MS 质谱原理介绍及其应用

第二讲. 质谱及其应用 HPLC-ESIMS (液质联用仪) HP GC-MS (气质联用仪) FT-ICRMS With ESI And MALDI 傅立叶离子回旋共振高分辨质谱仪 第一章 质谱学概念及发展简介 §1.1: 什么叫质谱 １：Mass Spectrometry is used to determine the mass and structure of molecules based on the mass-to-charge (m/z) ratio of the molecular ion and its fragments. 2: 质谱是带电原子、分子或分子碎片按荷质比 （或质量）的大小顺序排列的图谱  不同于光谱,没有光与波长的概念 但也有几何粒子光学概念  研究对象： 荷电粒子--分子离子、碎片离子等 传统形成模式： 化合物在高真空受热气化，气态分 子受一定能量的电子轰击后，失去一个价电子，成 为带正电荷的分子离子，并进一步碎裂为碎片离子。  行为特征：荷电粒子在电场与磁场的综合（共同）作 用下，按荷质比排列。  表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 现形式： 44 1    amu44 z m 22 2    amu44 z m 例: CH3-CH2-CH3 + e -  CH3-CH2-CH3 + + 2e- CH3-CH2-CH3 + e -  CH3-CH2-CH3 ++ + 3e- m/z = mass-to-charge ratio（荷质比） = )(charge daltons) or (amu mass  Spectra are plotted in terms of relative molecular ion abundance vs. m/z.  Molecular ion peak －the peak arising from the entire molecule with 1 positive charge.  Base peak －the peak with the highest abundance (i.e. the most stable molecular fragment).  Abundance is commonly expressed as a percentage of the base peak, where the base peak = 100% abundance 80604020 72 55 45 27 100 50 §1.２ 质谱学的特点 １）不能确定能级之间的跃迁－与化合物的能态无关 本质上将并非一种波谱学方法，但所得图谱有所相似 ２）破坏性：无法回收，但所需样品量少，（10-11g ) 灵敏度极高，分析速度快，所得质量数十分准确，有 利于确定化合物的组成． ３）可进行混合物分析。（自身ＭＳn, 串联质谱；可参与 联用）． ４）可进行气相离子化学的研究（ICR, Ion Trap等) (1) The foundations of mass spectrometry lie in the work of Thomson and Aston at the Cavendish Laboratories, Cambridge University. From 1897, the work carried out by Thomson and his co-workers receive 7 Nobel prizes in Physics and Chemistry. Thomson's original work on the existence and properties of canal rays (positive ions) was taken up by Aston and by the end of the First World War he had demonstrated the existence of several isotopes of non-radioactive elements. Aston used electrostatic and magnetic fields to separated isotope ions be their masses and focus them onto a photographic plate. Over the next few years a number of key names took up the early development of mass spectrometry, including Dempster, Herzog, Bainbridge and Nier. By the end of the 1930's mass spectrometry had become an established technique for the separation of atomic ions by mass. §1.３ 发展简介 (2) In the 1940's the applications of mass spectrometry began to spread away from the previous mostly academic work into more practical fields like nuclear isotope enrichment and the analysis of the components of petroleum. The World's first commercial instrument became available in 1948 (The MS-2 - marketed by Vickers in Manchester, England). The MS-2 made use of EI ionisation and had an extremely limited mass range of about 300 Da with a very limited resolution. (3) In the early 1950's, the fragmentation of small organic molecules was beginning to be understood, but the mass spectrometer was still extremely limited by mass and resolution. At this time, time-of-flight (TOF) analysis (Wiley and Maclaren) and quadruple analysis (Paul) were conceived. These early instruments were the forerunners of today's 'cheap' benchtop instruments seen in just about every chemical, biochemical lab in the world. . (4) The