TABLE 2.
Method validation data for the analyzed retinoids
The measured concentrations are the mean concentrations of interday measurements.
| Analyte | atRA | 13-cisRA | 4-oxo-atRA | Retinol | RP | |
|---|---|---|---|---|---|---|
| Standard curve concentration range (in serum) | 1–1000 nM | 1–1000 nM | 2.7–444 nM | 0.15–37.5 µM | 3–750 µM | |
| Linearity (R2) | 0.998 | 0.999 | 0.999 | 0.999 | 0.993 | |
| QC1 | Known concentration | 1.6 nM | 1.6 nM | 7.6 nM | 0.4 µM | 7.8 µM |
| Measured concentration | 1.6 nM | 1.6 nM | 7.5 nM | 0.4 µM | 7.6 µM | |
| Accuracy% | 100.1 | 96.6 | 98.8 | 98.0 | 97.8 | |
| Intraday CV% | 8.9 | 8.7 | 4.7 | 7.3 | 7.1 | |
| Interday CV% | 8.8 | 8.4 | 4.9 | 8.4 | 11.3 | |
| QC2 | Known concentration | 25.9 nM | 25.9 nM | 47.4 nM | 1.6 µM | 31.3 µM |
| Measured concentration | 24.9 nM | 25.1 nM | 45.7 nM | 1.5 µM | 30.9 µM | |
| Accuracy% | 96.1 | 96.8 | 96.5 | 96.5 | 98.9 | |
| Intraday CV% | 3.2 | 3.6 | 3.5 | 5.3 | 6.6 | |
| Interday CV% | 3.3 | 5.6 | 3.7 | 6.7 | 8.5 | |
| QC3 | Known concentration | 222 nM | 222 nM | 296 nM | 6.3 µM | 125 µM |
| Measured concentration | 202 nM | 216 nM | 291 nM | 6.0 µM | 121 µM | |
| Accuracy% | 91.1 | 97.2 | 98.1 | 96.5 | 96.6 | |
| Intraday CV% | 3.8 | 6.1 | 2.9 | 5.0 | 7.1 | |
| Interday CV% | 7.4 | 6.7 | 3.2 | 8.0 | 6.9 | |
| Liver QC | Measured concentration | 139.5 pmol/g | 31.3 pmol/g | 188.5 pmol/g | 2.2 nmol/g | 66.2 nmol/g |
| Intraday CV% | 5.3 | 6.2 | 5.2 | 6 | 12.3 | |
| Interday CV% | 8.8 | 11.9 | 8.9 | 10.1 | 15.2 | |
CV, coefficient of variation.