5种氨基酸热失重行为及其热解生成氢氰酸的研究

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

摘要: 采用改造后的商品化热重分析仪,对不同升温速率和裂解气氛下甘氨酸(Gly)、丙氨酸(Ala)、亮氨酸(Leu)、异亮氨酸(Ile)、脯氨酸(Pro)等5种氨基酸热解特性及生成氢氰酸(HCN)的行为进行了研究。结果表明:①除Gly外,其他4种氨基酸生成HCN的产率随着升温速率的提高而增加;②当有O₂存在时,HCN的产率较N₂裂解气氛下有明显降低,当O₂含量达到20%时,5种氨基酸生成HCN的产率均低于0.25%;③在不同的升温速率和裂解气氛下,Gly生成HCN的产率均高于其他4种氨基酸;在10%O₂+90%N₂气氛和40℃/min的升温速率下,5种氨基酸生成HCN产率顺序:Gly > Leu > Ile > Pro > Ala。

Abstract: 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.