The
cotton samples were then rapidly withdrawn after different
immersion times. The desorbed dye concentrations (qde)
were determined using a calibration curve based on absorbance
at lmax 487 nm (Cary 1E UVevisible spectrophotometer)
versus dye concentration in standard lac dye solutions.
The amount of dye adsorbed on cotton after desorption was
calculated by subtraction.