Polymorphic effects at the eutectic melting in the H2O–glycine system

• Published in: Journal of thermal analysis and calorimetry Vol. 111; no. 3; pp. 2187 - 2194
• Main Authors: Drebushchak, V. A., Ogienko, A. G., Boldyreva, Elena V.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-03-2013
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Water; Eutectic melting; Glycine; DSC; Eutectic temperature; Polymorphism
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-012-2761-0

Solid mixtures of ice with three glycine polymorphs were heated up to the eutectic melting and the DSC has detected the eutectic temperatures of −2.8 °C for α-, −3.6 °C for β-, and −2.8 °C for γ-glycine. DSC peaks of the eutectic melting are rather strange in shape, indicating unclear processes in the solutions. Accurate DSC measurements of extremely small samples can probably provide us with the physicochemical tool for the investigation of polymorphic differences among different solutions. This may be important in relation to different bioavailability of solutions prepared from different polymorphs. Eutectic temperature of −4.7 °C in water–glycine system allows us to suggest that the unknown polymorph of glycine exists.