Thank You for your help these were great ideas. But, unfortunately this is an experiment that I am conducting at my high school and I am therefore supposed to do the whole process by myself. This being said, my high school does not have access to any type of spectroscopy or HPLC (I only have access to TLC) so those processes are not realistic for me. My first step is to identify that something was leached from a polycarbonate bottle. I was thinking that because BPA is non-polar and has a greater density than water it will be separate and therefore possible to identify if some sort of dye was added to the mixture. Is this possible or would the amount of BPA not be great enough to become visual.