Table 5. Stability of four cobalamins in rat plasma in various stresses determined by SPE-HPLC-MS/MS (n = 3).
| Analyte | Spiked (ng/ml) | Room temperature 4hr | 3 freeze-thaw cycles | Auto-sampler 5°C 24hr | -80 °C 30 days |
|---|---|---|---|---|---|
| OHCbl | 0.2 | 105% | 95.4% | 95.7% | 94.2% |
| 1 | 94.6% | 107% | 111% | 91.1% | |
| 4 | 94.5% | 91.0% | 113% | 90.9% | |
| CNCbl | 0.2 | 104% | 103% | 102% | 95.5% |
| 1 | 107% | 106% | 109% | 102% | |
| 4 | 114% | 103% | 113% | 94.7% | |
| AdoCbl | 0.2 | 98.7% | 112% | 106% | 112% |
| 1 | 108% | 114% | 104% | 105% | |
| 4 | 112% | 106% | 112% | 97.7% | |
| MeCbl | 0.2 | 108% | 88% | 94.3% | 101% |
| 1 | 109% | 106% | 96.4% | 98.4% | |
| 4 | 112% | 102% | 104% | 98.4% |