2.7. Validation of analytical method
The accuracy for the analysis of nine NSAIDs in pig serum was
estimated by the equation: accuracy (%) = 100% − |100% − recovery
(%)| where the recovery (%) is the total fortified sample concentration
divided by the total theoretical sample concentration. The
analysis precision was estimated by the relative standard deviation
(RSD) obtained from replicate measurements of freshly prepared
matrix-matched standard samples at three concentration levels of
20, 100, and 200 ng mL−1, where five fortified samples were prepared
for each concentration level. For each concentration level,
the spiked samples (n = 5) were analyzed on 1 day to show the
analysis repeatability (intra-day precision) and over a period of
three consecutive days (n = 15) to show the analysis reproducibility
(inter-day precision) of the developed analytical method.