Abstract: Thermal decomposing curves of quercetin in different heating speeds were obtained in the nitrogen atmosphere by TG-DTG technique. Four thermal analysis kinetic methods (Achar, Coats-Redfern, Kissinger and Ozawa) were used to speculate the probable mechanism of thermal decomposing reaction and the kinetic parameters. The shelflife of quercetin at room temperature was calculated by the kinetic parameters of the first stage. With the improvement of the heating rate, thermal decomposing tempreture of quercetin rose. The most probable kinetic mechanisms of the two-stage thermal decomposition were nucleation and growth and chemical reactions, corresponding with Avrami-Erofeev Equation and Reaction Order. In accordance with the data of TG and Gaussian, one molecule of quercetin lost two oxygen atoms at the first stage of decomposition and lost one benzene ring at the second stage. The shelflife of quercetin at room temperature was about 1.5~2 years based on the apparent activation energy (Ea) and pre-exponential factor (A) of the first stage.

Key words: quercetin, TG-DTG, thermal decomposition, non-isothermal kinetics, Gaussian simulation