Endogenous Metabolite Spectral Library

Standard spectral library of metabolically relevant small molecules detectable in several biological samples (e.g. urine, cell lysates). This library contains 101 reference compounds, 2,324 MS/MS spectra (1,572 positive- and 752 negative-mode), and was generated from authentic standards analyzed by pHILIC LC-MS/MS on a Q Exactive HF Orbitrap (Thermo Fisher Scientific) with electrospray ionization in both polarities and HCD fragmentation. Data-dependent acquisition (Top 5) followed the method described by Zaal et al. (10.1007/978-1-0716-4116-3_6.), with the following modifications for MS/MS events: resolution 30,000; AGC target 5 × 10⁵; maximum injection time 120 ms; isolation window 1.0 m/z; normalized collision energies 20, 30, and 40.