A systematic investigation of comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry with dynamic pressure gradient modulation for high peak capacity separations.

A systematic investigation of comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry with dynamic pressure gradient modulation for high peak capacity separations.
Anal Chim Acta. 2020 Oct 16;1134:115-124
Authors: Schöneich S, Trinklein TJ, Warren CG, Synovec RE
Abstract
Dynamic pressure gradient modulation (DPGM) in full modulation mode is optimized for comprehensive two-dimensional (2D) gas chromatography (GC × GC) with time-of-fight mass spectrometry (TOFMS) detection to obtain high peak capacity separations and demonstrate broad applicability for complex samples. A pulse valve introduces an auxiliary carrier gas flow at a T-union connecting the first dimension (1D) column to the second dimension (2D) column. At a sufficiently high auxiliary pressure (Paux) the 1D flow is temporarily stopped. Then, during each modulation period (PM) the valve is turned off briefly, a period termed the pulse width (pw), allowing the 1D effluent to essentially be reinjected onto the 2D column for the modulated separations. Modifications to the modulator assembly are provided to improve performance. Method optimization is demonstrated for a 116-component test mixture by tuning the Paux and the pw. For a PM = 2 s and 1F of 0.10 ml/min, the optimal pw and initial Paux selected were 200 ms and 330.9 kPa (33 psig), respectively. The 30 min separation of the test mixture provided a 1D peak capacity of 1nc = 330 and a...

Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Schöneich S, Trinklein TJ, Warren CG, Synovec RE Tags: Anal Chim Acta Source Type: research