Isopropyl is one of the denaturant used.
A bottle of chlorophyll powder I've seen said it was extracted from spinach. Here's a nice extraction method that should clean up your extract pretty well.
It uses acetone for the extraction, and then cleans extracts the extract by adding water and hexane. The water will mix with the acetone hold onto the acetone and other junk in the first extract, and the hexane will extract the chlorophyll from the water/acetone mix. You can then blow down/evaporate the hexane to get rid of it and make some powdered chlorophyll to use in whatever solvent you want.