GC-MS分析柠檬挥发油的化学成分

GC-MS Analysis of Chemical Constituents of Volatile Oil from Lemon

目的:借助于气相色谱质谱联用技术(GC-MS)对柠檬挥发油类化学成分进行研究;方法:自然风干柠檬片,分别利用水蒸气蒸馏和有机溶媒提取方法,获得其中脂溶性物质。并利用GC-MS方法,与NIST数据库进行比对,分析精油的化学成分。结果:从水蒸气蒸馏获得馏分中确定了30种成分,占总积分面积的99.1%。它们的化学结构包括21个单萜,6个倍半萜和三个其他类型物质。其中含量前五位的化合物分别为柠檬烯(7,41.37%),(+)-α-蒎烯(4,17.47%),(1R)-(+)-反式-异柠檬烯(8,17.28%),γ-松油烯(10,10.96%)和β-蒎烯(2,2.77%)。本文还对化合物7二级质谱进行解析,不饱和键是奇电子离子的重要位点,环内双键优先丢失电子。并且由单电子引起的裂解可得到丰度较高的离子,通常为基峰离子。结论:本实验的结果与文献报道柠檬挥发油的化学组成基本一致,主要为萜类成分,且单萜数量高于倍半萜。

Objective:To study the chemical constituents of lemon volatile oil by GC-MS.Methods:The chemical components of essential oil were analyzed by GC-MS method and NIST database.Results:30 components were determined from the distillation of water vapor,accounting for 99.1%of the total integral area.Their chemical structures include 21 monoterpenes,6 sesquiterpenes and three other types of substances.Among them,the compounds of the top five were limonene(7,41.37%),(+)-α-pinene(4,17.47%),1R-(+)-trans isocitronene(8,17.28%),γ-terpinene(10,10.96%),andβ-pinene(2,2.77%).The secondary mass spectrometry of compound 7 was analyzed.The cracking caused by oxygen containing group was the first step,followed by unsaturated bond,which was the important site of odd electron ions.Moreover,the ion with high abundance can be obtained by the cracking of single electron,usually the base peak ion.Conclusion:The results of this experiment are consistent with the chemical composition of lemon volatile oil reported in the literature,mainly terpenoids,and the number of monoterpenes is higher than sesquiterpene.