TABLE 2.
Validation Results of DBS Including Accuracy and Imprecision Within-Day and Between-Day
| Compound | QC Concentrations (μg/L) | Within-Day (n = 6) | Between-Day (n = 12) | ||||
| Actual | Measured* | Accuracy (Bias %) | Imprecision (CV%) | Accuracy (Bias %) | Imprecision (CV%) | ||
| Amlodipine | QC low | 21.01 | 22.1 | 5.5 | 3.6 | 5.3 | 6.5 |
| QC medium | 210.1 | 231.1 | 7.1 | 8.7 | 10.0 | 13.1 | |
| QC high | 300.1 | 315.4 | −6.2 | 12.9 | 5.1 | 14.4 | |
| Barnidipine | QC low | 8.2 | 7.9 | −14.4 | 5.8 | −2.6 | 9.5 |
| QC medium | 79.0 | 92.4 | 13.6 | 6.0 | 17.1 | 6.0 | |
| QC high | 114.3 | 129.8 | 13.0 | 2.3 | 13.5 | 7.0 | |
| Bumetanide | QC low | 15.5 | 15.4 | −14.4 | 7.5 | −0.6 | 8.9 |
| QC medium | 154.7 | 164.5 | 13.6 | 2.6 | 6.3 | 5.0 | |
| QC high | 221.1 | 328.4 | 13.0 | 2.7 | 48.6‡ | 7.4 | |
| Candesartan (−) | QC low | 122.7 | 86.8 | −30.9‡ | 17.5 | −29.2‡ | 21.3‡ |
| QC medium | 563.3 | 553.6 | −7.9 | 6.5 | −1.7 | 9.2 | |
| QC high | 804.7 | 770.4 | −17.0† | 11.1 | −4.3 | 11.1 | |
| Canrenone | QC low | 77.8 | 72.6 | −18.7† | 10.0 | −6.6 | 13.9 |
| QC medium | 777.5 | 835.0 | 14.2 | 2.4 | 7.4 | 4.9 | |
| QC high | 1110.7 | 1189.7 | 12.6 | 2.8 | 7.1 | 6.0 | |
| Chlorthalidone (−) | QC low | 41.5 | 34.0 | −9.2 | 14.3 | −18.2† | 18.3† |
| QC medium | 207.7 | 202.8 | 7.6 | 10.8 | −2.3 | 9.8 | |
| QC high | 296.6 | 294.3 | 7.4 | 11.1 | −0.8 | 13.3 | |
| Doxazosin | QC low | 67.1 | 60.6 | −9.0 | 2.7 | −9.7 | 5.4 |
| QC medium | 671.1 | 681.3 | 3.9 | 3.0 | 1.5 | 5.1 | |
| QC high | 958.7 | 960.3 | 3.8 | 2.0 | 0.2 | 4.1 | |
| Enalapril | QC low | 4.4 | 5.1 | 12.6 | 6.2 | 16.5† | 6.8 |
| QC medium | 30.6 | 34.2 | 14.2 | 2.3 | 11.8 | 14.5 | |
| QC high | 43.7 | 49.1 | 15.2† | 9.1 | 12.2 | 5.7 | |
| Enalaprilat | QC low | 3.2 | 3.5 | 16.3† | 8.0 | 9.8 | 11.7 |
| QC medium | 22.5 | 28.4 | 19.0† | 3.6 | 26.2‡ | 11.2 | |
| QC high | 32.2 | 40.4 | 17.9† | 13.7 | 25.7‡ | 14.1 | |
| Hydrochlorothiazide (−) | QC low | 85.7 | 75.2 | −2.6 | 12.4 | −12.3 | 24.6‡ |
| QC medium | 428.4 | 380.0 | 14.9 | 13.6 | −11.3 | 10.4 | |
| QC high | 612.0 | 590.5 | 15.7† | 8.8 | −3.5 | 16.0† | |
| Irbesartan | QC low | 72.8 | 76.2 | 7.4 | 3.4 | 4.7 | 4.2 |
| QC medium | 728.0 | 744.1 | 8.7 | 8.9 | 2.2 | 6.9 | |
| QC high | 1040.0 | 1067.6 | 10.1 | 7.2 | 2.7 | 9.4 | |
| Losartan | QC low | 12.1 | 12.2 | 2.2 | 4.2 | 1.7 | 7.0 |
| QC medium | 84.4 | 95.7 | 9.4 | 1.9 | 13.5 | 7.5 | |
| QC high | 120.5 | 135.4 | 12.5 | 8.7 | 12.4 | 5.4 | |
| Losartan-carboxylic acid | QC low | 24.4 | 22.2 | −7.8 | 8.4 | −8.9 | 8.5 |
| QC medium | 171.0 | 169.5 | −10.1 | 1.9 | −0.9 | 10.0 | |
| QC high | 244.3 | 239.5 | −8.3 | 10.2 | −2.0 | 7.7 | |
| Metoprolol | QC low | 15.3 | 15.4 | 4.2 | 4.2 | 0.4 | 5.0 |
| QC medium | 153.4 | 155.0 | 7.2 | 2.6 | 1.1 | 6.5 | |
| QC high | 219.2 | 220.2 | 3.2 | 3.7 | 0.5 | 6.2 | |
| Nifedipine | QC low | 19.9 | 27.2 | 14.1 | 9.8 | 36.7‡ | 19.2 |
| QC medium | 199.1 | 335.3 | −9.2 | 3.4 | 68.3‡ | 40.8‡ | |
| QC high | 284.5 | 340.7 | −28.0† | 4.4 | 19.8† | 27.2‡ | |
| Perindopril | QC low | 7.1 | 4.6 | −4.7 | 5.0 | −35.7‡ | 27.3‡ |
| QC medium | 71.4 | 42.5 | −2.7 | 10.3 | −40.5‡ | 30.6‡ | |
| QC high | 102.0 | 61.0 | −0.7 | 9.8 | −40.2‡ | 39.0‡ | |
| Perindoprilat | QC low | 5.8 | 6.4 | 0.6 | 7.0 | 9.0 | 12.5 |
| QC medium | 58.3 | 67.5 | 10.2 | 11.7 | 15.8† | 3.7 | |
| QC high | 83.3 | 97.1 | 14.7 | 9.7 | 16.6† | 6.7 | |
| Spironolactone | QC low | 19.9 | 18.3 | −14.2 | 7.5 | −7.7 | 7.9 |
| QC medium | 198.8 | 207.2 | 8.9 | 3.2 | 4.2 | 7.3 | |
| QC high | 284.0 | 291.3 | 8.0 | 2.2 | 2.6 | 6.3 | |
| Telmisartan (−) | QC low | 280.5 | 266.2 | 16.9† | 18.2† | −5.1 | 6.8 |
| QC medium | 1402.2 | 1431.5 | 10.4 | 12.0 | 2.1 | 5.2 | |
| QC high | 2003.2 | 2062.8 | 15.0 | 11.5 | 3.0 | 13.1 | |
| Valsartan | QC low | 140.17 | 153.2 | 19.2† | 5.9 | 9.3 | 8.8 |
| QC medium | 1401.7 | 1476.4 | 15.8† | 12.5 | 5.3 | 8.7 | |
| QC high | 2002.4 | 2132.0 | 18.1† | 12.8 | 6.5 | 12.7 | |
*
Each value represents the mean of duplicate samples measured.
†
Value does not meet the requirement of <15%.
‡
Value does not meet the requirement of <20%.
NA, not available; CV, coefficient of variation.