Standard Definitions of Terms Relating to Mass Spectrometry

1. 2. 121 142 3. 2005 11 2 3 IUPAC Draft Recommendation: Standard Definitions of Terms Relating to Mass Spectrometry 2 16) 4. 5. Da, u, ev, Pa, m/z IUPAC 6. (-) (/) LC-MS (liquid chromatograph mass spectrometer) LC/MS (liquid chromatography mass spectrometry) 7. daughter ion 115 8. 13

( ) abundance sensitivity m 1 m / m 1 m 1 accelerating voltage accelerator mass spectrometry (AMS) MeV acceptance accurate mass 1 mda (1 10 3 u) measured accurate mass exact mass additivity of mass spectra 14

adduct ion (cationized molecule) [M NH 4 ],[M Na],[M Cl] adiabatic ionization a-ion a C C N (fragment ion) a-cleavage a- a (homolytic cleavage) analog ion (CH 3 CO ) (CH 3 CS ) analyte (fast atom bombardment) (electrospray ionization) (matrix) anion radical (radical anion) 15

anionized molecule anion: (pseudo-molecular ion quasi-molecular ion) (molecular-related ion) appearance energy (AE) (electron ionization) (fragment ion) (appearance potential) appearance potential (AP) (appearance energy) array detector associative ion/molecule reaction associative ionization A M atmospheric pressure chemical ionization (APCI) (chemical ionization) 16

atmospheric pressure ionization (API) (atmospheric pressure chemical ionization), (electrospray ionization), (liquid ionization) atmospheric pressure matrix-assisted laser desorption/ionization (AP MALDI) (matrix-assisted laser desorption/ionization) atmospheric pressure photoionization (APPI) (photoionization) (atmospheric pressure chemical ionization) atmospheric pressure spray atomic mass unit (amu) (unified atomic mass unit) atomic weight (relative atomic mass) (IUPAC) (standard atomic weight) 17

(unified atomic mass unit) autodetachment autoionization (ionization energy) A M M M e average mass (monoisotopic mass) B/E linked scan B/E B/E B/E (linked scan at constant B/E) B[1 (E/E 0 )] 1/2 /E linked scan B[1 (E/E 0 )] 1/2 /E B[1 (E/E 0 )] 1/2 /E (linked scan at constant B[1 (E/E 0 )] 1/2 /E) B 2 /E linked scan B 2 /E B 2 /E B 2 /E (linked scan at constant B 2 /E) background mass spectrum 18

(residual mass spectrum) base peak (BP) base peak chromatogram (base peak) (hyphenated method) bath gas (bu#er gas) b-cleavage b- b (homolytic cleavage) b-ion b C N N (fragment ion) blackbody infrared radiative dissociation (BIRD) (ion trap) (infrared multiphoton dissociation) bu#er gas (ion trap) (collision quadrupole) (collision gas) 19

calculated exact mass p. 40, exact mass capillary electrophoresis mass spectrometry (CE/MS) capillary-skimmer collision-induced dissociation (electrospray ionization) (collision-induced dissociation) (nozzle-skimmer collision-induced dissociation) (skimmer collision-induced dissociation) (collision-induced dissociation) (skimmer) cation radical (radical cation) cationized molecule cation (pseudomolecular ion quasi-molecular ion) (molecular-related ion) center-of-mass collision energy (collisional excitation) 1 E lab M i (collision gas) 20

M n E cm E cm E lab [M n /(M n M i )] 5keV 1,000 u He 19.9 ev (center-of-mass kinetic energy) (laboratory collision energy) center-of-mass kinetic energy (center-of-mass collision energy) centroid acquisition m/z (continuum acquisition) channel electron multiplier (continuous dynode electron multiplier) channeltron (continuous dynode electron multiplier) charge exchange ionization (ion/molecule reaction) charge exchange reaction (charge transfer reaction) 21

charge inversion mass spectrum (charge inversion reaction) m/z charge inversion reaction (precursor ion) M M (collision gas) X M M M X M X 2 M X M X e charge mediated fragmentation (fragmentation) (charge remote fragmentation) charge number 1 q e z z q/e charge permutation reaction (charge number) charge remote fragmentation (CRF) (fragmentation) [M H], [M Na] (even-electron ion) (high-energy collision-induced dissocia- 22

tion) (remote site fragmentation) (charge mediated fragmentation) charge stripping reaction (CSR) z M z (collision gas) M (z r) (ionizing collision) M z X M (z r) re (X s se ) charge transfer reaction (charge exchange reaction) (charge number) (ion/neutral reaction) (charge permutation reaction) (electron capture reaction) (charge stripping reaction) chemical ionization (CI) (reagent gas) [R H] X (reactant ion) M M 23

[R H] M [M H] R C 2 H 5 M [M H] C 2 H 6 X M [M H] HX (negative ion chemical ionization) chemi-ionization (penning ionization) (associative ionization) (chemical ionization) chromatogram (chromatography) chromatograph (chromatography) chromatography c-ion c C N N C a N (fragment ion). cleavage (homolytic cleavage) (heterolytic cleavage) (frag- 24

mentation) (dissociation) cluster M A B M n,a n,a n B m (n, m 2) cluster ion (cluster). M n, M n, [M n H],[M n H] collision cell (collision-induced dissociation) (collision gas) collision chamber (collision cell) collision gas (collisional excitation) (ion/molecule reaction) collision quadrupole m/z (bu#er gas) (collision gas) (quadrupole) (hybrid mass spectrometer) q EBqQ RF (RF-only quadrupole) 25

(ion guide) collision reaction cell (charge exchange reaction) (ion/neutral reaction) (hexapole) (octapole) (inductively coupled plasma mass spectrometry) collisional activation (CA) (collisional excitation) collisional excitation (collision gas) (center-of-mass collision energy) collisionally activated dissociation (CAD) (collision-induced dissociation) collision-induced dissociation (CID) (fragmentation) (collisionally activated dissociation) (collisional excitation) complex ion (spark source mass spectrometry) 26

consecutive reaction monitoring (CRM) n 3 MS n MS n constant neutral loss scan 2 (mass analyzer) (tandem mass spectrometer) (metastable ion decay) (collision-induced dissociation) (constant neutral loss spectrum) constant neutral loss spectrum m/z (precursor ion) constant neutral mass gain scan 2 (mass analyzer) (tandem mass spectrometer) (collision gas) (ion/molecule reaction) (constant neutral mass gain spectrum) constant neutral mass gain spectrum (collision gas) (ion/molecule reaction) m/z (product ion) continuous dynode electron multiplier (secondary electron) 27

discrete dynode electron multiplier (channel electron multiplier) (channeltron) (secondary electron multiplier) continuous flow fast atom bombardment (CF-FAB) (analyte) (fast atom bombardment) continuum acquisition (profile acquisition) (centroid acquisition) conversion dynode corona discharge Coulomb explosion (1) M z n (2) (electrospray ionization) 28

