The NIST 23 Mass Spectral Library
& Search Software (NIST 2023/2020/2017/EPA/NIH)

About

Four-page brochure of NIST 17 (PDF)

Benefits:

• Identify unknown compounds from EI (GC/MS) and MS/MS spectra, using library searching.
• Hundreds of thousands of EI MS spectra, MS/MS spectra, GC data & retention indices, and/or chemical names/structures.
• World's most widely used and trusted mass spectral reference library.
• Search software included. Supports most MS software systems (Agilent ChemStation/MassHunter, Thermo Xcalibur/Chromeleon, Shimadzu GCMS Solutions, Waters MassLynx, Thermo Xcalibur, PE TurboMass, etc.).

Description

The NIST 23 (2023) mass spectral library, the successor to the NIST 20/17/14, is a fully evaluated collection of electron ionization (EI) and MS/MS mass spectra, with chemical and GC data, plus search software to identify your own unknown spectra. It is a product of a more than three decade, comprehensive evaluation and expansion of the world's most widely used mass spectral reference library by a team of experienced mass spectrometrists at the National Institute of Standards and Technology (NIST) in which each spectrum was examined for correctness.

NIST 23 Components

NIST 23 is not just a mass spectral library. It contains these components:

• Electron ionization (EI) mass spectral library - ~394K carefully evaluated spectra of 347,100 unique compounds, with identifications, nearly all with chemical structures. 40K increase from NIST 20 (largest EI increase ever). You may search names of NIST compounds online.
• MS/MS library - 2.4 million spectra of 51K compounds (60% more than NIST 20), 186K precursor ions. Covers a variety of fragmentation methods: 49,590 HRAM (high res accurate mass) compounds, 50,071 QTOF/HCD/IT-HRAM/QqQ compounds, 49,561 ion trap (low res, up to MS4) compounds, 561 APCOI HRAM compounds. Variety of precursor ion types: 44,191 protonated, 19,620 deprotonated, 14,318 water/ammonia loss, 44,547 other in-source generated. (Also available separately as the NIST MS/MS Database.)
• Gas Chromatography (GC) data library - 492K retention index values (Kovats/Lee), 153K compounds in the EI library, covering both polar and non-polar columns. 40K increase from NIST 17. Includes retention indices with GC column conditions and literature citations. (Also available separately as the NIST GC Database.)
• NIST MS Search software (version 3.0) - software for searching (identifying) compounds from their mass spectra and for browsing mass spectral libraries. Also includes MS interpretation programs for analyzing mass spectra on the basis of chemical structure, molecular formula, isotopic patterns, and more.
• AMDIS software - software for deconvoluting gas/liquid chromatograms
• Documentation - Approximately 50 page electronic manual on setup and basic usage. Additional information is in the help files.

Libraries are formatted the binary format suitable for use alone or by the NIST MS Search software (and AMDIS). Additional instrument-specific formats (e.g. Agilent ChemStation and MassHunter) are available separately to permit library searching directly within your GC/MS or LC/MS data system.

With each purchase, we ship a DVD (installs software, libraries, and documentation). If you don't have a DVD drive, you can electronic download using the web address and license number on the DVD label.

Online Search (NIST)

To check for compounds in the NIST library, you may search names of compounds online.

Summary Statistics

Statistics for NIST versions are given below.

(*) plus quality improvements

See also What's New in NIST 23.

Electron Ionization (EI) mass spectral library

This is a "fully evaluated" collection of electron ionization (EI) mass spectra. It is the product of a more than three decade, comprehensive evaluation and expansion of the world's most widely used mass spectral reference library by a team of experienced mass spectrometrists in which each spectrum was examined for correctness. Each spectrum has been carefully evaluated, and all decisions regarding selection or deletion were made only after agreement of two experienced mass spectral evaluators, as described in presentations at major conferences. While computer methods assisted in finding chemical identification errors and inconsistencies, and revealed certain varieties of mass spectral errors, manual interpretation was the principal basis for this evaluation effort.

The NIST Electron Ionization (EI) mass spectral library consists of 394K spectra of 347K unique compounds. Besides spectra, typical data include name, formula, molecular structure (.mol), molecular weight, CAS number, contributor name, list of peaks, synonyms, and estimated and/or measured retention index.

Figure: NIST MS Search software showing EI mass spectrum and compound information.

