文摘
Rates of thermal decomposition of sulfur-containing amino acids such as D,L-methionine, L-cysteine, and L-cystine are studied. It is established that the amino acids decompose at 190–240¡ãC to give the gaseous and liquid decomposition products in the polyphasic system formed. The rate of summary process is described by the first order kinetic equation up to 30–50 % conversion. In spite of close values of the effective activation energies of thermal decomposition of D,L-methionine, L-cysteine, and L-cystine (195, 193, and 184 kJ mol−1 respectively) the effective rate constants at one and the the same temperature differ by one or two orders of magnitude in the above-mentioned series. Sulfur-containing compounds prevail in the gaseous decomposition products, while in the liquid phase the nitrogen-containing ones are accumulated.
