气相色谱-质谱法研究香叶基-β-D-吡喃葡萄糖苷的热裂解行为

Study on the Pyrolysis Behavior of Geranyl-β-D-Glucopyranoside by Gas Chromatography-Mass Spectrometry

为了研究香叶醇的糖苷类香料前体香叶基-β-D-吡喃葡萄糖苷的热裂解行为,在200,300,400℃条件下,分别采用在线模式的裂解仪无氧裂解和离线模式的高温熔盐加热裂解,热解产生的物质均经毛细管气相色谱-质谱仪进行定性和定量检测。根据实验结果,对香叶基-β-D-吡喃葡萄糖苷的裂解机理进行了初步探讨。实验发现,香叶基-β-D-吡喃葡萄糖苷在200℃条件下裂解量很少;300℃条件下裂解产生大量香叶醇,而其他杂质较少;随着温度的升高,400℃条件下裂解产生的副产物明显增加。实验结果表明以300℃条件下裂解效果最好。同时,香叶基-β-D-吡喃葡萄糖苷热裂解产生了特征香味成分香叶醇,其裂解的基本反应是O-糖苷键的断裂。在试验的两种方法中,在线裂解模式实验方法先进,定性直接,结果准确;离线裂解模式实验方法操作方便,简单易行,而且在定性基础上可以实现定量分析。

In order to investigate the pyrolysis behavior of the flavor precursor of geranyl-β-D- glucopyranoside, the glycoside was pyrolyzed at 200, 300, 400 ℃ in an on-line pyrolyzer under anaerobic conditions and in an off-line mode separately. Gas chromatography-mass spectrometry （GC/MS） was used for the qualitative and quantitative analysis of the pyrolysis products. The thermal degradation mechanism of geranyl-β-D-glucopyranoside was discussed according to the results. Little geranyl-β-D-glucopyranoside was pyrolyzed at 200 ℃ and there were a large amount of geraniol and little by-products produced at 300 ℃. With the increasing temperature to 400 ℃, both the pyrolytic products and by-products were significantly increased. Therefore, it indicated that the optimized temperature of pyrolysis was 300 ℃. The main pyrolysis product of the glycoside was geraniol. It showed the primary decomposition reaction took place with the breaking of glycosidic linkage, mode experiment was a rapid and mode can be used as a quantitative the cleavage of O-glycosidic bond as expected. The on-line good qualitative method for the pyrolysis, and the off-line method based on the qualitative analysis.