(Rayleigh limit) curved field reflectron R 2 V 2 x 2 x V R (reflectron) cycloidal mass spectrometer (prolate trochoidal mass spectrometer) cyclotron motion q B v qv B dalton (Da) Da SI SI (unified atomic mass unit) 10 kda, 1 MDa, 10 mda Daly detector (photomultiplier) (conversion dynode) daughter ion (product ion) 29

daughter ion analysis (product ion analysis) daughter ion scan (product ion scan) daughter ion spectrum (product ion spectrum) deconvolution (electrospray ionization) (multiplycharged ion) 0 delayed extraction (DE) (desorption ionization) (time-of-flight mass spectrometer) (mass resolution) delayed extraction deprotonated molecule M H [M H] (fast atom bombardment) (electrospray ionization) 30

Derrick shift MIKE (collision-induced dissociation) (collision gas) (precursor ion) (product ion) MIKE MIKE (mass-analyzed ion kinetic energy spectrometry) desorption chemical ionization (DCI) (in-beam chemical ionization) (in-beam method) desorption electron ionization (DEI) (in-beam electron ionization) (in-beam method) desorption electrospray ionization (DESI) (electrospray ionization) desorption ionization (DI) (field desorption) (fast atom bombardment) (matrix-assisted laser desorption/ionization) desorption ionization on silicon (DIOS) (porous silicon) 31

(desorption ionization) (surface-assisted laser desorption/ionization) detection limit (sensitivity) diagnostic ion (precursor ion) (product ion) (electron ionization) (diagnostic ion) di#erential pumping di#usion pump 10 5 10 8 Torr 10 2 Torr dimeric ion [M 2 ] direct analysis of daughter ions (DADI) MIKE (mass-analyzed ion kinetic energy 32

spectrometry) direct chemical ionization (in-beam chemical ionization) (in-beam method) direct dissociation (molecular ion) direct exposure method (in-beam method) direct exposure probe (DEP) (direct insertion probe) (ionization chamber) (desorption electron ionization) (desorption chemical ionization) (direct inlet) direct infusion (electrospray ionization) direct inlet (electron ionization) (chemical ionization) (ionization chamber) 33

(reactant ion) direct insertion probe (DIP) (ionization chamber) (direct inlet) direct liquid introduction (DLI) (chemical ionization) (ionization chamber) direction focusing m/z (magnetic sector) discharge ionization 19 discrete dynode electron multiplier (secondary electron) (continuous dynode electron multiplier) (secondary electron multiplier) 34

dissociative ionization A BC A B C e (dissociative Penning ionization) (dissociative ionization) dissociative Penning ionization (dissociative ionization) distonic ion (diradical) (radical cation) (radial anion) CH 2 OH 2 (distonic ion) CH 3 OH double-focusing mass spectrometer (velocity focusing) (direction focusing) (electric sector: E) (magnetic sector: B) E B (forward geometry, EB geometry) B E (reverse geometry BE geometry) dynamic field mass spectrometer m/z dynamic pulse heating 2500 K 35

E 2 /V linked scan E 2 /V E 2 /V E 2 /V (linked scan at constant E 2 /V) einzel lens 3 electric sector (sector mass spectrometer) (time-of-flight mass spectrometer) (electrostatic energy analyzer) electrohydrodynamic ionization (EHI EHDI) ( 10 kv) (spray ionization) (cluster ion) (massive-cluster impact ionization) [M H] [M Na] 36

electron accelerating voltage (electron ionization) electron a$nity E EA M M M e M M electron capture chemical ionization (ECCI) (chemical ionization) electron capture dissociation (ECD) (multiply protonated molecule) (charge number) (odd-electron ion) [M nh] (n 1) electron capture ionization (ECI) M electron capture reaction (charge transfer reaction) 37

(multiply-charged ion) (autoionization) transferionization electron energy (electron ionization) (electron volt, ev) electron impact ionization (electron ionization) electron ionization (EI) 1 10 150 ev (electron impact ionization) electron volt (ev) 1 ev SI SI 1eV 1.602176487(40) 10 19 J 2 electrospray (ES) kv electrospray ionization (ESI) (electrospray) 38

kv Taylor cone (Rayleigh limit) electrostatic energy analyzer (ESA) (electric sector) emittance (1) (ion optics) (2) 3/2 (perviance) [A V 3/2 ] energy focusing even-electron ion [M H],[M H],CH 3,NH 4,OH 39

even-electron rule (odd-electron ion) (fragmentation) (even-electron ion) (odd-electron rule) exact mass (10 3 u) (monoisotopic mass) calculated exact mass Accurate mass excess energy (fragmentation) extracted ion chromatogram (EIC) 1 m/z (relative intensity) (hyphenated method) Faraday cup (secondary electron) 40

fast atom bombardment (FAB) kev Ar, Xe (matrix fast atom bombardment) (solid fast atom bombardment) (gas-phase fast atom bombardment) fast ion bombardment (FIB) kev (liquid secondary ionization) fast particle bombardment (FPB) kev kev (fast atom bombardment) (fast ion bombardment) field desorption (FD) (field desorption/ionization) field desorption/ionization (field desorption) field emitter (field desorption) (field ionization) 41

field ionization (FI) field ionization kinetics (FIK) (field ionization) field-free region (FFR) first stability region (transmission quadrupole mass spectrometer) (Paul ion trap) (Mathieu stability diagram) fission fragment ionization (plasma desorption/ionization) flash desorption (electron ionization) (chemical ionization) 42

focal plane detector (FPD) m/z (mass spectrograph) forward geometry (double-focusing mass spectrometer) forward library search (mass spectral library) (reverse library search) Fourier transform ion cyclotron resonance mass spectrometer (FT-ICRMS) m/z m/z (cyclotron motion) (ion cyclotron resonance mass spectrometer) 43

Fourier transform mass spectrometry (FTMS) m/z (Fourier transform ion cyclotron resonance mass spectrometry) fragment fragment ion 1 (product ion) (precursor ion) (daughter ion) fragment ion scan (product ion scan) fragment ion spectrum (product ion spectrum) fragment peak (fragment ion) fragmentation 44

fringe field (electric sector) (magnetic sector) full width at half maximum (FWHM) 1 (sector mass spectrometer) 10 2 (mass resolution) gas chromatograph-mass spectrometer (GC-MS) gas chromatography/mass spectrometry (GC/MS) gas-phase fast atom bombardment (fast atom bombardment) glow discharge ionization granddaughter ion (2nd generation product ion) gridless reflectron 45

