How to calculate the percent degradation of an organic using UV-visible spectrophotometer?

The percent degradation of an organic dye in water can be calculated using UV-visible spectrophotometer. Beer-Lambert law explains a direct relationship between concentration of the dye and absorbance at lambda max. According to this law concentration of any given dye in solution is directly proportional to the absorbance of dye solution at λ_max. Equation (1) is used to calculate the percent degradation.

Where

R (%) = percent degradation

C_o = Concentration of the dye at zero time

C = Concentration of the dye at specific time

According to Beer-Lambert law equation 1 can be written as follows

Where

A_o = absorbance of the dye at zero minute

A_t = absorbance of the dye at specific time

Thus, equation (2) is used to calculate the degradation efficiency of a catalyst or percent degradation of any given dye in water. A_o is the absorbance of the given dye at lambda max before the degradation starts, while A_t is the absorbance of the dye at different time intervals as the degradation reaction proceeds to forward direction. Histogram of percent degradation is plotted as percent degradation of the dye at y-axis against concentration of catalyst or oxidizing agent used for degradation is plotted at x-axis.