Page 428 - Multidimensional Chromatography

420 Multidimensional Chromatography

Figure 15.8 Multidimensional GC–MS separation of urinary acids after derivatization with
methyl chloroformate: (a) pre-column chromatogram after splitless injection; (b) Main-col-
umn selected ion monitoring chromatogram (mass 84) of pyroglutamic acid methyl ester.
Adapted from Journal of Chromatography, B 714, M. Heil et al., ‘Enantioselective multidi-
mensional gas chromatography–mass spectrometry in the analysis of urinary organic acids’,
pp. 119–126, copyright 1998, with permission from Elsevier Science.

separation of unleaded gasoline from their system is shown in Figure 15.10. The
chromatographic system consisted of a DB-1701 pre-column, followed by the paral-
lel traps, and then a DB-5 analytical column, mounted inside an HP 5890 gas chro-
matograph. Customized valves were used to reduce extra-column band broadening
that might be caused by the traps and tubing. This technique could be easily applied