Combining Laser Ablation Electrospray Ionization Mass Spectrometry with Collision Cross Section of Improved Metabolite and Lipid Identification from Clinical Samples
Laser Ablation Electrospray Ionization Mass Spectrometry (LAESI-MS) is an innovative technology that allows imaging mass spectrometry and molecular signature profiling on complex clinical samples ranging from tissues to high throughput well plate analyses. The “sweet spot” for LAESI analysis is in targeting pharmaceuticals, metabolite and lipid distribution within complex samples. However, a main problem in any platform for metabolic or lipidomic analysis is that there often are numerous candidates under one isobaric peak, which limits a complete definition of the species. Here, we discuss analytical strategies using collision cross sections (CCS) generated by traveling wave ion mobility mass spectrometry (TWIMS) to increase confidence in identifications from complex samples. We show that coupling LAESI with TWIMS generates CCS that match CCS collected using traditional liquid chromatography coupled to electrospray ionization. Comparison of LAESI-TWIMS imaging data generated from normal and Alzheimer’s brain tissue sections shows that CCS is a highly useful tool in generating biologically relevant metabolic information from complex clinical samples.