Performance Evaluation of Gas Chromatography–Atmospheric Pressure Chemical Ionization–Time-of-Flight Mass Spectrometry for Metabolic Fingerprinting and Profiling

摘要: Gas chromatography-atmospheric-pressure chemical ionization-time-of-flight mass spectrometry (GC-APCI-TOFMS) was compared to GC × GC-electron ionization (EI)-TOFMS, GC-EI-TOFMS, GC-chemical (CI)-quadrupole (qMS), and GC-EI-qMS in terms of reproducibility, dynamic range, limit detection, quantification using a mix 43 metabolites 12 stable isotope-labeled standards. Lower limits for GC-APCI-TOFMS ranged between 0.06 7.81 μM, relative standard deviations calibration replicates were 0.4% 8.7%. For all compounds techniques, except four cases, R(2) values above 0.99. Regarding quantification, inferior only but outperformed other techniques tested. further applied the metabolic fingerprinting two Escherichia coli strains. Of 45 features that differed significantly (false discovery rate < 0.05) strains, 25 identified through highly accurate reproducible (Δm ± SD below 5 mDa over m/z 190-722) measurements. Starting from quasimolecular ion, six additional had not been found previous study GC-EI-TOFMS an EI spectral library identification purposes. Silylation adducts formed APCI source assisted unknown compounds, as their formation is structure-dependent observed lacking carboxylic group.