Table 3.
Retention times and compound specific selected reaction monitoring (SRM) parameters for some of the ceramide phosphoryl ethanolamines containing saturated sphingoid base core. The methods comprised of one segment. In each method to attain maximum sensitivity only seven cer-PE were included, in which precursor ion to double dehydrated product ion arising from sphingoid base is monitored
| Cer-PE Analyte SRM Transitions: | Precursor [M+H]+ → Product ion | Retention Time (min) | Collision Enery (V) | Tube Lens (V) |
|---|---|---|---|---|
| Method 1 for d14:0 | ||||
| d17:1Δ4 c12:0 (ISTD) | 591.46 → 250.19 | 6.17 | 28 | 94 |
| d14:0 c16:0 | 607.49 → 210.28 | - | 28 | 96 |
| d14:0 c18:0 | 635.49 → 210.28 | 7.17 | 29 | 98 |
| d14:0 c20:0 | 663.53 → 210.28 | 7.96 | 30 | 100 |
| d14:0 c22:0 | 691.50 → 210.28 | 8.92 | 30 | 102 |
| d14:0 c24:0 | 719.58 → 210.28 | 9.96 | 30 | 102 |
| Method 2 for d16:0 | ||||
| d17:1Δ4 c12:0 (ISTD) | 591.46 → 250.19 | 6.19 | 28 | 94 |
| d16:0 c14:0 | 607.49 → 238.20 | NI | 28 | 96 |
| d16:0 c16:0 | 635.49 → 238.20 | NI | 29 | 98 |
| d16:0 c18:0 | 663.53 → 238.20 | NI | 30 | 100 |
| d16:0 c20:0 | 691.50 → 238.20 | NI | 30 | 102 |
| d16:0 c22:0 | 719.58 → 238.20 | NI | 30 | 106 |
*
10 μL of solution was injected by an auto-sampler for LC-ESI-MS/MS experiments. NI = Not Identified.