Degradation kinetics of butylmethoxydibenzoylmethane (avobenzone) in aqueous solution

The degradation kinetics of avobenzone in aqueous solution was studied at 60 ± 0.2 °C over a pH range of 2.0-10.0. The degradation rates were determined by high performance liquid chromatography. The reaction is found to follow first-order kinetics and the rate constant for the decomposition at 25 °C is estimated by extrapolation. The breakdown of avobenzone is shown to be hydroxide ion catalyzed and the Arrhenius plots showed the temperature dependence of avobenzone degradation.