The effects of gamma rays upon monohydrated and anhydrous asparagine: a DSC study in sealed pans

Non-irradiated and gamma irradiated monohydrated ( l Asn·H 2 O) and anhydrous ( l Asn) asparagines, in solid state, were studied by means of DSC. The samples were irradiated at room temperature with gamma radiations using a 137 Cs source. The exposure doses ranged between 1 and 10 kGy. All samples were scanned in sealed pans, from room temperature to a temperature beyond the melting point. The DSC scans of l Asn·H 2 O samples in sealed crucibles revealed the presence of two dehydration processes and one of decomposition and only decomposition in the case of l Asn. The influence of gamma irradiation consisted in decreasing the enthalpy of dehydration and of decomposition. A decomposition mechanism is proposed.