Computerized optimization of flows and temperature gradient in flow modulated comprehensive two-dimensional gas chromatography

Informational entropy and syentropy percent were used to optimize the flows in the first (1D) and in the second (2D) dimension (1Fm and 2Fm, respectively) as well as the temperature program rate (r) for the flow modulated GC × GC-FID separation of C6-C12 aromatic hydrocarbons in a low boiling petrochemical sample. The separations were performed on a column series consisting of a 25 m × 0.25 mm i.d. × 0.2 μm df of the polar ionic liquid SLB-IL 100 (1,9-di(3-vinylimidazolium)nonane bis(trifluoromethylsulfonyl)imide) in the first dimension and 5 m × 0.25 mm i.d. × 0.25 μm df apolar HP-5MS (5% phenyl-95% methylpolysiloxane) in the second dimension. A dependence of a distribution of individual aromatic hydrocarbons in the 2D retention plane on the carrier gas flows (1Fm, and 2Fm,) and temperature gradient (r) was examined in this study. It was found that informational entropy and synentropy percent are advantageous criteria to characterize the distribution of peaks in the 2D retention plane. Maximum informational entropy and synentropy percents correspond to the maximum distribution of C6-C12 aromatic hydrocarbons in the corresponding 2D retention plane gained by the given separation using optimized values of individual carrier gas column volume flows and the temperature rate at the temperature programmed GC × GC separations.