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Thermal independent modulator for comprehensive two dimensional gas chromatography


Luong, J and Guan, X and Xu, S and Gras, R and Shellie, RA, Thermal independent modulator for comprehensive two dimensional gas chromatography, Analytical Chemistry, 88, (17) pp. 8428-8432. ISSN 0003-2700 (2016) [Refereed Article]

Copyright Statement

Copyright 2016 American Chemical Society

DOI: doi:10.1021/acs.analchem.6b02525


We introduce a modulation strategy for comprehensive two-dimensional gas chromatography (GC×GC) with complete thermal independence between the cooling and heating stages and without the need for GC oven heat for remobilization. Based on this approach, a compact thermal independent modulator (TiM) with thermoelectric cooling and micathermic heating has been successfully innovated for use in GC×GC. The device operates externally to a gas chromatograph, does not require liquid cryogen, and has minimal consumables requirements. The augmentation of an additional gas flow stream results in a number of critical chromatographic parameter improvements such as the decoupling of flows of first- and second-dimension columns to attain both efficiency and speed optimized flow in each dimension, the potential for independent retention time locking or scaling in either dimension, the improvement of modulator reinjection efficiency, as well as facilitating back-flushing for the first dimension to enhance system cleanliness and throughput. TiM was found to be useful for chromatographic applications over a volatility range equivalent to nC6 to nC24 under conditions used. Repeatability of retention time for model compounds such as benzene, toluene, ethyl benzene, and xylenes were found to be quite satisfactory with relative standard deviations of less than 0.009% in 1D and less than 0.008% in 2D (n = 10). Typical peak widths of 120 ms or less with a relative standard deviation of less than 4.7% were achieved for the aromatic model compounds. In this article, the performance of the modulator is demonstrated and a series of challenging chromatographic applications are presented to illustrate usefulness of the apparatus.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Analytical chemistry
Research Field:Analytical chemistry not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the chemical sciences
UTAS Author:Luong, J (Mr Jim Luong)
UTAS Author:Gras, R (Ms Ronda Gras)
UTAS Author:Shellie, RA (Professor Robert Shellie)
ID Code:115245
Year Published:2016
Web of Science® Times Cited:33
Deposited By:Chemistry
Deposited On:2017-03-10
Last Modified:2022-08-22

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