Table 1.
Nominal and determined concentrations of quality control (QC) samples by microbiological and HPLC assay methods
| Assays |
Nominal concentration (ng/ml)
|
|||||
|---|---|---|---|---|---|---|
| 250 | 500 | 1000 | 2000 | 3000 | ||
| Microbiological Intra-assay | Mean concentration obtained (ng/ml) (n=3) | 345.06 | 600.59 | 873.98 | 1651.43 | 3261.38 |
| Precision (SD) | 44.36 | 138.60 | 112.37 | 404.46 | 452.97 | |
| Precision (RSD, %) | 12.86 | 23.08 | 12.86 | 24.49 | 13.89 | |
| Accuracy | 138.02 | 120.11 | 87.39 | 82.57 | 108.71 | |
| Microbiological Inter-assay | Mean concentration obtained (ng/ml) (n=3) | 327.99 | 464.32 | 870.53 | 1570.46 | 2944.52 |
| Precision (SD) | 14.79 | 124.32 | 151.93 | 395.31 | 786.25 | |
| Precision (RSD, %) | 4.51 | 26.78 | 17.45 | 25.17 | 26.70 | |
| Accuracy | 131.19 | 92.86 | 87.05 | 78.52 | 98.15 | |
| HPLC Intra-assay | Mean concentration obtained (ng/ml) (n=3) | 248.57 | 492.14 | 990.74 | 1994.82 | 2712.25 |
| Precision (SD) | 10.59 | 4.33 | 17.08 | 10.95 | 538.64 | |
| Precision (RSD, %) | 4.26 | 0.88 | 1.72 | 0.55 | 19.86 | |
| Accuracy | 99.43 | 98.43 | 99.07 | 99.74 | 90.41 | |
| HPLC Inter-assay | Mean concentration obtained (ng/ml) (n=3) | 258.56 | 496.34 | 1002.85 | 2002.43 | 3011.78 |
| Precision (SD) | 13.15 | 9.03 | 16.17 | 15.11 | 7.80 | |
| Precision (RSD, %) | 5.08 | 1.82 | 1.61 | 0.75 | 0.26 | |
| Accuracy | 103.42 | 99.27 | 100.28 | 100.12 | 100.39 | |