Name: 1-Decanol
Formula: C10H22O
MW: 158 Exact Mass: 158.167066 CAS#: 112-30-1 NIST#: 374910 ID#: 37364 DB: mainlib
Other DBs: Fine, TSCA, RTECS, HODOC, NIH, EINECS, IRDB
Contributor: NIST Mass Spectrometry Data Center, 2010
InChIKey: MWKFXSUHUHTGQN-UHFFFAOYSA-N
10 largest peaks: 
	70	999 |	55	987 |	56	859 |	69	823 |	43	732 |
	41	727 |	83	724 |	84	476 |	57	452 |	97	389 |
Synonyms:
1.Decyl alcohol; 2.n-Decan-1-ol; 3.n-Decanol; 4.n-Decyl alcohol;
5.Alcohol C10; 6.Alfol 10; 7.Capric alcohol; 8.Caprinic alcohol;
9.Decanol; 10.Nonylcarbinol; 11.Sipol L10; 12.T-148; 13.Decylic Alcohol;
14.Decan-1-ol; 15.Decanol-(1); 16.Agent 504; 17.Antak; 18.Dytol S-91;
19.Decyl, n- alcohol; 20.Lorol 22; 21.Primary decyl alcohol; 22.Royaltac;
23.C 10 alcohol; 24.Epal 10; 25.Royaltac-85; 26.Royaltac M-2; 27.Lorol C10;
28.Nonylcacarbinol; 29.1-Hydroxydecane; 30.Conol 10N; 31.Kalcohl 10H;
32.NSC 406313; 33.Nacol 10-99

The NIST EI Library focuses on:

• Drugs, metabolites, and poisons,
• Pesticides and fungicides,
• Organics present in soil, water and air,
• Aminoacids, di- & tri-peptides,
• Common sample contaminants,
• Common analytical derivatives of the above

Here is a breakdown by mass: (NIST 17)

The best quality spectra are placed in the Main Library; and good-quality, alternate spectra are provided in the Selected Replicates Library.

NIST includes a collection salts and low-volatile substances not expected to be measurable by GC/MS. Here's a breakdown by mass (data from 2008 version, of 717 spectra of 672 compounds):

To check whether certain compounds or classes of compounds exist within the NIST database, you may do an online search of compounds in the NIST MS database.