(reflectron) hard ionization (fragmentation) (soft ionization) heavy ion induced desorption (HIID) MeV u (fast particle bombardment) Herzog shunt (field-free region) (electric sector) (magnetic sector) heterolysis (heterolytic cleavage) heterolytic cleavage (fragment) 2 2 high temperature mass spectrometer (Knudsen cell mass spectrometer) high-energy collision-induced dissociation 1keV (laboratory collision energy) (collision-induced dissociation) (low-energy collision-induced dissoci- 46

ation) 1 (single collision) high-field asymmetric waveform ion mobility spectrometry (FAIMS) FAIMS 50 (RF-DC ion mobility spectrometry) (ion mobility spectrometry) homolysis (homolytic cleavage) homolytic cleavage (fragment) 2 1 (odd-electron ion) 1 (fragmentation) (even-electron ion) homolytic cleavage hybrid mass spectrometer MS/MS (mass spectrometry/mass spectrometry) (massanalyzer) hydrogen/deuterium exchange (HDX) (collision gas) 47

hyphenated method ICF flange ICF (conflat flange) (International ConFlat flange) imaging mass spectrometry m/z in-beam chemical ionization (in-beam method) in-beam electron ionization (in-beam method) in-beam method (ionization chamber) (reactant ion) (electron ionization) (chemical ionization) (direct exposure method) (field desorption) (ion/molecule reaction) (in-beam chemical ionization) (inbeam electron ionization) 48

M [M H] (direct chemical ionization) (desorption chemical ionization) (desorption electron ionization) inductive cleavage 2 inductively coupled plasma (ICP) MHz MHz Ar 5,000 7,000 K inductively coupled plasma mass spectrometry (ICP-MS) (inductively coupled plasma) infrared multiphoton dissociation (IRMPD) CO 2 (low-energy collision-induced dissociation) (fragmentation) in-gel digestion 49

(peptide mass fingerprinting) in-source collision-induced dissociation (collisional excitation) (ion desolvation) in-source decay (ISD) (matrix-assisted laser desorption/ionization: MALDI) (postsource decay) MALDI (ionization chamber) (fragmentation) (prompt fragmentation) MALDI c (c-ion) z (z-ion) intensity m/z (relative intensity) internal standard m/z intramolecular proton bound protonated molecule (protonated 50

molecule) ion fragment ion accelerating voltage ion collector (Faraday cup) (secondary electron multiplier) ion cooling (ion trap) (sensitivity) (mass resolving power) MS/MS (mass spectrometry/mass spectrometry) ion cyclotron resonance mass spectrometer (ICRMS) (cyclotron motion) m/z m/z Q (cyclotron motion) (Fourier transform ion cyclotron resonance mass spectrometer) 51

ion desolvation ion energy loss spectrum (relative intensity) (ion kinetic energy spectrometry) MIKE (mass-analyzed ion kinetic energy spectrometry) ion gate (ion mobility spectrometry) (time-of-flight mass spectrometer) (mass gate) ion guide 4 180 (collision quadrupole) ion kinetic energy spectrometry (IKES) IKE (double-focusing mass spectrometer) (metastable ion) (electric sector) (scan) (ion energy loss spectrum) MIKE (mass-analyzed ion kinetic energy spectrometry) 52

ion mirror (time-of-flight mass spectrometer) (energy focusing) (reflectron) ion mobility spectrometry (IMS) (bu#er gas) (charge number) (v) (E) (v me) (m) (mobility) ion optics ion source (ionization chamber) ion spray (pneumatically-assisted electrospray ionization) ion trap (IT) 53

(Paul ion trap) (Penning ion trap) (Kingdon trap) ion trap mass spectrometer (ITMS) (ion trap) (Paul ion trap) m/z (time-of-flight mass spectrometer) m/z (linear ion trap) Kingdon trap Orbitrap (Fourier transform ion cyclotron resonance: FT-ICR) ion/ion reaction (ion ion reaction) ion/molecule reaction (charge exchange reaction) (ion-molecule reaction) 54

ion/neutral complex (fragmentation) (precursor ion) (product ion) (ion-neutral complex) ion/neutral exchange reaction (ion neutral exchange reaction) ion/neutral reaction (ion neutral reaction) ionic dissociation 1 1 (charge number) ionization ionization chamber (reactant ion) 55

ionization cross section ionization e$ciency ionization e$ciency curve ionization energy (IE) 1 ionization potential (ionization energy) ionizing cell ionization chamber ionizing collision 1 ionizing voltage (electron ionization) 56

ion-pair formation 1 2M [M H] [M H] AX A X AX A X ion-to-photon detector (photomultiplier) (conversion dynode) isomeric ion isotope cluster (isotope pattern) isotope dilution mass spectrometry (IDMS) (internal standard) isotope e#ect (isotope labeling) (gas chromatography/mass spectrometry) (fragment ion) isotope labeling 1 (frag- 57

mentation) (internal standard) isotope pattern (isotope cluster) isotope peak (isotopolog ions) isotope ratio mass spectrometry (IRMS) isotopically enriched ion C 13 C 13 C 1.1 isotopolog ions (monoisotopic ion) CH 4 CH 3 D (isotope pattern) isotopomeric ions 58

kinetic energy analyzer kinetic energy release (KER) (1) (metastable ion decay) (precursor ion) (2) (metastable ion) (metastable peak) kinetic energy release distribution (KERD) (metastable ion) (kinetic energy release) kinetic method (tandem mass spectrometry) (relative abundance) 59

Kingdon trap (ion trap) m/z (mass analyzer) Orbitrap, Knudsen cell 1mm RF Knudsen cell mass spectrometer (high temperature mass spectrometer) (electron ionization) Knudsen e#usion mass spectrometer (Knudsen cell mass spectrometer) 60

laboratory collision energy (collision-induced dissociation) (V) (charge number) z e (electron volt) (center-of-mass collision energy) laser ablation (LA) laser beam ionization laser desorption (LD) fragment laser desorption/ionization (LDI) laser ionization (LI) laser microprobe mass spectrometry (LMMS) 61

(laser desorption/ionization) laser spray (LS) kv W (electrospray) linear ion trap (LIT) (Paul ion trap) linked scan 2 (mass analyzer) (tandem mass spectrometer) (magnetic sector) (electric sector) 1 (sector mass spectrometer) 2 (product ion spectrum) (precursor ion spectrum) (constant neutral loss spectrum) (constant neutral mass gain spectrum) linked scan at constant B/E B/E B/E (magnetic sector) (electric sector) 1 (sector mass spectrometer) V B 62

