Pegasus ht tof ms

Metabolomic analysis of colonic contents was conducted by multiple mass spectrometry (MS) platforms, including gas chromatography mass spectrometry/time-of-flight (GC-MS/TOF) and ultrahigh-performance liquid chromatography/mass spectrometry (UHPLC/MS). GC-MS/TOF analysis was performed on the Agilent 7890A gas chromatograph system coupled with the Pegasus HT TOF MS (Leco) while UHPLC/MS analysis was conducted on the Agilent 1290 UHPLC system coupled to TripleTOF 6600 system (Q-TOF, AB Sciex, Concord, ON, Canada). Further multivariate statistical analysis was performed on the SIMCA software (Version 14.1, MKS Data Analytics Solutions, Concord, ON, Canada). Group differences and group separation variables were analyzed using Orthogonal projections to latent structures-discriminate analysis (OPLS-DA). The predictive ability parameter Q2 and goodness-of-fit parameter R2Y were obtained for estimating the model quality after seven-fold cross validation. The metabolite set enrichment analysis and pathway analysis were carried out to generate the related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of each differential metabolite and biomarker metabolic pathways, separately, on the web-based tool MetaboAnalyst (http://www.meta-boanalyst.ca, accessed on 17 March 2021).

GC-MS analysis was performed on a Leco Pegasus HT TOF-MS equipped with an Agilent 7890A gas chromatograph at the Swedish Metabolomics Center, Umeå, Sweden, https://www.swedishmetabolomicscentre.se/. The derivatized samples, 1 μl, were auto-injected (splittless) at a temperature of 270 °C. The ion source temperature was 200 °C and the ionization energy was 70 eV. Mass spectra were collected in the mass range 50 to 800 m/z. n-alkanes (C8-C40) were used as external retention index standards.
For samples J1_1–6 a 30 m GC-column with an inner diameter of 0.25 mm was used. The purge delay time was 75 seconds and the rate was 20 mL/min. Helium was used as carrier gas (1 mL/min). The GC oven temperature was 70 °C for 2 minutes and then increased 20 °C/minute to 320 °C, where it was held constant for 8 minutes. The detector voltage was 1670 V.
All other samples employed a 10 m GC-column with an inner diameter of 0.18 mm. The purge delay time was 60 seconds and the rate was 20 mL/min. Helium was used as carrier gas (1 mL/min). The GC oven temperature was 70 °C for 2 minutes and then increased 40 °C/minute to 320 °C, where it was held constant for 2 minutes. The detector voltage was 1920 V.

The metabolomics data of human faecal samples were quantified by GC–TOF–MS (Agilent 6890N GC coupled with a LECO Pegasus HT TOF–MS). The details of analytical condition as described in previous study^{65 (link)}.