Concentration (μg/L urine) | n | Storage period | % of 0 h | ||
---|---|---|---|---|---|
Prepared sample stability | 0.67 | 2 | 0 h | ||
0.67 | 2 | 18 h | 96 | ||
0.67 | 2 | 24 h | 99 | ||
0.67 | 2 | 48 h | 98 | ||
0.67 | 2 | 72 h | 95 | ||
Freeze-thaw stability (three cycles) | 0.67 | 3 | 92 | ||
Long-term stability | 25 °C | 0.67 | 3 | 1 week | 94 |
4 °C | 0.67 | 3 | 1 week | 92 | |
0.67 | 3 | 1 month | 105 | ||
−80 °C | 0.67 | 3 | 1 week | 105 | |
0.67 | 3 | 1 month | 100 |