Targeted Metabolomics Analysis by UHPLC-HR-MS

The UHPLC-HR-MS system was composed of a Vanquish Flex Binary pump LC and a Q Exactive Plus MS equipped with an electrospray ionization (ESI) source, the Orbitrap-based FT-MS system (Thermo Fischer Scientific Inc., Dreieich, Germany). The chromatography was performed on a Kinetex Biphenyl column (100 × 2.1 mm, 2.6 µm particle size) composed of SecurityGuardTM Ultra Cartridges (Phenomenex, Bologna, Italy). Elution was carried out with formic acid in H₂O 0.1% v/v (solvent A) and formic acid in acetonitrile 0.1% v/v (solvent B) with a linear solvent gradient (5 to 60% B within 16 min). Samples (5 µL) were injected into the LC system at a flow rate of 0.5 mL/min, maintaining autosampler and column oven temperatures at 4 and 35 °C, respectively. MS parameters were applied as previously reported [8 (link)].