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摘要：本文研究了高分辨质谱直接进样分析食用油中甘油三酯的方法。使用异丙醇为溶剂，将食用油溶解后加入甲醇，然后直接使用质谱进行检测。采用对于非极性物质效果较好的APCI电离源，选择样品进样流速为1200μL/h，干燥气温度为180℃，APCI电晕针电流为5000nA，对食用油进行APCI-FTMS测定。对特定的一级质谱的谱峰，测定其二级质谱，推出甘油三酯中1-位和3-位连接的单个脂肪酸类型。然后将这些脂肪酸与一级质谱的主峰质量结合，得到2-位的脂肪酸类型，从而推出该一级质谱谱峰代表的甘油三酯的结构。使用该方法，实际测定了玉米油和猪油的主要甘油三酯的类型，显示两者在甘油三酯类型方面存在差异。同时该法方便快捷，节省了许多前处理或分离的时间。8364
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关键词：甘油三酯；质谱；大气压电离；直接进样
Direct analysis triglyceride in edible oil by mass spectrometric
Abstract: The thesis studied the direct analytical method of triglyceride in edible oil by atmospheric Pressure Chemical Ionization- high resolution mass spectrometry. After the edible oil sample was dissolved in isopropyl alcohol, the sample solution was added in methanol and detected directly by mass spectrometry. Using the APCI ionization source which is better for non- polar substances，sample injection flow rate was selected as 1200μL / h, drying gas temperature was selected as 180 ºC, APCI corona needle current was selected as 5000nA，for edible oil APCI-FTMS determination. For the particular mass spectral peaks of triglyceride, its MS/MS was measured to find single fatty acids connected triglyceride 1- and 3- bit site. Then make these fatty acids get a combination qualitative with the main peak to get 2- position fatty acid type. The spectral peak was then conjectured its represented triglyceride structure. The main types of triglycerides in corn oil and lard were actually determined by the method, and shows that the differences are existed in the types of triglycerides. Meanwhile, this method is convenient and also saves a lot of time for pre-processing or separation
Key Words：Triglycerides；Mass spectrometry；APCI；Direct injection
目录
1.前言 1
1.1 选题意义 1
1.2 文献综述 2
1.2.1傅立叶变换质谱 2
1.2.2.轨道阱质谱 2
1.2.3.磁质谱 3
1.2.4.飞行时间质谱 4
1.2.4.1电喷雾化学电离与飞行时间质谱联用 4
1.2.4.2基质辅助激光解析电离与飞行时间质谱联用 4
1.2.5小结 6
2.仪器与试剂 7
2.1 仪器： 7
2.1.1 SolariX 70 FT-MS测样流程 7
2.2试剂： 7
2.3 样品来源 7
3.实验内容 8
3.1样品处理 8
3.2实验方法 8
4.结果与讨论 8
4.1样品溶液配比 8
4.2质谱仪器条件选择 10
4.2.1 ESI电离 10
4.2.2 APCI源 10
4.2.3小结 10
4.3 APCI源条件选择 11
4.3.1 流速 11
4.3.2 干燥气温度 12
4.3.3电晕针电流 13
4.4质谱测定甘油三酯的结果 13
4.4.1几种食用油中甘油三酯的检测 14
4.4.2玉米油中甘油三酯的二级质谱检测 15
4.4.3猪油中甘油三酯的二级质谱检测 17
4.4.4 用一级质谱判断玉米油掺杂猪油的样品 19