Table 1.
LC-HRMS method validation data (method A)
| Analyte | QC sample | Nominal concentration (µM) |
Mean calculated concentration (µM) |
Accuracy (%) |
Intra-day precision (%) |
Inter-day precision (%) |
RE (%), (CV, %) |
ME (%), (CV, %) |
PE (%), (CV,%) |
Calibration range (µM) |
Calibration model |
Internal standard |
LOD (µM) |
LOQ (µM) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R/S-DHMA 3-sulfate | LOW | 1.0 | 0.85 | −15.3 | 4.6 | 9.3 | 96(19) | −2(12) | 93(15) | 0.5−75 | Linear 1/X2 | M6G | 0.1 | 0.5 |
| MED | 20.0 | 19.2 | −4.2 | 4.8 | 6.7 | – | – | – | ||||||
| HIGH | 60.0 | 53.5 | −10.9 | 4.9 | 6.4 | 88(13) | −7(12) | 83 (22) | ||||||
| R/S-DHMA 4-sulfate | LOW | 1.0 | 0.88 | −12.1 | 6.4 | 9.7 | 96(11) | −1(5) | 95(11) | 0.5–75 | Linear 1/X2 | M6G | 0.1 | 0.5 |
| MED | 20.0 | 19.7 | −1.3 | 4.5 | 7.4 | – | – | – | ||||||
| HIGH | 60.0 | 54.4 | −9.3 | 3.8 | 6.5 | 89(12) | 0(8) | 87(15) | ||||||
| R/S-HMMA sulfate | LOW | 0.33 | 0.31 | −6.4 | 4.7 | 10.3 | 96(14) | −1(8) | 96(11) | 0.2–67 | Quadratic 1/X2 | M6G | 0.03 | 0.2 |
| MED | 25.0 | 24.1 | −3.6 | 5.1 | 7.3 | – | – | – | ||||||
| HIGH | 58.0 | 55.5 | −4.8 | 6.1 | 7.5 | 90(13) | 3(9) | 93(7) | ||||||
| S-HMMAglucuronide | LOW | 0.33 | 0.28 | −15.3 | 4.5 | 7.8 | 94(5) | −1(6) | 92(7) | 0.2–25 | Linear 1/X2 | M6G | 0.03 | 0.2 |
| MED | 6.5 | 6.2 | −7.3 | 3.2 | 5.4 | – | – | – | ||||||
| HIGH | 20.0 | 20.0 | 0.0 | 3.4 | 6.1 | 83(15) | 11(6) | 92(18) | ||||||
| R-HMMAglucuronide | LOW | 0.33 | 0.28 | −16.0 | 4.7 | 6.6 | 95(5) | −1(8) | 93(7) | 0.2–25 | Linear 1/X2 | M6G | 0.03 | 0.2 |
| MED | 6.5 | 6.2 | −7.6 | 3.0 | 5.0 | – | – | – | ||||||
| HIGH | 20.0 | 19.7 | −1.7 | 3.7 | 6.0 | 75(7) | 12(7) | 84(10) |