Research on the effect of photoprotectants on photostabilization of rotenone

This study examined the photostabilization of rotenone when exposed to ultraviolet light (UV) in the presence of some photoprotectants. Rotenone with and without photoprotectants in methanol were applied onto the surface of glass slides. The remaining concentration of rotenone was analyzed by HPLC at particular intervals. The dissipation half-life values for the degradation of rotenone under ultraviolet radiation were obtained by first-order kinetic equation. It indicated that the addition of UV531, UV326, Photo-stabilizer 770, Photo-stabilizer 622, Vitamin C, Antioxidant 168, Antioxidant 1010 and Antioxidant 1098 provided moderate degree of photostabilization of rotenone and that addition of UV-P provided the best photostabilization, which due to the competitive energy absorption of UV photons by the photoprotectants. The dissipation half-life values of rotenone after irradiation under UV suggested that the addition of UV-P (in 1:1 mol ratio) could provide better photostabilization of rotenone molecule.