Determination of six major fatty acids in fatty oil of Brassica rapa L. seed by GC

Objective To assay palmitic acid,stearic acid,oleic acid,linoleic acid,linolenic acid and erucic acid in the fatty oil of Brassica rapa L.seed by GC.Methods The separation was carried out on a 30 m×0.25 mm RTX-WAX quartz capillary column.The intial temperature was kept at 200 ℃ for 4 min,then raised to 230 ℃ at the speed of 4 ℃ min and maintain the temperature for 6 min.The carrier gas was nitrogen,The airflow speed was 1.16 ml/min and triage injection with the split ratio of 90/1.The injection and detection temperature were both 250℃.The palmitic acid,stearic acid,oleic acid,linoleic acid,linolenic acid and erucic acid were quantifide by Intrenal standard method.Results The standard curves of palmitic acid,stearic acid,oleic acid,linoleic acid,linolenic acid and erucic acid were linear within the rang of 0.385 7～2.372 7 mg/ml,0.045 5～0.274 4mg/ml,0.518 7～3.019 8mg/ml,0.468 9～2.9647mg/ml,0.396 9～2.0201mg/ml,4.256 8～24.2907mg/ml and the coefficient were 0.999 6,0.999 3,0.999 7,0.999 5,0.999 5,0.999 4,respectivly.The six fatty acid recoveries were 96.88%,97.81%,97.67%,98.07%,96.90%,97.63% and the RSD were 2.0%,2.1%,2.3%,2.3%,2.3% and 2.0%.Conclustion This method is sensitive,accurate and reliable.It can be used for the quality control of the fatty oil of Brassica rapa L.seed.