Calculation for interference

I just finished validate product using UV spectrometre. I get stuck at specificity. Could somebody help me, how to calculate interference when using UV method. Thanks

u can do as follow

take absorbance of blank,placedo,standard and test at specified wavelength
and check the interference

u have to prove that at specified wavelength ur test having no intereference with blank and placebo preparation by checking absorbance at specified wavelength.