References of "Weggler, Benedikt"
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See detailMedical Application: Breath Volatile Compounds in Asthma Patients
Stefanuto, Pierre-Hugues ULiege; Zanella, Delphine ULiege; dejong, Thibaut et al

Scientific conference (2019, June)

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See detailRapid screening of complex biological matrices: Utilizing kendrick mass defect for group type evaluation of GC×GC-HR(EI)ToF/MS data
Weggler, Benedikt ULiege; Gruber, Beate; Zanella, Delphine ULiege et al

Poster (2019, May 13)

Characterization of highly complex matrices implicates scientific challenges such as wide presence of “true” unknowns, concentration ranges of various compound classes and limited, available amounts of ... [more ▼]

Characterization of highly complex matrices implicates scientific challenges such as wide presence of “true” unknowns, concentration ranges of various compound classes and limited, available amounts of sample. Cutting-edge, discovery based separation techniques such as multidimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GCxGC-HRToF/MS), are commonly applied to such analytical challenges. Nevertheless, most studies focus on target analysis and tend to disregard important details of the sample composition. The high separation capacity of GCxGC-ToF/MS allows for in-depth chemical analysis of the molecular composition. However, high amounts of data, containing several thousands of compounds per experiment, are generally acquired during such analyzes. Coupling GCxGC to high-resolution mass spectrometry (HRMS) further increases the amount of data and therefore requires advanced data reduction and mining techniques. Commonly, the main approach for the evaluation of dense data sets either focuses on the chromatographic separation for e.g. group type analysis, or utilizes exact mass data applying Kendrick Mass Defect (KMD) analysis or van Krevelen plots. The presented approach integrated the accurate mass data into the chromatographic information by combining KMD information and knowledge-based rules. This combination allows for fast, visual data screening as well as first quantitative estimation of the sample's composition. Moreover, the resulted sample classification significantly reduces the number of variables, allowing distinct chemometric analysis in non-targeted studies such as detailed hydrocarbon analysis (DHA), environmental and forensic investigations. [less ▲]

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See detailUnit duty-cycle differential flow modulation GC×GC-MS: insights on the modulation process
Franchina, Flavio ULiege; Zanella, Delphine ULiege; Weggler, Benedikt ULiege et al

Poster (2019, May)

One of the major limitations of current-day flow-modulated comprehensive two-dimensional gas chromatography (FM GC×GC) is the generation of high gas flows (e.g., 20 mL/min) in the second analytical ... [more ▼]

One of the major limitations of current-day flow-modulated comprehensive two-dimensional gas chromatography (FM GC×GC) is the generation of high gas flows (e.g., 20 mL/min) in the second analytical dimension, if unit sampling duty cycle is considered [1]. Even though such high flows are necessary to efficiently flush the content of the modulator onto the second dimension, they also greatly restrict the employment of mass spectrometry (MS), which is nowadays considered as the most powerful and informative detection tool. One way to enable the use of MS systems, in FM applications, is to divert a substantial part of the second-dimension flow to waste, with an obvious negative impact on sensitivity. The present contribution is focused on the development of unit sampling duty cycle methods using flow-modulated comprehensive two-dimensional gas chromatography in combination with mass spectrometry. Specifically, a FM GC×GC-MS approach was developed in which the flows necessary to efficiently flush the modulator were greatly reduced (<5 mL/min) [2]. The approach finely reconsiders the accumulation and injection phases of modulation and allows a full transfer onto the second dimension and the detector with no need to divert the flow [3]. The efficiency of the set-up is demonstrated on real-world samples (petrochemical and fragrance). [less ▲]

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