E B E (field-free region) (product ion spectrum) B/E (B/E linked scan) linked scan at constant B[1 (E/E 0 )] 1/2 /E B[1 (E/E 0 )] 1/2 /E B[1 (E/E 0 )] 1/2 /E (magnetic sector) (electric sector) 1 (sector mass spectrometer) V B E B[1 (E/E 0 )] 1/2 /E B E (field-free region) (constant neutral loss spectrum) (constant neutral mass gain spectrum) E 0 E B[1 (E/E 0 )] 1/2 /E (B[1 (E/E 0 )] 1/2 /E linked scan) linked scan at constant B 2 /E B 2 /E B 2 /E (magnetic sector) (electric sector) 1 (sector mass spectrometer) V B E B 2 /E B E (field-free region) (precursor ion spectrum) B 2 /E (B 2 /E linked scan) 63

linked scan at constant E 2 /V E 2 /V E 2 /V (magnetic sector) (electric sector) 1 (sector mass spectrometer) E V E 2 /V E V (field-free region) (product ion spectrum) E 2 /V (E 2 /V linked scan) liquid chromatograph-mass spectrometer (LC-MS) liquid chromatography/mass spectrometry (LC/MS) liquid ionization (LI) Ar (ion/molecule reaction) (matrix) (soft ionization) (atmospheric pressure ionization) (Penning ionization) liquid secondary ionization (LSI) 64

(fast particle bombardment) (secondary ionization) low-energy collision-induced dissociation 1,000 ev (laboratory collision energy) (collision-induced dissociation) (multiple collision) (collisional excitation) (high-energy collision-induced dissociation) m/z m/z m z (charge number) (unified atomic mass unit) (mass-to-charge-ratio) m/z m/z m/z 100 m/z 100 m/z thomson, Th magnetic deflection (magnetic sector) magnetic field scan 65

magnetic sector m/z magnetic shim (magnetic sector) (fringe field) mass SI (kg) SI (unified atomic mass unit) mass accuracy (ppm) (exact mass) mass analysis m/z mass analyzer m/z 66

mass calibration m/z m/z mass chromatogram (extracted ion chromatogram) mass defect (1) (mass number) (nominal mass) (monoisotopic mass) (mass excess) (2) (mass defect) mass discrimination (sensitivity) mass excess (mass defect) mass fragmentogram (gas chromatography/mass spectrometry) m/z (relative intensity) (selected ion monitoring) 67

mass gate m/z (ion gate) mass limit m/z mass marker (sector mass spectrometer) m/z (mass calibration) mass number A (nominal mass) mass range m/z mass resolution m/z m/z D(m/z) (m/z)/d(m/z) 1. m/z 2. D(m/z) D(m/z) 68

3. D(m/z) 2 mass resolving power (mass resolution) m/z D(m/z) mass selective axial ejection (mass selective instability) (Paul ion trap) m/z mass selective instability (Paul ion trap) m/z mass spectral library m/z (monoisotopic mass spectrum) mass spectrograph m/z (focal plane detector) (mass spectrometer) 69

mass spectrometer m/z mass spectrometric detector mass spectrometric thermal analysis (MTA) mass spectrometry (mass spectrometer) (mass spectrograph) (mass spectroscopy) mass spectrometry/mass spectrometry (MS/MS) MS/MS m/z 1 m/z (precursor ion) (tandem mass spectrometry) (mass analyzer) (tandem mass spectrometry in space) (ion trap) (tandem mass spectrometry in time) mass spectroscope (mass spectrometer) 70

(mass spectrograph) mass spectroscopy m/z (relative abundance) (mass spectrometry) mass spectrum (relative abundance) m/z mass-analyzed ion kinetic energy spectrometry (MIKES) MIKE (magnetic sector) (electric sector) 1 (reverse geometry) (sector mass spectrometer) V B m/z (precursor ion) (field-free region) (product ion) (electric sector) (scan) (product ion spectrum) (kinetic energy release distribution) (double-focusing mass spectrometer) (direct analysis of daughter ions) massive-cluster impact ionization (MCI) ( 0.01 mm) 71

10 7 u 10 20 kv (fast atom bombardment) (electrohydrodynamic ionization) mass-to-charge ratio m/z m/z Mathieu stability diagram (transmission quadrupole mass spectrometer) (Paul ion trap) matrix (fast atom bombardment) (liquid secondary ionization) (matrix-assisted laser desorption/ionization) (massive-cluster impact ionization) (liquid ionization) matrix fast atom bombardment (fast atom bombardment) 72

matrix-assisted laser desorption/ionization (MALDI) (matrix) (laser desorption/ionization) matrix-assisted plasma desorption (MAPD) (analyte) (plasma desorption/ionization) Matsuda plate Mattauch Herzog geometry (electric sector) p/(4 2) (magnetic sector) p/2 (magnetic deflection) (double-focusing mass spectrometer) (mass spectrograph) McLa#erty rearrangement EI g g 6 g 73

measured accurate mass p. 14, accurate mass membrane inlet mass spectrometry (membrane introduction mass spectrometry) membrane interface mass spectrometry (membrane introduction mass spectrometry) membrane introduction mass spectrometry (MIMS) (analyte) (membrane separator) (membrane inlet mass spectrometry) (membrane interface mass spectrometry) metastable ion (MI) (mass analyzer) (stable ion) (unstable ion) metastable ion decay (MID) (metastable ion) 74

metastable peak (metastable ion) microchannel plate (MCP) (continuous dynode electron multiplier) (secondary electron) microelectrospray (micro-es) 1 ml min 1 (electrospray ionization) (nanoelectrospray) milli-atomic mass unit (millidalton, mda) milli-mass unit (mmu) (unified atomic mass unit) 1 dalton, Da 10 SI (millidalton, mda) molecular anion (molecular ion) 75

molecular beam mass spectrometry (MBMS) molecular cation (molecular ion) molecular ion 1 1 (radical ion). molecular protonated ion (protonated molecule) molecular weight (atomic weight) u, Da, g molecular-related ion (pseudo-molecular ion quasi-molecular ion) (protonated molecule) (cationized molecule) [M Na] [M H] momentum dispersion (magnetic sector) 76

monoisotopic mass (exact mass) MS/MS spectrum MS/MS (precursor ion spectrum) (product ion spectrum), (1st generation product ion spectrum) MS 3 spectrum MS 3 (2nd generation product ion spectrum) MS n MS n n (multiple-stage mass spectrometry) (precursor ion) (product ion) n n MS n 1 (triple quadrupole mass spectrometer) n 2 (ion trap mass spectrometer) n 2 MS/MS n (nth generation product ion) multiphoton ionization (MPI) (photoionization) multiple collision (collision gas) (product ion) 77

(ion trap) (collision cell) (triple quadrupole mass spectrometer) (collisioninduced dissociation) multiple reaction monitoring (MRM) (selected reaction monitoring) multiple-stage mass spectrometry m/z 2 n (nth generation product ion) MS n multiply deprotonated molecule M H [M nh] n (electrospray ionization) multiply protonated molecule M H [M nh] n (electrospray ionization) multiply-charged ion M 3,M 3,[M 5H] 5 [M 5H] 5 nanoelectrospray (nano-es) 100 nl min 1 78

