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.