After determination of the λmax of the colored
complex (521 nm) using a Shimadzu
UV- spectrophotometer the absorbance of
the all standards (converted to coloured complex)
were taken to construct a calibration
curve. The calibration curve was constructed
by plotting the concentration versus the corresponding
absorbance. Molar absorptivity
was found 0.0328 L mol-1 cm-1 using Beer -
Lambert plots (Fig. 1).