香兰素的热解研究

Study on Pyrolysis of Vanillin

为了研究香兰素在卷烟中的热解情况,采用离线裂解仪在400、500、600、700和800℃下对香兰素进行了裂解试验,并采用毛细管气相色谱/质谱法对裂解产物进行了简单定性定量,共鉴定出42种裂解产物,并根据香兰素的键能对简单酚类的形成机理进行了初步推测。结果表明:①在400℃下香兰素几乎不裂解,而后随着温度的升高,香兰素的裂解率逐渐提高,裂解产物也逐渐增加,尤其是在700℃和800℃下,裂解产物显著增加,但仍有部分未裂解;②在香兰素裂解产物中,既有重要的香味成分,也有分子量比香兰素大的环氧化合物和稠环芳烃。

In order to investigate the pyrolysis of vanillin in a burning cigarette, vanillin was pyrolyzed in a furnace-type pyrolyzer at 400℃, 500℃, 600℃, 700℃, and 800℃,respectively. The volatile and semi-volatile pyrolytic products were trapped by a 0.7m × 0.53cm (Length × internal diameter) crystalline silica capillary immersed in liquid nitrogen, then eluted with dichloromethane, and simply qualitatively and quantitatively analyzed with GC/MS. 42 pyrolytic products were identified. The formation mechanism of simple phenols,one of the pyrolytic products of vanillin, was roughly speculated according to the bonding energy of vanillin. The results showed that: 1) little vanillin was pyrolyzed at 400℃, the pyrolytic products and pyrolytic rates of vanillin were increased with the increase of temperature, the pyrolytic products were significantly increased at 700℃ and 800℃, however, still there was a little of vanillin remained; and 2) of the pyrolytic products, there were key flavor compounds and there were (epoxides) and polycyclic aromatic hydrocarbons which molecular weights were higher than vanillin.