Limits of detection and quantification
The lowest amount of analyte in a sample that can be detected but not necessarily quantified is known as the limit of detection. The lowest amount of analyte in a sample that can be quantified with sufficient precision and accuracy is the limit of quantitation. The quantification and detection limits were determined using the signal-to-noise ratio approach using Eqns. (1) and (2).
LOQ =10 σ/ S…………… Eq. (A.1)
LOD = 3.3 σ/ S…………… Eq. (A. 2)
Where S is the slope of the calibration curve and is the standard deviation of the intercept of the calibration plot.