关键词: 奎宁, 热重-红外联用, 热分解动力学, 贮存期

Abstract: Thermal decomposition curves of quinine were measured by thermo-gravimetric and Fourier-transform infrared spectroscopy coupled technology,and the experimental data of TG were synergistically processed by Achar method and Coats-Redfern method to infer the thermal decomposition mechanism and the kinetics parameters (apparent activation energy E_a and pre-exponential factor A),which were also used to calculate the shelflife of quinine.Based on TG data and FT-IR spectra analysis,thermal decomposition of the first stage started from 219.93 ℃ to 389.93 ℃,chemical bonds between oxygen atoms and quinolone ring cracked and released ROH,CO,CO₂,R-O-R,R-NH₂,etc.,which was followed by Chemical Reaction mechanism and corresponding with Reaction Order equation (the order of reaction,n = 2).At the second stage,residual molecular skeleton (quinolone ring) was thermally cracked deeply from 389.93 ℃ to 800 ℃ and the gases such as CO₂,H₂O and NH₃ were released.According to the kinetic parameters of thermolysis at the first stage,the shelflives of quinine were inferred,which were 4-5 years at room temperature (25 ℃).

Key words: quinine, TG-FTIR, thermal decomposition kinetics, shelflife