| As one of the nutrients on which human beings depend for survival,lipids play many important physiological functions.To further study the role and function of lipids in molecular biology and other fields,it is necessary to accurately identify and quantify them.however,the high structural diversity of lipids poses a major challenge to lipidomics,especially in natural vegetable oils containing up to 95?98% triglycerides.Compared with the obvious defects of sample matrix effect in shotgun mass spectrometry,the development of high performance liquid chromatography-mass spectrometry technology has greatly promoted the further development of lipidomics.All kinds of lipids in the sample,first separated in liquid chromatography,then entered the mass spectrum in turn for identification,which greatly improved the selectivity and sensitivity of lipid analysis,and reduced the matrix effect to a certain extent.Time of flight-mass spectrometry has extremely high mass resolution and accuracy,unlimited mass charge ratio range and high speed acquisition capability.Ultra-high performance liquid chromatography has more rapid,sensitive and adequate chromatographic separation.The combination of the two will greatly improve the efficiency of lipid structure identification in complex biological samples.This project mainly takes lipids in edible oils as the research object.Firstly,the ultra-performance liquid chromatography-time of flight-tandem mass spectrometry high coverage qualitative analysis technology is established,and then the triglyceride quantitative method based on this technology is established,so as to achieve high throughput,high coverage and high efficiency qualitative and quantitative analysis of lipids.And the above method was applied to the analysis of lipid composition of Prinsepia utilis Royle oil and the adulteration identification of edible oil.In addition,based on the above method,this experiment preliminarily explored the content and influencing factors of minor components in different rapeseed oil.The major result are as follows:1.A method of ultra-performance liquid chromatography-time of flight-tandem mass spectrometry was established and applied to analyze the types,composition and relative content of lipids in the Prinsepia utilis Royle oil.The results showed that the Prinsepia utilis Royle oil contained 39.17% oleic acid,36.16% linoleic acid and 16.38% palmitic.The ratio of saturated fatty acid:monounsaturated fatty acid:polyunsaturated fatty acid was close to 0.6:1:1.And there were 169 kinds of lipids,including 76 phospholipids,84 glycerides and 9 glycolipids.Among them,phosphatidylinositols and triacylglycerols were dominant phospholipids and glycerides,respectively.Meanwhile,glycolipids mainly contained digalactosyldiacylglycerols.Ultra-performance liquid chromatography-time of flight-tandem mass spectrometry has the advantages of high sensitivity,good accuracy and high throughput.It provides a reliable analysis platform for lipid in plants.2.In order to more accurately quantify triacylglycerol,an absolute quantitative method for triacylglycerol based on ultra-performance liquid chromatography-time of flight-tandem mass spectrometry was established.Twenty kinds of mono-fatty acid triglyceride standards,two mixed fatty acid triglyceride standards,and one deuterated-labeled triglyceride standard were used to draw a standard curve,and the response factor and the fitting calibration formula were calculated.The results showed that compared with the single internal calibration method,the accuracy is improved by 82%.3.The above method was used to compare and analyze phospholipids,fatty acids,vitamins E? phytosterols in 9 different rapeseed oils.The results showed that the relationship between minor component content and brand difference is not obvious,but it has strong correlation with grade and processing technology.Quality assessment and price prediction models can be established based on minor component content,processing technology and grade. |
PDF Full Text Request