EFFECT OF FOOD DYES ON RADICALS IN AQUEOUS-MEDIA

The rates of reaction of photogenerated hydroperoxy and hydroxyl radic als on the photostability of aqueous solutions of dequalinium chloride irradiated with simulated sunlight at 38 +/- 1 degrees C have been in vestigated, with and without the addition of amaranth and quinoline ye llow. These reactions follow second-order kinetics and the dyes tested markedly increase the rate constants of the reactions. Hydroperoxy ra dicals react with hydroxyl radicals preferentially to the dequalinium chloride resulting in lower reaction rate constants for the latter. Ac etaldehyde was used as a scavenger of hydroperoxy radicals.