基于衍生化技术的游离脂肪酸质谱分析方法及其应用研究

发布时间：2018-06-06 18:41

本文选题：游离脂肪酸 + 化学衍生化　；参考：《中国农业科学院》2017年硕士论文

【摘要】：游离脂肪酸(Free fatty acid,FFA)又称非酯化脂肪酸(nonestesterified fatty acid,NEFA),是类脂代谢物的主要组成部分。在油脂生产和储存过程中,甘油三酯的水解会产生FFAs,容易导致油脂的氧化和酸败,影响油的品质和功能。在粗制油中FFAs组成可用于描述压榨油的质量和评估油损伤程度。FFA成分可以作为油品在不同水分、温度、含氧量、光照贮藏以及煎炒过程中的降解参数。食用油中FFA的传统测定方法是滴定法测定酸价和气相色谱法(Gas chromatography,GC)。滴定法测定酸价得到的是食用油中游离脂肪酸总量,不能对各游离脂肪酸进行定性分析,也不能得到各种游离脂肪酸的含量;GC虽然能够提供食用油中各游离脂肪酸的定性与定量信息,但食用油基质复杂,游离脂肪酸含量低、具有强极性和弱挥发性,因此需要先经过复杂的样品前处理以富集和纯化游离脂肪酸,然后再将游离脂肪酸进行甲酯化衍生后,才能进行GC分析,整个过程非常繁琐、费时,且需要耗费大量有机溶剂,此外,上述方法还存在稳定性差,检测灵敏度低等缺点。因此,建立一种高效、高灵敏度、高通量和高准确性的分析方法十分有必要。本课题以游离脂肪酸为研究对象,将化学衍生化技术与电喷雾串联质谱(ESI-MS/MS)技术相结合,开展基于化学衍生化技术的游离脂肪酸高选择性、高灵敏定性和定量分析新方法研究,以解决现有技术在游离脂肪酸分析检测中的技术瓶颈。本论文研究结果如下:1.基于衍生化技术的游离脂肪酸质谱分析方法的建立。通过N,N-二乙基乙二胺(DEEA)衍生化技术结合鸟枪法-中性丢失扫描-电喷雾质谱技术(shotgun-NLS-ESI-MS/MS),使游离脂肪酸的分析灵敏度提高了2200~6700倍;通过质谱中性丢失扫描模式实现了游离脂肪酸的快速定性分析,结合内标进行定量分析,为解决游离脂肪酸质谱分析离子化效率低,灵敏度差等问题提供了新思路。2.将基于衍生化技术的质谱分析方法应用于食用油中游离脂肪酸的定性和定量分析,并将分析结果和气相色谱-火焰离子化检测器(GC-FID)、高效液相色谱-质谱联用法(HPLC-MS)测得的结果进行了比较,验证了所建立分析方法的可行性。Shotgun-ESI-MS/MS分析方法,样品前处理简单,无需经过FFAs的分离富集,食用油样品只需要用正己烷稀释后便可以进行DEEA的衍生化反应,反应完成后即可进行质谱分析。3.基于衍生化技术的质谱分析方法应用于7种食用油中游离脂肪酸的分析。对微波加热处理不同时间后的7种食用油中游离脂肪酸组分及含量的变化进行了分析,共检测到食用油中的8种FFAs,其中游离脂肪酸C18:1、C18:2和C18:3经微波处理后含量有所增加。4.基于衍生化技术的质谱分析方法应用于微波预处理油菜籽冷榨油中游离脂肪酸的分析。应用shotgun-NLS-ESI-MS/MS方法共检测到菜籽油中8种游离脂肪酸,微波预处理后的油菜籽冷榨油中游离脂肪酸含量有所增加。结合主成分分析,成功的区分了不同来源的冷榨菜籽油。所建立的游离脂肪酸检测方法简单有效,能够有效监控菜籽油中游离脂肪酸的含量变化,对保障油品安全与品质具有重要的意义。
[Abstract]:Free fatty acid (FFA), also known as non esterified fatty acids (nonestesterified fatty acid, NEFA), is the main component of lipid metabolites. In the process of oil production and storage, the hydrolysis of triglycerides will produce FFAs, which can easily lead to the oxidation and failure of oil and affect the quality and function of oil. The composition of FFAs in crude oil can be made. The.FFA components used to describe the quality of the press oil and the assessment of the degree of oil damage can be used as the degradation parameters in the process of different moisture, temperature, oxygen content, light storage and frying. The traditional method for determination of FFA in edible oil is the titration method for the determination of acid value and gas chromatography (Gas chromatography, GC). The titration method for the determination of acid value is obtained. The total amount of free fatty acids in edible oil can not be qualitatively analyzed and the content of free fatty acids can not be obtained. Although GC can provide qualitative and quantitative information of free fatty acids in edible oil, the base of edible oil is complex, the content of free fatty acid is low, and it has strong and weak volatility. Therefore, it needs first. After complex sample pretreatment, the free fatty acids are enriched and purified, and then the free fatty acids can be methylated and derivatized to carry out GC analysis. The whole process is tedious, time-consuming, and requires a lot of organic solvents. In addition, the methods also have the disadvantages of poor stability and low detection sensitivity. Therefore, a kind of high efficiency is established. The analytical method of high sensitivity, high throughput and high