NIST spectra have been obtained from thousands of sources. Major sources include

# Spectra, Name  (data from 2014 version)
44447 V.G.Zaikin,R.S.Borisov, Topchiev Inst. Petrochem. Synth (TIPS RAS), Moscow
30498 A.A.Kutin, Moscow, Russia
29729 Chemical Concepts
22527 NIST Mass Spectrometry Data Center
      31(2014),  199(2013), 1347(2012),  270(2011), 4034(2010), 1126(2009),   60(2008),
       237(2007), 1335(1998),   48(1995), 2775(1994),  211(1992), 2183(1990), 8672(other)
16737 Japan AIST/NIMC Database: 9026(MS-NW-X), 7711(MS-IW-X)
11135 L.N.Kulikova,R.S.Borisov,V.G.Zaikin, Peoples' Friendship University of Russia, Moscow
 9136 J. Little, Eastman chemical company,Kingsport,TN
 7895 Div. of Experiment Therapeutics WRAIR, WRAMC, Washington DC 20307
 4794 V.A.Korolev, Moscow, Russia
 4581 A.T.Lebedev, Moscow State University, Russia
 3760 LAC, NIDDK, NIH, Bethesda, MD 20892
 2836 D.HENNEBERG, MAX-PLANCK INSTITUTE, MULHEIM, WEST GERMANY
 2807 ASES Database, Dalian Institute, P.R. China
 2735 CARL DJERASSI DEPT OF CHEM STANFORD UNIV STANFORD CALIF 94305
 2308 Asinex Ltd, Moscow, Russia
 1886 Institute of Organic Chemistry, USSR: 1988,1990
 1862 A.Mazepa, Phys.-Chem.Institute, Odessa, Ukraine
 1728 RADIAN CORP
 1683 Humboldt-Universitat zu Berlin, Department of Chemistry, Analytical Group
 1666 A.Pleshkova, Nesmeyanov Inst.Org.Elem.Cpds, Moscow
 1662 Chuck Anderson, Aldrich Chemical Co.
 1279 Drug Lab
 1105 TNO Volatile Compounds in Food - Chemical Concepts
 1093 Organic Synthesis Lab, MSU, Moscow
 1045 William W. Christie, Mylnefield Lipid Analysis, Invergowrie, Dundee, Scotland, UK
  995 John Halket,Royal Holloway, University of London, UK
  898 A. Brossi, LC, NIDDK, NIH, Bethesda, MD 20892
  812 Patti Price, Georgia Bureau of Investigation, Decatur, Georgia
  797 V.A.KOPTYUG, ATLAS OF MASS SPECTRA OF ORGANIC COMPOUNDS
  787 H. Fales, LC, NHLBI, NIH, Bethesda, MD 20892
  704 Tox21 Consortium/NIST Mass Spectrometry Data Center, 2012
  702 J.E. WILKINSON S-CUBED, SAN DIEGO, CA.
  600 Dr. Jiri Zamecnik, DCIEM, North York, Canada, GP Library
  566 R.T.HOLMAN,UNIVERSITY OF MINNESOTA
  549 Philip Morris R&D
  542 AAFS Toxicology Section MS DB Committee, U. Alberta, Canada
  522 A.S.Moskovkin,I.M.Karnaukh, Russian Center on Disaster Medicine
  495 Finnigan MAT: Toxicological Library (LIBR-TX)
  492 B. Derendyaev, Novosibirsk Institute of Organic Chemistry
  406 P.A. Leclercq, Lab. Instrum. Anal., Eindhoven Univ. Technol., Netherlands
  396 Leung Pu, NIH, Bethesda, Maryland, U.S.
  395 A. Lebedev, Chemistry Department, Moscow State University
  384 J. Klune, Insect Chem. Ecol. Lab., USDA, Beltsville, MD 20705
  354 Insect Chem. Ecol. Lab., USDA, Beltsville, MD 20705
  374 G.S. KING, CHEM. PATHOL. DEP., QUEEN CHARLOTTE'S HOSP., LONDON
  364 R RYHAGE MS-LAB KAROLINSKA INSTITUTET STOCKHOLM SWEDEN
  352 L. Cohen, LC, NIDDK, NIH, Bethesda, MD 20892
  343 Darrick Lee, Cayman Chemical, Ann Arbor, MI
  333 J.M. Halket, Trace Anal. Unit (TAU), London, UK
  332 HD Science, UK
  326 N.D.Kagramanov, Moscow, Russia
  317 W.Jennings, T.Shibamoto
  310 F. TURECEK,HEYROVSKY INST PHYS CHEM & ELECTROCHEM,PRAGUE,CZECH
  308 A. Mujsce, AT&T Bell Labs., Murray Hill, N.J., USA
  296 O A MAMER, MCGILL UNIVERSITY, MONTRE
  295 G. Lange, Inst. Org. Chem., Univ. Wurzburg, Germany
  279 TAT
  272 K. Kirk, LC, NIDDK, NIH, Bethesda, MD 20892
  144 K. Kirk, LBC, NIDDK, NIH, Bethesda, MD 20892
  272 Richard Turcotte. Direction des laboratoires d'expertises et d'analyses alimentaires, Quebec, Canada.
  262 K. Jacobson, LBC, NIDDK, NIH, Bethesda, MD 20892
