Stability | Spiked conc (ng∙mL−1) | Calculated comparison sample concentration (ng∙mL−1)d | Calculated stability sample concentration (ng∙mL−1)d | Avg% | ||
Mean ± SD | % CV | Mean ± SD | % CV |
| ||
Bench topa | 15 | 14.89 ± 0.09 | 3.8 | 14.86 ± 0.15 | 8.5 | 98 |
4750 | 4742.6 ± 48.5 | 2.5 | 4738.2 ± 84.3 | 3.2 | 98.5 | |
9500 | 9484.7 ± 103.4 | 2.1 | 9435.3 ± 122.4 | 1.3 | 100 | |
Freeze and thawb | 15 | 14.94 ± 0.1 | 5.8 | 14.82 ± 0.2 | 8.4 | 96.4 |
4750 | 4746.4 ± 86.3 | 2.7 | 4743.8 ± 57.8 | 3.1 | 98.9 | |
9500 | 9503.7 ± 104.4 | 1.9 | 9498.2 ± 121.3 | 1.5 | 100 | |
Long termc | 15 | 14.88 ± 0.1 | 4.2 | 14.79 ± 0.14 | 5.2 | 97 |
4750 | 4748.5 ± 72.6 | 2.4 | 4745.3 ± 62.3 | 3.0 | 99 | |
9500 | 9451.6 ± 113.4 | 2.6 | 9448.2 ± 97.6 | 1.7 | 99.5 |