Continuous water infusion enhances atmospheric pressure chemical ionization of methyl chloroformate derivatives in gas chromatography coupled to time-of-flight mass spectrometry-based metabolomics.
Anal Chem
; 86(18): 9186-95, 2014 Sep 16.
Article
en En
| MEDLINE
| ID: mdl-25152309
The effects of continuous water infusion on efficiency and repeatability of atmospheric pressure chemical ionization of both methyl chloroformate (MCF) and methoxime-trimethylsilyl (MO-TMS) derivatives of metabolites were evaluated using gas chromatography-time-of-flight mass spectrometry. Water infusion at a flow-rate of 0.4 mL/h yielded not only an average 16.6-fold increase in intensity of the quasimolecular ion for 20 MCF-derivatized metabolite standards through suppression of in-source fragmentation but also the most repeatable peak area integrals. The impact of water infusion was the greatest for dicarboxylic acids and the least for (hetero-) aromatic compounds. Water infusion also improved the ability to detect reliably fold changes as small as 1.33-fold for the same 20 MCF-derivatized metabolite standards spiked into a human serum extract. On the other hand, MO-TMS derivatives were not significantly affected by water infusion, neither in their fragmentation patterns nor with regard to the detection of differentially regulated compounds. As a proof of principle, we applied MCF derivatization and GC-APCI-TOFMS to the detection of changes in abundance of metabolites in pancreatic cancer cells upon treatment with 17-DMAG. Water infusion increased not only the number of metabolites identified via their quasimolecular ion but also the reproducibility of peak areas, thereby almost doubling the number of significantly regulated metabolites (false discovery rate < 0.05) to a total of 23.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Agua
/
Metabolómica
/
Formiatos
/
Cromatografía de Gases y Espectrometría de Masas
Tipo de estudio:
Guideline
/
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Anal Chem
Año:
2014
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Estados Unidos