Acronyms in Mass Spectrometry

November 1, 2006
Kenneth L. Busch
Special Issues

Volume 0, Issue 0

Spectroscopy columnist Ken Busch once again brings readers his comprehensive list of common acronyms used in the field of mass spectrometry.

Acronyms used in mass spectrometry appear in printed publications of researahers working in established areas, and also are coined at and used in meetings, presentations, and proceedings. The latter especially reflect new applications, with new audiences, each of which generates a unique technical jargon. Acronyms reflect the diverse and vibrant discipline of mass spectrometry, but shorthand-speak can become common, and practitioners in one subdiscipline tend to become more isolated, even in conversation, from their colleagues in other areas. Researchers enjoy coining acronyms as much as the federal government, and our acronym-laden language can become intimidating. Additionally, a new acronym can rise to general use, or can be orphaned and its meaning lost. In this installment, we add more acronyms to the already extensive collection, culled from recent publications, proceedings, and web sites in the field of mass spectrometry. Inclusion of an acronym in this list is not explicitly an endorsement for its use by the community; the nomenclators eventually make their judgments, but the community itself enforces a certain discipline. Immortality in the annals of science is not to be gained by coining a new acronym; a truly useful acronym quickly becomes distributed so widely that its originator is forgotten, and even commercial trademark protection can be insufficient.

Kenneth L. Busch

For some recent additions to the acronym list, a short description is provided, along with a recent (not necessarily the first) reference. Visit the reference given for a more complete description. Space constraints preclude extensive discussions here — but perhaps later in a future coffee-table book, when mass spectrometers themselves shrink to the same scale. Most acronyms are composed of uppercase letters, but a few traditionally are given as sequences of lowercase letters, or a mixture, and sometimes including punctuation, all to the consternation of spell-checkers, editors, and indexers everywhere. We retain acronyms in this list but not specialized nomenclature or abbreviations. If your favorite acronym is missing, if you would like to argue for an acronym's deletion, or to correct an error, please contact the author at

A Anion

AA Amino acid

ACMS Asilomar Conference on Mass Spectrometry

ADC Analog-to-digital converter

ADO Average dipole orientation

AE Appearance energy

AEI Associated Electric Industries, a past MS manufacturer

AGC Automatic gain control

AGHIS All-glass-heated-inlet system

AMS Accelerator mass spectrometry; adolescent mass spectrometrists

amu atomic mass unit

AN Auger neutralization; application note (in JASMS)

ANP 2-amino-5-nitropyridine (a MALDI matrix)

ANZSMS Australian and New Zealand Society for Mass Spectrometry

AP Appearance potential; atmospheric pressure

APCI Atmospheric pressure chemical ionization

API Atmospheric-pressure ionization

APPI Atmospheric-pressure photoionization

AREX Axial resonant excitation

ARMS Angle-resolved mass spectrometry

ASGDIMS Atmospheric-sampling glow discharge ionization mass spectrometry

ASMS American Society for Mass Spectrometry

ASTM American Society for the Testing of Materials

ATT 6-Aza-2-thiothymine (a MALDI matrix)

AVS Accelerating-voltage scan; American Vacuum Society

B Magnetic sector mass analyzer, magnetic field; magnetic sector field strength or flux density

BAMS Bioaerosol mass spectrometry

BAT Best anode temperature

BDE Bond dissociation energy

B/E Linked scan for product ions in MS-MS

B2E Linked scan for parent ions in MS-MS

BEoQ A reverse-geometry sector instrument followed by an octupole collision cell followed by a quadrupole mass filter

BEqQ A reverse-geometry sector instrument followed by a collision quadrupole followed by a quadrupole mass filter

BEMS Biomedical and Environmental Mass Spectrometry (a former MS journal)

BET Best emitter temperature

BIAMS™ Biomolecular interaction analysis mass spectrometry

BIRD Blackbody infrared radiative dissociation

BMS Biomedical Mass Spectrometry; Biological Mass Spectrometry

BMSS British Mass Spectrometry Society

BNG Bradbury–Nelson gate

BrMASS Brazilian Mass Spectrometry Society

BSMS Belgian Society for Mass Spectrometry

BTEX Benzene, toluene, ethylbenzene, and xylene

c "Conventional" collision cell

C Cation; coulomb; short communication in JASMS

CA Collisional activation

CAD Collisionally activated decomposition

CAF Chemically assisted fragmentation

CCA α-Cyano-4-hydroxycinnamic acid (a MALDI matrix)

