Comprehensive two-dimensional gas chromatography using partial modulation via a pulsed flow valve with a short modulation period

摘要

AbstractPartial modulation via a pulsed flow valve for comprehensive two-dimensional (2D) gas chromatography (GC × GC) is demonstrated, producing narrow peak widths,2Wb, on the secondary separation dimension,2D, coupled with short modulation periods,PM, thus producing a high peak capacity on the2D dimension,2nc. The GC × GC modulator is a pulse flow valve that injects a pulse of carrier gas at the specifiedPM, at the connection between the primary,1D, column and the2D column. Using a commercially available pulse flow valve, this injection technique performs a combination of vacancy chromatography and frontal analysis, whereby each pulse disturbance in the analyte concentration profile as it exits the1D column results in data that is readily converted into a2D separation. A three-step process converts the raw data into a format analogous to a GC × GC separation, incorporating signal differentiation, baseline correction and conversion to a GC × GC chromatogram representation. A 115-component test mixture with a wide range of boiling points (36–372°C) of nine compound classes is demonstrated using modulation periods ofPM= 50, 100, 250, and 500ms, respectively. For the test mixture with aP