Table 3.
Intra-sample, intra-day and inter-day validation
| Compound | Intra-sample RSD (%) of RT | Intra-day RSD (%) of PA (n = 4) | Inter-day RSD (%) of PA (n = 4) |
|---|---|---|---|
| ESI− | |||
| Fumaric acid | 0.45 | 4.70 | 7.59 |
| Succinic acid | 0.34 | 5.61 | 8.77 |
| Aspartic acid | 0.00 | 2.42 | 5.46 |
| Malic acid | 0.45 | 6.97 | 9.83 |
| Glutamic acid | 0.00 | 5.41 | 7.07 |
| Phospho(enol)pyruvic acid | 2.48 | 4.88 | 9.97 |
| Gallic acid | 0.27 | 4.53 | N.Q. |
| Cis-Aconitic acid | 0.25 | 3.94 | N.Q. |
| Shikimic acid | 0.62 | 1.63 | N.Q. |
| Azelaic acid | 0.14 | 5.43 | N.Q. |
| Citric acid | 0.28 | 2.20 | 3.79 |
| Isocitric acid | 0.00 | 1.79 | 5.11 |
| Gluconic acid | 0.00 | 4.05 | 3.51 |
| Kaempferol | 0.07 | 4.70 | N.Q. |
| Chlorogenic acid | 0.17 | 4.27 | N.Q. |
| Trehalose 6-phosphate | 0.00 | 6.37 | 5.34 |
| ESI+ | |||
| Proline | 0.42 | 4.02 | 1.91 |
| Isoleucine | 0.46 | 0.98 | 3.82 |
| Leucine | 0.20 | 2.32 | 7.24 |
| Asparagine | 0.00 | 7.024 | 7.91 |
| Glutamine | 0.00 | 2.32 | 4.30 |
| Lysine | 0.59 | 4.82 | 7.28 |
| O-Acetyl-serine | 0.96 | 2.74 | 4.90 |
| Methionine | 0.35 | 2.95 | 8.08 |
| Histidine | 0.00 | 3.32 | 2.85 |
| Phenylalanine | 0.13 | 2.02 | 3.81 |
| Arginine | 0.00 | 3.89 | 3.76 |
| Tyrosine | 0.35 | 1.26 | 7.14 |
| Tryptophan | 0.00 | 4.85 | 4.60 |
| Thiamine | 0.77 | 5.82 | 4.11 |
| Glutathione reduced | 0.52 | 6.09 | 8.94 |
| S-adenosyl-methionine | 1.13 | 5.95 | 5.78 |
| Glutathione oxidized | 0.21 | 2.48 | 8.72 |
Sample RSD (%) of RT was calculated from ten repeated injections of the same extract (replicate 1). Intra-day and inter-day RSD (%) were calculated from four biological replicates. Inter-day quantification was realized within 6 months
RT Retention time, PA peak area, N.Q. not quantified