Lipids are one of the four classes of biomolecules and play important roles in plasma membrane formation,¹  signal transduction,²  and energy storage.³  The representative biological processes in which lipids are involved include inflammation,⁴  apoptosis,⁵  and oncogenesis.^6–8  In contrast to the linear structures of DNAs and proteins, lipids are structurally diverse molecules and the total number of lipids is estimated to be over 400 000 in nature. For instance, the structures of phospholipids are only complete when the lipid type, fatty acyls, carbon–carbon double bond (CC) location/geometry (cis/trans), and sn (stereospecific numbering)-positions of fatty acyls are all characterized. Each of the above structural moieties is highly diverse, thereby leading to an extremely large number of lipids in the biological kingdom. Even now, we have limited understanding about the implications of this huge lipid diversity. However, over the past decade research on lipids has made significant progress in fundamental lipid biology, biomedical applications, and disease diagnostics, which necessitates the structural elucidation and quantitative analysis of lipids to support functional studies.