A “second generation” design of differential flow modulation for comprehensive two-dimensional gas chromatography (GC×GC) was recently introduced [1,2]. This new configuration, based on the original device from Seeley et al. [3], adopts a reverse fill/flush injection dynamic instead of the forward flush/fill implemented in the “first generation” devices. Advantages include: (a) higher efficiency of band re-injection with improved 2D peak-widths and symmetry, (b) adjustable collection channel volume, (c) better handling of the overloading phenomenon without dramatic loss of peak-capacity/ resolution, and operation with hydrogen and helium carrier. In this study, the first Capillary Flow Technology (CFT) reverse-inject differential flow modulator was implemented with different column configurations (lengths, diameters and stationary phase coupling) and detector combinations (Mass Spectrometry -MS and Flame Ionization Detection - FID) to evaluate its potential in the quantitative profiling of medium-to-highly complex essential oils and food volatiles fractions. In particular, a parallel dual-secondary column dual-detection configuration that has shown to improve the information potential of thermally modulated GC×GC platforms in terms of MS identification, reliability and accurate FID quantitation [4], was used here for the detailed characterization of essential oils (lavender, mint and vetiver) and food volatiles of interest for aroma blueprinting (extra-virgin olive oil and roasted hazelnuts). Experimental results demonstrate that by changing column dimensions and configuration, the system flexibility can be greatly improved affording: (a) to extend the modulation period to match for 2D selectivity exploitation, (b) to operate with carrier gas linear velocities close-to-optimal values in both dimensions and (c) to handle overloaded peaks without dramatic losses in 2D peak-capacity and resolution. References [1] Griffith JF, WinnifordWL, Sun K, Edam R, Luong JC. A reversed-flow differential flow modulator for comprehensive two-dimensional gas chromatography. J Chromatogr A 2012;1226:116-123[2] Xu S, Luong J, Aybar J, Miliazza A, Firor R. Characterization of a New Reversed Flow Modulator for GC×GC. Proceedings of the 38th ISCC and 11th GC×GC Symposium May 2014 Riva del Garda Italy [3] Bueno PA, Seeley JV. Flow-switching device for comprehensive two-dimensional gas chromatography. J.. Chromatogr A 2004;1027:3-10. [4] Nicolotti L, Cordero C, Bressanello D, Cagliero C, Liberto E, Magagna F, Rubiolo P, Sgorbini B, Bicchi C. Parallel dual secondary column-dual detection: A further way of enhancing the informative potential of two-dimensional comprehensive gas chromatography. J. Chromatogr A. 2014;1360:264-274
Potential of the Reversed-Inject Differential Flow Modulator for Comprehensive Two-dimensional Gas Chromatography in the Quantitative Profiling of Complex Natural Samples
CORDERO, Chiara Emilia Irma;BICCHI, Carlo;
2015-01-01
Abstract
A “second generation” design of differential flow modulation for comprehensive two-dimensional gas chromatography (GC×GC) was recently introduced [1,2]. This new configuration, based on the original device from Seeley et al. [3], adopts a reverse fill/flush injection dynamic instead of the forward flush/fill implemented in the “first generation” devices. Advantages include: (a) higher efficiency of band re-injection with improved 2D peak-widths and symmetry, (b) adjustable collection channel volume, (c) better handling of the overloading phenomenon without dramatic loss of peak-capacity/ resolution, and operation with hydrogen and helium carrier. In this study, the first Capillary Flow Technology (CFT) reverse-inject differential flow modulator was implemented with different column configurations (lengths, diameters and stationary phase coupling) and detector combinations (Mass Spectrometry -MS and Flame Ionization Detection - FID) to evaluate its potential in the quantitative profiling of medium-to-highly complex essential oils and food volatiles fractions. In particular, a parallel dual-secondary column dual-detection configuration that has shown to improve the information potential of thermally modulated GC×GC platforms in terms of MS identification, reliability and accurate FID quantitation [4], was used here for the detailed characterization of essential oils (lavender, mint and vetiver) and food volatiles of interest for aroma blueprinting (extra-virgin olive oil and roasted hazelnuts). Experimental results demonstrate that by changing column dimensions and configuration, the system flexibility can be greatly improved affording: (a) to extend the modulation period to match for 2D selectivity exploitation, (b) to operate with carrier gas linear velocities close-to-optimal values in both dimensions and (c) to handle overloaded peaks without dramatic losses in 2D peak-capacity and resolution. References [1] Griffith JF, WinnifordWL, Sun K, Edam R, Luong JC. A reversed-flow differential flow modulator for comprehensive two-dimensional gas chromatography. J Chromatogr A 2012;1226:116-123[2] Xu S, Luong J, Aybar J, Miliazza A, Firor R. Characterization of a New Reversed Flow Modulator for GC×GC. Proceedings of the 38th ISCC and 11th GC×GC Symposium May 2014 Riva del Garda Italy [3] Bueno PA, Seeley JV. Flow-switching device for comprehensive two-dimensional gas chromatography. J.. Chromatogr A 2004;1027:3-10. [4] Nicolotti L, Cordero C, Bressanello D, Cagliero C, Liberto E, Magagna F, Rubiolo P, Sgorbini B, Bicchi C. Parallel dual secondary column-dual detection: A further way of enhancing the informative potential of two-dimensional comprehensive gas chromatography. J. Chromatogr A. 2014;1360:264-274File | Dimensione | Formato | |
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