Pinkneo

Hi, I am currently working on an enzyme experiment involving casein as the substrate. So basically, several protocols state that after stopping the activity with TCA, the solution should be read at 280nm and a tyrosine standard curve is used for comparison. My problem is that other aromatic amino acids can also be read at 280nm. How do I adjust my computation so that I will only be quantifying tyrosine and not the other amino acids?