Greg - I haven't personally attempted the dropper-method (quoted below from DC's previous post). But, any misteps in the process (i.e. inaccurate ratio-measurements or cross-contamination) could easily influence the results. You'd undoubtedly have a better go at it using your lab equipment. Also, exposure to sun + time might further delineate the levels and/or stamina of dye-content in each sample.
Let me know if you decide to pursue the matter. I have a couple of contestants to contribute.
1. Take an eye dropper
2. Put a couple of drops of blue dye of the products in question in separate quart containers of the exact same amount of water (try and be as accurate as you can with the drops, the more drops the better as this will reduce the error. but not too many as the product will be too hard to evaluate) Try and get exactly the same amount of dye in exactly the same amount of water. As long as the dye solution is not too concentrated you should be able to see through the solution. The darker the solution the stronger the dye products. Repeat with as many products and compare side by side.
