Calibration graph.
Pipette 0, 0,25, 0,5, 0,75 and 1,0 ml of apo carotenic ester standard solution (4.1.2) into five 100 ml volumetric flasks. Dilute to volume with petroleum spirit (4.2) and mix. The approximate concentrations of the solutions range from 0 to 2 ig/ml and are calculated accurately by reference to the concentration of the standard solution (4.1.2) (W.P)/100 mg/ml. Measure the absorbances at 440 nm against a petroleum spirit (4.2) blank. Plot the values of absorbance on the y axis against apo carotenic ester concentration on the x axis.
