Page 236 - Multidimensional Chromatography

230 Multidimensional Chromatography

Figure 10.6 Analysis of nitrogen- and sulfur-containing compounds using an MDGC sys-
tem: (a) pre-column chromatogram; (b) main column chromatogram, TIC; (c) main column
chromatogram, nitrogen trace; (d) main column chromatogram, sulfur trace of the selected cut
shown in A, of a whiskey extract. The conditions were as follows: precolumn, Carbowax 20M,
15 m 0.25 mm i.d., 0.25 m film thickness; main column, 5% diphenylpolysiloxane,
60 m 0.25 mm i.d., 0.25 m film thickness; column segments to selective detectors, 5 m;
column segment to MS detector, 15 m. Reprinted from Proceedings of the 15th International
Symposium on Capillary Chromatography, K. MacNamara and A. Hoffmann, ‘Simultaneous
nitrogen, sulphur and mass spectrometric analysis after multi-column switching of complex
whiskey flavour extracts’, 1993, with permission from Prof. P. Sandra.

slow response of the IR spectrometer was solved by the use of an efficient off-line
interface. The matrix isolated eluents can be analysed by infrared spectrometry in a
near real-time analysis. Figure 10.7 shows the separation of a fraction of eucalyptus
oil. By using this technique, even minor components can be detected with sufficient
IR spectral quality to permit their identification by a spectral library search.