Study on Thermo-gravimetric Behavior of Five Amino Acids and Pyrolytic Formation of Hydrocyanic Acid

The effects of heating rate and atmosphere on the yield of hydrocyanic acid (HCN)from pyrolysis of glycine (Gly),alanine (Ala), leucine (Leu),isoleucine (Ile)and proline (Pro)were investigated by a modified thermo-gravimetric analyzer. The results showed that: 1)with the increase of heating rate, the yields of HCN increased except that from Gly;2)the yields of HCN in the presence of oxygen were significantly lower than that in nitrogen atmosphere; 3)the yield of HCN from Gly was higher than from the other 4 amino acids under the test conditions. In an atmosphere containing 10% O₂+90% N₂ and at a heating rate of 40℃/min, the amino acids in the order of HCN yield were Gly > Leu > Ile > Pro > Ala.