气相色谱法测定牛蒡子脂肪油中3种脂肪酸含量

Determination of 3 Kinds of Fatty Acids in Arctium Fructus by GC

目的:建立气相色谱法(GC)测定不同产地牛蒡子脂肪油中亚油酸、油酸、棕榈酸含量的方法。方法:采用PEG-20M弹性石英毛细管柱(0.5μm×0.32 mm×30 m);气化室温度280℃,FID检测器,温度300℃,柱温初温165℃,保持3min,以3.5℃.min-1升至205℃,然后以35℃.min-1升至230℃,保持22 min。载气氮气(99.99%)。以石油醚为提取溶媒,提取10批不同产地牛蒡子药材生品及5批不同产地炮制品中的脂肪油,经甲酯化后,以十七烷酸甲酯为内标物,进行测定比较。结果:亚油酸在0.122 3～1.958 1μg线性关系良好(r=0.999 8);油酸在0.039 2～0.626 4μg线性关系良好(r=0.999 8);棕榈酸在0.037 2～0.596 4μg线性关系良好(r=0.999 8)。各产地牛蒡子脂肪油中均以亚油酸含量为最高,炮制前后对脂肪酸含量的影响较大。结论:方法准确、可靠、重复性好,可用于牛蒡子脂肪油中亚油酸、油酸、棕榈酸的质量控制。

Objective： To assay linoleic acid,oleic acid and stearic acid in the fatty oil of Arctium Fructus from different areas by GC.Method： The GC separation was performed on a PEG-20M quartz capillary column（30 m×0.32 mm×0.5 μm） and the initial temperature was programmed from 165 ℃ to 205 ℃ at 3.5 ℃·min-1and kept for 3 min,then raised to 230 ℃ at 30 ℃·min-1and maintain for 22 min,inject temperature at 280 ℃,FID detector temperature was at 300 ℃,carrier gas was N2（99.99%）.Petroleum ether was used to extract the fatty oil from both crude and processed Arctium Fructus of different areas and after methyl esterification,determination and comparison were carried out by taking margaric acid methyl ester as internal standard.Result： The standard curves of linoleic acid,oleic acid and stearic acid were linear within the range of 0.122 3-1.958 1 μg,0.039 2-0.626 4 μg,0.037 2-0.596 4 μg and the coefficient were 0.999 8,0.999 8,0.999 8 respectively.The content of linoleic acid was the highest in fatty oil of Arctium Fructus from all areas,and the content of fatty acids would be significantly affected by processing.Conclusion： The method can be used to control the quality of linoleic acid,oleic acid and stearic acid in the fatty oil of Arctium Fructus,which is accurate,reliable and repeatable.