(electrospray ionization) (microelectrospray) (nanospray) nanospray (nanoelectrospray) negative ion M,[M H],[M O] negative ion chemical ionization (NICI) (chemical ionization) M OH F M [M H] Cl M [M Cl] e M M OH or F M [M H] H 2 OorHF Cl M [M Cl] neutral fragment reionization (NFR) (collision cell) MS/MS (mass spectrometry/mass spectrometry) neutral loss (precursor ion) 79

neutralization reionization mass spectrometry (NRMS) m/z (collision gas) (collision cell) (fragmentation) Nier-Johnson geometry (electric sector) p/2 p/3 (magnetic deflection) (magnetic sector) (double-focusing mass spectrometer) nitrogen rule C, H, O, S, P (nominal mass) nominal mass (mass number) non-classical ion 5 80

nozzle-skimmer collision-induced dissociation (capillary-skimmer collision-induced dissociation) nth generation product ion n (precursor ion) (product ion) n 4 M 1 M 2 M 3 M 4 M 5 M 4 M 5 M 3 M 2 M 1 (multiple-stage mass spectrometry) (granddaughter ion) nth generation product ion spectrum n n (nth generation product ion) octapole 8 (octapole lens) (mass analyzer) (ion guide) odd-electron ion M (radical ion) 81

odd-electron rule (even-electron rule). oil di#usion pump 10 7 Pa (di#usion pump) oil sealed vacuum pump (rotary vane pump) onium ion orbitrap (Kingdon trap) organic secondary ion mass spectrometry kev kev Ar,Xe,Cs (static secondary ion mass spectrometry) 82

orthogonal acceleration (orthogonal extraction) orthogonal extraction (timeof-flight mass spectrometer) (ion mobility spectrometry) (orthogonal acceleration) parent ion (precursor ion) parent ion scan (precursor ion scan) parent ion spectrum (precursor ion spectrum) partial charge exchange reaction (partial charge transfer reaction) partial charge transfer reaction particle beam (PB) 83

(ionization chamber) (electron ionization) (chemical ionization) (liquid chromatograph-mass spectrometer) pascal (Pa) SI Nm 2 1Pa 10 mbar, 133 Pa 1 Torr 1 mmhg. Paul ion trap m/z m/z m/z (ion trap) (Mathieu stability diagram) peak peak intensity peak matching m/z m/z (reference ion) 84

m/z Penning ion trap (ion trap) (Fourier transform ion cyclotron resonance mass spectrometer) (mass analyzer) Penning ionization 2 (chemi-ionization) photodissociation 1 photo-induced dissociation (PID) 1 2 (infrared multiphoton dissociation) photoionization (PI) (hn) 85

plasma desorption/ionization (PDI) 252 Cf 106 Tc 22 142 Ba 18 (fission fragment ionization) pneumatically-assisted electrospray ionization (electrospray ionization) (ionspray) point detector pole-piece positive ion M,[M H],[M Na] post-acceleration detector (PAD) m/z 86

post-source decay (PSD) (1) (matrixassisted laser desorption/ionization) (metastable ion decay) (2) (collisioninduced dissociation) (product ion) m/z (reflectron) (reflectron time-of-flight mass spectrometer) precursor ion (product ion) (unimolecular dissociation) (ion/molecule reaction) (parent ion) precursor ion scan (precursor ion spectrum) (parent ion scan) precursor ion spectrum (product ion) (precursor ion) (parent ion spectrum) 87

pre-ionization state (autoionization) principal ion BBr 3 11 B 79 Br 81 2 Br (isotope pattern) CH 13 3 CH 3 CH 2 D 2 (isotopically enriched ion) (isotopolog ion) principal isotope product ion (precursor ion) (fragment ion) (unimolecular dissociation) (ion/molecule reaction) (daughter ion) product ion analysis (product ion spectrum) (daughter ion analysis) product ion scan (product ion spectrum) (daughter ion scan) 88

(product ion analysis) product ion spectrum (precursor ion) (product ion) (fragment ion spectrum) (daughter ion spectrum) MS/MS (MS/MS spectrum) (precursor ion spectrum) (2nd generation product ion spectrum) profile acquisition (continuum acquisition) prolate trochoidal mass spectrometer m/z (cycloidal mass spectrometer) prompt fragmentation (in-source decay) proteome PROTEin genome 1994 M. R. Wilkins 89

(proteomics) proteomics (proteome) proton a$nity (PA) 298 K ( DH) (protonated molecule) (multiply protonated molecule) (proton acceptor) (proton donor) (deprotonated molecule) [M H] Brønsted Brønsted protonated molecular ion (protonated molecule) protonated molecule M H [M H] (pseudo-molecular ion quasi-molecular ion) [M Na],[M H] (protonated molecular ion) 2 90

proton-bound dimer M (M H M) 2 M 1 M 2 (M 1 H M 2 ) pseudo-molecular ion (protonated molecule) (cationized molecule) [M Na] [M H] pyrolysis gas chromatography mass spectrometry (PyGC/MS) pyrolysis mass spectrometry (PyMS) quadratic field reflectron 2 (reflectron) quadrupole ion storage (QUISTOR) (Paul ion trap) quadrupole ion trap (QIT) (Paul ion trap) quadrupole lens 4 91

quadrupole mass filter (QMF) (transmission quadrupole mass spectrometer) quadrupole mass spectrometer (QMS) (transmission quadrupole mass spectrometer) quasi-equilibrium theory (QET) Eyring Rosenstock, Wallenstein, Wahrhaftig Eyring 1952 (molecular ion) (non-radiative transition) Rice Ramsperger Kassel Marcus RRKM Miller Klots Chesnavichi Bowers (statistical phase space theory) (kinetic energy release) quasi-molecular ion (protonated molecule) (cationized molecule) [M Na] [M H] 92

radial electrostatic field analyzer (electrostatic energy analyzer) (electric sector) radical anion (radical ion) radical cation (radical ion) radical ion M M. 2 M (2 )(2 ) Rayleigh limit (electrospray ionization) reactant ion (chemical ionization) (reagent gas) CH 5,NH 4, t-c 4 H 9 93

reagent gas (ion/molecule reaction) (precursor ion) (product ion) (chemical ionization) (reagent ion) CH 4, NH 3, iso-c 4 H 10 (ion trap) (collision cell) reagent ion (chemical ionization) rearrangement ion (fragmentation) rearrangement reaction (rearrangement ion) (McLa#erty rearrangement) recombination energy 1 (vertical ionization energy) reconstructed ion chromatogram (extracted ion chromatogram) reference ion (stable ion) 94

reflectron (time-of-flight mass spectrometer) m/z (mass resolving power) (ion mirror) reflectron time-of-flight mass spectrometer (field-free region) (product ion) 2 (post-source decay) relative abundance (relative intensity) relative atomic mass (atomic weight) relative intensity 100 (base peak) m/z m/z 100 95

( S) (height) (area) (abundance) relative molecular mass (unified atomic mass unit) (molar mass) relative sensitivity coe$cient (spark source mass spectrometry) (1.00) (relative intensity) remote site fragmentation (charge remote fragmentation) repeller voltage (ionization chamber) residual gas analyzer (RGA) residual mass spectrum 96

