Table 5.

Multiple reaction monitoring (MRM) transitions for molecular species of sphingomyelin precursor and fragment ions

Sphingomyelins	Precursor/fragment ion m/z
d18:1/12:0	647.7/184.4*
d18:1/16:0	703.8/184.4
d18:1/18:0	732.1/184.4
d18:1/20:0	759.8/184.4
d18:1/22:0	787.9/184.4
d18:1/24:0	815.9/184.4
d18:1/26:0	843.9/184.4
d18:1/16:1	701.5/184.4
d18:1/18:1	729.4/184.4
d18:1/20:1	757.4/184.4
d18:1/22:1	785.4/184.4
d18:1/24:1	813.9/184.4
d18:1/26:1	841.9/184.4

Dihydrosphingomyelins	Precursor/fragment ion m/z
d18:0/16:0	706.9/184.4
d18:0/18:0	734.8/184.4
d18:0/20:0	761.8/184.4
d18:0/22:0	789.9/184.4
d18:0/24:0	817.9/184.4
d18:0/26:0	845.9/184.4

^*Internal standard.