海藻中脂肪酸的提取和分析方法研究

发布时间：2018-03-31 11:42

  本文选题：海藻　切入点：脂肪酸　出处：《温州大学》2016年硕士论文

【摘要】：海藻中因含有不饱和脂肪酸如我们人体必需的DHA、EPA等不饱和脂肪酸而具有营养价值和医药方面的研究价值。快速、灵敏、准确的测定海藻中脂肪酸的分析方法,对于深入研究脂肪酸与海藻生物活性之间的关系具有重大意义。本论文旨在通过比较不同衍生化试剂与脂肪酸衍生化反应,选择最佳衍生化试剂,对脂肪酸结构进行修饰提高质谱响应信号,建立一种快速、灵敏、准确的衍生化高效液相色谱-串联质谱法,并应用于海藻中脂肪酸含量的测定。主要内容如下:第一部分研究建立了海藻中总脂质的提取方法。通过多种不同的提取方法如溶剂浸提法、超声波提取法、索氏提取法、改进的Folch法对海藻粉末进行总脂质的提取,最终选择以改进的Folch法提取海藻中的总脂质。采用单因素实验选取液料比、提取功率、提取温度和提取时间,得到最佳工艺条件为:以二氯甲烷-甲醇为提取溶剂、提取时间为90 min、最佳温度为50℃、最佳功率为80 W。羊栖菜中总脂质提取率为5.7%。第二部分建立了柱前衍生高效液相色谱串联质谱测定脂肪酸的方法。以N-(2-羟乙基)-吡咯烷、N,N-二甲基乙二胺、N,N-二甲基乙醇胺为衍生试剂对脂肪酸进行衍生,优化了衍生条件。通过衍生条件、衍生剂价格等因素的比较,最终确定N,N-二甲基乙二胺为最佳衍生剂,由于N,N-二甲基乙二胺含有氮原子,氮原子是负电性,通过碘甲烷反应形成季铵盐,大大提高了质谱的离子化效率。在本章中同时比较了衍生化后的脂肪酸和未衍生化的脂肪酸的检测限,结果表明,三种饱和脂肪酸和五种不饱和脂肪酸衍生后的质谱检测灵敏度提高了100倍以上。并且N,N-二甲基乙二胺中N,N-二甲基官能团是水溶性基团,与脂肪酸反应,使其水溶性提高,因而缩短脂肪酸衍生物在液相柱中的保留时间,节省了检测时间。第三部分采用高效液相色谱串联质谱法测定海藻中的脂肪酸。结果表明:二十二碳六烯酸在三种海藻中几乎不存在,二十碳五烯酸(20:5)和α-亚麻油酸在海藻中含量较多,在海藻中有些脂肪酸存在同分异构体现象,在三种海藻中棕榈酸含量均较高。由于采用二级质谱对脂肪酸进行定量分析,即使未完全分离仍能准确测定,因此提高了方法的选择性,缩短了检测时间,为海藻中脂肪酸的测定提供了一种快速、灵敏、准确的分析方法。
[Abstract]:The seaweed contains unsaturated fatty acids such as DHAA EPA, which is essential to our human body, which has nutritional value and medical value. Rapid, sensitive and accurate method for the determination of fatty acids in seaweed. It is of great significance to study the relationship between fatty acid and algal bioactivity. This paper aims to select the best derivatization reagent by comparing different derivatization reagents and fatty acid derivatization reactions. The structure of fatty acids was modified to improve the response signal of mass spectrometry. A fast, sensitive and accurate derivatization high performance liquid chromatography-tandem mass spectrometry (HPLC-MS) method was established. It has been applied to the determination of fatty acids in seaweed. The main contents are as follows: in the first part, the extraction methods of total lipids in seaweed were established, such as solvent extraction, ultrasonic extraction, Soxhlet extraction, etc. The improved Folch method was used to extract total lipids from seaweed powder, and the modified Folch method was used to extract total lipids from seaweed. The single factor experiment was used to select the ratio of liquid to material, extraction power, extraction temperature and extraction time. The optimum conditions were obtained as follows: the extraction solvent was methane-dichloromethane, the extraction time was 90 min, and the optimum temperature was 50 鈩，

本文编号：1690588