Table 1. Mean Interday Back-Calculated Standard and Calibration Curve Results (n = 3).
| compound | nominal concentration (ng/mL) | back-calculated
concentration (ng/mL) |
mean back-calculated concentration (ng/mL) | % deviation | %CV | ||
|---|---|---|---|---|---|---|---|
| day 1 | day 2 | day 3 | |||||
| NDMA | 25.0 | 25.1 | 24.6 | 25.9 | 25.2 | 0.72 | 2.58 |
| 50.0 | 51.5 | 52.2 | 48.1 | 50.6 | 1.25 | 4.32 | |
| 100.0 | 98.2 | 102.6 | 98.9 | 99.9 | –0.09 | 2.38 | |
| 250.0 | 250.5 | 263.4 | 253.6 | 255.8 | 2.32 | 2.64 | |
| 500.0 | 518.2 | 485.1 | 494.3 | 499.2 | –0.17 | 3.43 | |
| 1000.0 | 995.7 | 950.9 | 1040.2 | 995.6 | –0.44 | 4.48 | |
| 5000.0 | 4864.1 | 4965.6 | 4963.1 | 4931.0 | –1.38 | 1.17 | |
| r2 | 0.999 | 0.998 | 0.999 | ||||
| Fcal | 12 945.996 | ||||||
| FANOVA | 2.158 × 10–28 | ||||||
| p value | slope | 2.158 × 10–28 | |||||
| y-intercept | 0.425 | ||||||
| NDEA | 25.0 | 24.7 | 24.6 | 24.1 | 24.5 | –2.12 | 1.31 |
| 50.0 | 49.6 | 51.0 | 51.1 | 50.6 | 1.17 | 1.67 | |
| 100.0 | 105.0 | 102.5 | 105.9 | 104.5 | 4.50 | 1.69 | |
| 250.0 | 244.8 | 232.3 | 264.2 | 247.1 | –1.16 | 6.51 | |
| 500.0 | 531.4 | 505.3 | 489.8 | 508.8 | 1.77 | 4.14 | |
| 1000.0 | 905.8 | 965.0 | 999.7 | 956.9 | –4.31 | 4.96 | |
| 5000.0 | 5075.5 | 5284.3 | 4548.5 | 4969.4 | –0.61 | 7.63 | |
| r2 | 0.996 | 0.997 | 0.996 | ||||
| Fcal | 17 667.266 | ||||||
| FANOVA | 1.129 × 10–29 | ||||||
| p value | slope | 1.129 × 10–29 | |||||
| y-intercept | 0.941 | ||||||
| DIPNA | 50.0 | 46.2 | 51.8 | 51.1 | 49.7 | –0.55 | 6.11 |
| 100.0 | 96.7 | 101.5 | 99.6 | 99.3 | –0.73 | 2.45 | |
| 250.0 | 248.1 | 257.1 | 241.0 | 248.7 | –0.52 | 3.25 | |
| 500.0 | 508.4 | 494.3 | 520.5 | 507.7 | 1.55 | 2.58 | |
| 1000.0 | 1015.4 | 965.3 | 978.2 | 986.3 | –1.37 | 2.64 | |
| 5000.0 | 5200.9 | 4954.9 | 5042.8 | 5066.2 | 1.32 | 2.46 | |
| r2 | 0.999 | 0.999 | 0.999 | ||||
| Fcal | 794.423 | ||||||
| FANOVA | 4.573 × 10–15 | ||||||
| p value | slope | 4.573 × 10–15 | |||||
| y-intercept | 0.920 | ||||||
| EIPNA | 50.0 | 51.9 | 49.4 | 47.3 | 49.5 | –0.93 | 4.64 |
| 100.0 | 94.1 | 97.3 | 101.6 | 97.7 | –2.33 | 3.84 | |
| 250.0 | 263.0 | 255.9 | 227.2 | 248.7 | –0.53 | 7.63 | |
| 500.0 | 499.9 | 485.7 | 517.1 | 500.9 | 0.19 | 3.14 | |
| 1000.0 | 984.9 | 993.8 | 975.2 | 984.6 | –1.54 | 0.95 | |
| 5000.0 | 4973.3 | 5200.5 | 5454.9 | 5209.6 | 4.19 | 4.62 | |
| r2 | 0.998 | 0.999 | 0.996 | ||||
| Fcal | 1671.131 | ||||||
| FANOVA | 1.290 × 10–17 | ||||||
| p value | slope | 1.290 × 10–17 | |||||
| y-intercept | 0.945 | ||||||