SLDIMALDI的基本原理 MALD|是指用小分子有机物作为基质,样品与基质体 积摩尔比为1:(100~5000,均匀混合后,在真空下干 燥或自然干燥后送入离子源。混合物在真空下受激光辐 照,基质吸收激光能量,并转变成基质的电子激发能,瞬间 使固态基质转变成气态,并被电离成基质离子。而不带电 的中性样品与基质离子、质子及金属阳离子之间的碰撞 过程中,发生样品的离子化,从而产生质子化分子、阳离 子化分子或多电荷离子或多聚体离子。离子化后的分子 被电场加速进入飞行时间质量分析器而被检测 基质在 MALDI- TOF MS的方法中的作用主要是从 激光脉冲中吸收能量并使被测分子分离成单分子状态。 0/27/2005 Chaoqun Wu, Fudan University
10/27/2005 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 26 SLD/MALDI 的基本原理 MALDI 是指用小分子有机物作为基质,样品与基质体 积摩尔比为1∶(100～50000) ,均匀混合后,在真空下干 燥或自然干燥后送入离子源。混合物在真空下受激光辐 照,基质吸收激光能量,并转变成基质的电子激发能,瞬间 使固态基质转变成气态,并被电离成基质离子。而不带电 的中性样品与基质离子、质子及金属阳离子之间的碰撞 过程中,发生样品的离子化,从而产生质子化分子、阳离 子化分子或多电荷离子或多聚体离子。离子化后的分子 被电场加速进入飞行时间质量分析器而被检测。 基质在MALDI－TOF MS 的方法中的作用主要是从 激光脉冲中吸收能量并使被测分子分离成单分子状态
3. Applications of MS: Structural information can be generated Particularly using tandem mass spectrometers Fragment sample analyse products Useful for peptide oligonucleotide sequencing Plus identification of individual compounds in complex mIxtures 0/27/2005 Chaoqun Wu, Fudan University
10/27/2005 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 27 3. Applications of MS: • Structural information can be generated • Particularly using tandem mass spectrometers • Fragment sample & analyse products • Useful for peptide & oligonucleotide sequencing • Plus identification of individual compounds in complex mixtures
How does a Mass Spectrometry work 3 fundamental parts: the ionisation source, the analyser, the detector Samples easier to manipulate if ionised Separation in analyser according to mass-to-charge ratios(m/z,质荷比) Detection of separated ions and their relative abundance Signals sent to data system and formatted in a m/z spectrum 0/27/2005 Chaoqun Wu, Fudan University
10/27/2005 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 28 How does a Mass Spectrometry work: • 3 fundamental parts: the ionisation source, the analyser, the detector • Samples easier to manipulate if ionised • Separation in analyser according to mass-to-charge ratios (m/z, 质荷比 ) • Detection of separated ions and their relative abundance • Signals sent to data system and formatted in a m/z spectrum
Typical MS experiment Sample M+/Fragmentation Molecule(M)lonization (1)Sample SDs- Excised (2)Trypsin Peptide fractionation PAGE proteins digestion mixture Mass analyzer Q ←吕聚 Mass spectrum (3) Peptide chromatography On-line search H)MS 1)MS/MS EAAAosTK Data Analysis 息 co 51627p-4) 1o0 OAAEL L 0/27/2005 Chaoqun Wu, Fudan University
10/27/2005 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 29 Typical MS experiment Mass Spectrum Mass Analyzer Ionization Sample M+/Fragmentation Molecule (M) Data Analysis On-line Search
The components of a mass Inlet system Spectrometer lon lon Source Analyzer Detector Mass spectrum Computer 0/27/2005 Chaoqun Wu, Fudan University
10/27/2005 Chaoqun Wu, Fudan University Chaoqun Wu, Fudan University 30 The Components of a Mass Inlet system Spectrometer Ion Source Analyzer Ion Detector Mass Spectrum m/z Computer