Gas chromatograph mass spectrometer qp2010 gc ms

Acetic acid, propionic acid, butyric acid, and its isomer isobutyric acid in stool samples of the mice were detected by Gas Chromatograph Mass spectrometer-QP2010 (GC-MS) (Shimadzu, Tokyo, Japan). Each stool sample in methanol (50 mg/mL) was homogenized by vigorous vortexing for 10 s and ultrasound sonication for 10 min. The mixture was then centrifuged at 14,000 rpm for 5 min at room temperature. The supernatant was further diluted with methanol by 10-fold and 1 µL of sample was vaporized at 230 °C upon injection. An Agilent J&W fused silica capillary column DB-FFAP (Agilent, Santa Clara, CA, USA) was used to separate the compounds. Samples were then ionized by electron impact at −70 eV at 200 °C, and analyzed by Quadrupole mass spectrometer. GCMSsolution Software (Shimadzu, Japan) was employed to identify each SCFA based on their corresponding mass spectra and retention times; and to quantify concentrations of the SCFAs by the peak areas of the total ion current (TIC) with reference to the calibration curve of the standards (Supplementary Figure S1) [52 (link)].

The SCFAs in stool samples of the mice, including acetic acid, propionic acid, butyric acid, and its isomer isobutyric acid, were detected using Gas Chromatograph Mass Spectrometer-QP2010 (GC-MS) (Shimadzu, Tokyo, Japan). Every stool sample was homogenized with 50 mg/mL methanol by vortex for 10 seconds and treated by ultrasound for 10 minutes. Next, the mixed samples in each group were centrifuged at room temperature at 14,000 rpm for 5 minutes. The supernatant was diluted with methanol 10 times. Upon injection, 1 μL of sample was evaporated at 230°C. The compounds were separated via an Agilent J&W fused silica capillary column DB-FFAP (Agilent, Santa Clara, CA, USA). After being ionized by electron impact at -70 eV at 200°C, the samples were analyzed via a quadrupole mass spectrometer. Each SCFA was identified using GCMSsolution software (Shimadzu, Japan). The concentrations of SCFAs were quantified according the peak areas of the total ion current.