synovec and co-workers used the GC
GC separation of mix-
tures of toluene, ethylbenzene, m- and o-xylenes and propylbenzene in white gas
to investigate the use of generalized rank annihilation methods (GRAMs) for
quantitation purposes (41), while Kinghorn and Marriott used the separation of
kerosine to demonstrate the cryogenic modulator (42). Although quantitation of