Problem:

I have been checking my sample for Hydroxyl radical scavenging activity. I have dissolved Hydrogen peroxide in Phosphate buffer. My sample is clear and reagent is also clear but when I have mixed my sample extract with Hydrogen peroxide reagent a precipitant is formed. Control is very less than solution that is kept for reaction to proceed.

So I am getting an answer in negatives (230 nm).

Question: Is that formation of precipitate affect the absorbance of the solution?

Question: Does precipitation increase the OD value compare to clear solution?

Mine is mushroom powder. It is extracted with Ethanol. Extract is dried and finally it is dissolved with solvent above said. That has been used for Hydroxyl radical scavenging activity. Hydrogen peroxide 0.01 milli molar reagent is prepared with Phosphate buffer. First i have taken reading for H2O2 and added extract kept for ten mins and took reading. in 230 nm..