Measurement of retention in comprehensive two-dimensional gas chromatography using flow modulation with methane dopant.

Flow modulation of methane-doped carrier gas is used to visualize the second dimension hold-up time in GC x GC continuously throughout the run. This provides an internal reference of hold-up time and presents a straightforward means of examining retention in each dimension of GC x GC. Retention factors on similar and dissimilar column pairs are examined. Stationary phase bleed is shown to be retained by the second dimension column. Copyright (c) 2010 Elsevier B.V. All rights reserved.