第四章质量分析器及亚稳离子 ●●●●● ●●●● ●●0 ●●● ●●●● 41磁质谱 Magnetic Sector 42四极杆 Quadrupole 43离子阱 lon Trap 44飞行时间 Time-of-Flight(ToF) 45回旋共振 Fourier transform ion cyclotron resonance(FT-ICR) 4.6亚稳离子 metastable ion
第四章 质量分析器及亚稳离子 4.1 磁质谱 Magnetic Sector 4.2 四极杆 Quadrupole 4.3 离子阱 Ion Trap 4.4 飞行时间 Time-of-Flight (ToF) 4.5 回旋共振 Fourier transform ion cyclotron resonance (FT- ICR) 4.6 亚稳离子 metastable ion
●●●●● ●●●● 质量分析器 ●●0 ●●● ●●●● ◆质量分析器是质谱计的核心 ◆不同类型的质量分析器构成不同类型的质谱计 ◆不同类型的质谱计其功能,应用范围,原理, 实验方法均有所不同
◆质量分析器是质谱计的核心 ◆不同类型的质量分析器构成不同类型的质谱计 ◆不同类型的质谱计其功能，应用范围，原理， 实验方法均有所不同。 质量分析器
Mass Analysers ●●●●● ●●●● ●●0 Factors to Consider ●●● ●●●● Upper mass limit Highest m/z that can be detected May be offset by multiple charges ● Resolution o Distinct signals for similar m/z ratios ● Transmission: Ratio of ions reaching detector: ions produced ●CoSt
Mass Analysers: Factors to Consider ⚫ Upper mass limit: ⚫ Highest m/z that can be detected ⚫ May be offset by multiple charges ⚫ Resolution: ⚫ Distinct signals for similar m/z ratios ⚫ Transmission: ⚫ Ratio of ions reaching detector: ions produced ⚫ Cost
Mass Analysers ●●●●● ●●●● ●●0 Resolution(Resolving Power)::08 Ability to resolve two signals of similar m/z o Resolved if valley is <10% o Higher resolution: greater accuracy e.g. R=20,000: Separate m/z 100.0000 from m/z100.0050 ● Accuracy needed High Resolution Mass Spectrometry(HRMS) o Determine elemental com position of an ion o Vital to confirm structure
Mass Analysers: Resolution (Resolving Power) ⚫ Ability to resolve two signals of similar m/z ⚫ Resolved if valley is <10% ⚫ Higher resolution: greater accuracy ⚫ e.g. R=20,000: Separate m/z 100.0000 from m/z 100.0050 ⚫ Accuracy needed: ⚫ High Resolution Mass Spectrometry (HRMS) ⚫ Determine elemental composition of an ion ⚫ Vital to confirm structure
Mass Analysers. ●●●●● ●●●● ●●0 High Resolution Mass spectromete ●●● ●●●● o HRMS or accurate mass determination o Determines elemental composition Consider two ions: 1)[C24H19N] nominal mass: 321 2)[C21H23NS nominal mass: 321 Using C=12, H=1, N14 and s=32 o Can we differentiate these two ions o Need to calculate the monoisotopic accurate mass
Mass Analysers: High Resolution Mass Spectrometry ⚫ HRMS or accurate mass determination ⚫ Determines elemental composition ⚫ Consider two ions: 1) [C24H19N]+ : nominal mass: 321 2) [C21H23NS]+ : nominal mass: 321 ⚫ Using C=12, H=1, N=14 and S=32 ⚫ Can we differentiate these two ions? ⚫ Need to calculate the monoisotopic accurate mass