CCE-ES Controlled-current electro- chemistry electrospray

The electrospray ionization process is, at its core, an electrochemical process. As such, the insights and strategies developed over years of classical analytical electrochemistry can be brought to bear to generate additional sensitivity and specificity from the electrospray ionization. Many research workers are advancing this field. In this paper, oxidations and reductions of electrochemically active compounds are reflected in the positive and negative ion electrospray mass spectra. Because the current demands on the electrochemical system are small, relatively simple, battery-operated circuitry is devised to operate in conjunction with the electrospray source. See V. Kertesz and G.J. Van Berkel, J. Amer. Soc. Mass Spectrom. 17(7), 953–961 (2006).

CDEM Continuous-dynode electron multiplier

CDNT Conformation-dependent neutralization theory

CE Charge exchange; collision energy; capillary electrophoresis

CEC Consolidated Electric Corporation (a former MS manufacturer)

CEMA Channel electron-multiplier array

cf ConFlat™

CFFAB Continuous-flow fast atom bombardment

CFP Continuous flow probe

CHCA Cyano-4-hydroxycinnamic acid (a MALDI matrix)

CI Chemical ionization

CID Collision-induced dissociation

CIDI Collisionally induced dissociative ionization

CIT Cylindrical ion trap

CM Center-of-mass

CMD Carbohydrate membrane desalter

CNL Constant neutral loss

CODA Component detection algorithm

COM Center-of-mass

COMSPARI Comparison of spectral retention information

CREMS Charge-reduction electrospray mass spectrometry

CRM Charged residue model; certified reference material

CS Charge stripping

CSMS Canadian Society for Mass Spectrometry

CV Compensation voltage; cone voltage

CX Charge exchange

CXP Collision-cell exit potential

CZE–MS Capillary zone electrophoresis mass spectrometry

D Disproportionation factor; deuterium

Da Dalton

DA Dopant-assisted

DAC Digital-to-analog converter

DADI Direct analysis of daughter ions

DAPCI Desorption atmospheric- pressure chemical ionization

DAR Data-acquisition routine

DART Direct analysis in real time

DB Database

dbe Double-bond equivalent

DCI Desorption (or direct) chemical ionization

DCT Double charge transfer

DCTB trans-2-[3-{4-tert- Butylphenyl}-2-methyl-2- propenylidene] malononitrile (a MALDI matrix)

DE Delayed extraction

DEI Desorption (or direct) electron ionization

DESI Desorption electrospray ionization

DF Double focusing

DFTPP Decafluorotriphenylphos- phine

DHB 2,5-Dihydroxybenzoic acid (a MALDI matrix)

DI Desorption ionization

DIADS Delimited ion abundance database search

DIN Direct injection nebulizer

DIOSMS Desorption ionization on silicon mass spectrometry

DIP Direct-insertion probe

DLI Direct liquid introduction

DLV Direct laser vaporization

DMS Differential mobility spectrometry

DNFW from the Latin for "Please do not mess with the instrument"

DP Direct probe; declustering potential; diffusion pump

DPBD Diphenyl butadiene (a MALDI matrix)

DS Data system

DTIMS Drift-tube ion mobility spectrometry

E Energy; electric sector

EA Electron affinity

EAD Electron avalanche desorption

ECD Electron-capture dissociation

ECID Electron-capture–induced dissociation

ECMS Electron-capture mass spectrometry

ECNCI Electron-capture negative chemical ionization

ECNI Electron-capture negative ionization

A moderator gas used in a chemical ionization source decreases the energy of electrons emitted from a filament to energies sufficiently low that the electrons are captured by electrophilic compounds to form stable molecular negative ions M-. . The electron-capture cross section can be increased with use of a proper electrophilic derivative. In this work, a pentafluorobenzoyl ester derivative is prepared of triclosan, a common antibacterial agent in consumer products. An analytical protocol for determination of this agent in plasma and milk samples is developed and validated. See M. Allmyr, M.S. McLachlan, G. Sandborgh-Englund, and M. Adolfsson-Erici, Anal. Chem. 78(18), 6542–6546 (2006).

