GNPS - PNACIC LC-IMS-MS/MS Internal Standards

Samples containing stable isotope-labeled internal standards added to plasma and liver samples. Standards were obtained from a mix of NIH standards representing nine metabolite classes and the QreSS kit from Cambridge Isotope Laboratories (MA, USA). The samples were chromatographically separated using hydrophilic interaction liquid chromatography (HILIC) and reversed-phase liquid chromatography (RPLC) chemistries in separate injections. The LC system was coupled to an Agilent 6560 ion mobility quadrupole time of flight mass spectrometer (Agilent Technologies, CA, USA), and the standards were analyzed in both positive and negative ionization mode. The MS/MS data were acquired at collision energies of 10, 20, and 40eV using an all-ions fragmentation approach with frames alternating between high and low fragmentation using a mass range of 50-1500 m/z.