Gcms tq8040 gas chromatograph mass spectrometer

FA contents were measured as previously described (26 (link)) with some modifications. About 500 to 1000 age-synchronized adult worms were washed off plates and washed three times with water. Worm pellets were resuspended with 1.2 ml of 2.5% sulfuric acid in methanol and incubated at 80 °C for 1 h. Then, 1 ml of supernatant was mixed with 1.2 ml of hexane and 1.8 ml of water to extract FA methyl esters (FAMEs) for GC-MS analysis. The Supelco 37 Component FAME Mix (Sigma) was used to determine the retention time. The Shimadzu GCMS-TQ8040 Gas Chromatograph Mass Spectrometer equipped with SH-Rxi-5sil MS column was used.

Furthermore, 5–10 mg of feces was mixed with 90 μL of Milli-Q and 10 μL of 2 mM internal standard containing acetic acid, butyric acid, and crotonic acid for 5 min. The mixture was homogenized with 50 μL of 36% HCl and 200 μL of 97% diethyl ether and was centrifuged at 3000 rpm for 10 min at room temperature. Subsequently, 80 μL of the supernatant organic layer was transferred to a new glass vial and combined with 16 μL of N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide as a derivatization reagent. The vials were immediately capped tightly with electronic crimper (Agilent), incubated for 20 min in an 80 °C water bath, and then left at room temperature in the dark for 48 h for derivatization. The derivatized samples were analyzed using a GC-MS-TQ8040 gas chromatograph mass spectrometer (Shimadzu Corporation, Kyoto, Japan), and the injection was performed using an AOC-20i autoinjector (Shimadzu Corporation, Kyoto, Japan). The capillary column was a BPX5 column (0.25 mm × 30 m × 0.25 μm; Shimadzu GLC). Pure helium gas was used as a carrier gas and delivered at a flow rate of 1.2 mL min-1. The head pressure was 72.8 kPa with split (split ratio of 30:1). The injection port and interface temperatures were 230 °C and 260 °C, respectively. This analysis measured the 10 types of fecal SCFAs (C1:0–C6:0).