(background mass spectrum) resonance ion ejection (Paul ion trap) resonance ionization (RI) (resonance-enhanced multiphoton ionization) resonance-enhanced multiphoton ionization (REMPI) (multiphoton ionization) 1 (ionization cross section) reverse geometry (double-focusing mass spectrometer) reverse library search (mass spectral library) (forward library search) 97

RF-DC ion mobility spectrometry FAIMS (high-field asymmetric waveform ion mobility spectrometry) RF-only quadrupole RF (collision quadrupole) rotary pump (rotary vane pump) rotary vane pump (rotary pump) 10 2 Pa (turbo molecular pump) (oil rotary pump) scan (time-of-flight mass spectrometer) (Fourier transform mass spectrometry) (scan) second field-free region (electric sector) (magnetic sector) (doublefocusing mass spectrometer) (ionization chamber) 98

second law treatment (high temperature mass spectrometer) DH 0 v (third law treatment) secondary electron secondary electron multiplier (SEM) 100 ev 1 Cu Be 2 (discrete dynode electron multiplier) (continuous dynode electron multiplier) secondary ion mass spectrometry (SIMS) Ar,O 2,Cs (liquid secondary ion mass spectrometry) 99

secondary ionization secondary neutral mass spectrometry (SNMS) (secondary ion mass spectrometry) (fast atom bombardment) sector mass spectrometer (magnetic sector) 1 m/z (electric sector) 1 (doublefocusing mass spectrometer) selected ion detection (SID) (selected ion monitoring) selected ion flow tube (SIFT) m/z (ion/molecule reaction) selected ion monitoring (SIM) 1 m/z (liquid chromatography/mass spectrometry) 100

(gas chromatography/mass spectrometry) 14 selected reaction monitoring (SRM) 2 (MS n ) (product ion spectrum) 1 (product ion) (tandem mass spectrometry in space) (tandem mass spectrometry in time) (precursor ion) m/z m/z (selected ion monitoring) (multiple reaction monitoring) self-chemical ionization (self-ci) (analyte) (reactant ion) (chemical ionization) sensitivity 101

(detection limit) separator (gas chromatograph-mass spectrometer) He simple cleavage (fragmentation) (rearrangement reaction) single collision 1 (multiple collision) (collision gas) 1 1 L (collision cell) n 1 snl 1 s (doublefocusing mass spectrometer) (collision-induced dissociation) single-focusing mass spectrometer (direction focusing) (double-focusing mass spectrometer) skimmer 1mm 102

(electrospray ionization) (ion desolvation) skimmer collision-induced dissociation (capillaryskimmer collision-induced dissociation) soft ionization (fragmentation) (hard ionization) solid fast atom bombardment (fast atom bombardment) sonic spray ionization (SSI) (atmospheric pressure ionization) (multiply protonated molecule) space charge e#ect (space charge) (sensitivity) (mass resolving power) (mass accuracy) 103

spark ionization spark source mass spectrometry (spark ionization) spike (isotope dilution mass spectrometry) spray ionization (electrospray ionization) (thermospray ionization) (sonic spray ionization) sputtered neutral mass spectrometry (secondary neutral mass spectrometry) stability diagram (Mathieu stability diagram) stable ion (rearrangement reaction) (metastable ion) (unstable ion) 104

static field static secondary ion mass spectrometry (secondary ion mass spectrometry) 1 10 13 ions/cm 2 stored waveform inverse Fourier transform (SWIFT) SWIFT (Paul ion trap) (Fourier transform ion cyclotron resonance mass spectrometer) MS/ MS (mass spectrometry/mass spectrometry) (precursor ion) superelastic collision (collision of the second kind) surface ionization (SI) (ionization energy) Saha Langmuir 105

surface-assisted laser desorption/ionization (SALDI) (desorption ionization) (desorption ionization on silicon) surface-enhanced laser desorption/ionization (SELDI) SELDI (analyte) (matrix-assisted laser desorption/ionization) surface-induced dissociation (SID) (collision-induced dissociation) surface-induced reaction (SIR) sustained o#-resonance irradiation (SORI) (Fourier transform ion cyclotron resonance mass spectrometer) (ion/neutral reaction) (cyclotron motion) (Penning ion trap) (collisional excitation) 106

(low-energy collision-induced dissociation) tandem mass spectrometer MS/MS (mass spectrometry/mass spectrometry) tandem mass spectrometry MS/MS (mass spectrometry/mass spectrometry) tandem mass spectrometry in space (mass analyzer) MS/MS (mass spectrometry/mass spectrometry) (precursor ion) (product ion) m/z MS/MS (MS/MS in space) tandem mass spectrometry in time (Paul ion trap) (Fourier transform ion cyclotron resonance mass spectrometer) 1 (mass analyzer) (product ion spectrum) MS/MS (mass spectrometry/mass spectrometry) (precursor ion) (product ion) MS/MS (MS/MS in time) target gas (collision gas) 107

thermal ionization (TI) thermal surface ionization (TSI) (surface ionization) 1,000 W Re thermogravimetry mass spectrometry (TG/MS) thermospray (TS) Pa thermospray ionization (TSI) (thermospray) (discharge ionization) (electron ionization) third law treatment (high temperature mass spectrometer) DH 0 v (298 K) DH 0 v (second law treatment) 108

thomson (Th) m/z time lag focusing (TLF) (time-of-flight mass spectrometer) (energy focusing) (delayed extraction) time-of-flight mass spectrometer (TOF-MS) (field-free region) m/z (reflectron time-of-flight mass spectrometer) Torr 1Torr 1 mmhg 1.33 mbar 133 Pa SI pascal, Pa total emission current (electron ionization) total ion chromatogram (total ion current chromatogram) total ion current (TIC) m/z m/z 109

total ion current chromatogram (TICC) (gas chromatography/mass spectrometry) (liquid chromatography/mass spectrometry) (total ion current) total ion chromatogram (TIC) total ion current chromatogram (TICC) total ion detection (TID) (total ion monitoring) total ion monitoring (TIM) (selected ion monitoring) (liquid chromatography/mass spectrometry) (gas chromatography/mass spectrometry) m/z transmission e$ciency (mass analyzer) transmission quadrupole mass spectrometer 4 (quadrupole) (Mathieu equation) 110

m/z m/z (quadrupole mass filter) (Mathieu stability diagram) triple quadrupole mass spectrometer (transmission quadrupole mass spectrometer) 2 m/z (collision cell) (tandem mass spectrometer) trochoidal focusing mass spectrometer prolate trochoidal mass spectrometer troidal field turbo molecular pump (rotary vane pump) (di#erential pumping) unified atomic mass unit (u) 12 1 111