  259 A.Pleshkova, Moscow,Russia
  255 A.Pleshkova, Inst. Org. Elem. Cpds, Moscow
  251 Dmitri Zagorevskii, Scientific Instruments & Applications
  251 MASS SPECTROMETRY CENTER, UNIV. OF UTAH; ALDRICH
  242 J. Daly, M. Garraffo, T. Spande, LBC-NIDDK-NIH, Bethesda, MD
  241 S. MARKEY UNIV. OF COLO. MED. CTR., DENVER, COLORADO, USA
  235 Dennis Rohrbaugh, CBDCOM/ERDEC, Edgewood, MD
  231 H. Luftmann, Org. Chem. Inst., Westfalisch-Wilhelms Univ., Munster, Germany
  230 CONTINENTAL OIL CO., PONCA CITY, OKLA, USA
  217 N.Klyuev, Institute of Ecology & Evolution, RAS, Moscow
  212 S.M. Lee, CA Export Lab. Services, CA, USA
  211 J. SHAW, BORRISTON RESEARCH, ROCKVILLE, MD, USA
  198 D.G.Hayward MS, Center for Food Safety and Applied Nutrition, FDA, College Park MD.
  194 J.VOTH UNIV. OF CALIFORNIA, DAVIS, CALIFORNIA, 95616, USA
  192 BAY
  189 P. VAINIOTALO, DEPT. CHEM., UNIV. JOENSUU, JOENSUU, FINLAND
  188 Susan Richardson
  179 ATLAS OF MASS SPECTRA OF ORGANIC COMPOUNDS, V. A. KOPTYUG, ED.
  175 V.A. KOPTYUG, ATLAS OF MS OF ORG. CMPDS., ED. 2
  173 Dr. P.K. Shah, NYC Police Laboratory, NY
  166 W.T.RAINEY OAK RIDGE NATIONAL LABORATORY,OAK RIDGE,TN.USA
  162 A.I. Gren, Phys.-Chem. Inst., Acad. Sci. Ukraine, Odessa, Ukraine
  162 Dmitri Zagorevskii, University of Missouri-Columbia, Columbia, MO
  162 G. Lange, Inst. Org. Chem., Univ. Wurzburg, Wurzburg, Germany
  161 A. Brossi, LAC, NIDDK, NIH, Bethesda, MD 20892
  160 R.E.Ardrey ET AL.Pharmaceutical Mass Spectra,L.,1985
  157 Association of Official Racing Chemists
  157 N.W. Davies, Centr. Sci. Lab., Univ. Tasmania, Hobart, Australia
  156 Institute of Chemistry, SAS, Bratislava, Slovakia
  151 S.A. Rang et al., IR & MS of Unsatd. Hydrocarbons, 1977
  149 ChemBridge Corp.
  145 MASS SPECTROMETRY CENTER, UNIV. OF UTAH EPA-PTSEL
  144 CATALOGUE OF MASS SPECTRA OF PESTICIDES, APRIL, 1975; J. FREUDENTHAL & L. G. GRAMBERG, NAT'L INST. OF PUBLIC HEALTH, THE NETHERLANDS
  142 VERIFIN - Methodology
  141 Mark Whitten, Florida Museum of Natural History, U. of Florida
  139 FOOD RESEARCH REPORT 1XX, K.E. MURRAY & COLLEAGUES, DIV. OF FOOD RESEARCH, CSIRO, AUSTRALIA
  137 VERIFINN
  135 B.R. PETTIT, QUEEN CHARLOTTE'S MAT. HOSP., LONDON, U.K.
  134 J.T. CLERC, ORGANIC CHEM. LAB., ETH, ZURICH, SWITZ.
  132 R. P. Adams and V. Dev, Synthesis and GCMS analysis of angelates and tiglates as an aid to identification of these components in essential oils, Flavour and Fragrance Journal, 25, 71, 2010
  129 Virginia Division of Forensic Science
  127 E. Zissis, LC, NIDDK, NIH, Bethesda, MD 20892
  126 Frank Antolasic, RMIT Applied Chemistry Department, Victoria Australia 3001
  123 S K.-T. Yu et al. RI and mass spectra of PFP and HFB esters of carboxylic acid, Nat Inst for Petroleum and Energy Research, 1990
  122 R. C. DOUGHERTY
  119 H. ALDERCREUTZ, UNIVERSITY OF HELSINKI, HELSINKI, FINLAND
  117 M.G.HORNING,INST.FOR LIPID RES,BAYLOR COLL.OF MED,HOUSTON,TEX
  115 H.LAATSCH,INST. ORG. CHEM.,GEORG-AUGUST-UNIV. GOTTINGEN,W.GER.
  111 Pu Leung, NIH, Bethesda, MD
  110 D.J.HARVEY UNIV. DEPT. OF PHARMACOLOGY, OXFORD, UK
  110 T.A.BLAZER, DU PONT, GIBBSTOWN, N.J., USA
  107 OGDEN BioServices Corp., NCI, Rockville, MD 20852
  104 USAF ACADEMY, COLORADO SPRINGS, COLORADO 80840; J LLOYD PFLUG
  102 J.M. MILLER,BROCK UNIVERSITY,ONTARIO,CANADA
  102 L. Tsai, LB, NHLBI, NIH, Bethesda, MD 20892
  102 P. BRUCK, MAGYAR TUDOMANYOS AKADEMIA, HUNGARY
  101 CSV Ltd., Moscow, Russia
  101 FDA, Los Angeles District Laboratory
  101 R.W.A.OLIVER UNIV. OF SALFORD, SALFORD, LANCASHIRE, UK
  ...and thousands of other sources...

