References of "Dubois, Lena"
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See detailTD-GCxGC-HRTOFMS in biological applications 
Focant, Jean-François ULiege; Pesesse, Romain ULiege; Dubois, Lena ULiege et al

Conference (2017, September)

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See detailAdvanced method optimization for volatile aroma profiling of beer using two-dimensional gas chromatography time-of-flight mass spectrometry
Stefanuto, Pierre-Hugues ULiege; Perrault, Katelynn ULiege; Dubois, Lena ULiege et al

in Journal of Chromatography. A (2017)

The complex mixture of volatile organic compounds (VOCs) present in the headspace of Trappist and craft beers was studied to illustrate the efficiency of thermal desorption (TD) comprehensive two ... [more ▼]

The complex mixture of volatile organic compounds (VOCs) present in the headspace of Trappist and craft beers was studied to illustrate the efficiency of thermal desorption (TD) comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) for highlighting subtle differences between highly complex mixtures of VOCs. Headspace solid-phase microextraction (HS-SPME), multiple (and classical) stir bar sorptive extraction (mSBSE), static headspace (SHS), and dynamic headspace (DHS) were compared for the extraction of a set of 21 representative flavor compounds of beer aroma. A Box-Behnken surface response methodology experimental design optimization (DOE) was used for convex hull calculation (Delaunay’s triangulation algorithms) of peak dispersion in the chromatographic space. The predicted value of 0.5 for the ratio between the convex hull and the available space was 10% higher than the experimental value, demonstrating the usefulness of the approach to improve optimization of the GC × GC separation. Chemical variations amongst aligned chromatograms were studied by means of Fisher Ratio (FR) determination and F‐distribution threshold filtration at different significance levels (α = 0.05 and 0.01) and based on z‐score normalized area for data reduction. Statistically significant compounds were highlighted following principal component analysis (PCA) and hierarchical cluster analysis (HCA). The dendrogram structure not only provided clear visual information about similarities between products but also permitted direct identification of the chemicals and their relative weight in clustering. The effective coupling of DHS-TD-GC × GC-TOFMS with PCA and HCA was able to highlight the differences and common typical VOC patterns among 24 samples of different Trappist and selected Canadian craft beers. [less ▲]

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See detailA Minimally-Invasive Internal Gas Reservoir Monitoring Method for Postmortem Examinations
Perrault, Katelynn ULiege; Stefanuto, Pierre-Hugues ULiege; Dubois, Lena ULiege et al

in Forensic Science International (2017), 277

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See detailEnhanced Chemical Profiling of Human Decomposition in a Case Study
Dubois, Lena ULiege; Perrault, Katelynn ULiege; Stefanuto, Pierre-Hugues ULiege et al

in Forensic Science International (2017), 277

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See detailMonitoring Changes in the Volatile Profile of Aging Human Blood
Dubois, Lena ULiege; Perrault, Katelynn ULiege; Stefanuto, Pierre-Hugues ULiege et al

in Forensic Science International (2017), 277

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See detailThe Odor of Death: An Overview of Current Knowledge on Characterization and Applications
Verheggen, François ULiege; Perrault, Katelynn ULiege; Caparros Megido, Rudy ULiege et al

in Bioscience (2017)

After death, the human body undergoes various processes that result in the emission of volatile organic compounds (VOCs). The interest in these VOCs has increased substantially in recent years because ... [more ▼]

After death, the human body undergoes various processes that result in the emission of volatile organic compounds (VOCs). The interest in these VOCs has increased substantially in recent years because they are key attractants for necrophagous insects and vertebrate scavengers. Identifying cadaveric VOCs has required the effective development of analytical tools for collecting, separating, identifying, and quantifying the suite of VOCs released throughout decomposition. Analytical developments for studying cadaveric VOCs in vertebrates, ecological interactions of cadaveric VOCs with the abiotic and biotic environment, and the necessity for convergence of these two areas for the progression of future knowledge are discussed herein. [less ▲]

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See detailA new method for identifying experimental and Palaeolithic hafting adhesives using GC×GC-HRTOFMS
Cnuts, Dries ULiege; Perrault, Katelynn ULiege; Dubois, Lena ULiege et al