accuracy is very necessary. This subject takes the free fatty acid as the research object, combines the chemical derivatization technology with the electrospray ionization tandem mass spectrometry (ESI-MS/MS) technology to develop the high selectivity of free fatty acids based on chemical derivatization technology, and study the new method of high sensitivity qualitative and quantitative analysis. To solve the technical bottlenecks of free fatty acid analysis and detection of existing technologies. The results of this paper are as follows: 1. based on the establishment of free fatty acid mass spectrometry analysis method based on derivatization technology, N, N- two ethyl ethylenediamine (DEEA) derivatization technology combined with the method of bird shooting neutral loss scanning electrospray mass spectrometry (shotgun-NLS-ESI-MS/MS) The sensitivity of the analysis of fatty acids increased by 2200~6700 times. The rapid qualitative analysis of free fatty acids was realized by the neutral loss scanning mode of mass spectrometry and quantitative analysis combined with the internal standard. A new idea was provided to solve the problems such as low ionization efficiency and poor sensitivity of free fatty acid mass spectrometry analysis..2. will be based on the mass spectrometry based on the derivatization technology. The analytical method was applied to the qualitative and quantitative analysis of free fatty acids in edible oil, and the results were compared with the results obtained by gas chromatography flame ionization detector (GC-FID) and high performance liquid chromatography mass spectrometry (HPLC-MS). The feasibility of the analytical method and the sample pretreatment were verified. Simple, without the separation and enrichment of FFAs, the edible oil samples only need to be diluted with hexane to carry out the derivative reaction of DEEA. After the reaction is completed, the mass spectrometric analysis of.3. is applied to the analysis of free fatty acids in 7 kinds of edible oils. 7 kinds after microwave heating are treated at different time. Analysis of the changes of free fatty acid components and content in edible oil, 8 kinds of FFAs in edible oil were detected. The content of free fatty acid C18:1, C18:2 and C18:3 increased after microwave treatment..4. based on the analysis of mass spectrometry based on derivatization technology was applied to the analysis of free fatty acids in the cold pressing oil of Rapeseed by microwave pretreatment. 8 kinds of free fatty acids in rapeseed oil were detected by shotgun-NLS-ESI-MS/MS method. The content of free fatty acids in the cold pressed oil from rapeseed after microwave pretreatment was increased. The cold pressed rapeseed oil from different sources was successfully distinguished by the combination of principal component analysis. The free fatty acid detection method was simple and effective and can effectively monitor rapeseed oil. The change of free fatty acids in oil plays an important role in ensuring the safety and quality of oil products.
【学位授予单位】：中国农业科学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ645.6;O657.63

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