Nominal concentration (ng/mL) | Mean (ng/mL) | Recovery % | Precision (% RSD) |
---|---|---|---|
Room temp. for 8 h | |||
20 | 18.77 ± 0.58 | 93.84 | 3.08 |
150 | 148.23 ± 1.84 | 98.82 | 1.24 |
400 | 396.81 ± 5.55 | 99.20 | 1.40 |
Three freeze–thaw cycles | |||
20 | 18.98 ± 0.42 | 94.89 | 2.22 |
150 | 150.03 ± 1.28 | 100.02 | 0.86 |
400 | 397.17 ± 6.35 | 99.29 | 1.60 |
Stored at 4 °C for 24 h | |||
20 | 19.00 ± 0.32 | 95.02 | 1.70 |
150 | 149.06 ± 1.55 | 99.37 | 1.04 |
400 | 397.22 ± 5.92 | 99.31 | 1.49 |
Stored at −20 °C for 30 days | |||
20 | 19.00 ± 0.32 | 94.98 | 1.67 |
150 | 147.82 ± 0.96 | 98.55 | 0.65 |
400 | 395.48 ± 4.69 | 98.87 | 1.19 |