Dehydration of irradiated and non-irradiated <Emphasis Type="Italic">L</Emphasis>-α-asparagine monohydrate

Dehydration of irradiated and non-irradiated asparagine monohydrate was investigated by means of a computer interfaced PerkinElmer 1B DSC in isothermal conditions and static atmosphere. Isothermal runs were performed at 358, 363, 368 and 373 K. Samples were γ-irradiated at room temperature, using a ¹³⁷Cs source with an activity of 3·10¹³ Bq and a dose rate of 4·10² Gy h⁻¹, with irradiation times between 8–116 h. Isothermal kinetics were analyzed via the common factorized rate equation. Šesták-Berggren conversion function was found to best fit the experimental data. Of the three fitting parameters, only the one associated with the activation energy was found to follow a coherent variation with the exposure time. Even within this simple model, that makes the activation energy a useful stability criterion within a set of similar samples.