MS/MS Library

2023 Details

51,501 Compounds, 60% More than 2020 400 K Precursor Ions – 2.4 M Spectra

Fragmentation Methods: 49,590 HRAM (High Res Accurate Mass) compounds, 50,071 QTOF, HCD, IT-HRAM, QqQ compounds, 49,561 Ion Trap Compounds (Low Res., up to MS4) compounds, 561 APCI HRAM Compounds

Precursor Ion Types: 44,191 Protonated, 19,620 Deprotonated, 14,318 Water/Ammonia Loss, 44,547 Other In-Source Generated

2017 Details

This release contains two MS/MS libraries (nist_msms and nist_msms2), one for small molecules, di and tri peptides and the other for commercially available peptides. It has 652,475 spectra of 123,881 ions of 15,243 different compounds including 1,436 biologically-relevant peptides. See NIST MS/MS for details on the MS/MS library.

Most of the MS/MS spectra have been measured on ion trap and collision cell (qTOF, QQQ, and HCD) instruments using electrospray ionization, although spectra from a number of other instrument types and ionization methods are represented.

The MS/MS Library can optionally be purchased separately at a lower price (with a complete copy of the MS Search software), if you are not interested in the other data in NIST.
Tip: Even though MS/MS and EI spectra differ and MS/MS spectra are therefore only directly library searched against the MS/MS library, there are still ways to utilize the EI library for MS/MS interpretation. See the article Structural Identification of Unknowns from Spectra Obtained Using LC/MS and CAD Techniques and EI Mass Spectral Database.

Figure: MS/MS search tab in NIST14. Spectra organized by positive/negative charge, mass, formula, compound name, and acquisition energy/conditions.

Gas Chromatography (GC) Data Library

Gas phase retention data for compounds common to the EI and NIST Retention Data collection are provided with links to the EI library. This involves 492K Kovacs retention indices and corresponding GC methods, column conditions and literature citations for compounds, 153K of which are in the EI spectra library. Data include both non-polar and polar columns. Most values were abstracted from the open literature and then compared to replicate values and estimates to find and remove errors. We also continue to provide estimates of retention indices for most compounds in the library using an extension of a method developed earlier for boiling points [2-3].

GC data includes

• GC column info: column type (Capillary or Packed), column class (Semi-standard non-polar, Standard non-polar, or Standard polar), column diameter (e.g. 0.25 mm), column length (e.g. 30 m), active phase (e.g. DB-5), substrate (e.g. Chromosorb W), phase thickness (e.g. 0.25 um), and carrier gas (e.g. N2/Helium/H2/etc.).
• GC method: description, program type (Ramp, Complex, or Isothermal), Start Temp, End Temp, Start Time, End Time, and Heat Rate
• Retention index data: Retention index type (Normal alkane RI, Linear RI, Kovats RI, Lee RI, Normal alkane RI value specified by scale definition, Lee RI value specified by scale definition) and retention index (e.g. 514).
• Compound identification: Name (e.g. Limonene), Formula (e.g. C10H16), Synonyms (e.g. Cyclohexene, 1-methyl-4-(1-methylethenyl)-), INCHIKEY (e.g. XMGQYMWWDOXHJM-UHFFFAOYSA-N) (lookup), ID (e.g. 33687), CAS Number (e.g. 138-86-3), and NIST NIST Number (e.g. 79639).

Typical GC data for a compound (decanol) is below:

Experimental RI median±deviation (#data) 
Semi-standard non-polar:	1273±2 (69)
Standard non-polar:     	1257±3 (73)
Polar:                  	1760±9 (70)
Estimated non-polar retention index (n-alkane scale): 
Value: 1258 iu
Confidence interval (Alcohols):  41(50%) 176(95%) iu

Retention index. 
1. Value: 1256 iu
Column Type: Capillary
Column Class: Standard non-polar
Active Phase: CP-Sil PONA GB
Column Length: 100 m
Carrier Gas: He
Column Diameter: 0.25 mm
Phase Thickness: 0.25 um
Data Type: Linear RI
Program Type: Ramp
Start T: 140 C
End T: 230 C
Heat Rate: 5 K/min
Start Time: 10 min
End Time: 25 min
Source: Cunicao, M.M.; Lopes, A.R.; Cocco, L.C.; Yamamoto, C.I.; Plocharski,
R.C.B.; Miguel, M.D.; Junior, A.G.; Auer, C.G.; Miguel, O.G., Phytochemical
and antibacterial evaluation of essential oils from Ottonia Martiana Miq.
(Piperaceae), J. Braz. Chem. Soc., 18(1), 2007, 184-188.

2. Value: 1255.2 iu
Column Type: Capillary
Column Class: Standard non-polar
Active Phase: DB-1
Column Length: 30 m
Carrier Gas: He
Column Diameter: 0.25 mm
Phase Thickness: 0.25 um
Data Type: Linear RI
Program Type: Ramp
Start T: 40 C
End T: 325 C
Heat Rate: 3 K/min
Source: Sun, G.; Stremple, P., Retention index characterization of flavor,
fragrance, and many other compounds on DB-1 and DB-XLB, 2003.

...214 more GC records (omitted from this display)...

The GC data is useful not only for the GC retention index values but also for the GC column conditions and cited literature that goes with it.