next major development was that of gas chromatography and its coupling to mass spectrometry. This allowed, for the first time, the analysis of mixtures of analytes without laborious separation by hand. The development of GC-MS was the trigger for the development of modern mass spectrometry. In 1956, the first biologically important molecules were successfully analysed. New ionisation techniques developed over the last 25 years (fast particle desorption, electrospray ionisation and matrix-assisted laser desorption/ionsation) have opened up the world of biological chemistry to mass spectrometry. Just about every compound class can be analysed by some sort of mass spectrometry for a description of the most important techniques) and the present mass records extend well into the megadalton range. The Five Mass Spectrometry Nobel Prize Pioneers Joseph John Thomson 1906 Nobel Prize for Physics United Kingdom University of Cambridge Cambridge, United Kingdom b. 1856 d. 1940 "in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases" Francis William Aston 1922 Nobel Prize for Chemistry United Kingdom University of Cambridge Cambridge, United Kingdom b 1877 d 1945 "for his discovery, by means of his mass spectrograph, of isotopes, in a large number of non-radioactive elements, and for his enunciation of the whole-number rule" Wolfgang Paul 1989 Nobel Prize for Physics University of Bonn Bonn, Federal Republic of Germany b. 1913 d. 1993 "for the development of the ion trap technique" John Bennet Fenn 2002 Nobel Prize for Chemistry Virginia Commonwealth University Richmond, VA, USA b. 1917 "for the development of soft desorption ionisation methods (ESI) for mass spectrometric analyses of biological macromolecules" Koichi Tanaka 2002 Nobel Prize for Chemistry Shimadzu Corp. Kyoto, Japan b. 1959 "for the development of soft desorption ionisation methods (MALDI) for mass spectrometric analyses of biological macromolecules 按功能与应用领域的拓展而发展 无机质谱  有机质谱  生物质谱    同位素测定 有机化合物 生命物质  我国质谱研究情况 张青莲院士 梁晓天院士 陈耀祖院士 整体研究力量薄弱，受制于仪器购置等  按离子源的发展 第二章 质谱仪器构成及主要参数 §２.１ 质谱仪器构成 (1) 进样系统（The inlet system or Introduction System） 可分为： 储罐进样 探头进样 色谱进样 (2) 离子源（ion source）： 核心部位 (3) 分析系统（ mass analyzer or analysis system) (4) 检测系统（detection system or detector) (5) 记录系统 ( recorder system)  所有部件均需处于高真空系统.  离子源与质量分析器最为重要 §２.２ 质谱的主要技术指标 １：主要技术参数 ２：一些技术指标的定义 Ａ：分辨率（分辨本领，质量分辨，Resolution) m mRp   2 21 mmm  m=m2-m1 Rp=7200 两种定义方法：１０％谷定义；半峰高宽 Ｒp提高，灵敏度下降（狭缝变小，通过的粒子数减少） Ｂ：质量范围 （ＭＡＳＳ ＲＡＮＧＥ） 指能够测量质谱的最大质量数 （加速电压最高档的 质量范围－某台仪器的分辨率为１００００，在加速电压 最高档的质量范围仅为３００． Ｃ：灵敏度 （Sensitivity） 在额定分辨率下，质谱仪能给出定性质谱的最小样 品量． Ｄ：质量精度 （Ａccurary 高分辨质谱－ＨＲＭＳ） 某一天然产物：Ｍcal =364.2509 Mexp = 364.2501 6 364 104.1 exp   MMcal 进行精确质量测定时，必须有两个先决条件 １）仪器具有足够的分辨本领 ２）被测峰具有足够的峰强度 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 m/z 1.0e+06 2.0e+06 3.0e+06 4.0e+06 5.0e+06 6.0e+06 7.0e+06 8.0e+06 9.0e+06 1.0e+07 1.1e+07 1.2e+07 1.3e+07 1.4e+07 1.5e+07 a.i. Cefpirome 计算值： .515 1166 C H N O S22 23 6 5 2 + 500 510 520 530 540 m/z 1.0e+06 2.0e+06 3.0e+06 4.0e+06 5.0e+06 6.0e+06 7.0e+06 8.0e+06 9.0e+06 1.0e+07 1.1e+07 1.2e+07 1.3e+07 1.4e+07 1.5e+07 a.i.