| A-linolenic acid belongs to the n-3 series unsaturated fatty acid, which is one of human body essential unsaturated fatty acids. Its application had amplitude to many fields, such as medicine and health-care food etc. . In the thesis the chromatographic methods were set up for analyzingα-linolenic acid in descurainia sophia. The GC-MS method was set up firstly to analyze the chemical constituents of the fatty acids from seeds of descurainia sophia, then, the HPLC methods were set up to analyze the content ofα-linolenic acid in descurainia sophia oil.The thesis was divided into two parts: the summary (introduction) and the experiment. On the basis of looking into relevant literatures, the part of introduction reviewed and prospected the botany of descurainia sophia characteristics,the research and development progress as pharmaceuticals,health-care raw materials and industrial values,the analysis methods of linolenic acid and other related areas of research progress. This paper introduced the principle of chromatography technology,equipment combined with new methods and new detection technology.In the part of experiment, the best experimental conditions were identified to analysis theα-linolenic acid in the seeds of descurainia sophia on the basis of systematized experiment on conditions, including GC,HPLC separation conditions,MS conditions and ELSD,PAD detection conditions. The chromatographic conditions of GC/MS included HP-5 flexible silica capillary column (30m×0.25mm×0.25μm) .The high-purity helium gas flow rate was 1.2mL/min. The injector temperature was 280℃. The temperature program was began with 80℃then rose to 290℃by 4℃each minute, then keep a constant temperature for 30min. MS conditions included EI source with 70eV ionization energies. The ion source temperature was 230℃. Quadrupole temperature was 150℃and the transfer line was maintained at 280℃. The relative molecular mass scanning range was 30～400amu. The theses findings showed that there are a variety of fatty acids in the seeds of descurainia sophia, in which theα-linolenic acid has the highest content (content 36.4%). In addition, there also has the Octadecadienoic acid,Tricosanoic acid,Heneicosanoic acid,11-Docosanoic acid,Hexadecanoic acid and so on.The PAD and ELSD were used to analyzeα-linolenic acid by RP-HPLC methods. The chromatographic conditions of the HPLC-PAD method included ZORBAX Eclipse XDB-C18 column (4.6×150 mm, 5μm). Methanol (100%) was the mobile phase with flowing rate 0.8mL/min-1 .The column temperature was 30℃and the detection wavelength was 204nm. The injection volume was 5μL.The results indicate that the standard curve ofα-linolenic acid was linear over the range of 1～5μg, the correlation coefficient(r) was 0.9998(n=5), detection limits was 0.605μg/mL, the average recovery was 99.9% with RSD 0.82%(n=9). The chromatographic conditions of the HPLC-ELSD method included ZORBAX Eclipse XDB-C18 column (4.6×150 mm, 5μm), Methanol-water (95%: 5%) as the mobile phase, flow rate was 0.8mL/min-1 and the column temperature was 30℃. The injection volume was 20μL. The tube temperature was 32℃and the gas flow was 1.4L/min. The results indicate that the standard curve ofα-linolenic acid was linear over the range of 4～20μg, the correlation coefficient(r) was 0.9991(n=5), the average recovery was 99.8% with RSD 0.53%(n=9).Through experiments, the linear range,accuracy,precision,reproducibility and other indicators assessment of the analysis methods established were carried out. Results showed that the methods were simple,rapid and reliable. That can be used in the content determination ofα-linolenic acid in the seeds of descurainia sophia, which were more advanced and practical methods than that of the literature had reported.The established methods were used to analyze the actual samples. And the content ofα-linolenic acid which was the major components in the seeds oil of descurainia sophia was calculated. It has provided important fact to developing and applicating the seeds oil of descurainia sophia.
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