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In this paper, the enthalpies of dissolution of matrine in ethanol (EtOH) were measured using a RD496-2000 Calvet microcalorimeter at 309.65 K under atmospheric pressure. The differential enthalpy ( dif H m ) and molar enthalpy ( sol H m ) of dissolution of matrine in ethanol were determined. And the relationship between heat and the amount of solute was also established. Based on the thermodynamic and kinetic knowledge, the corresponding kinetic equation that described the dissolution process was determined to be dα dt = 2.36 × 10 −4 (1 − α) 1.09 . Moreover, the half-life, t 1/2 = 48.89 min, sol H m = −12.40 kJ · mol −1 , sol S m = −354.7 J · mol −1 · K −1 , and sol G m = 97.43 kJ · mol −1 of the dissolution process were also obtained. The results show that this work not only provides a simple method for the determination of the half-life for a drug but also offers a theoretical reference for the clinical application of matrine.

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Variations of H + , Mn 2+ , and BrO − 3 during chemical oscillating reactions involving amino acids were investigated using H 2 SO 4 -BrO − 3 -Mn 2+ -acetone as an oscillator, and the thermodynamic functions ( S, H , and G) were calculated. The results indicated that the oscillating reaction is a process from disorder to order. In the oscillating system, the heat provided by the environment is used to increase the internal energy and entropy. When external positive entropy flow could make the system reach negative entropy flow, the system starts to oscillate and to maintain oscillations by a stable entropy.

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