Predictions of comprehensive two-dimensional gas chromatography separations from isothermal data

Two-dimensional retention times and peak widths in temperature programmed comprehensive two-dimensional gas chromatography were predicted using a theoretical model developed from experimental data obtained under isothermal conditions. A Matlab program was written to calculate the following parameters: dead time (tM), elution temperature (Te), retention time (tR), hold-up width (wM) and peak width (wR). The two-dimensional retention times of a sample mixture that contained n-alkanes and polyaromatic hydrocarbons (PAHs) were predicted and were observed to be in excellent agreement with experimentally determined values. The relative deviation between the model and the experimental data was less than 2 and 7% for the primary and secondary retention times, respectively. The relative deviation of peak width was less than 7 and 10% in the primary and secondary dimensions, respectively. The advantage of this model was its simplicity, informed entirely from experimental data, with no reliance on theoretical parameters. This prediction model would be useful for optimizing GC × GC separation conditions and for confirming compound identifications of components that are chromatographically resolved but that have nearly identical mass spectra.