Comprehensive Isotope Ratio Metabolomics : Gas chromatography Isotope Ratio Mass Spectrometry of urinary metabolites and exhaled breath

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We have developed an analytical procedure to measure the carbon isotopic composition of multiple compounds even when there is a partial overlap in the chromatographic profiles and applied this procedure to measure the carbon isotopic composition of different metabolites in human urine and exhaled breath. Method development and validation was performed with CRM IAEA-600 caffeine after calibration of the reference CO2 gas using a mixture of certified undecane, pentadecane and eicosane δ(13C) standards. The alternative data treatment procedure included the correction of time-lag between Faraday cup amplifiers (44 ms at mass 45 and -160 ms at mass 46), the calculation and correction of chromatographic isotope effects on each peak (isotope shifts) and the calculation of the isotope ratio for each compound using the linear regression slope procedure with data only at the top of the chromatographic peak. In that way, partial chromatographic overlap between different metabolites can be tolerated (resolution equal or higher than 1). The reproducibility (SD) of the carbon isotope composition of 93 metabolites in human urine (n = 8) from one volunteer was typically better than 0.5 δ(13C) (range 0.1-2.0 δ(13C), median 0.4 δ(13C)). The method was applied to follow the carbon isotope composition of different metabolites in human urine and exhaled breath after the oral administration of 100 mg of universally labelled 13C-glucose to another human volunteer. It was demonstrated that isotopically labelled compounds could be detected in both samples even 2 h after administration. So, the developed methodology can be applied to multiple types of samples containing a large number of partially overlapping analytes including environmental applications, anti-doping control or metabolomics studies, including the use of enriched isotope tracers.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:1170

Enthalten in:

Analytica chimica acta - 1170(2021) vom: 25. Juli, Seite 338606

Sprache:

Englisch

Beteiligte Personen:

Rodas Sánchez, Laura [VerfasserIn]
Rodríguez González, Pablo [VerfasserIn]
García Alonso, J Ignacio [VerfasserIn]

Links:

Volltext

Themen:

Carbon Isotopes
Carbon isotope ratios
Exhaled breath
Journal Article
Metabolomics
Urine

Anmerkungen:

Date Completed 09.06.2021

Date Revised 09.06.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.aca.2021.338606

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM326388230