SL MRM transition ion pair
(m/z)
Calibration curve Correlation coefficient (r2) LOD
(S/N=5)
Cer C16
C18
C24
538.6>264.3
566.6>264.3
650.7>264.3
y=0.4746x-0.0068
y=0.5681x-0.0117
y=0.3270x-0.0040
0.9911
0.9905
0.9917
1 pg
1 pg
1 pg
GC C16
C18
C24-1
700.7>264.4
728.8>264.4
810.8>264.3
y=0.1856x-0.0016
y=0.2757x-0.0016
y=0.3202x-0.0029
0.9950
0.9982
0.9941
1 pg
1 pg
1 pg
LacCer C16
C24
862.7>264.3
974.8>264.3
y=1.7887x+0.0055
y=1.3099x+0.0027
0.9986
0.9991
1 pg
10 pg
Sulfatide C16
C24
778.7>97.0
890.6>97.0
y=0.1252x+0.0100
y=0.4184x+0.0361
0.9942
0.9917
50 pg
50 pg
Curves for GC and GalCer on SP-LC-MS/MS
GC C16
C18
C24-1
700.7>264.4
728.8>264.4
810.8>264.3
y=0.2163x-0.0013
y=0.2370x+0.0007
y=0.2243x-0.0018
0.9997
0.9999
0.9997
25 pg
25 pg
25 pg
GalCer C16
C24-1
700.7>264.4
810.8>264.3
y=0.2275x-0.0071
y=0.3142x-0.0083
0.9997
0.9996
25 pg
25 pg
Table 1: Calibration curve parameters for sphingolipid species.