An Ion Mobility-Mass Spectrometry Imaging Workflow
Mass spectrometry imaging (MSI) is a powerful technique for the label-free spatially-resolved analysis of biological tissues. Coupling ion mobility (IM) separation with MSI allows separation of isobars in the mobility dimension and increases confidence of peak assignments. Recently, imaging experiments have been implemented on the Agilent 6560 Ion Mobility Quadrupole Time of Flight Mass Spectrometer, making MSI experiments more broadly accessible to the MS community. However, the absence of data analysis software for this system presents a bottleneck. Herein, we present a vendor-specific imaging workflow to visualize IM-MSI data produced on the Agilent IM-MS system. Specifically, we have developed a Python script, the ion mobility-mass spectrometry image creation script (IM-MSIC), which interfaces Agilent’s Mass Hunter Mass Profiler software with the MacCoss lab’s Skyline software and generates drift time and mass-to-charge selected ion images. In the workflow, Mass Profiler is used for an untargeted feature detection. The IM-MSIC script mediates user input of data and extracts ion chronograms utilizing Skyline’s command-line interface, then proceeds towards ion image generation within a single user interface. Ion image post-processing is subsequently performed using different tools implemented in accompanying scripts.