Table 3.
Method validation results for the 21 folate compound standards listed in Table 1.
| Compound | LLOQ (ng/ml) |
Linearity (R2) |
Intraday reproducibility (%RSD) |
Interday reproducibility (%RSD) |
Stability in different storage conditions: t1/2 (hour) |
||
|---|---|---|---|---|---|---|---|
| 50:50 methanol: water |
50:50 methanol: water + 0.1% ascorbic acid |
50:50 methanol: water + 0.1% ascorbic acid + 20mM NH4OAc |
|||||
| Pteroic acid | 5 | 0.970 | 14 | 26 | 24 | 24 | 16 |
| pABGlu | 1 | 0.998 | 9 | 10 | > 96 | > 96 | > 96 |
| PteGlu | 5 | 0.998 | 10 | 9 | > 96 | 78 | > 96 |
| H2PteGlu | 5 | 0.978 | 8 | 15 | <0.5 | 10 | > 96 |
| H4PteGlu | 5 | 0.994 | 15 | 21 | <0.5 | 93 | 46 |
| 5,10-CH=H4PteGlu | 100 | 0.998 | 18 | 7 | 12 | > 96 | > 96 |
| 5,10-CH2-H4PteGlu | 5 | 0.989 | 10 | 13 | 4.5 | 14 | > 96 |
| 5-CH3-H4PteGlu | 1 | 0.998 | 11 | 11 | 42 | > 96 | > 96 |
| 5-CHO-H4PteGlu | 5 | 0.993 | 9 | 5 | > 96 | > 96 | > 96 |
| 5-CH3-H4PteGlu2 | 5 | 0.997 | 13 | 13 | 7.8 | > 96 | > 96 |
| 5-CHO-H4PteGlu2 | 5 | 0.997 | 9 | 8 | 85 | > 96 | > 96 |
| pABGlu3 | 5 | 0.987 | 10 | 3 | > 96 | > 96 | > 96 |
| PteGlu3 | 10 | 0.998 | 12 | 9 | > 96 | > 96 | > 96 |
| 5-CH3-H4PteGlu3 | 5 | 0.989 | 9 | 12 | 9.7 | > 96 | > 96 |
| 5-CHO-H4PteGlu3 | 5 | 0.999 | 10 | 2 | > 96 | > 96 | > 96 |
| 5-CH3-H4PteGlu4 | 10 | 0.978 | 12 | 14 | 18 | > 96 | > 96 |
| 5-CHO-H4PteGlu4 | 10 | 0.997 | 11 | 17 | 70 | > 96 | > 96 |
| pABGlu5 | 50 | 0.995 | 16 | 21 | > 96 | > 96 | > 96 |
| 5-CH3-H4PteGlu5 | 50 | 0.976 | 13 | 28 | 42 | > 96 | > 96 |
| 5-CHO-H4PteGlu5 | 50 | 0.994 | 18 | 18 | 39 | > 96 | > 96 |
| pABGlu7 | 200 | 0.982 | 6 | 4 | > 96 | > 96 | > 96 |