HILIC-Enabled 13C Metabolomics Strategies: Comparing Quantitative Precision and Spectral Accuracy of QTOF High- and QQQ Low-Resolution Mass Spectrometry

• Published in: Metabolites Vol. 9; no. 4; p. 63
• Main Authors: Feith, André, Teleki, Attila, Graf, Michaela, Favilli, Lorenzo, Takors, Ralf
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 02.04.2019; MDPI
• Subjects: 13C-tracer studies; Accuracy; Calibration; Carbon; Chromatography; Corynebacterium glutamicum; HILIC; IDMS; Intermediates; Isotopic distribution; Labeling; LC-QQQ-MS/MS; LC-QTOF-HRMS; Mass spectrometry; Mass spectroscopy; Metabolism; Metabolites; Metabolomics; NMR; Nuclear magnetic resonance; Quantitative metabolomics; Scientific imaging; Spectral accuracy; Standard deviation
• ISSN: 2218-1989; 2218-1989
• DOI: 10.3390/metabo9040063

Dynamic 13C-tracer-based flux analyses of in vivo reaction networks still require a continuous development of advanced quantification methods applying state-of-the-art mass spectrometry platforms. Utilizing alkaline HILIC chromatography, we adapt strategies for a systematic quantification study in non- and 13C-labeled multicomponent endogenous Corynebacterium glutamicum extracts by LC-QTOF high resolution (HRMS) and LC-QQQ tandem mass spectrometry (MS/MS). Without prior derivatization, a representative cross-section of 17 central carbon and anabolic key intermediates were analyzed with high selectivity and sensitivity under optimized ESI-MS settings. In column detection limits for the absolute quantification range were between 6.8–304.7 (QQQ) and 28.7–881.5 fmol (QTOF) with comparable linearities (3–5 orders of magnitude) and enhanced precision using QQQ-MRM detection. Tailor-made preparations of uniformly (U)13C-labeled cultivation extracts for isotope dilution mass spectrometry enabled the accurate quantification in complex sample matrices and extended linearities without effect on method parameters. Furthermore, evaluation of metabolite-specific m+1-to-m+0 ratios (ISR1:0) in non-labeled extracts exhibited sufficient methodical spectral accuracies with mean deviations of 3.89 ± 3.54% (QTOF) and 4.01 ± 3.01% (QQQ). Based on the excellent HILIC performance, conformity analysis of time-resolved isotopic enrichments in 13C-tracer experiments revealed sufficient spectral accuracy for QQQ-SIM detection. However, only QTOF-HRMS ensures determination of the full isotopologue space in complex matrices without mass interferences.