12 1 1.660 538 782(83) 10 27 kg u SI SI m/z (charge number) SI kg atomic mass unit amu 16 16 1 (standard atomic weight) 16 1 2 3 unimolecular dissociation unstable ion (collision cell) (in-source decay), (metastable ion) (stable ion) vaporization coe$cient (Knudsen cell) a a c P e J c J c a c P e (2pMkT) 1/2 a c 112

J v J v J c J v a a v a 1 (Knudsen cell mass spectrometer) velocity focusing m/z (time-of-flight mass spectrometer) vertical ionization voltage scan (accelerating voltage) (electric field scan) Wien filter x-ion x C C (fragment ion) C y-ion y C N (fragment ion) C 113

z-ion z C N N C a (fragment ion) C 114

anion radical (radical anion) appearance potential (AP) (electron ionization) IUPAC (appearance energy) atomic mass unit (amu) unified atomic mass unit, u dalton, Da B/E linked scan B/E B/E B/E B/E (linked scan at constant B/E) B[1 (E/E 0 )] 1/2 /E linked scan B[1 (E/E 0 )] 1/2 /E B[1 (E/E 0 )] 1/2 /E B[1 (E/E 0 )] 1/2 /E B[1 (E/E 0 )] 1/2 /E (linked scan at constant B[1 (E/E 0 )] 1/2 /E) B 2 /E linked scan B 2 /E B 2 /E B 2 /E B 2 /E (linked scan at constant B 2 /E) cation radical (radical cation) 115

cycloidal mass spectrometer (prolate trochoidal mass spectrometer) daughter ion (product ion) daughter ion analysis (product ion analysis) daughter ion scan (product ion scan) daughter ion spectrum (product ion spectrum) direct analysis of daughter ions (DADI) MIKE (mass-analyzed ion kinetic energy spectrometry) E 2 /V linked scan E 2 /V E 2 /V E 2 /V E 2 /V (linked scan at constant E 2 /V) electron impact ionization (electron ionization) field desorption/ionization (field desorption) 116

fragment ion scan (product ion scan) fragment ion spectrum spectrum) (product ion granddaughter ion (2nd generation product ion) ionization potential (ionization energy) ion spray (pneumatically-assisted electrospray ionization) mass chromatogram (extracted ion chromatogram) mass excess (mass defect) mass spectroscope (mass spectrometer) (mass spectrograph) mass spectroscopy (mass spectrometry) 117

mass-to-charge-ratio m/z milli-atomic mass unit (millidalton mda) milli-mass unit (mmu) (millidalton mda) molecular protonated ion (protonated molecule) molecular-related ion (protonated molecule) (cationized molecule) [M Na] [M H] MS/MS spectrum MS/MS (precursor ion spectrum) (product ion spectrum) MS 3 spectrum MS 3 (2nd generation product ion spectrum) multiple reaction monitoring (MRM) (selected reaction monitoring: SRM) nanospray (nanoelectrospray) 118

orbitrap (Kingdon trap) parent ion (precursor ion) parent ion scan (precursor ion scan) parent ion spectrum (precursor ion spec- trum) protonated molecular ion (protonated molecule) pseudo-molecular ion (protonated molecule) (cationized molecule) [M Na] [M H] quasi-molecular ion (protonated molecule) (cationized molecule) [M Na] [M H] reconstructed ion chromatogram (extracted ion chromatogram) 119

selected ion detection (selected ion monitoring) target gas (collision gas) thomson (Th) m/z m/z Torr 1Torr 1 mmhg 133 Pa, 1 Pa 10 mbar. SI pascal, Pa total ion chromatogram (TIC) (total ion current chromatogram) total ion detection (TID) (total ion monitoring) trochoidal focusing mass spectrometer prolate trochoidal mass spectrometer 120

isotopomeric ions 58 Einzel lens 36 acceptance 14 analog ion 15 anion radical 15, 115 anionized molecule 16 abundance sensitivity 14 oil sealed vacuum pump 82 oil di#usion pump 82 array detector 16 stable ion 104 stability diagram 104 ion 51 ion/ion reaction 54 ion mobility spectrometry (IMS) 53 ion kinetic energy spectrometry (IKES) 52 ion energy loss spectrum 52 ionization 55 ion guide 52 ionic dissociation 55 ionization energy (IE) 56 ionization e$ciency 56 ionization e$ciency curve 56 ionization chamber 55 ionizing cell 56 ion accelerating voltage 51 ionization cross section 56 ionizing voltage 56 121

ionization potential 56, 117 ion gate 52 ion source 53 ion optics 53 ion-to-photon detector 57 ion collector 51 ion cyclotron resonance mass spectrometer (ICRMS) 51 ion spray 53, 117 ion desolvation 52 ion-pair formation 57 transmission e$ciency 110 ion trap (IT) 53 ion trap mass spectrometer (ITMS) 54 ion/neutral complex 55 ion/neutral exchange reaction 55 ion/neutral reaction 55 ion/molecule reaction 54 ion mirror 53 ion mobility spectrometry (IMS) 53 ion cooling 51 isomeric ion 57 single collision 102 imaging mass spectrometry 48 in-source collision-induced dissociation 50 in-source decay (ISD) 50 in-beam electron ionization 48 in-beam method 48 in-beam chemical ionization 48 Wien filter 113 kinetic energy analyzer 59 kinetic energy release (KER) 59 122

kinetic energy release distribution (KERD) 59 momentum dispersion 76 liquid ionization (LI) 64 liquid chromatography/mass spectrometry (LC/MS) 64 liquid chromatograph-mass spectrometer (LC-MS) 64 liquid secondary ionization (LSI) 64 energy focusing 39 emittance 39 MS n 77 mass spectrometry/mass spectrometry (MS/MS) 70 electrospray (ES) 38 electrospray ionization (ESI) 38 electrohydrodynamic ionization (EHI EHDI) 36 orbitrap 82, 119 octapole 81 onium ion 82 parent ion 83, 119 parent ion scan 83, 119 parent ion spectrum 83, 119 curved field reflectron 29 associative ionization 16 associative ion/molecule reaction 16 rotary pump 98 dissociative ionization 35 dissociative Penning ionization 35 cleavage 24 chemical ionization (CI) 23 chemi-ionization 24 123

di#usion pump 32 fission fragment ionization 42 excess energy 40 gas chromatography/mass spectrometry (GC/MS) 45 gas chromatograph-mass spectrometer (GC-MS) 45 accelerator mass spectrometry (AMS) 14 accelerating voltage 14 cationized molecule 20 cation radical 20, 115 bath gas 19 bu#er gas 19 sensitivity 101 base peak (BP) 19 base peak chromatogram 19 odd-electron ion 81 odd-electron rule 82 gas-phase fast atom bombardment 45 pseudo-molecular ion 91, 119 quasi-molecular ion 92, 119 reverse geometry 97 reverse library search 97 capillary-skimmer collision-induced dissociation 20 capillary electrophoresis mass spectrometry (CE/MS) 20 flash desorption 42 resonance ionization (RI) 97 resonance ion ejection 97 resonance-enhanced multiphoton ionization (REMPI) 97 pneumatically-assisted 124