ECP Emitter-current programmer

EDD Energy-distribution difference

EE Even-electron ion

EED Electron excitation dissociation

EHI Electrohydrodynamic ionization

EI Electron ionization; electron impact

EIEIO Electron-induced excitation of ions from organics

EIS External ion source

EJMS European Journal of Mass Spectrometry

EM Electron multiplier

EM-MS Electron monochromator mass spectrometry

An electron monochromator produces a well-defined source of electrons that can be used as part of an electron ionization source to create both positive and negative ions. Stable molecular negative ions are formed only for electrophilic compounds in the presence of low energy electrons, which can be produced by the electron monochromator. In this study, the authors use EM-MS to quantify three different dinitroaniline pesticides present in tobacco smoke. The pesticide residues derive from the farming practices used to produce the various tobacco products. See A.J. Dane, C.J. Havey, and K. Voorhees, Anal. Chem. 78, 3227–3233 (2006).

EMP Electron multiplier

EOID Electro-optical ion detector

EP Entrance potential

EPD Electron photodetachment dissociation

Polyanions formed from DNA were stored in a QIT and irradiated with laser light. The irradiation caused electron loss from the polyanion to form a radical anion, and subsequent CID of the anion provided a MS-MS spectrum that provided good sequence information and a lack of internal cleavages. Preliminary work indicates that even noncovalent bonds of the DNA can be preserved through the initial electron photodetachment process. See V. Gabellica, T. Tabarin, R. Antoine, F. Rosu, I. Compagnon, M. Broyer, E. De Pauw, and P. Dugourd, Anal. Chem. 78, 6564–6572 (2006).

ERMS Energy-resolved mass spectrometry

ES Electrospray; electrospray ionization

ESA Electrostatic analyzer

ESCI Combined electrospray and atmospheric pressure ionization source

ESI Electrospray ionization

ESMS European Society for Mass Spectrometry

ESP Electrospray ionization

ESPI Electrospray ionization

esu Electrostatic unit

ET Electron transfer

ETD Electron-transfer dissociation

ETV Electrothermal vaporization

eV Electron volt

FA Flowing afterglow; ferulic acid (a MALDI matrix)

FAB Fast-atom bombardment

FAIMS High-field asymmetric waveform ion mobility spectrometry

FAME Fatty acid methyl ester

FC Faraday cup

FD Field desorption

FFID Fission-fragment-induced desorption

FFR Field-free region

FI Field ionization

FIA Flow-injection analysis

FIB Fast-ion bombardment

FID Free-induction decay

FIK Field ionization kinetics

FIMS Field-ionization mass spectrometry

FNB Fast-neutral beam

FRET Fluorescence resonance energy transfer

FTICR Fourier-transform ion cyclotron resonance

FTMS Fourier-transform mass spectrometry

FT–TOF Fourier-transform time-of- flight mass spectrometry

FWHH Full width at half height

FWHM Full width at half maximum

G Multiplier gain; glycerol (an LSIMS matrix)

GC Gas chromatography

GC–MS Gas chromatography–mass spectrometry

GDMS Glow discharge mass spectrometry

GEMIOS Gas and electromagnetic ion optical simulator

GEMMA Gas-phase electrophoretic mobilty molecular analysis

GIANT Gas-phase ion and neutral thermochemistry (a published compilation of such data)

GLP Good laboratory practice

GPC Gel permeation chromatography

HABA 2-(4-Hydroxyphenylazo) benzoic acid (a MALDI matrix)

HASTE High-amplitude short-time excitation

4-HBSA 4-Hydroxybenzenesulfonic acid (an LSIMS matrix)

HCCA α-Cyano-4-hydroxycinnamic acid (a MALDI matrix)

HCD Heated capillary dissociation

HCP Hollow cathode plume

H/D Hydrogen–deuterium

HDX Hydrogen–deuterium exchange

HE High energy

HECD Hot electron capture dissociation

2-HEDS 2-Hydroxyethyl disulfide (an LSIMS matrix)

HILIC Hydrophilic interaction liquid chromatography

HKSMS Hong Kong Society for Mass Spectrometry

HMM High molecular mass

HPA 3-Hydroxypicolinic acid (a MALDI matrix)

2-HPEA 2-Hydroxyphenethyl alcohol (an LSIMS matrix)

HPMS High-pressure mass spectrometer

HRMS High-resolution mass spectrometry

HSI Hyperthermal surface ionization

HSMS Headspace mass spectrometry

HT Hadamard transform; high tension, which is a Britishism for HV (high voltage)

