I think you can take a control and subtract its OD. Hope it helps.

I assume you use an aqueous buffer to extract the enzymes? Can you extract the chlorophyll with ethanol before (without sonication)? Or does that destroy your enzyme? Using a control like Arushi Jain suggested would still make sense.

Hello, how was your extract prepared? We can discuss the use of a solvent (polarity) and performing a liquid-liquid partition or the use of a stationary phase (e.g. reversed-phase silica).

You just take the absorbance of your extract then you can deduct it from the enzymatic absorbance.