厦门大学化学化工学院：《有机化学》课程教学资源（课件讲稿，双语版）第九章 核磁共振谱和质谱（9-12）An Introduction to Mass Spectrometry

ORGANIC CHEMISTRY Chapter g 58309 9.12 An introduction to mass Spectrometry 质谱 Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 9.12 An Introduction to Mass Spectrometry 质谱

ORGANIC CHEMISTRY Chapter g o a mass spectrometer produces a spectrum of masses based on the structure of a molecule o It is a spectrum or plot of the distribution of ion masses corresponding to the formula weight of a molecule. fragments derived from the molecule. or both 45 ,88 45ψ丸$101101111181112n f Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 A mass spectrometer produces a spectrum of masses based on the structure of a molecule. It is a spectrum or plot of the distribution of ion masses corresponding to the formula weight of a molecule, fragments derived from the molecule, or both

ORGANIC CHEMISTRY Chapter g 9. 13 The Mass Spectrometer Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 9.13 The Mass Spectrometer

ORGANIC CHEMISTRY Chapter g lightest aler io vapo 3 electron beam ionises charged particle beam l n sample heaviest 6 magnetic field separates particles electron based on mass charge ratio Source 4 particles accelerated into magnetic fjeld magnet Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9

ORGANIC CHEMISTRY Chapter g o In an electron impact mass spectrometer molecules in gaseous state under low pressure are bombarded with a beam of high energy electrons o One of the things this bombardment can do is dislodge one of the electrons of the molecule and produce a positively charged ion called the molecular ion aniston fragmentation 十 radical cati an adical cati on 2e molecule moleculat fragment Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 In an electron impact mass spectrometer molecules in gaseous state under low pressure are bombarded with a beam of high energy electrons. One of the things this bombardment can do is dislodge one of the electrons of the molecule and produce a positively charged ion called the molecular ion

ORGANIC CHEMISTRY Chapter g 9.14 The Mass Spectrum Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 9.14 The Mass Spectrum

ORGANIC CHEMISTRY Chapter g 103 CHOH BO 60 440 CrlE 20 0 HH 10 20 30 50 60 80 90 100110 mMT Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9

ORGANIC CHEMISTRY Chapter g 9. 15 Determination of molecular Formulas and molecular Weights Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 9.15 Determination of Molecular Formulas and Molecular Weights

ORGANIC CHEMISTRY Chapter g 9. 15a The Molecular lon and isotopic P eaks M·+1 Elements:C.H.N M:+2 Elements: O.S. Br. C1 CHCHaCHBr 1221: n 5 75 10o m/E Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 9.15A The Molecular Ion and Isotopic Peaks M + 1 Elements: C, H, N M + 2 Elements: O, S, Br, Cl

ORGANIC CHEMISTRY Chapter g 9. 15B High-Resolution Mass Spectrometry o High-Resolution Mass Spectrometry can measure m/z values to three or four decimal place and thus provide an extremely accurate method for determining molecular weights o These spectrometers also allow us to determine molecular formulas Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 9 9.15B High-Resolution Mass Spectrometry High-Resolution Mass Spectrometry can measure m/z values to three or four decimal place and thus provide an extremely accurate method for determining molecular weights. These spectrometers also allow us to determine molecular formulas