Hydrolysis of Aspirin Studied by Spectrophotometric and Fluorometric Variable-Temperature Kinetics

Pseudo-first-order rate constants for the hydrolysis of acetylsalicylic acid as a function of temperature have been obtained by variable-temperature kinetic experiments. A method, based on a generalization of non-isothermal analysis, has been used that takes advantage of the capabilities of modern data collection and processing systems. Both spectrophotometric and, for the first time under non-isothermal conditions, fluorometric measurements have been carried out. The results obtained are identical to those obtained under the same conditions but using traditional constant-temperature kinetic runs. This provides the possibility of reducing the amounts of time and chemicals usually spent in collecting kinetic data in mechanistic studies in solution by an order of magnitude.