Figure 3.
Common fragmentations of sphingomyelin (top center) showing cleave of the phosphocholine headgroup in the positive mode and neutral loss of the fatty acid in the negative mode. Complex sphingolipids fragment via neutral loss of the fatty acid and dehydration of the sphingoid base (lower left), as do the long chain sphingoid bases (lower right). These unique species are used for determination of sphingoid base, fatty acid, and head group combinations for building a “parts list” for LC-MS/MS.