Ceramide Analysis by Multiple Linked-Scan Mass Spectrometry Using a Tandem Quadrupole Instrument

Ceramides are a special class of sphingolipids and play a central role in sphingolipid metabolism, and have diverse structures. In this book chapter, tandem quadrupole mass spectrometric approaches applying multiple linked scannings including various constant neutral loss scan (NLS) and precursor ion scan (PIS), the unique applicable feature of a triple-stage quadrupole (TSQ) instrument for analysis of ceramides desorbed as [M−H]⁻ and [M+Li]⁺ ions are described. These multiple dimensional tandem mass spectrometric approaches are fully adapted to the conventional shotgun lipidomics workflow with minimal or without prior chromatographic separation to profile ceramide molecules, and thus detection of a whole class of ceramide or various specific ceramide subclasses in crude lipid extract can be achieved. With addition of internal standard(s), semi-quantitation of ceramide in the lipid extract of biological origin is possible. Examples have shown promise in ceramide profiling of several whole lipid extracts from porcine brain, the model Dictyostelium Discoideum cells for cancer study, and skin.