Hi, I'm currently doing a DPPH assay on flower and leaf extract of the Clitoria ternatea. I found out that the absorbance for the leaf is satisfying when concentration increases the absorbance decreases. But for flower extract, the absorbance increases when the concentration increases. I found out that the extract as well absorbs the wavelength used in the assay. Can anyone suggest any correction to the method so can get a satisfying result like the leaf extract