Table 1. Correlation of acylcarnitines with age.
| m/z | RT (s) | SLC | Database | Common name | Median intensity | Correlation (ρ) | p-value |
| C18 positive | |||||||
| 162.1116 | 42 | 2b | HMDB00062 | Carnitine (C0) | 3.60E6 | -0.0437 | 0.5797 |
| 454.3869 | 470 | 3 | LMFA07070010 | Eicosenoylcarnitine (C20:1) | 2.60E5 | 0.3249 | 2.32E-5 |
| 452.3712 | 391 | 3 | LMFA07070011 | Eicosadienoylcarnitine (C20:2) | 1.78E5 | 0.2827 | 2.56E-4 |
| 456.4025 | 465 | 3 | HMDB06460 | Arachidyl carnitine (C20:0) | 9.27E4 | 0.282 | 2.65E-4 |
| 312.2154 | 93 | 3 | HMDB13325 | Decadienoylcarnitine (C10:2) | 3.01E5 | 0.2754 | 3.73E-4 |
| 444.3665 | 348 | 3 | LMFA07070028 | Hydroxystearoylcarnitine (C18OH) | 7.27E4 | 0.2439 | 1.70E-3 |
| 310.1998 | 76 | 3 | LMFA07070016 | Decatrienoylcarnitine (C10:3)* | 1.03E6 | 0.2363 | 2.39E-3 |
| 472.3387 | 335 | 3 | HMDB06510 | Docosahexaenoylcarnitine (C22:6) | 2.42E4 | 0.2344 | 2.60E-3 |
| 398.3245 | 334 | 3 | HMDB06317 | Hexadecenoylcarnitine (C16:1)* | 6.73E5 | 0.2341 | 2.63E-3 |
| 218.1375 | 258 | 2b | HMDB00824 | Propionylcarnitine (C3:0) | 5.14E4 | 0.2327 | 2.79E-3 |
| 396.3088 | 313 | 3 | HMDB13334 | Hexadecadienoylcarnitine (C16:2)* | 2.30E5 | 0.2005 | 0.0103 |
| 422.3244 | 323 | 3 | HMDB06318 | Octadecatrienoylcarnitine (C18:3) | 2.19E5 | 0.1947 | 0.0128 |
| 388.3037 | 286 | 3 | HMDB13166 | Hydroxymyristoylcarnitine (C14OH) | 1.21E5 | 0.1735 | 0.0268 |
| 474.3564 | 347 | 3 | HMDB06321 | Docosapentaenoylcarnitine (C22:5) | 4.26E4 | 0.1683 | 0.0318 |
| 420.3089 | 314 | 3 | HMDB06463 | Octadecatetraenoylcarnitine (C18:4) | 2.62E4 | 0.1553 | 0.0478 |
| 464.3352 | 309 | 3 | LMFA07070036 | Hydroxyicosatetraenoylcarnitine (C20:4OH) | 4.94E3 | 0.1539 | 0.0498 |
| 262.1637 | 258 | 2b | LMFA07070041 | Hydroxyvalerylcarnitine (C5OH) | 1.51E4 | -0.1602 | 0.0411 |
| 246.1687 | 265 | 2b | HMDB13128 | Valerylcarnitine (C5:0)* | 5.07E4 | -0.1612 | 0.0398 |
| 374.2519 | 311 | 3 | HMDB13327 | Dodecanedioylcarnitine (C12DC) | 8.53E4 | -0.1914 | 0.0144 |
| 304.1741 | 257 | 3 | HMDB13328 | Pimelylcarnitine (C7DC) | 2.97E4 | -0.1976 | 0.0114 |
| 302.231 | 301 | 3 | HMDB13288 | Nonanoylcarnitine (C9:0) | 6.07E4 | -0.2174 | 5.30E-3 |
| Anion exchange | |||||||
| 310.2014 | 57 | 3 | LMFA07070016 | Decatrienoylcarnitine (C10:3)* | 3.30E5 | 0.2421 | 1.85E-3 |
| 398.3265 | 76 | 3 | HMDB13207 | Hexadecenoylcarnitine (C16:1)* | 3.68E5 | 0.1945 | 0.0128 |
| 426.3576 | 111 | 3 | HMDB06351 | Octadecenoylcarnitine (C18:1) | 2.55E6 | 0.1808 | 0.0209 |
| 396.3108 | 65 | 3 | HMDB13334 | Hexadecadienoylcarnitine (C16:2)* | 1.21E5 | 0.1723 | 0.0279 |
| 369.2828 | 59 | 3 | HMDB13331 | Tetradecadienoylcarnitine (C14:2) | 1.20E5 | 0.1682 | 0.0318 |
| 288.2169 | 63 | 2b | HMDB00791 | Octanoylcarnitine (C8:0) | 5.17E5 | 0.1632 | 0.0374 |
| 372.3109 | 71 | 3 | HMDB05066 | Myristoylcarnitine (C14:0) | 2.51E5 | 0.1547 | 0.0486 |
| 286.2013 | 570 | 2b | HMDB13324 | Octenoylcarnitine (C8:1) | 2.72E4 | -0.1681 | 0.032 |
| 246.1698 | 581 | 2b | HMDB13128 | Valerylcarnitine (C5:0)* | 7.13E3 | -0.1778 | 0.0232 |
| 330.2272 | 584 | 3 | HMDB13202 | Ketodecanoylcarnitine (Oxo-C10) | 2.08E3 | -0.1905 | 0.0149 |
Correlation analyzed by Spearman (ρ) and significance of correlation (p-value) are shown for each acylcarnitine detected on both C18 and anion exchange columns. Mass-to-charge ratio (m/z), retention time (RT), Schymanski level of confidence (SLC), and Human Metabolome Database (HMDB) or Lipid Maps (LMFA) database identifier are given for each acylcarnitine. Although no significant correlation was found for free carnitine (C0), values are given for reference. A SLC of 3 indicates a putative identification using LCMS data, whereas a SLC of 2b indicates a probable match using additional diagnostic MS/MS data. All acylcarnitines were detected as an M + H adduct. *, acylcarnitine identified by both C18 and anion exchange.