Poster (2016, September)

Hafting adhesives can be seen as an indication of the cognitive and technical capabilities of the manufacturers and therefore play a key role in the debate on human evolution [1], [2]. These adhesives are ... [more ▼]

Hafting adhesives can be seen as an indication of the cognitive and technical capabilities of the manufacturers and therefore play a key role in the debate on human evolution [1], [2]. These adhesives are mainly from plant origin (resins, gums or tar) and are often mixed with beeswax and other additives in order to make them less brittle. Archaeological evidence indicates that these adhesives were already in use in the Paleolithic from at least 120.000 years ago [3]. Discoveries for this period are however very rare and only become abundant from the Neolithic onwards [4]. Their longer exposure to biochemical alteration processes limits the chance of survival in the archaeological record. If they are present on Paleolithic stone tools, they appear often in such small quantities that they are challenging to identify by traditional gas chromatography – mass spectrometry (GC-MS) or even to remove them effectively from the stone tool. The destructive nature of traditional GC-MS analysis can damage these rare samples for other analyses. Our study aims to overcome this problem by using headspace solid phase microextraction (HS-SPME) for sample extraction and analysis by comprehensive two-dimensional gas chromatography –high-resolution time-of-flight mass spectrometry (GC×GC-HRTOFMS), which has the benefit of analyzing the volatile organic compound (VOC)s from the substance and it does not destroy the complete matrix of the adhesive. We present the results of a pilot study intended to examine the potential of this technique for analyzing Palaeolithic adhesives. The study involved (1) an examination of experimental compound adhesives (containing pine and spruce resin, acacia gum and birch tar; beeswax and additives like charcoal, flax or ochre), (2) a blind test on experimental samples to test the reliability of the method and to determine the minimal quantity necessary for analysis, and (3) the analysis of different Palaeolithic adhesives and of experimental samples of at least 15 years old. The analysis was done on extracted and non-extracted adhesives. A unique chromatographic fingerprint was obtained for all experimental adhesive samples. The VOC profile of these adhesives proved to be extremely complex and therefore benefitted significantly from multidimensional separation techniques. GC×GC-HRTOFMS provided an optimal chromatographic separation of adhesive components. HRTOFMS data was used in order to obtain high-resolution mass spectral data to contribute to compound identification. Our study demonstrates that GC×GC-HRTOFMS is a well suited method for identifying small quantities of compound adhesives with significant potential for Palaeolithic contexts. The additional sensitivity afforded by this technique in comparison to traditional GC-MS is a substantial benefit for these quantities. Furthermore, by only analyzing the VOCs of the adhesives, these rare archeological samples are not destroyed and can still be used for other types of analysis. [1] L. Wadley, ‘Compound-Adhesive Manufacture as a Behavioral Proxy for Complex Cognition in the Middle Stone Age’, Curr. Anthropol., vol. 51, no. s1, pp. S111–S119, Jun. 2010. [2] L. Barham, From Hand to Handle: The First Industrial Revolution. Oxford: Oxford University Press, 2013. [3] P. P. A. Mazza, F. Martini, B. Sala, M. Magi, M. P. Colombini, G. Giachi, F. Landucci, C. Lemorini, F. Modugno, and E. Ribechini, ‘A new Palaeolithic discovery: tar-hafted stone tools in a European Mid-Pleistocene bone-bearing bed’, J. Archaeol. Sci., vol. 33, no. 9, pp. 1310–1318, Sep. 2006. [4] M. Regert, ‘Investigating the history of prehistoric glues by gas chromatography-mass spectrometry.’, J. Sep. Sci., vol. 27, no. 3, pp. 244–54, Feb. 2004. [less ▲]

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See detailExploring variable electron ionization for forensic blood VOC profiling
Dubois, Lena ULiege; Perrault, Katelynn ULiege; Stefanuto, Pierre-Hugues ULiege et al

Scientific conference (2016, July 07)

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See detailTime travelling into human prehistory using GC×GC-TOFMS
Perrault, Katelynn ULiege; Dubois, Lena ULiege; Stefanuto, Pierre-Hugues ULiege et al

Scientific conference (2016, July 07)

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