GC X GC with Fluidic Modulation for Enantioselective Essential Oil Analysis

Properly informed column selection greatly simplifies the process of method development and provides greater flexibility in instrument settings for comprehensive two-dimensional gas chromatography (GC×GC) with fluidic modulation. In the present investigation a long (20 m) narrow-bore (0.10 mm i.d.) column was used in the first separation dimension. In this way, the separation column itself provided sufficient pressure-drop to alleviate flow disturbance in the first dimension column caused by actuating the modulator valve. The use of a narrow-bore column in the first dimension is highly beneficial because it is also more suited to lower volumetric flow-rates and therefore permits use of a longer modulation period without causing sample loop breakthrough. Enantioselective separation of spearmint essential oil was performed to demonstrate performance of a fluidic modulation system.