| Conc. (ng/ml) |
Stability condition |
Conc. (ng/ml) (Mean ± SD) |
% Drug Remaining |
% RSD |
| LQC
(20 ng/mL) |
Initial (0 h) |
19.71 ± 0.31 |
100 |
1.57 |
| Short-term stability (25°C, 24 h) |
19.64 ± 0.34 |
99.64 |
1.73 |
| Long-term stability (−80°C, 30 days) |
19.58 ± 0.27 |
99.34 |
1.37 |
| Three cycles freeze–thaw stability
(three cycles, −20°C to 25°C) |
19.50 ± 0.29 |
98.93 |
1.48 |
| Post-preparative stability (10°C, 24 h) |
19.46 ± 0.28 |
98.73 |
1.43 |
| HQC
(1000 ng/mL) |
Initial (0 h) |
992.76 ± 16.58 |
100 |
1.67 |
| Short-term stability (25°C, 24 h) |
984.89 ± 15.92 |
99.20 |
1.61 |
| Long-term stability (−80°C, 30 days) |
978.56 ± 16.23 |
98.56 |
1.65 |
| Three cycles freeze–thaw stability
(three cycles, −20°C to 25°C) |
970.45 ± 16.04 |
97.75 |
1.65 |
| Post-preparative stability (10°C, 24 h) |
966.51 ± 15.94 |
97.35 |
1.64 |