3.4. Analytical parameters of the RP-HPLC method
3.4.1. Linearity of the calibration curve
Linearity of standard curve was tested by analysing three sets of
vitamin D2 standards prepared in methanol (1, 2, 3, 4 and 5 ng/
100 ll). Calibration curve were plotted with concentration of standard
versus peak area of vitamin D2. The resulting simple linear
regression and correlation coefficients of the calibration curve
were y = 2076.5x + 1064.7 and R2 = 0.995, respectively. The calibration
curves were linear over the range 1–5 ng/100 ll.