Table 2.
Intra- and inter-day precision and accuracy for CysGly and GSH
| Concentration (μM)
|
% RSD | % Bias | ||
|---|---|---|---|---|
| Spiked | Measured (mean ± SD) | |||
| Intra-assay reproducibilitya | ||||
| Quality Controls | ||||
| CysGly | 7.5 | 7.3 ± 0.1 | 1.5 | −3.3 |
| 30.0 | 29.8 ± 0.7 | 2.4 | −0.7 | |
| 150.0 | 164.2 ± 3.1 | 1.9 | 9.5 | |
| GSH | 2.0 | 2.1 ± 0.1 | 4.1 | 7.4 |
| 8.0 | 8.1 ± 0.2 | 2.1 | 1.5 | |
| 40.0 | 38.9 ± 0.7 | 1.7 | −2.9 | |
| Inter-assay reproducibilityb | ||||
| Quality Controls | ||||
| CysGly | 7.5 | 7.4 ± 0.4 | 5.1 | −1.7 |
| 30.0 | 29.9 ± 1.1 | 3.6 | −0.3 | |
| 150.0 | 165.0 ± 5.4 | 3.3 | 10 | |
| GSH | 2.0 | 2.1 ± 0.1 | 4.9 | 5.5 |
| 8.0 | 8.2 ± 0.3 | 3.6 | 2.8 | |
| 40.0 | 39.1 ± 1.2 | 3.1 | −2.3 | |
| Standards | ||||
| CysGly | 6.25 | 6.3 ± 0.2 | 2.7 | 0.6 |
| 12.5 | 12.5 ± 0.2 | 1.9 | 0.1 | |
| 25.0 | 25.2 ± 0.4 | 1.5 | 0.8 | |
| 50.0 | 48.3 ± 1.0 | 2.2 | −3.4 | |
| 100.0 | 102.3 ± 0.3 | 0.3 | 2.3 | |
| 200.0 | 199.3 ± 1.0 | 0.5 | −0.4 | |
| GSH | 1.56 | 1.5 ± 0.1 | 4.6 | −4.4 |
| 3.13 | 3.4 ± 0.1 | 3.0 | 7.4 | |
| 6.25 | 6.5 ± 0.1 | 2.1 | 4.0 | |
| 12.5 | 12.3 ± 0.2 | 1.8 | −1.7 | |
| 25.0 | 24.5 ± 0.3 | 1.1 | −1.9 | |
| 50.0 | 50.4 ± 0.2 | 0.4 | 0.7 | |
a
Twelve quality control samples per concentration.
b
Six to twelve quality control samples or two standards per day per concentration for three days.