electrospray ionization 86 Kingdon trap 60 tandem mass spectrometry in space 107 space charge e#ect 103 even-electron ion 39 even-electron rule 40 Coulomb explosion 28 Knudsen cell 60 Knudsen cell mass spectrometer 60 Knudsen e#usion mass spectrometer 60 cluster 25 cluster ion 25 gridless reflectron 45 glow discharge ionization 45 chromatograph 24 chromatography 24 chromatogram 24 calculated exact mass 20 exact mass 40 in-gel digestion 49 atomic mass unit (amu) 17, 115 detection limit 32 atomic weight 17 high-energy collision-induced dissociation 46 high temperature mass spectrometer 46 fast ion bombardment (FIB) 41 fast atom bombardment (FAB) 41 fast particle bombardment (FPB) 41 post-acceleration detector (PAD) 86 RF-DC ion mobility spectrometry 98 blackbody infrared radiative dissociation (BIRD) 19 solid fast atom bombardment 103 125

corona discharge 28 constant neutral mass gain scan 27 constant neutral mass gain spectrum 27 constant neutral loss scan 27 constant neutral loss spectrum 27 continuum acquisition 28 conversion dynode 28 thermospray (TS) 108 thermospray ionization (TSI) 108 cycloidal mass spectrometer 29, 116 cyclotron motion 29 recombination energy 94 reconstructed ion chromatogram 94, 119 di#erential pumping 32 reference ion 94 residual gas analyzer (RGA) 96 residual mass spectrum 96 triple quadrupole mass spectrometer 111 tandem mass spectrometry in time 107 self-chemical ionization (self-ci) 101 collision quadrupole 25 quadrupole ion storage (QUISTOR) 91 quadrupole ion trap (QIT) 91 quadrupole mass spectrometer (QMS) 92 quadrupole mass filter (QMF) 92 quadrupole lens 91 sustained o#-resonance irradiation (SORI) 106 laboratory collision energy 61 126

mass 66 mass analysis 66 mass accuracy 66 mass calibration 67 mass discrimination 67 mass limit 68 mass accuracy 66 mass number 68 mass selective axial ejection 69 mass selective axial ejection 69 mass selective instability 69 mass-to-charge ratio 72, 118 mass range 68 mass resolution 68 mass resolving power 69 mass spectroscopy 71, 117 mass spectrometry (MS) 70 mass spectrograph 69 mass spectrometer 70 mass spectrometric detector 70 mass analyzer 66 mass discrimination 67 autoionization 18 autodetachment 18 magnetic field scan 65 magnetic sector 66 sector mass spectrometer 100 magnetic field scan 65 magnetic deflection 65 reagent ion 94 reagent gas 94 principal ion 88 center-of-mass kinetic energy 21 127

center-of-mass collision energy 20 heavy ion induced desorption (HIID) 46 appearance energy (AE) 16 appearance potential (AP) 16, 115 principal isotope 88 metastable ion (MI) 74 metastable ion decay (MID) 74 metastable peak 75 forward geometry 43 quasi-equilibrium theory (QET) 92 forward library search 43 focal plane detector (FPD) 43 collision gas 25 collisional activation (CA) 26 collisionally activated dissociation (CAD) 26 collision cell 25 collision chamber 25 collision cell 25 collision reaction cell 26 collision-induced dissociation (CID) 26 collisional excitation 26 vaporization coe$cient 112 desorption ionization on silicon (DIOS) 31 intensity 50 diagnostic ion 32 hydrogen/deuterium exchange (HDX) 47 vertical ionization 113 (SWIFT ) stored waveform inverse Fourier transform (SWIFT) 105 skimmer 102 skimmer collision-induced dissociation 103 scan 98 static secondary ion mass 128

spectrometry 105 spark ionization 104 spark source mass spectrometry 104 spike 104 sputtered neutral mass spectrometry 104 spray ionization 104 positive ion 86 electrostatic energy analyzer (ESA) 39 forward geometry 43 accurate mass exact mass 14, 40 infrared multiphoton dissociation (IRMPD) 49 separator 102 (SELDI ) surface-enhanced laser desorption/ ionization (SELDI) 106 total ion chromatogram 109, 120 total ion detection (TID) 110, 120 total ion current (TIC) 109 total ion current chromatogram (TICC) 110 total ion monitoring (TIM) 110 pre-ionization state 88 precursor ion 87 precursor ion scan 87 precursor ion spectrum 87 selected ion detection (SID) 100, 120 selected ion monitoring (SIM) 100 selected reaction monitoring (SRM) 101 selected ion flow tube (SIFT) 100 centroid acquisition 21 total emission current 109 scan 98 relative sensitivity coe$cient 96 relative intensity 95 relative atomic mass 95 129

relative abundance 95 relative molecular mass 96 accurate mass 14 measured accurate mass 74 velocity focusing 113 kinetic method 59 sonic spray ionization (SSI) 103 soft ionization 103 target gas 107, 120 turbo molecular pump 111 first stability region 42 atmospheric pressure ionization (API) 17 atmospheric pressure chemical ionization (APCI) 16 atmospheric pressure spray 17 atmospheric pressure photoionization (APPI) 17 atmospheric pressure matrix-assisted laser desorption/ionization (AP MALDI) 17 third law treatment 108 dynamic pulse heating 35 second field-free region 98 second law treatment 99 time lag focusing (TLF) 109 multiply-charged ion 78 multiply deprotonated molecule 78 multiply protonated molecule 78 multiphoton ionization (MPI) 77 multiple collision 77 multiple reaction monitoring (MRM) 78, 118 multiple-stage mass spectrometry 78 deprotonated molecule 30 desorption ionization (DI) 31 130

desorption electrospray ionization (DESI) 31 desorption chemical ionization (DCI) 31 desorption electron ionization (DEI) 31 dalton (Da) 29 fringe field 45 single-focusing mass spectrometer 102 simple cleavage 102 tandem mass spectrometry 107 tandem mass spectrometer 107 adiabatic ionization 15 unimolecular dissociation 112 unimolecular dissociation 112 delayed extraction (DE) 30 nitrogen rule 80 charge mediated fragmentation 22 charge remote fragmentation (CRF) 22 channel electron multiplier 21 channeltron 21 extracted ion chromatogram (EIC) 40 neutralization reionization mass spectrometry (NRMS) 80 neutral fragment reionization (NfR) 79 direct insertion probe (DIP) 34 superelastic collision 105 direct liquid introduction (DLI) 34 direct dissociation 33 direct chemical ionization 33 direct exposure probe (DEP) 33 direct infusion 33 direct inlet 33 131