Table 2.
Theoretical Cortisol Concentrations (ng/ml) | ||
---|---|---|
20.000 | 0.625 | |
Within Day | ||
Mean Measured Concentration (n=5) | 20.422 | 0.628 |
Standard Deviation | 0.504 | 0.061 |
Precision (%RSD) | 2.5% | 9.7% |
Accuracy (% difference) | 2.1% | 0.5% |
Between Day | ||
Mean Measured Concentration (n=15) | 21.420 | 0.531 |
Standard Deviation | 2.631 | 0.099 |
Precision (%RSD) | 12.3% | 18.7% |
Accuracy (% difference) | 7.1% | −15.1% |
Extraction Recovery (%, n=5) | 97 | 103 |
Matrix Spike Recovery (%, n=3) | 92 |
Precision is expressed as % RSD: (standard deviation)/(mean measured concentration)x100; Accuracy is expressed as % difference: [(measured-theoretical conc)/theoretical conc]x100.