SCS Mass Spectrometry Laboratory

Transcription

1 SCS Mass Spectrometry Laboratory Contact Information 31 Noyes Laboratory (8:00-5:00 M-F) Furong Sun Staff Furong Sun Lab Director Kevin Tucker Spectrometrist Haijun Yao Spectrometrist

2 Instrumentation and ionization techniques Submitted Samples Waters 70-VSE Double focusing Sector (3) (EI/CI, FAB) Water GCT Premier (EI, CI, FD, FI, LIFDI and GCMS) Waters Q-TOF Ultima (HR ESI, LCMS) Waters Synapt Q-TOF (HR ESI, LCMS) Self-Service or Submitted Samples Waters Quattro Ultima Triple Quadrupole (LCMS, MRM) Waters ZMD Single Quadrupole (LR ESI) AB Sciex Voyager DE-STR TOF (2) (MALDI) Bruker Daltonics UltrafleXtreme TOF/TOF (MALDI, TLC, imaging)

3 We can offer following services Low and High resolution ESI, FD/FI and EI/CI LR APCI, FD/FI, MALDI and LIFDI TLC MALDI MALDI imaging GC/MS LC/MS and LCMS/MS (MRM, DDA)

4 SCS Mass Spectrometry Laboratory 70-VSE Waters GCT These instruments are used for EI/CI, FD/FI, FAB and GC/MS.

5 SCS Mass Spectrometry Laboratory Quattro Ultima ESI/APCI Q-Tof - HR ESI, LCMS ZMD - LR ESI Synapt HR ESI, APGC These instruments are used for LR and HR ESI and LCMS.

6 SCS Mass Spectrometry Laboratory Voyager - MALDI Bruker Daltonics UltrafleXtreme MALDI TOF-TOF

7 Mass Spectrometry for small molecules Molecular Weight From molecular ion M + or (M+H) + [also (M+Na) + or (M+K) + ] Structure From fragments Hard ionization MS/MS Elemental Composition From exact mass

8 Mass Spectrometry for biomolecules Molecular weight determination, structure information For example - Protein, peptides, DNA/RNA, Carbohydrates, Oligonucleotides, Oligosaccharide, Lipids, Natural products, Dendrimers, Porphyrins, Metalloporphyrins Identification, sequence and modifications For example - Protein, peptides, DNA/RNA, Carbohydrates, Oligonucleotides, Oligosaccharide, Lipids, Natural products

9 Parts of a Mass Spectrometer Inlet Source Analyzer Detector Probe Leak Valve Syringe Plate GC LC EI CI FI FD MALDI ESI APCI Sector Quadrupole TOF Hybrid Electron Multiplier Photomultiplier Array Detector MCP

10 Electronic Impact Chemical Ionization

11 Electrospray ionization (ESI): How it works Sample (in solution) passed through needle biased at several kv Charged droplets pass through capillary where solvent evaporates and molecules begin to inherit the droplets charge Droplets shrink until their surface tension can no longer support the charge density Rayleigh limit Coulombic explosion occurs and the droplet bursts into smaller droplets that repel each other Process repeats until all of the solvent in gone and analytes are multiply charged. A very big deal because it couples flowing, liquid samples to mass spec!

12 Features of Electrospray MS Soft ionization ions are produced in solution It can be used for small and large molecules Multiple charged ions are usually produced for large molecules Suitable for using as an interface with HPLC Fast data acquisition High sensitivity, superior mass resolution and accuracy Sample must be soluble and stable in solution, polar relative clean

13 Matrix-assisted laser desorptionionization (MALDI) Demonstrated almost simultaneously in 1988 by German and Japanese research groups Hillenkamp & Karas (Germany) and Tanaka (Japan) Tanaka won the 2002 NP Sample is dispersed in matrix (usually a crystalline solid) and exposed to laser beam Matrix material absorbs radiation and explodes producing desorbed and ionized analyte molecules. Can analyze very large molecules without fragmenting; SOFT ionization Fig