Figure: NIST MS Search software showing GC method and retention index data for a compound with an EI mass spectrum.

See NIST GC/RI for details on this library.

References:
[1]. Babushok, V.I., Linstrom, P.J., Reed, J.J., Zenkevich, I.G., Brown, R.L., Mallard, W.G., Stein, S.E., Development of a database of gas chromatographic retention properties of organic compounds. J.Chromatog. A, 2007, 1157, 414-421.
[2]. Stein, S.E., Brown, R.L. Estimation of normal boiling points from group contributions. J.Chem.Inform.Comput.Sci., 1994, 34, 581-587.
[3]. Stein, S.E., Babushok, V.I., Brown, R.L., Linstrom, P.J., Estimation of Kovats retention indices using group contributions. J.Chem.Inf.Modeling, 2007, 47, 975-980.

NIST MS Search Software

(Note: See What's New in NIST23 for more recent changes.)

Figure: NIST MS Search software

The updated, full-featured NIST MS Search Program for Windows has a full range of integrated tools.  The new updated version of this widely used, full-featured software is designed for identifying compounds from their mass spectra and for exploring mass spectral libraries.  It also contains tools for deconvoluting gas/liquid chromatograms and interpreting mass spectra.

• Library Searching via Multiple Search Modes
• Chemical Identity
• Structure Similarity
• Impurity Reduction
• Neutral Loss
• Four Peak Types
• Library Building
• GC/MS Deconvolution
• MS Interpretation
• Chemical Substructure Analysis
• Chemical Substructure Identification
• Molecular Weight Estimation
• Chlorine/Bromine Analysis
• Isotope/Formula Generator
• Integration with multiple Instrument Data Systems

Overview

This software provides a flexible means of accessing data in the NIST and User libraries including:

• chemical identification by optimized, documented spectrum-matching methods,
• analyzing mass spectra of compounds not in the library using library data,
• finding spectra with pre-selected characteristics,
• viewing spectra by name, formula, CAS registry number, molecular weight, or ID number,
• User library building and maintenance, and
• integration with a number of commercial GC/MS data systems and spectral analysis tools.

When the program is first started, seven tiled windows appear on the screen (the Desktop), each with its own data and behavior.  The behavior of any Window may be modified by making it active (clicking on it) and then pressing the AdjustWin button at the bottom of the Desktop.  As you become familiar with program operation, you may wish to change the dimensions of some Windows or even close some of them to create a custom Desktop.  When the program is restarted, it will begin with the most recent Desktop.  To save a window-arrangement Desktop for future use, select Desktop from the Menu Bar and then Save As from the resulting Menu.  Prior Desktops may be restored using one of the predefined names or your own name.  Such arrangements describe the geometry and type of information shown in each Window, not the actual data contained in it.  To restore a previous hit list, select it from the list at the top of the Hit List Window.

Library Searching - Identify unknown compounds and substructures using fully documented and optimized procedures, or search by a wide range of compound and spectral properties.

Library Building - Maintain your own libraries, add your own chemical structures and search using the same optimized procedures developed for NIST.

Flexible User Interface - Set multiple Desktop configurations with up to seven independently configured windows to examine search results and match your needs.

Use with Your Instrument Data Systems - Direct transfer between a number of commercial data systems and the NIST Search Program.

Adding User-Drawn Structures
Users may import their own chemical structures with selected user spectra.  This is done in the Tools/Librarian section of the program by connecting a user-drawn structure in standard MOL-file format with a user spectrum.  Such structure-drawing programs are widely  available (for example, ISIS/Draw may be freely downloaded from http://www.mdli.com/prod/freesw.html).  As before, if a user spectrum is given its CAS registry number and the Main Library has a structure for it, this structure will automatically be shown with user spectra unless the user has attached an imported structure to the spectrum.

Aids for Automation and Reporting
A variety of methods for automated searching and reporting of results are available.  From the File menu selection, if Print automation is on, printing will follow each library search.  A set of print options is also available from the "User Search Options" Window (select Search, then User spectrum).  This is of particular use when using this NIST Program with other data acquisition programs.

What's New in NIST23

Main scope of changes:

• The NIST 23 MS/MS Tandem library has grown to ~50,000 compounds (2.4M spectra) - all at multiple fragmentation energies and conditions.
• NIST 23 EI library (GC/GS) has added spectra of 40,000 compounds with their retention indices to their EI Library, most of them selected by, measured and evaluated at NIST.
• NIST has made significant enhancements to their metadata and their software, Mass Spectral Search 3.0.

