Comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry featuring tandem ionization: Challenges and opportunities for accurate fingerprinting studies

Chiara Cordero, Alessandro Guglielmetti, Carlo Bicchi, Erica Liberto, Lucie Baroux, Philippe Merle, Qingping Tao, Stephen E. Reichenbach

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The capture of volatile patterns from food is a fingerprinting that opens access to a high level of information related to functional variables (origin, processing, shelf-life etc.) and their impact on sample composition and quality. When the focus is on food volatilome, comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC×GC-TOF MS) is undoubtedly the most effective technique to obtain a highly representative fingerprinting. A recently patented ion source, featuring variable-energy EI, when operated at low energies (10 eV, 12 eV, 14 eV), claims enhanced intensity of structure-indicating ions while minimizing the inherent loss of sensitivity due to low EI energies. The spectral acquisition is done by multiplexing between two ionization energies and generates tandem data streams in a single run. This study explores the potentials of combined untargeted/targeted (UT) fingerprinting with tandem signals to study the complex volatile metabolome of high quality cocoa. The quality of the spectra at 70 eV is confirmed by similarity match factors above a fixed threshold (950) while spectral differences between hard (70 eV) and soft (12 eV, 14 eV) ionization are computed in terms of spectral similarity and signal-to-noise ratio (SNR). Tandem signals are then processed independently and after fusion in a single stream (summed signal) by the UT fingerprinting work-flow; signal characteristics (SNR, detectable 2D peaks, spectral peak intensities) are then computed and adopted to define the best strategy to discriminate and classify samples. Classification performance, on processed cocoa from four different origins, is validated by cross-comparing results between single ionization channels and fused data streams and considering both targeted and untargeted features. Classification results indicate the potential for superior performances of UT fingerprinting with fused data streams (summed signals), while signal characteristics at low ionization energies not only offer additional elements to better discriminate and/or identify isomeric analytes but also to achieve wider dynamic range of exploration.

Original languageEnglish (US)
Pages (from-to)132-141
Number of pages10
JournalJournal of Chromatography A
Volume1597
DOIs
StatePublished - Jul 19 2019

Fingerprint

Cocoa
Ionization potential
Signal-To-Noise Ratio
Tandem Mass Spectrometry
Gas chromatography
Gas Chromatography
Ionization
Mass spectrometry
Signal to noise ratio
Ions
Food
Metabolome
Workflow
Ion sources
Multiplexing
Mass Spectrometry
Fusion reactions
Processing
Chemical analysis

Keywords

  • Comprehensive two-dimensional gas chromatography
  • Fused data streams
  • Tandem ionization
  • Template matching
  • UT fingerprinting

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Organic Chemistry

Cite this

Comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry featuring tandem ionization : Challenges and opportunities for accurate fingerprinting studies. / Cordero, Chiara; Guglielmetti, Alessandro; Bicchi, Carlo; Liberto, Erica; Baroux, Lucie; Merle, Philippe; Tao, Qingping; Reichenbach, Stephen E.

In: Journal of Chromatography A, Vol. 1597, 19.07.2019, p. 132-141.

Research output: Contribution to journalArticle

Cordero, Chiara ; Guglielmetti, Alessandro ; Bicchi, Carlo ; Liberto, Erica ; Baroux, Lucie ; Merle, Philippe ; Tao, Qingping ; Reichenbach, Stephen E. / Comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry featuring tandem ionization : Challenges and opportunities for accurate fingerprinting studies. In: Journal of Chromatography A. 2019 ; Vol. 1597. pp. 132-141.
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AU - Baroux, Lucie

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AU - Tao, Qingping

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