On the determination of a detector response enhancement factor for flow modulated comprehensive two-dimensional gas chromatography

Comparison of conventional one-dimensional gas chromatography (1D-GC) and comprehensive two-dimensional gas chromatography (GC × GC) shows that the detector signal in GC × GC is significantly enhanced. The value of this enhancement depends on the operating parameters, such as the modulation time and the non-modulated (1D column) and corresponding modulated (2D column) peak widths. Determination of the enhance factors in flow modulated GC × GC for separation of hydrocarbon samples using flame ionization detection (FM GC × GC-FID) was studied. A term named detector response enhance factor (DREF) has been designed to express the value of the signal enhancement. Two methods were used to calculate DREF: (i) employing 2D peak height, and (ii) using a theoretical approach. Comparison of FM GC × GC-FID and 1D-GC-FID method illustrates that the DREF increases from 10 to 33 times, in 1–6 s modulation time intervals.

► The new criterion is introduced for a GC × GC method enhancement degree.
► Two procedures were used to calculate enhancement factors for GC × GC method.
► The flow modulator focuses zones similarly as does the thermal modulator.