Table 1. Relative Retention Times (RRT) and Mass Spectrometry Data of Low-Molecular-Weight Metabolites in the Plasma and Brain.
| compound | RTa | RRTb | quantification ionc | mass fragmentd |
|---|---|---|---|---|
| pyruvic acid | 04:56.3 | 0.427 | 174 | 89, 115, 174 |
| lactic acid | 05:02.1 | 0.436 | 117 | 117, 147, 191 |
| alanine | 05:31.9 | 0.479 | 116 | 116, 147, 190 |
| oxalic acid | 05:57.8 | 0.516 | 147 | 117, 133, 147 |
| hydroxybutanoic acid | 06:09.3 | 0.533 | 233 | 147, 177, 205 |
| valine | 06:44.7 | 0.584 | 144 | 144, 156, 218 |
| urea | 07:03.4 | 0.611 | 147 | 147, 189 |
| serine1 | 07:11.2 | 0.622 | 116 | 116, 132, 147 |
| ethanolamine | 07:16.0 | 0.629 | 174 | 100, 147, 174 |
| glycerol | 07:16.6 | 0.630 | 147 | 147, 177, 205 |
| phosphoric acid | 07:17.8 | 0.632 | 299 | 211, 299, 314 |
| leucine | 07:18.5 | 0.633 | 158 | 102, 147, 158 |
| isoleucine | 07:31.3 | 0.651 | 158 | 147, 158, 218 |
| proline | 07:36.7 | 0.659 | 142 | 142, 143, 147 |
| glycine | 07:40.0 | 0.664 | 174 | 147, 174, 248 |
| succinic acid | 07:44.3 | 0.670 | 147 | 147, 149, 247 |
| fumaric acid | 08:04.5 | 0.699 | 245 | 143, 147, 245 |
| serine2 | 08:07.1 | 0.703 | 116 | 100, 147, 204 |
| threonine | 08:21.1 | 0.723 | 291 | 117, 218, 291 |
| β-alanine | 08:47.0 | 0.760 | 174 | 147, 174, 248 |
| malic acid | 09:14.9 | 0.800 | 147 | 100, 147, 218 |
| aspartic acid | 09:32.0 | 0.825 | 100 | 100, 147, 232 |
| methionine | 09:35.4 | 0.830 | 176 | 128, 147, 176 |
| pyroglutamic acid | 09:38.5 | 0.835 | 156 | 147, 156, 230 |
| GABAe | 09:39.9 | 0.837 | 304 | 147, 174, 304 |
| cysteine | 09:51.2 | 0.853 | 220 | 100, 147, 220 |
| glutamic acid | 10:20.7 | 0.895 | 246 | 128, 156, 246 |
| phenylalanine | 10:28.8 | 0.907 | 218 | 100, 192, 218 |
| asparagine | 10:44.7 | 0.930 | 116 | 116, 132, 231 |
| xylitol | 11:01.4 | 0.954 | 217 | 103, 147, 217 |
| ribitol | 11:03.9 | 0.958 | 217 | 103, 147, 217 |
| glutamine | 11:31.3 | 0.997 | 156 | 147, 156, 245 |
| l-2-chlorophenylalaninef | 11:33.2 | 1.000 | 218 | 147, 218, 226 |
| citric acid | 11:47.0 | 1.020 | 273 | 147, 273, 348 |
| fructose1 | 12:06.5 | 1.048 | 103 | 103, 147, 217 |
| fructose2 | 12:10.3 | 1.054 | 103 | 103, 147, 217 |
| mannose | 12:12.7 | 1.057 | 319 | 147, 205, 319 |
| glucose1 | 12:17.4 | 1.064 | 319 | 147, 205, 319 |
| glucose2 | 12:26.3 | 1.077 | 319 | 147, 205, 319 |
| lysine | 12:31.8 | 1.085 | 317 | 156, 174, 317 |
| C16:1 | 13:16.8 | 1.149 | 311 | 117, 132, 311 |
| C16:0 | 13:24.2 | 1.160 | 313 | 117, 132, 313 |
| inositol | 13:36.0 | 1.177 | 305 | 147, 217, 305 |
| C18:2 | 14:25.7 | 1.249 | 337 | 129, 262, 337 |
| C18:1n9 | 14:27.5 | 1.251 | 339 | 117, 129, 339 |
| tryptophan | 14:27.7 | 1.252 | 202 | 147, 202, 218 |
| C18:0 | 14:35.8 | 1.263 | 341 | 117, 132, 341 |
| sucrose | 16:31.7 | 1.431 | 217 | 147, 217, 361 |
| cholesterol | 19:28.0 | 1.685 | 329 | 129, 329, 368 |
a
Retention time (m:s).
b
Relative retention time (retention time of analyte/retention time of L-2-cholorophenylalanine).
c
Specific mass ion used for quantification.
d
Three highest intensity ions.
e
GABA, 4-aminobutyric acid; C16:1, palmitoleic acid; C16:0, palmitic acid; C18:2, linoleic acid; C18:1n9, oleic acid; C18:0, stearic acid.
f
Internal standard.