A chemiluminescence reaction between hydroxyl radical and rhodamine 6G and its applications

A novel chemiluminescence (CL) reaction between hydroxyl radical and ascorbic acid is described in this paper. Hydroxyl radical generated on line by the reaction between Fe3+ solution and H2O2 solution in HCl medium could oxidize rhodamine 6G to produce weak chemiluminescence. It was found that ascorbic acid could enhance the chemiluminescence and the excited rhodamine 6G was the emitter of the chemiluminescence reaction. The possible mechanism of the CL system was also discussed. Ascorbic acid can be determined in the range of 2.0 x 10(-6)-8.0 x 10(-4) mg/ml with a detection limit of 1 x 10(-6) mg/ml (3 sigma). A complete analysis could be done in 1 minute with the relative standard deviation of 3.1% for 5.0 x 10(-5) mg/ml (n = 11). In order to study the chemiluminescence reaction further, the application to the determination of ascorbic acid in food using the chemiluminescence reaction combined with flow injection is investigated.