Table 1.
Method validation results
| Compound | Sensitivity | Linearity | Expected concentration (µM) | Precision and accuracy | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Within-run (n = 5) | Between-run (n = 10) | ||||||||||
| LOD (µM) | LOQ (µM) | Regression coefficient (R2) | Slope CV (%)a | Measured concentration (µM) | Precision (CV %) | Accuracy (%) | Measured concentration (µM) | Precision (CV %) | Accuracy (%) | ||
| l-Arginine | 1.7 | 3.2 | 0.998 | 3.20 | 5 25 100 200 |
4.867 ± 0.198 25.49 ± 0.97 99.17 ± 2.68 203.08 ± 4.70 |
9.14 3.86 1.64 2.32 |
102.74 98.09 100.83 98.49 |
5.142 ± 0.035 24.8 ± 01.01 101.85 ± 3.39 199.52 ± 5.44 |
3.63 4.09 3.33 2.73 |
97.23 100.87 98.19 100.24 |
| ADMA | 0.03 | 0.08 | 0.997 | 3.66 | 0.05 0.25 1.0 2.5 |
0.058 ± 0.0001 0.233 ± 0.0003 1.012 ± 0.0004 2.493 ± 0.008 |
14.88 7.53 2.09 3.52 |
86.10 107.14 98.80 100.30 |
0.056 ± 0.0003 0.235 ± 0.022 1.022 ± 0.049 2.477 ± 0.076 |
10.21 9.42 4.84 3.07 |
89.29 106.47 97.89 100.93 |
| SDMA | 0.02 | 0.05 | 0.997 | 3.33 | 0.05 0.25 1.0 2.5 |
0.058 ± 0.00003 0.239 ± 0,0002 0.990 ± 0,002 2.505 ± 0.006 |
8.99 6.39 3.98 3.20 |
85.62 104.53 101.03 99.81 |
0.057 ± 0.00003 0.230 ± 0.016 1.013 ± 0.038 2.506 ± 0.077 |
9.92 7.11 3.77 3.09 |
87.72 108.79 98.74 99.75 |
| l-Citrulline | 0.36 | 1.08 | 0.998 | 6.12 | 1 10 20 50 |
1.036 ± 0.003 10.00 ± 0.07 20.304 ± 0.428 50.019 ± 0.829 |
5.35 2.58 3.22 1.82 |
96.53 101.14 98.50 99.96 |
1.034 ± 0.093 9.88 ± 0.044 20.083 ± 0.617 50.163 ± 1.47 |
9.01 2.13 3.07 2.93 |
96.72 101.25 99.58 99.67 |
| DMA | 0.06 | 0.19 | 0.992 | 3.89 | 0.014 0.7 2.8 7.0 |
0.164 ± 0.00026 0.698 ± 0.001 2.71 ± 0.034 7.19 ± 0.016 |
9.84 5.49 6.80 1.75 |
85.32 100.26 103.18 97.30 |
0.152 ± 0.00004 0.64 ± 0.06 2.61 ± 0.15 7.46 ± 0.19 |
4.19 9.74 5.56 5.87 |
92.41 109.69 107.24 93.81 |
LOD limit of detection, LOQ limit of quantification, CV coefficient of variation
aVariability of standard curve slopes is expressed as coefficient of variation