HTMS High temperature mass spectrometry

HT-TOFMS Hadamard transform time-of-flight mass spectrometry

HV High voltage

HXMS Hydrogen–deuterium exchange mass spectrometry

IAA Indole acrylic acid (a MALDI matrix)

IC Ion chromatography

ICAT Isotope-coded affinity tag

ICDR Ion cyclotron double resonance

ICEMS Ion-pair liquid chromatography electrospray ionization mass spectrometry

IC–MS Ion chromatography–mass spectrometry

ICP–MS Inductively coupled plasma– mass spectrometry

ICR Ion cyclotron resonance

IDMS Isotope dilution mass spectrometry

IE Ionization energy; ionizing energy; ion evaporation

IELC Ion-exchange liquid chromatography

IJMSIP International Journal of Mass Spectrometry and Ion Physics (volumes 1–62)

International Journal of Mass Spectrometry and Ion Processes (after volume 62)

IJMS International Journal of Mass Spectrometry

IKE(S) Ion kinetic energy (spectrometry)

IMAC Immobilized metal affinity chromatography

IMS Ion mobility spectrometry; imaging mass spectrometry

Imaging mass spectrometry based on MALDI uses mass spectra convoluted with planar (x,y) coordinates to provide spatial tracking of both endogenous and exogenous compounds with spatial resolution and molecular specificity. In this work, the authors track drug and drug metabolite distributions within whole-body tissue sections. When the tissue sections are sampled in time, the temporal distributions also can be established. This work is one example of a rapidly growing area of application. See S. Khatib-Shahidi, M. Andersson, J.L. Herman, T.A. Gillespie, and R.M. Caprioli, Anal. Chem. 78, 6448–6456 (2006).

IMSS International Mass Spectrometry Society; Irish Mass Spectrometry Society

INC Ion-neutral complex

IP Ionization potential

IPD Ion-photon detector

IRMPD Infrared multiphoton dissociation

IRMS Isotope ratio mass spectrometry

ISD In-source decay

ISMAS Indian Society for Mass Spectrometry

ISP Ionspray

ISR Ion–surface reaction

ITD™ Ion-trap detector

ITMS Ion-trap mass spectrometry

ITPMS Isotacophoresis mass spectrometry

IUPAC International Union of Pure and Applied Chemistry

JASMS Journal of the American Society for Mass Spectrometry

JEOL Japan Electro-Optics Laboratory

JMS Journal of Mass Spectrometry

K Kelvin

KCMS Knudsen cell mass spectrometry

kDa Kilodalton

KERD Kinetic energy release distribution

K+IDS Potassium ion desorption spectrometry

KM Kinetic method

KNN K-nearest neighbor

L Length (of flight tube)

LA Laser ablation

While MALDI is used for biological analyses, the direct impact of a laser on a surface such as a silicate glass produces a vaporized aerosol that can then be directed into an ICP-MS system for elemental analysis. For the ICP-MS system to provide an accurate analysis, the vaporization and transfer efficiency must be mass- and element-independent. This ideal case is not achieved in practice, and the authors of this careful work on laser ablation study two different laser ablation systems, and different carrier gases, as means of sample introduction in ICP-MS. See Z. Wang, B. Hattendorf, and D. Gunther, J. Amer. Soc. Mass Spectrom. 17(5), 641–651 (2006).

LAMMA™ Laser microprobe mass analyzer

LAMPAS Laser mass analyzer for particles in the airborne state

LBO Light beam oscillograph

LC-MS Liquid chromatography– mass spectrometry

LD Laser desorption

LDI Laser desorption ionization

LDLP Laser desorption–laser photoionization

LE Low energy

LI Liquid ionization

LIAD Laser-induced acoustic desorption

LIMA™ Laser ionization mass analyzer; laser ion microprobe analyzer

LIT Linear ion trap

LMCO Low mass cut-off

LMM Low molecular mass

LMMS Laser microprobe mass spectrometer

LMS Laser mass spectrometry

LMW Low molecular weight

LOD Limit of detection

LOQ Limit of quantification

LRB Laboratory reagent blank

LSIMS Liquid matrix secondary ion mass spectrometry

LTOF Laser time-of-flight; linear time-of-flight

LV/EI Low voltage electron ionization

m Mass of the ion in units of u

M/A Matrix/analyte ratio

MAGIC Monodisperse aerosol generator interface to chromatography

MALD Matrix-assisted laser desorption

MALDI Matrix-assisted laser desorption ionization

MAPS Method for analyzing patterns in spectra

MB Molecular beam

MBMS Molecular beam mass spectrometry

MCA Multichannel analyzer

MCI Massive cluster impact

MCMS Midwest Center for Mass Spectrometry

MCP Microchannel plate (detector)