New features of the program and database are:

• Major Spectrum Type choice (EI, Tandem, Peptide, All) helps to suppress display of search parameters most probably not used.
• Name search sorting has been increased from 16 to 249 characters; the list of names has been split into two panes: compound list in the upper pane and spectrum list in the lower pane. All spectra derived from a selected compound are shown in the spectrum list (EI: replicate, derivatives, stereoisomers; Tandem: energy, instrument, fragmentation type).
• A list of 'Other Databases' (compound references) for each compound has been significantly extended. See file Other_DBs.xlsx
• Added a new search method - Partial Spectrum Search - for searching with abbreviated spectra.
• All retention indices are displayed in the EI hit list. They are used for EI search with RI match factor correction. If experimental data is not available for a compound, a reliable AI predicted value is used in its place.
• Hovering a mouse pointer around a peak in a spectrum plot displays peak annotation.

Changes to the program (compared to MS Search v2.4 / NIST 20):

• Term "In-source/EI with accurate ion m/z" replaced with "HiRes No Precursor"
• "Penalize rare compounds" EI library search option has been retired.
• PubChem InChiKey search has been replaced with Google search.
• Major mass spectral text file extension has been changed from .MSP to .MSPEC. Extension .MSP is still recognized.

Features added to recent versions (NIST 20 MS Search v.2.4 and earlier):

• Major expansion of coverage of analytically important compounds of all classes, based on documented importance of each compound.
• For the first time ever, almost all spectra measured and fully evaluated entirely at NIST.
• Modernized and enhanced evaluation procedure allowing for multiple evaluations of spectra.
• Enhanced comparison of replicate spectra and 'best of replicates' selection. The entire library is now based on chemical structures using the NIST-developed InChIKey representation.
• Enhanced quality control using greatly improved MS Interpreter program that links ions to originating structures in the precursor molecule.
• Enhanced method for assisting the examination of results having many spectra generated by Tandem spectra. See "What's New in MS Search Program" topic in MS Search help for more details.

Some noteworthy features of the program and database in recent versions:

• A new search type, the 'Hybrid Search' for all spectrum types, enable finding many more similar compounds in the hit list. It requires a precursor mass.
• A new neutral loss search is available that eliminates restrictions on the maximum loss considered.
• Improved algorithms for scoring high mass accuracy searches that account for sparse spectra.
• Peaks shifted in the 'Hybrid Search' are shown before and after shifting.
• New filters for tandem mass spectra to limit hits by charge, precursor type, instrument, msn, and mass accuracy.
• An 'InChI' presearch that limits identification to compounds with the same structure as the search spectrum.
• Searching by exact precursor m/z.
• MS/MS browsing window and MS/MS library
• New type of mass spectrum search: MS/MS Identity search for searching for MS/MS spectra in MS/MS libraries. The updated Lib2NIST converter is a tool for creating MS/MS libraries. To create a MS/MS library, run Lib2NIST and check "MS/MS spectra only" option. For this search to work, the MS/MS spectra must contain precursor m/z values.
• Derivatives for GC/MS can be represented as their precursor molecules using a large number of derivative types.
• Retention indexes in some of Main and Replicates libraries spectra. Automatic Retention Index estimation from chemical structure (right-click spectrum text window, select Properties, Retention Indices). Polar columns were new to the 2008 release.
• Structural replicates display (in addition to usual CAS number matching) in Main and Replicate libraries, including a new feature: displaying derivatives and a wider range of tautomers. Select matching method in Options, Replicates.
• Structure searching - the program will find all chemical structures similar to the structure of the search spectrum. The searching can be done using structural data from the NIST MS database, from the user database or from a structure drawn in most chemical drawing packages. A structure may be exported to chemical drawing software. The Structure similarity search algorithm has been changed: now it includes homologue recognition that generates a match factor of 1000 for homologs. You will need to rebuild structure search databases in user libraries (as you usually need to do after editing a user library containing structures.)
• Searching in the Contributor/Comment spectral records and extracting tagged fields into the displayed spectrum text information.
• Drag and Drop - Data can be dragged and dropped between windows. Point mouse to the name of the compound in the spectrum plot window, press and hold the left mouse button, drag the spectrum and drop it into Spec List or Compare Window.
• User Library Structures - This feature has been present for some time, but many are unaware of it.
• Compare Views - There are a number of different ways for you to visually compare two spectra.
• Direct interaction with a number of chemical drawing packages - the clipboard can be used with some of them, most can be used by use of intermediate files.
• The NIST MS Search program takes advantages of many normal Windows conventions. Look at the context sensitive options on the right mouse button click and on buttons at the top of the window.
• Thermodynamics-based MS Interpreter program version 3.0. This program now works for both low and high mass accuracy spectra and permits using a mouse to select parts of a chemical structure for mass and formula determination and analysis.

