TABLE 1.
MRM parameters and retention times for iTRAQ-labeled sphingoid bases in this study
| Sphingoid Base | Q1 (m/z) | CE (V) | CXP (V) | RT (min) |
|---|---|---|---|---|
| iSo d16:1 | 416.4 | 35 | 9 | 2.0 |
| iSo d17:1 | 430.4 | 35 | 9 | 2.8 |
| iSo d18:1 | 444.4 | 40 | 10 | 3.6 |
| iSo d20:1 | 472.4 | 40 | 10 | 4.3 |
| iSa d16:0 | 418.4 | 40 | 9 | 2.9 |
| iSa d17:0 | 432.4 | 40 | 9 | 3.4 |
| iSa d18:0 | 446.4 | 45 | 10 | 3.9 |
| iSa d20:0 | 474.4 | 45 | 10 | 4.5 |
| ipS t16:0 | 434.4 | 40 | 9 | 1.9 |
| ipS t18:0 | 462.4 | 45 | 10 | 3.5 |
| ipS t20:0 | 490.4 | 45 | 10 | 4.2 |
| iS1P d17:1 | 510.4 | 40 | 9 | 3.4 |
| iSa1P d17:0 | 512.4 | 50 | 9 | 3.9 |
| iHexSo d16:1 | 578.4 | 35 | 9 | 1.6 |
| iHexSo d18:1 | 606.5 | 40 | 10 | 3.2 |
| iHexSo d20:1 | 636.5 | 40 | 10 | 4.1 |
| iHexSa d18:0 | 608.5 | 45 | 10 | 3.7 |
| iHexpS t18:0 | 624.5 | 45 | 10 | 3.2 |
CE, collision energies; CXP, collision cell exit potential; Hex, hexosyl; i, iTRAQ-labeled; pS, phytosphingosine; Q, quadrupole; RT, retention time; S1P, sphingosine 1-phosphate; Sa, sphinganine; Sa1P, sphinganine 1-phosphate; So, sphingosine; V, voltage.