Schematic Diagram of Mass Spectrometer Vacuum System Inlet

Schematic Diagram of Mass Spectrometer Vacuum System Inlet System Reservoir DIP GC LC Ion Source EI CI FAB API ESI Mass Analyzer Magnetic Secter Quadrupole Ion trap TOF Detector Data Processor Print out

SAMPLE ANALYSIS by MASS SPECTROMETRY SAMPLE Single component Mixture Multiple component vaporizable Y Y N DIP -EI -CI DIP -FAB -ESI MALDI GC/MS -EI -CI vaporizable N Vaporizable + nonvaporizable LC collection LC/MS -ESI -APCI non- -FAB -ESI MALDI

Ionization modes NAME YEAR IONIZATION AGENT Electron Ionization (EI) 1920 Energetic Electrons Chemical Ionization (CI) 1965 Chemical Reagent Field Desorption (FD) 1969 High Electrode Potential Field Ionization (FI) 1970 High electrode Potential Plasma Desorption (PD) 1974 Secondary Ion Mass (SIMS) 1977 Secondary Ions Laser Desorption (LD) 1978 Laser Beam Thermal Desorption (TD) 1978 Heat Fast atom bombardment (FAB) 1981 Fast Atom Thermospray (TSP) 1985 Thermospray of Liquid Electrospray (ESI) 1989 Electro Potential Matrix-assisted Laser Desorption (MALDI) 1990 Laser Beam 252 Cf Fission Fragment

FAB Ionization

Continuous flow FAB(CF-FAB) • 기존 FAB의 문제를 많이 해결 • Matrix와 시료를 probe tip에 적용하는 대신, probe가 연속 적으로 sample solution을 일정 유속으로 target에 공급 • 소량의 organic matrix를 사용하게 되며, 더 낮은 chemical background로 signal-to-noise ratio를 증가시킬 수 있도 록 함. • CF-FAB의 가장 큰 장점은 HPLC 혹은 capillary electrophoresis의 연결에 유용

Most Organic Compounds are not Suitable

MECHANISM OF ESI • 시료가 SS Nedle을 통해 ES chamber에 들어옴 • Capillary tip으로부터 liquid가 electrostatic dispersion 되어서 droplet이 spray 됨 • bath gas(nitrogen)에 의해 declustering 되면서 solvent 분자를 소실하여 각각의 ion형성

Electrospray ion의 형성 + + Evaporation + + +++ +` + ++ + ++ ++

ESI source

SCHEMATIC OF ESI ION SOURCE

ESI spectra를 이용한 MW 계산 • • ESI 이온화시 잔류용매에 있는 과량의 양성자에 의해 분석물질은 다가 이온으로 변할 수 있음 Assume a molecule of mw = 900 ESI spectrum yields ions that appear to carry 1, 2 & 3 charges M + H+ MH+ 901 M + 2 H+ (MH 2)+2 451 M + 3 H+ (MH 3)+3 301 mw = [(m/z)* charge state] – charge state mw 1 = (901*1) – 1 = 900 mw 2 = (451*2) – 2 = 900 mw 3 = (301*3) – 3 = 900

ESI의 단점 • 모든 유기물화합물에 적용하기 어렵다. • -------> ionic, polar • spray의 형성이 buffer, salt 농도에 민감하게 영향을 받음 • Spectra can be influenced by solution and gas-phase chemistry occurring in the ES source

ESI 분석용 용매 Suitable Water Methanol Ethanol n-Propyl alcohol Isopropyl alcohol t-Butyl alcohol Acetonitrile Acetone Pyridine Tetrahydrofuran Aniline Nitromethane Acetic acid Chloroform Hexamethylphosphoretriamide N-Methylformamide Dimethyl sulfoxide Dichloromethane 1, 2 -Dichloroethane Tetrachloroethane Not suitable Benzene Toluene Ligroin Carbon tetrachloride Carbon disulfide Styrene Formamide Hexane Cyclohexane

APCI Mechanisms Vaporation ---> Solvent ionized ----> Charge transfer to analyte

APCI Source

LC/MS interface

ESI, APCI, CI의 mass spectro

Mass Analyzers의 종류 • Magnetic Sector Analyzer ; Single Focusing, Double Focusing • Quadrupole Mass Analyzer • Time of Flight Mass Analyzer

HRMS Analyser

Single-focusing magnetic-sector MS

Double focusing type

High resolution • Resolution (Rs = m/Δm) Low Rs 100 < Rs <1000 ) Medium Rs 2000 < Rs <10000 High Rs 10000 < Rs Δm = 1 ( unit Rs 0. 01 < Δm < 1 Δm < 0. 01 40㎜ H 50% 10㎜ h M 2 M 1 h / H ⅹ 100 = 10% Rs = M / Δm = M 1 / (M 2 -M 1) 300 301 (m/z) Rs = M / Δm = 300/(1ⅹ(10/40)) = 1200