Fig. 2: Composition of MALDI-TIMS-MS2 frame data with multiple fragmented precursor ions.
SIMSEF scheduled 11 precursor ions (magenta) for a, a TIMS-MS1 frame spectrum, here visualised as accumulated spectrum with merged mobility dimension. The corresponding acquired MS2 frame visualised as b, the total ion mobilogram showing the intensity distribution along the mobility dimension and c, the mobility-m/z heatmap of the TIMS-MS2 pixel, showing precursor m/z isolation windows (magenta) and ion mobility MS2 extraction windows for individual precursors (blue). d, an extracted TIMS-MS2 scan for the precursor m/z 701.5121 within 1.29 − 1.33 Vs/cm2 (bold blue) was annotated with the rule-based lipid annotation module and enriched by manual annotation of fragment signals. The observed headgroup fragment (m/z 152.9964) and signals for chain fragment ions (FA18:0; FA18:1) allow annotation of this precursor as PA 18:0_18:1. The applied collision energy produced high-quality fragment spectra for lipid species between m/z 400 – 850, while being too low for larger and too high for smaller molecules.