MCPD Microchannel plate detector

MEND Matched filtration with experimental noise determination

MDMS Microdialysis mass spectrometry

MDL Method detection limit

MELDI Material-enhanced laser desorption–ionization

The authors describe various functionalized carrier materials (listing cellulose, silica, a glycidyl methacrylate– divinylbenzene polymer, and diamond powder) that act as matrices for a relatively conventional MALDI-TOF analysis. The advantages of MELDI include the high capacity and selective functionality useful in binding serum constituents to be analyzed. The spectral effects of particle shape and pore size were delineated; highly porous spherical particles with diameters of a few micrometers were shown to provide superior mass spectra. See I. Feuerstein, M. Najam-ul-Huq, M. Rainer, L. Trojer, R. Bakry, N.H. Aprilita, G. Stecher, C. Huck, H. Klocker, G. Bartsch, A. Guttman, and G.K. Bonn, J. Amer. Soc. Mass Spectrom. 17(9), 1203–1208 (2006).

MESIMS Matrix-enhanced secondary ion mass spectrometry

MI Metastable ion

MID Multiple ion detection

MIKE(S) Mass-analyzed ion kinetic energy (spectrometry)

MIM Multiple ion monitoring

A lowered limit of detection can be achieved in mass spectrometric analyses with the use of selected ion monitoring; monitoring the intensities of several ions in time (for instance, as mixture components are eluted from a gas chromatograph) is called multiple ion monitoring. Early work suggested that monitoring ions of three different selected masses should be sufficient to confirm the presence of a targeted compound. However, using an expanded library of 100,000 electron ionization mass spectra, and more generalized restraints on the relative intensities of ions in the standard mass spectra of the targeted compound, recent work suggests that additional ions may need to be monitored and the potential for false positives reassessed. See S.E. Stein and D.N. Heller, J. Amer. Soc. Mass Spectrom. 17(6), 823–835 (2006).

MIMS Membrane introduction mass spectrometry

MIP Microwave-induced plasma

MNBA m-Nitrobenzyl alcohol, an LSIMS matrix

MNDO Modified neglect of differential overlap

MO Molecular orbital

MOWSE Molecular weight search

MPD Multiphoton dissociation

MPI Multiphoton ionization

MPM Multiple peak monitoring

MQDT Multichannel quantum defect theory

MRM Multiple reaction monitoring

MSn If n = 2, MS-MS. If n = 3, MS-MS-MS. Repeat as necessary.

MSB Mass Spectrometry Bulletin

MSD Mass-selective detector

MSDC Mass Spectrometry Data Center

MSE Matrix suppression effect

An electrospray sample deposition technique was used to deposit matrix–analyte solutions of varying thickness onto a surface then analyzed by MALDI mass spectrometry. A matrix suppression effect score was calculated by dividing a standard analyte ion response by the sum of the analyte and matrix ion responses for the samples of varying thickness. The matrix suppression is therefore a measure of how the matrix signal could be reduced relative to a persistent analyte ion signal. The well-known "first shot" effect could be observed in this work, and the results that showed an enhancement in matrix suppression effect with thinner layers considered in terms of a model that considers a first-step ionization of the matrix, enhanced in the near vicinity of the metal surface. See G. McCombie and R. Knochenmuss, J. Amer. Soc. Mass Spectrom. 17(5), 737–745 (2006).

MSM Multiple scattering method

MSR Mass Spectrometry Reviews

MS-MS Mass spectrometry-mass spectrometry

MSSJ The Mass Spectrometry Society of Japan

MSSS Mass spectral search system

The first mass spectral database used for organic compound identification was developed at NIH and used a system called the MSSS. It was implemented on a PDP-10 computer and was first described in the journal Analytical Chemistry in 1972. The first dial-up connection to the mainframe computer used a 110-baud modem. Feeling old yet? See S.R. Heller, Today's Chemist at Work 8(2), 45–46, 49–50 (1999).

