TABLE 1.
MS parameters and retention times
| MRM (m/z) | IS | IS MRM (m/z) | Retention Time (min) | DP (V) | EP (V) | CE (V) | CXP (V) | ||
| Free carnitine | C0 | 218.1 → 85.1 | d9-C0 | 227.5 → 85.1 | 5.9 | 61 | 10 | 23 | 15 |
| Hydroxypropionyl-carnitine | C3-OH | 290.1 → 85.1 | d3-C3 | 277.1 → 85.1 | 6.1 | 53 | 10 | 30 | 15 |
| Hydroxybutyryl-carnitine a | C4-OH a | 304.1 → 85.1 | d3-C4 | 291.4 → 85.1 | 6.2 | 55 | 10 | 32 | 15 |
| Hydroxybutyryl-carnitine b | C4-OH b | 304.1 → 85.1 | d3-C4 | 291.4 → 85.1 | 6.3 | 55 | 10 | 32 | 15 |
| 3-Hydroxyisobutyryl-carnitine | 2-M-C3-OH | 304.1 → 85.1 | d3-C4 | 291.4 → 85.1 | 6.4 | 55 | 10 | 32 | 15 |
| Acetyl-carnitine | C2 | 260.5 → 85.1 | d3-C2 | 263.2 → 85.1 | 6.4 | 41 | 10 | 18 | 15 |
| Hydroxyvaleryl-carnitine | C5-OH | 318.1 → 85.1 | d9-C5 | 311 → 85.1 | 6.5 | 58 | 10 | 33 | 15 |
| Propionyl-carnitine | C3:0 | 274.4 → 85.1 | d3-C3 | 277.1 → 85.1 | 6.9 | 46 | 10 | 29 | 15 |
| Hydroxyhexanoyl-carnitine a | C6-OH a | 332.2 → 85.1 | d3-C6 | 319.2 → 85.1 | 7.3 | 61 | 10 | 35 | 15 |
| Crotonyl-carnitine | C4:1 | 286.1 → 85.1 | d3-C4 | 291.4 → 85.1 | 7.3 | 52 | 10 | 29 | 15 |
| Hydroxyhexanoyl-carnitine b | C6-OH b | 332.2 → 85.1 | d3-C6 | 319.2 → 85.1 | 7.5 | 61 | 10 | 35 | 15 |
| Methacrylyl-carnitine | 2-M-C3:1 | 286.1 → 85.1 | d3-C4 | 291.4 → 85.1 | 7.5 | 52 | 10 | 29 | 15 |
| Isobutyryl-carnitine | 2-M-C3:0 | 288.2 → 85.1 | d3-C4 | 291.4 → 85.1 | 7.8 | 46 | 10 | 29 | 15 |
| Butyryl-carnitine | C4:0 | 288.2 → 85.1 | d3-C4 | 291.4 → 85.1 | 8 | 46 | 10 | 29 | 15 |
| Tiglyl-carnitine | 2-M-C4:1 | 300.2 → 85.1 | d9-C5 | 311 → 85.1 | 8.2 | 55 | 10 | 31 | 15 |
| 3-Methylcrotonyl-carnitine | 3-M-C4:1 | 300.2 → 85.1 | d9-C5 | 311 → 85.1 | 8.4 | 55 | 10 | 31 | 15 |
| 2-Methyl-butyryl-carnitine | 2-M-C4:0 | 302.1 → 85.1 | d9-C5 | 311 → 85.1 | 9.5 | 46 | 10 | 29 | 15 |
| Isovaleryl-carnitine | 3-M-C4:0 | 302.1 → 85.1 | d9-C5 | 311 → 85.1 | 9.6 | 46 | 10 | 29 | 15 |
| Valeryl-carnitine | C5:0 | 302.1 → 85.1 | d9-C5 | 311 → 85.1 | 9.7 | 46 | 10 | 29 | 15 |
| Fumaryl-carnitine | C4:1-DC | 372.5 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 9.9 | 56 | 10 | 27 | 15 |
| Malonyl-carnitine | C3-DC | 360.2 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 10.3 | 55 | 10 | 32 | 15 |
| Succinyl-carnitine | C4-DC | 374.2 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 10.8 | 56 | 10 | 33 | 15 |
| Hexanoyl-carnitine | C6:0 | 316.4 → 85.1 | d3-C6 | 319.2 → 85.1 | 10.9 | 56 | 10 | 27 | 15 |
| Methyl-malonyl-carnitine | C3-DC-M | 374.2 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 11.1 | 58 | 10 | 33 | 15 |
| Glutaryl-carnitine | C5-DC | 388.3 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 11.1 | 61 | 10 | 35 | 15 |
| Glutaconyl-carnitine | C5:1-DC | 386.3 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 11.2 | 60 | 10 | 35 | 15 |
| Adipyl-carnitine | C6-DC | 402.3 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 11.3 | 63 | 10 | 37 | 15 |
| Methylglutaryl-carnitine | C5-M-DC | 402.3 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 11.4 | 63 | 10 | 37 | 15 |
