核磁,质谱课件 仪器分析—质谱.pptVIP

质谱发展史 特点 质谱分析原理 质谱仪器构造 质谱定性分析及图谱解析 质谱定量分析 要求理解质谱法原理及质谱仪主要部件功能；了解质谱定性分析及图谱解析、定量分析方法。 Mass Spectrometry Fundamentals What and How -Measure mass (m) to charge (z) ratio (m/z) of ions a mass of 200 Da with 2 charges gives the same m/z ratio as a mass of 100 Da with 1 charge and cannot be distinguished. -Formation of ions in the gas phase (many ways) positive ion: by adding a proton: (M+H) + or by removing an electron: (M ) + negative ion: by removing a proton: (M-H) - or by adding an electron: (M) - -Charged ions can be manipulated and analyzed by electric and/or magnetic fields (mass analyzers), detected by detectors to generate mass spectra. Mass Spectrometry FundamentalsWhat are mass measurements good for ? To identify, verify, and quantitate metabolites, proteins, oligonucleotides, drug candidates, peptides, synthetic organic chemicals, polymers! Biomolecule characterization Proteins, peptides, oligonucleotides, sugars, polymers! Pharmaceutical and medical Bioavailability, drug metabolism, pharmacokinetics characterization of potential drugs, drug degradation analysis, screening of drug candidates, identifying drug targets, disease marker identification, diagnostic ! Environmental analysis Pesticides on foods, soil and groundwater contamination Forensic analysis/clinical ! Mass Spectrometry Molecular weight can be obtained from a very small sample. It does not involve the absorption or emission of light. A beam of high-energy electrons breaks the molecule apart. The masses of the fragments and their relative abundance reveal information about the structure of the molecule. Mass Spectrometry HOW DO WE ACHIEVE THIS? Mass Spectrometry Fundamentals Key topics: Mass spectrometer Ionization, Mass analyzers, Mass spectrometers Mass spectrum Isotope and mass, Isotope abundance Quality parameters of mass spectrometer Resolution, Mass accuracy, Sensitivity Charge state of protein and peptides MALDI-TOF MS, ES