Table 3. Intraday and Interday Accuracy and Precision.
| compound | nominal concentration (ppb) | intraday
(n = 3) |
interday
(n = 6) |
||||
|---|---|---|---|---|---|---|---|
| mean back-calculated concentration (ppb) | accuracy (% deviation) | precision (%CV) | mean back-calculated concentration (ppb) | accuracy (% deviation) | precision (%CV) | ||
| NDMA | 25.0 | 24.0 | –4.19 | 4.8 | 24.4 | –2.57 | 5.9 |
| 250.0 | 262.2 | 4.89 | 1.5 | 262.9 | 5.01 | 1.3 | |
| 1000.0 | 1047.8 | 4.78 | 1.3 | 1063.6 | 5.57 | 1.8 | |
| NDEA | 25.0 | 23.4 | –6.47 | 0.9 | 23.2 | –7.04 | 1.4 |
| 250.0 | 267.9 | 7.15 | 0.4 | 264.5 | 5.82 | 1.8 | |
| 1000.0 | 1062.6 | 6.26 | 1.3 | 1045.4 | 4.54 | 2.4 | |
| DIPNA | 50.0 | 53.2 | 6.42 | 0.9 | 52.0 | 3.98 | 2.9 |
| 250.0 | 247.2 | –1.12 | 4.0 | 257.0 | 2.79 | 4.8 | |
| 1000.0 | 994.2 | –0.58 | 4.6 | 1030.4 | 3.04 | 4.8 | |
| EIPNA | 50.0 | 52.2 | 4.34 | 2.0 | 47.9 | –4.19 | 11.5 |
| 250.0 | 268.1 | 7.25 | 1.9 | 255.4 | 2.17 | 6.5 | |
| 1000.0 | 1068.7 | 6.87 | 1.1 | 1051.3 | 5.13 | 2.5 | |