Calibration is the most important step in bioactive compound analysis. A good Precision and accuracy can only be obtained when a good calibration procedure is adopted. In the Spectrophotometric methods, the concentration of a sample cannot be measured directly, but is determined using physical measuring quantity ‘y’ (absorbance of a solution). An unambiguous empirical or theoretical relationship can be shown between this quanity and the concentration of an analyte. The calibration between y = g(x) the calibration function can be obtained by fitting an adequate mathematical model through the experimental data. The most convenient calibration function is linear, goes through the origin and is applicable over a wide.
