Uhplc q exactive hf x

Metabolites were detected using an LC-MS analysis platform (UHPLC -Q Exactive HF-X, Thermo Fisher Scientific, Waltham, MA, USA) at Majorbio (Shanghai, China). Chromatographic conditions: The chromatographic column was ACQUITY UPLC HSS T3 (100 mm × 2.1 mm I.D., 1.8 µm; Waters, Milford, MA, USA); mobile phase A consisted of 95% water +5% acetonitrile (containing 0.1% formic acid), and mobile phase B consisted of 47.5% acetonitrile +47.5% isopropanol +5% water (containing 0.1% formic acid). The injection volume was 2 μL, and the column temperature was 40 °C. The samples were ionized by electrospray ionization, and the positive and negative ion scanning modes were used to collect the mass spectrum signals.

The rumen and serum samples were analyzed using the LC–MS platform (Thermo, UHPLC -Q Exactive HF-X). Sequence data associated with this project have been deposited in MetaboLights (ID: MTBLS7520).

LC/MS analysis of lipid extracts was performed on an ultra-high performance liquid chromatography-tandem Fourier transform mass spectrometry (UHPLC-Q Exactive HF-X; Thermo, Waltham, MA, USA) system equipped with an Accucor C30 column (100 mm × 2.1 mm, 2.6 μm; Thermo, Bremen, Germany). The injection volume, column temperature, and flow rate were set as 2 μL, 40 °C, and 0.4 mL/min, respectively. The mobile phase consisted of solvent I [acetonitrile/water, 1:1 (v/v); containing 0.1% formic acid and 10 mmol/L ammonium acetate] and solvent II [acetonitrile/isopropyl alcohol/water, 10:88:2 (v/v); containing 0.02% formic acid and 2 mmol/L ammonium acetate]. Elution separation was performed according to the following gradient: 0–4 min, I/II (65:35, v/v); 4–12 min, I/II (40:60, v/v); 12–15 min, I/II (15:85, v/v); 15–18 min, I/II (0:100, v/v); and 18–20 min, I/II (65:35, v/v).
Afterward, the samples were ionized by electrospray, and the MS signals were collected by positive and negative ion scanning modes. Parameters are as follows: scan type, 200–2000 m/z; sheath gas flow rate, 60 psi; aux gas flow rate, 20 psi; aux gas heater temperature, 370 °C; ion spray voltage floating in the positive mode, 3 kV; ion spray voltage floating in the negative mode, −3 kV; and normalized collision energy, 20–40–60 V.