Uplc synapt g2 si qtof ms system

Serum and ileum samples were prepared by precipitation. Then, chlorpropamide (Sigma-Aldrich, Cat# C1290) was added as an internal standard to quantify bile acid levels. The bile acid concentrations in the supernatants were measured by a UPLC/Synapt G2-Si QTOF MS system (Waters Corp., Milford, MA) with an ESI source. Chromatographic separation was operated on an Acquity BEH C18 column (100 mm × 2.1 mm i.d., 1.7 μm, Waters Corp.). Column temperature was 45 °C, and the flow rate was 0.4 ml/min. The mobile phase included a mixture of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. The gradient elution was applied and MS detection proceeded in negative mode. A mass range of m/z 50 to 850 was acquired. Standards for all bile acids were used to identify the different bile acid metabolites detected by LC-MS.

For bile acid quantitation in serum, ileum, colon, and gallbladder, d5-TCA at 1 μM was used as an internal standard. Samples were prepared by acetonitrile precipitation and the supernatants were further diluted with 0.1% formic acid. The bile acid concentrations were determined by an UPLC/Synapt G2-Si QTOFMS system (Waters Corp., Milford, MA) with an ESI source. Chromatographic separation was archived on an Acquity BEH C18 column (100 mm × 2.1 mm i.d., 1.7 μm, Waters Corp.). The mobile phase consisted of a mixture of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). The gradient elution was applied. Column temperature was maintained at 45°C, and the flow rate was 0.4 mL/min. MS detection was operated in negative mode. A mass range of m/z 50 to 850 was acquired. All bile acid standards were purchased from Sigma-Aldrich (St. Louis, MO) or Toronto Research Chemicals (Toronto, Ontario, Canada).