MULTUM Multiturn mass spectrometer

MW Molecular weight

Mwt Molecular weight

N Neutral molecule or species

NBA m-Nitrobenzyl alcohol (an LSIMS matrix)

NCBI National Center for Biotechnology Information

NCE Normalized collision energy

NCI Negative ion chemical ionization

NET Normalized elution time

NI Negative ion

NICI Negative ion chemical ionization

NOBA m-Nitrobenzyl alcohol (an LSIMS matrix)

+NR+ Neutralization reionization; a positive ion is neutralized and then reionized

NRMS Neutralization reionization mass spectrometry

NSI Nanospray ionization

NSMS Norwegian Society for Mass Spectrometry

NVMS Dutch Society for Mass Spectrometry

o Orthogonal

oa Orthogonal acceleration

ODN Oligodeoxynucleotide

OE Odd-electron ion

OMS Organic Mass Spectrometry

oTOF Orthogonal (source) time-of- flight

PA Proton affinity

PAD Postacceleration detector

PAI Postablation ionization

PALMS Particle analysis by laser mass spectrometry

PBM Probability-based matching

PBMS Particle-beam mass spectrometry

PCA Principal component analysis

PCI Positive ion chemical ionization

P2CID Parallel collision-induced dissociation

A quadrupole-time-of-flight mass spectrometer is used to generate MS-MS spectra with higher signals than a single collision-induced dissociation (CID) process. A higher cone voltage is used to effect source CID, and then these energized ions are passed into a collision cell, where a second CID process ensues. The authors claim a two- to fourfold increase in the product ion intensities observed for higher mass ions, which increases, for example, the intensities of structurally informative sequence ions from peptides. See A.A. Ramos, H. Yang, L.E. Rosen, and X. Yao, Anal. Chem. 78(18), 6391–6397 (2006).

PCR Polymerase chain reaction

PD Plasma desorption; photodissociation

PDF Pulsed dynamic focusing

PDMS Plasma desorption mass spectrometry

PEPICO Photoelectron-photoion coincidence spectroscopy

PES Photoelectron spectroscopy

PFK Perfluorokerosene

PFT Porous flow-through (electrode)

PFTBA Perfluorotributylamine

PHD Pulse height distribution

PHT Peptide hits technique

PI Positive ion

PID Particle-induced desorption; photon-induced dissociation

PIE Photoionization efficiency

PIT Protein-identification technology

PIT-MS Proton-transfer ion-trap mass spectrometry

PIPECO Photoion-photoelectron coincidence spectroscopy

PLE Pressurized liquid extraction

PMF Peptide mass fingerprinting

PMM Peptide mass maps

PMS Parallel mass spectrometry

PPINICI™ Pulsed positive-ion negative-ion chemical ionization

ppm Part per million

PSD Postsource decay

PSI Pulsed sample introduction

PSM Peptide-spectrum match

PSPF Postsource pulse focusing

PTM Posttranslational modification

PTR Proton-transfer reaction

PTSM Polish Society for Mass Spectrometry

PyMS Pyrolysis mass spectrometry

q Quadrupole device used in rf-only mode as a collision cell

Q Quadrupole mass filter

Q Reaction endothermicity

QA Quality assurance

QC Quality control

qCID Collision-induced dissociation accomplished within an rf-only quadrupole

QCPE Quantum Chemistry Program Exchange

QET Quasi-equilibrium theory

QFTMS Quadrupole Fourier- transform mass spectrometry

QIT Quadrupole ion trap

QLT Quadrupole linear ion trap

QTOF Quadrupole followed by a time-of-flight mass analyzer

QUISTOR Quadrupole ion storage trap

r radius of electric or magnetic sector

RA Relative abundance; trans,trans-retinoic acid (a MALDI matrix)

RCM Rapid Communications in Mass Spectrometry

rdbe Rings plus double bonds equivalent

REE Rare earth elements

REMPI Resonance-enhanced multiphoton ionization

rf Radio frequency; Response factors

RGA Residual gas analyzer

RI Relative intensity

RIMS Resonance-ionization mass spectrometry

RiT Rectilinear ion trap

RLCT Rayleigh limiting charge theory

RN Resonance neutralization

ROOMS Regular old ordinary mass spectrometry

R2PI Resonant two-photon ionization

RP Resolving power

RPD Retarding potential difference

RPLC Reversed-phase liquid chromatography

RRKM Rice, Ramsperger, Kassel, and Marcus

RSMS Rapid single particle mass spectrometer

rTOF Reflectron time-of-flight

SA Sinapinic acid (a MALDI matrix)

