Download - UCSF Mass Spectrometry Facility：下载-加州大学旧金山分校的质谱装置.ppt

Course Outline Course Outline – cont. What is Mass Spectrometry? What do we use Mass Spectrometry for in this course? Outline: Lecture 1 Mass Measurement Mass definitions Isotopes Characteristics of a mass spectrum Instrumentation Ion sources Fragmentation methods Mass analyzers Ion detection methods Isotopic Abundances of Common Elements Isotope Pattern Changes with Mass Peptide Mass Measurement Charge State Determination Electrospray Mass Spectrum of Bovine Ubiquitin Ionization Methods for Biomolecule Analysis Electron Multiplier Image Current Detection in Orbitrap Linear Ion Trap - Orbitrap - ETD Mass Spectrometry Online Resources MALDI Very long sample lifetime; repeated measurements possible Good for mixtures Matrix peaks can interfere at MW 600 Salt tolerant Low maintenance Generate ions with few charges Electrospray Online LC/MS possible Poor for mixtures without LC Quantitation possible Good for MW 600 Generate highly charged ions Mass analyzersTOFQuadruploeIon TrapFTICROrbitrap Ion Optics Einzel lens modeled with SIMION ion optics simulation program (computing electric and magnetic fields and ion trajectories) / A device for manipulating ion beams. A mass spectrometer consists of many ion optical components + + + + Source Drift region (flight tube) detector V Ions formed in pulses. Measures time for ions to reach the detector. Time-of-Flight (TOF) Mass Analyzer or Linear and Reflector TOF Analyzers Reflector compensates for initial variation in kinetic energy, improving resolving power and mass accuracy. Uses a combination of RF and DC voltages to operate as a mass filter. Mass analyzer. Mass selection device Ion transport device (RF-only collision cell). Quadrupole Mass Analyzer/Filter + U + V cos wt -U - V cos wt Randall E. Pedder Extrel Application Note Mass scan and stability diagram Quadrupole Ion Trap Uses a combination of DC and RF fields to trap ions Ions are sequentially ejected by scanning the RF voltage Linear Trap Essentially a q