14 Features of MALDI-TOF MS Soft ionization - analyze intact biomolecules and synthetic polymers Broad mass range - analyze a wide variety of biomolecules Simple mixtures are okay Relatively tolerant of buffers and salts Fast data acquisition Easy to use and maintain, no water or gas hook ups required High sensitivity, superior mass resolution and accuracy

15 Ionization Techniques Short name Full name How it works EI Electron Ionization Impact of 70 ev electrons CI Chemical Ionization Transfer of H + from CH 5 + FI Field Ionization High Field (12kV) FAB Fast Atom Bombardment Beam of Xenon atoms FD Field Desorption High Field (12kV) MALDI Matrix-Assisted Laser Desorption Ionization Laser hits sample in UV-absorbing matrix ESI Electrospray Ionization Spray and desolvation of preformed ions

16 Ionization Technique Summary Ionization Volatile Thermal Size of molecules Amount Examples EI Yes Stable Small 1-2 mg Organics CI Yes Stable Small 1-2 mg Organics FI Yes Stable Small 1-2 mg Organics FD No Labile Medium 1-2 mg Non-polar organics, organometallics, porphyrins, PAHs MALDI No Labile Large 250fmol- 500pmol Peptides, proteins, DNA/RNA, polymers, dendrimers, fullerenes ESI No Labile Large 1-300pmol/mL Polar/ionic organics, peptides, proteins, biomolecules, organometallics, polymers

17 Flowchart of Mass Spectrometry Techniques

18 Resolution Leu-enkephalin Monoisotopic Mass = Average Mass = R= R= R=100

19 HR Exact Mass Measurement OH OH O OCH 3 OH HO HO C 21 H 22 O 4 Nominal Mass: 338 Exact Mass: Found Mass: (Error = 0.1 ppm) C 22 H 26 O 3 Nominal Mass: 338 Exact Mass: Found Mass: (Error = 1.0 ppm)

20 Relative Abundance Angiotensin, MW = m/z

21 Zoom Scan Angiotensin I (3 pmol/ml, 3 ml/min) ( ) (648.85) m/z m/z (432.90) (324.93) m/z m/z

22 Zoom Scan of a Protein Theory Data m/z m/z Interleukin 8, MW Theo. = Da, [M+4H] 4+ Ion

23 Multiply Charged Ions The mass detector operates on the basis of mass-to-charge ratio (m/z) Mass Assignments are normally made assuming a single charge per ion (i.e. m/z = m 1): Single charge- apparent mass = ((M + H) / 1) Double charge - apparent mass = ((M + 2H) / 2) Triple charge - apparent mass = ((M + 3H) / 3) 3 n charges - apparent mass = ((M + nh) / n) n

24 Chromatogram LCMS Mass Spectra

25 LC Tandem Mass Spectrometry (LCMSMS) Chromatogram Mass Spectra

26 LCMS Data Dependent Analysis (DDA) Chromatogram NAS_01 Qtof_27783_dda 100 0% 0% 0% 0% 21-Jan :30: :1,B 4: TOF MSMS ES+ BPI 2.35e Qtof_27783_dda 3: TOF MSMS ES BPI 2.03e Qtof_27783_dda 2: TOF MSMS ES BPI e Qtof_27783_dda 1: TOF MS ES BPI e Time MS and MS2 NAS_01 Qtof_27783_dda 203 (53.626) 100 0% 0% 0% QTOF 4: TOF MSMS ES+ 54 Qtof_27783_dda 711 (53.366) 1: TOF MS ES e m/z % Qtof_27783_dda 212 (53.786) : TOF MSMS ES+ 454 Qtof_27783_dda 310 (53.441) 2: TOF MSMS ES

27 Peptide sequencing

28 Proteomics: Protein and peptide sequencing using MS/MS The bottom-up approach to analysis: analyze the proteolytic pieces with MS/MS Problem: Often only partial peptide sequence coverage is achieved From Introduction to Proteomics: Tools for the New Biology, by Daniel C. Liebler, 2002, Humana Press