SAAMS South African Association for Mass Spectrometry

SCMS Sanibel Conference on Mass Spectrometry

SCX Strong cation exchange

SDM Selected dissociation monitoring

SDME Single-drop microextraction

SEAC Surface-enhanced affinity capture

SEC Size exclusion chromatography

SEEM Spanish Society for Mass Spectrometry

SELDI Surface-enhanced laser desorption ionization

SEND Surface-enhanced neat desorption

SFC-MS Supercritical fluid chromatography–mass spectrometry

SFE Supercritical fluid extraction

SFSM French Society for Mass Spectrometry

SGMS Swiss Group for Mass Spectrometry

SI Spray ionization; surface ionization

SID Surface-induced dissociation

SIFDT Selected ion flow drift tube

SIFT Selected ion flow tube

SILVER Spectrum intensity likelihood viewer

SIM Selected-ion monitoring

SIMBROC Simulated background and reduction/oxidation calculations

SIMS Secondary ion mass spectrometry

SIN Surface-induced neutralization

SIOMS Surface ionization organic mass spectrometry

SIR Selected-ion recording

SIRMS Stable-isotope-ratio mass spectrometry

SMB Supersonic molecular beam

SMOKE Stored modulation of kinetic energy

SMOW Standard mean ocean water

SMSS Swedish Society for Mass Spectrometry

S/N Signal-to-noise ratio

SOMO Singly occupied molecular orbital

SPE Solid-phase extraction

SPME Solid-phase microextraction

SRBC Simulated reduction and background calculations

SRM Selected reaction monitoring; standard reference material

SSIMS Static secondary-ion mass spectrometry

SSMS Spark source mass spectrometry

STIRS Self-training interpretive and retrieval system

STMT Stieltjes–Tchebycheff moment theory

SWIFT Stored-waveform inverse Fourier transform

SWIM Stored waveform ion modulation

t Ion flight time; time

T Tesla

TAC Time-to-amplitude converter

TAMS Tandem accelerator mass spectrometry

TDC Time-to-digital converter

TDMS Thermal desorption mass spectrometry

TEL Translational energy loss

TEPSICO Threshold electron photoion secondary ion coincidence

TES Translational energy spectroscopy

TGAMS Thermogravimetric analysis mass spectrometry

TG GC-MS Thermogravimetry gas chromatography–mass spectrometry

THAP 2,4,6-Trihydroxyacetophe- none (a MALDI matrix)

TI Thermal ionization

TIC Total ion current

TID Trapped-ion detector; thermally induced dissociation

TIMS Thermal-ionization mass spectrometry

TISI Turbo ionspray ionization

TIP™ True isotopic pattern

TLC-MS Thin layer chromatography–mass spectrometry

TMS Trimethylsilyl; tandem mass spectrometry; thermospray mass spectrometry

ToF Time-of-flight

TOF Time-of-flight

TOFMS Time-of-flight mass spectrometry

TQ Triple quadrupole

TQMS Triple-quadrupole mass spectrometry

TRPD Time-resolved photodissociation

TS Transition state; transition structure

TSP Thermospray

TSQ™ Triple-stage quadrupole

u Mass unit (1/12 of the mass of 12C), now replaced by dalton

UVLD Ultraviolet laser desorption

UVPD Ultraviolet photodissociation

v Ion velocity

V Accelerating voltage

VG Vacuum Generators, former name of a manufacturer of mass spectrometers

VOC Volatile organic compound

VMSOW Vienna mean standard ocean water

VTST Variational transition state theory

W Wien filter

z Charge state of the ion in units of the electric charge

ZPE Zero-point vibrational energy

Kenneth L. Busch (KLB) has taught the course: "Introduction to Mass Spectrometry" for the past 15 years at professional conferences. During those 15 years, mass spectrometry has been reinvented, reconfigured, redirected, and submerged in acronyms. Slang and jargon in mass spectrometry is a separate issue that will be tackled ASAP. The contents of this article represent the views of the author (MHOs), and not those of the National Science Foundation (NSF). KLB can be reached at