Thermally sensitive behavior explanation for unusual orthogonality observed in comprehensive two-dimensional gas chromatography comprising a single ionic liquid stationary phase.In this study, a theoretical concept and method to achieve a degree of orthogonality in comprehensive two-dimensional gas chromatography (GC × GC) for separation of fatty acid methyl esters (FAME) by using a single ionic liquid (IL) stationary phase (1-phase-GC × GC) were established.  Initial isothermal experiments employing six commercial IL columns were conducted at different temperatures.  On the basis of the temperature-dependent linear solvation energy relationship (LSER) concept, SLB-IL111 exhibited the greatest thermal sensitivity and degree of difference over the tested temperature (T) range, so it was selected for investigation of the 1-phase-GC × GC mode. 
THERM