Flow-modulation low-pressure comprehensive two-dimensional gas chromatography

• An approach defined flow-modulated low-pressure comprehensive 2D GC is proposed.
• Low-pressure conditions were generated across a 10 m × 0.53 mm ID second column.
• 100% of the flow exiting the modulator was directed to the mass spectrometer.
• The use of a long accumulation loop improved general peak shape.
• It is anticipated that the approach proposed will expand the use of flow modulation, especially in comprehensive 2D GC–MS experiments.

The present paper contains research data relative to an approach herein defined as flow-modulation (FM) low-pressure comprehensive two-dimensional gas chromatography, abbreviated as “GC × LP GC”. The abbreviation LP is positioned before the second GC abbreviation because LP conditions were generated across a mega-bore second-dimension column (10 m × 0.53 mm ID), it being connected to a quadrupole mass spectrometer (qMS). Flow modulation was performed with MS-compatible gas flows (7–8 mL/min), following recent research work [7]; using such an approach, the main disadvantage of flow modulation, specifically the generation of excessively high second-dimension flows, is avoided. A further noteworthy aspect of the investigation was the use of a long accumulation loop (e.g., 51 cm), a modification that greatly improved the general post-modulation peak shape quality. FM GC × LP GC–qMS applications on pure standard compounds, as well as on milk and fish oil fatty acid methyl esters, are shown and discussed.