A multiplexed dual-primary column comprehensive two-dimensional gas chromatography–mass spectrometry approach (2GC × GC–MS) is introduced. The approach splits injected samples into two first-dimension columns with different stationary phases, and recombines the two streams into one second-dimension column that terminates at a single detector. The approach produces two two-dimensional chromatograms for each injection, and is made possible by using a dual-stage modulator operated in contra-directional modulation mode. The dual two-dimensional chromatograms produced by this single detector system provide complementary information due to selectivity differences between the three separation columns used in the column ensemble. An aged Australian tea tree (Melaleuca alternifolia) essential oil was analyzed to demonstrate the 2GC × GC–MS approach. The number of compounds separated by each of the GC × GC separations in the 2GC × GC experiment is comparable to conventional GC × GC experiments with matching column configurations. Robust peak assignment was possible for this sample based on the combination of MS library matches and multiple linear retention index searching. Forty-nine components (22 unique) were identified using a non-polar × mid-polar column combination and 34 components (7 unique) were positively identified using a polar × mid-polar column combination. Twenty-seven peak assignments were corroborated by positive identification in both of the multiplexed separations.

Item Type:	Refereed Article
Keywords:	gas chromatography, comprehensive two-dimensional, dual first-dimension columns, multiplexed, essential oil
Research Division:	Chemical Sciences
Research Group:	Analytical chemistry
Research Field:	Separation science
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the chemical sciences
UTAS Author:	Savareear, B (Mr Benjamin Savareear)
UTAS Author:	Jacobs, MR (Mr Matthew Jacobs)
UTAS Author:	Shellie, RA (Professor Robert Shellie)
ID Code:	96189
Year Published:	2014
Web of Science® Times Cited:	8
Deposited By:	Austn Centre for Research in Separation Science
Deposited On:	2014-10-22
Last Modified:	2017-10-27
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