Low-temperature heat capacity and thermodynamic functions of vitamin B-12

作者：Knyazev A V^*; Smirnova N N; Plesovskikh A S; Shushunov A N; Knyazeva S S

来源：Thermochimica Acta, 2014, 582: 35-39.

DOI：10.1016/j.tca.2014.02.025

• Vitamin B-12
• Cyanocobalamin
• Adiabatic vacuum calorimetry
• Heat capacity
• Thermodynamic functions
• Differential scanning calorimetry

In the present work temperature dependence of heat capacity of vitamin B-12 (cyanocobalamin) has been measured for the first time in the range from 6 to 343 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B-12, namely, the heat capacity, enthalpy H degrees(T)-H degrees(0), entropy S degrees(T) S degrees(0) and Gibbs function G degrees(T)-H degrees(0) have been determined for the range from T -> 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermal stability of cyanocobalamin was also studied by differential scanning calorimetry.

• 出版日期2014-4-20