Table 2.
Stability data for V in plasma.
| Storage condition | Relative standard deviation (%) | Mean Percentage (%) of Day 0 |
|---|---|---|
| Extract stability a | ||
| Refrigerated extracts (15 days, 4°C) | ≤ 1.6 | 105 – 126 |
| Ambient extracts (6 days) | ≤ 1.0 | 97.7 – 113 |
| Plasma stability b | ||
| Freeze–thaw (3 cycles over 3 days) | ≤ 2.5 | 100 – 106 |
| Frozen matrix (−80°C, 60 days) | ≤ 2.6 | 100 – 122 |
a
Extract stability (refrigerated and ambient) was determined for quadruplicate QC samples fortified at 10.0, 100, and 500 ng V/mL plasma.
b
Freeze-thaw and frozen sample stability was determined for triplicate plasma samples fortified at 15.0 and 750 ng V/mL plasma.