What is Tandem Mass Spectrometry? (MS/MS) Activate MS1 MS2 Gas Surface Photons Electrons
http://www.iupac.org/goldbook/t06250.pdf
Major difference between MS and MS/MS: two analysis steps Ionization Analysis MS: Collide with target to produce fragments MS/MS: Ionization Selection Activation Analysis
Tandem Mass Spectrometry Widely Used Tool Many Instrument Types Many Applications
Why/when is MS/MS used? Why hook two mass analyzers together?
MS/MS is chemically selective -provides structural information on individual components of mixtures www.asms.org
Newborn Screening by MS/MS Currently, Neo Gen Screening monitors more than 60 chemical and chemical relationships in a single test. Tandem Mass Spectrometry measures these indicators or markers in a typical 2- minute run. http://www.neogenscreening.com/index.cfm
Proteomics Enzyme HPLC MS Proteins Peptide m/z Protein 1 Protein 2 SIYDGK FWSEFR TLLHPYK Peptide Sequence MS/MS
MS/MS often produces different spectra for isomers isomer distinction CH 3 CH 2 OH +.. CH 2 CH 2 OH 2 + Wysocki, Kenttamaa JACS 1990, 112, 5110-5116
isomer distinction not! EIMS http://www.varianinc.com/image/vimage/docs/csb/gcmsnote/gcms44.pdf
isomer distinction MS/MS http://www.varianinc.com/image/vimage/docs/csb/gcmsnote/gcms44.pdf
MS/MS or MS n provides fragmentation of cold ions -ions that do not gain enough energy to fragment in the ionization process http://www.currentseparations.com/issues/16-3/cs16-3c.pdf
Why MS/MS? mixture analysis, select each ion isomer distinction cold ionization methods provide limited energy to ion, no fragments
Reasons to understand MS/MS No ideal MS/MS exists Knowledge of differences and reasons for differences allows for Choice of proper instrument Proper interpretation of results Knowledge of limitations can lead to improved instruments or new approaches to solve problems
How is MS/MS accomplished? MS1 Activate MS2 Gas Surface Photons (UV or IR) Electrons
The activation step in MS/MS is actually two steps: Activation Unimolecular dissociation
Simulation of Two-Step Process http://monte.chem.ttu.edu/index.html/animations/html/ani-digli-5.html Hase Lab, Texas Tech
Two-step Process: activation + unimolecular dissociation Internal energy distribution Molecule: Different reaction pathways Energy dependent rate constants: k(e)=ν ([E-E 0 ]/E) s-1 (overly simplified) Instrument Configuration: Time for reaction
How is MS/MS accomplished? Activate MS1 MS2 Tandem-in-space (distinct analyzers) Tandem-in-time (trapping instrument)
Tandem in Space Triple quadrupole Collisions with gas
Tandem in Space Triple quadrupole Collisions with gas
Tandem in Space Orbitrap (Q/collision cell/orbitrap) Collide with gas Mass select Analyze m/z Ionize
Quadrupole ion trap Tandem in time
Tandem in Time MS/MS T1 T2 T3 Collisions with gas msec dissociation
MSn
Current MS/MS instruments Tandem in Time (Trapping) QIT, LIT Tandem in Space QqQ QqLIT QqTOF TOF TOF Trap-Orbi, Q-Orbi, Q-ICR
Activation Methods Post Source Decay (PSD) - MALDI instruments Collision Induced Dissociation (CID) low energy (ev) high energy (kev) single collision multiple collisions Sustained Off-Resonance Irradiation (SORI) Resonance Excitation (RE) Infrared Multiphoton Dissociation (IRMPD) Electron Capture Dissociation (ECD) Electron Transfer Dissociation (ETD) Surface-Induced Dissociation (SID) Blackbody Infrared Radiative Dissociation (BIRD) 29
Electron Capture Dissociation [M + nh] n+ + e - [[ M + nh] (n-1)+ ]* fragments www.hitachi-hta.com 30
or or z ion c ion Cooper H J, Håkansson H, Marshall A G, Mass Spectrom. Rev., 2005, 24, 201-222 31
Comparison of ECD and SORI-CAD in FTICR c and z ion series c 3 + c 2 + c 4 + c 5 + c 6 + c 8 + c 9 + c 10 + no loss of water, phosphate groups or phosphoric acid y 2 + y 4 + b 7 + b 9 + b 10 + Stensballe, et al. Rapid Commun. Mass Spectrom., 2000, 14, 1793-1800 32
Cleave Peptide Bonds without Cleaving Sugar 33 Cooper H J, Håkansson H, Marshall A G, Mass Spectrom. Rev., 2005, 24, 201-222
ECD for Peptide Bonds, IRMPD for Sugar ECD IRMPD Cooper H J, Håkansson H, Marshall A G, Mass Spectrom. Rev., 2005, 24, 201-222 34
Why are there so many MS/MS instrument types? Many ionization sources Many mass analyzers Sort by mass/charge with different resolution, different mass accuracy, different time frames for dissociation Many applications
Figures taken from several web sites and publications including: as noted on figures plus www.jeol.com/ms/ms.html#essays (not active) http://www.chemistry.vt.edu/chem-ed/ac-meths.html (not active) Edmond de Hoffmann JMS, 1996, 31, 129-137 Tandem Mass Spectrometry: A Primer