Table 1. Accuracy and precision of ceftriaxone determination.
The method was validated by analysing five replicate samples of each concentration and repeated over four days. Accuracy and precision must not exceed 15% for each concentration, except for the LLOQ that should not deviate by more than 20%.
| Value | Nominal conc.
(μg/ml) |
Intra-assay
precision (%RSD) |
Inter-assay
precision (%RSD) |
Total-assay
precision (%RSD) |
Accuracy (%) |
|---|---|---|---|---|---|
| LLOQ | 1.01 | 4.31 | 4.18 | 4.29 | 0.50 |
| QC 1 | 2.97 | 4.22 | 3.95 | 4.18 | -13.6 |
| QC 2 | 24.1 | 3.94 | 5.57 | 4.24 | -8.90 |
| QC 3 | 155 | 2.21 | 8.68 | 4.00 | -13.0 |
| ULOQ | 200 | 3.29 | 8.71 | 4.59 | 2.80 |
| Over-curve | 400 | 3.59 | 9.29 | 4.95 | -3.50 |
LLOQ, lower limit of quantification; QC, quality control; ULOQ, upper limit of quantification; Over-curve, i.e. sample dilution 10 times; RSD, relative standard deviation.