| Heptanoyl-carnitine | C7:0 | 330.2 → 85.1 | d3-C6 | 319.2 → 85.1 | 11.5 | 60 | 10 | 30 | 15 |
| Pimelyl-carnitine | C7-DC | 416.3 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 11.7 | 66 | 10 | 39 | 15 |
| Octanoyl-carnitine | C8:0 | 344.1 → 85.1 | d3-C8 | 347.4 → 85.1 | 11.9 | 66 | 10 | 33 | 15 |
| Decenoyl-carnitine | C10:1 | 370.2 → 85.1 | d3-C10 | 375.2 → 85.1 | 12.1 | 68 | 10 | 40 | 15 |
| Nonanoyl-carnitine | C9:0 | 358.2 → 85.1 | d3-C8 | 347.4 → 85.1 | 12.1 | 66 | 10 | 39 | 15 |
| Decanoyl-carnitine | C10:0 | 372.2 → 85.1 | d3-C10 | 375.2 → 85.1 | 12.3 | 56 | 10 | 37 | 15 |
| Iso-undecanoyl-carnitine | Iso-C11:0 | 386.3 → 85.1 | d3-C10 | 375.2 → 85.1 | 12.4 | 65 | 10 | 40 | 15 |
| Undecanoyl-carnitine | C11:0 | 386.3 → 85.1 | d3-C10 | 375.2 → 85.1 | 12.5 | 65 | 10 | 40 | 15 |
| Tetradecadienyl-carnitine | C14:2 | 424.3 → 85.1 | d3-C14 | 431.2 → 85.1 | 12.6 | 78 | 10 | 47 | 15 |
| Dodecanoyl-carnitine | C12:0 | 400.3 → 85.1 | d3-C12 | 403.2 → 85.1 | 12.7 | 73 | 10 | 44 | 15 |
| Hydroxyhexadecenyl-carnitine | C16:1-OH | 470.3 → 85.1 | d3-C16 | 459.2 → 85.1 | 12.8 | 87 | 10 | 53 | 15 |
| Isotridecanoyl-carnitine | Iso-C13:0 | 414.3 → 85.1 | d3-C12 | 403.2 → 85.1 | 13 | 80 | 10 | 45 | 15 |
| Tridecanoyl-carnitine | C13:0 | 414.3 → 85.1 | d3-C12 | 403.2 → 85.1 | 13.1 | 80 | 10 | 45 | 15 |
| Hexadecadienyl-carnitine | C16:2 | 452.3 → 85.1 | d3-C16 | 459.2 → 85.1 | 13.1 | 83 | 10 | 51 | 15 |
| Tetradecanoyl-carnitine | C14:0 | 428.3 → 85.1 | d3-C14 | 431.2 → 85.1 | 13.4 | 86 | 10 | 45 | 15 |
| Hydroxyhexadecanoyl-carnitine a | C16-OH a | 472.3 → 85.1 | d3-C16 | 459.2 → 85.1 | 13.4 | 87 | 10 | 53 | 15 |
| Hydroxyhexadecanoyl-carnitine b | C16-OH b | 472.3 → 85.1 | d3-C16 | 459.2 → 85.1 | 13.5 | 87 | 10 | 53 | 15 |
| Hydroxyoctadecenyl-carnitine | C18:1-OH | 498.4 → 85.1 | d3-C18 | 487.5 → 85.1 | 13.5 | 92 | 10 | 57 | 15 |
| Hexadecenyl-carnitine | C16:1 | 454.3 → 85.1 | d3-C16 | 459.2 → 85.1 | 13.6 | 84 | 10 | 51 | 15 |
| Isopentadecanoyl-carnitine | iso-C15:0 | 442.3 → 85.1 | d3-C14 | 431.2 → 85.1 | 13.6 | 85 | 10 | 48 | 15 |
| Pentadecanoyl-carnitine | C15:0 | 442.3 → 85.1 | d3-C14 | 431.2 → 85.1 | 13.7 | 85 | 10 | 48 | 15 |
| Octadecadienyl-carnitine | C18:2 | 480.3 → 85.1 | d3-C18 | 487.5 → 85.1 | 13.7 | 89 | 10 | 54 | 15 |
| Hexadecanoyl-carnitine | C16:0 | 456.5 → 85.1 | d3-C16 | 459.2 → 85.1 | 14.3 | 84 | 10 | 51 | 15 |
| Octadecenyl-carnitine | C18:1 | 482.3 → 85.1 | d3-C18 | 487.5 → 85.1 | 14.3 | 89 | 10 | 55 | 15 |
| Isoheptadecanoyl-carnitine | Iso-C17:0 | 470.4 → 85.1 | d3-C16 | 459.2 → 85.1 | 14.7 | 90 | 10 | 57 | 15 |
| Heptadecanoyl-carnitine | C17:0 | 470.4 → 85.1 | d3-C16 | 459.2 → 85.1 | 14.8 | 90 | 10 | 57 | 15 |
| Dodecadioyl-carnitine | C12-DC | 486.4 → 85.1 | d6-C5-DC | 394.2 → 85.1 | 15.6 | 86 | 10 | 45 | 15 |
| Octadecanoyl-carnitine | C18:0 | 484.4 → 85.1 | d3-C18 | 487.5 → 85.1 | 15.6 | 96 | 10 | 63 | 15 |
DP, declustering potential; EP, entrance potential; CE, collision energy; CXP, collision cell exit potential.