Ultraviolet Photodissociation Mass Spectrometry for Advanced Structural Analysis of Lipids

Advances in lipid science have deepened our understanding of lipid functions across biological systems. Mass spectrometry (MS) plays a central role in lipid analysis, offering high sensitivity for identification and quantification. Tandem MS with collision-induced dissociation (CID) is widely used for structural analysis, but often fails to resolve critical features, especially in isomeric lipids. To address these limitations, alternative methods such as UV photodissociation (UVPD) are increasingly used. UVPD accesses distinct fragmentation pathways, opening new avenues for structural analysis, though its underlying mechanisms remain only partially understood. In our recent study, we observed photofragmentation of lithium-cationized wax esters, and proposed a mechanism involving Norrish–Yang-type photochemistry. This project will investigate the photofragmentation in detail, combining experimental and theoretical approaches. We will target lipid classes where CID is inadequate, aiming to show that UVPD- driven fragmentation enables structural insights beyond those offered by CID.