Varian GC-MS 基本原理

一、质谱法概述...............................................................................................................................1 二、质谱仪......................................................................................................................................2 1．质谱仪的简介.............................................................................................................................2 2．仪器构造....................................................................................................................................2 2.1 进样系统....................................................................................................................................2 （1）色谱进样................................................................................................................................2 （2）其他进样系统.........................................................................................................................2 2.2 离子源........................................................................................................................................3 （1）电子轰击离子源（EI）.........................................................................................................3 （2）化学电离源（CI）.................................................................................................................4 2.3 质量分析器...............................................................................................................................7 （1）四极杆分析器（quadrupole mass filter） .............................................................................7 （2）离子阱(ion trap)......................................................................................................................8 2.4 真空系统...................................................................................................................................9 2.5 主要质谱仪分类.........................................................................................................................9 3．基本参数..................................................................................................................................11 4．离子的断裂规律.......................................................................................................................12 4.1 质谱图与质谱表.......................................................................................................................12 4.2 主要离子峰的类型...................................................................................................................13 （1）分子离子峰...........................................................................................................................13 （2）准分子离子峰.......................................................................................................................14 （3）碎片离子峰...........................................................................................................................14 （4）重排离子峰...........................................................................................................................14 （5）亚稳离子峰...........................................................................................................................14 （6）同位素离子峰.......................................................................................................................15 （7）多电荷离子...........................................................................................................................15 4.3 分子离子的确认......................................................................................................................15 4.4 碎片离子和假分子离子..........................................................................................................17 4.5 应用实例.................................................................................................................................17 4.6 主要有机物的断裂规律（产生分子离子、碎片离子等的方式） .......................................18 三、气质联用仪...........