New in NIST 20 Show/Hide

New in NIST 17 Show/Hide

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New in NIST 11 Show/Hide

NIST11 consists of

• The 2011 release of the NIST/EPA/NIH Electron Ionization (EI) Mass Spectral Database.
• The NIST MS/MS Database.
• The NIST GC Methods and Retention Index Database.
• A new version of the NIST Mass Spectral (MS) Program (v.2.0g).
• Enhanced versions of MS Interpreter and AMDIS are also included with NIST11.

NIST11 expands in three main areas:

• EI Database expanded (~10%) and improved.
• MS/MS database expanded by 6x.
• Updated search software & utilities with new features.

The NIST/EPA/NIH Database of Electron Ionization Mass Spectra now contains 243,893 carefully evaluated spectra for 212,961 compounds, an increase of nearly 10% from the 2008 version. This includes 23,433 new spectra of metabolites, drugs of abuse, derivatives of common compounds and many more, all measured specifically for this library. Other major enhancements have been made to the prior version including many replacements with higher quality spectra, a thorough review of chemical names and merging of the previous salts library into the main library.

The NIST Database of MS/MS spectra has undergone an even greater enhancement. The new collection more than doubles the number of compounds represented. Further, most spectra have been acquired on both ion trap and qtof/triple quad instruments, thereby increasing the number of spectra by over a factor of six compared to the 2008 version. Spectra for the latter instrument classes have been acquired over a wide range to energies to ensure matching regardless of instrument collision settings. Also, when available, high mass accuracy spectra are stored. New spectra include metabolites, peptides (biologically active peptides and all di-peptides and tryptic tri-peptides), contaminants, lipids and more. The near-final version contains 9,934 ion trap spectra for 9,138 different ions of 4,649 compounds, and 91,557 collision cell spectra (qtof and tandem quad) for 6,939 different ions of 3,774 compounds.

There have been a number of enhancements made to the NIST MS Search Program; not the least of which is the addition of an Exact Mass Search and the ability to sort Hit List by the number of synonyms and other databases (non-mass spectral databases) in which the compound can be found. Features introduced in NIST08, like the ability to use the EI Database and the Substructure Identification Tool in the interpretation of CAD spectra and the ability to display isomers and derivatives as replicate spectra, have been retained and are still available. Figure 1 shows one view of the new look of the Hit List window and Text Information window in the Lib Search Window of MS Search v.2.0g.

The NIST MS Search Program, since its introduction as a Windows version (v.2.0), has evolved into a power tool for not only the matching of spectra of unknown compounds against spectra for that compound in the EI and MS/MS Databases, but also the identification of unknowns encountered in toxicology, forensic, quality control, flavor and fragrances, environmental and many other fields through their mass spectra, regardless of the type of ionization or the analyzer used to determine the abundances of ions sorted according to their m/z values. The EI Database contains much more than just the mass spectra of compounds. It contains a primary and in many cases multiple synonyms including common and trade names. It contains names of other databases where specific compounds can be found, the name of the contributor, the compound's elemental composition, its nominal and exact mass, and the compound's chemical structure.

The NIST MS Search Program can be an invaluable tool in GC/MS method development through the use of the GC Method/RI Database, exposed in the NIST MS Search program. This utility can also be enhanced by the addition of the new NIST GC Method/RI Search Program, which can be used by itself in the GC laboratory. The NIST MS Search Program has evolved out of the needs of those in the NIST Mass Spectrometry Data Center that use it and the Databases on a daily basis. Many user suggested enhancements have been add to the Program which is distributed with NIST11.

Figure 1. Library Search Window of NIST MS Search provided with NIST11 with the Exact Mass Constraints dialog box overlaid. Note the Exact Mass field in the displayed Hit List spectrum and the two new columns for the number of synonyms for the compound and the number of other databases (non-mass spectral) containing the compound.

The following is lists a number of new features available in the NIST MS Search Program v.2.0g. Only by exploring, using the Help available in the Program and looking at the electronic manual that is provided will it be possible to begin to see all the features and benefits. Only through extensive utilization and practice will it be possible to see the entire picture available with the NIST MS Search Program.

• 1. The NIST MS Search Program v.2.0g which accompanies NIST11 has had an Exact Mass Search added to the list of Other Searches. It takes into account the presence or absence of an electron, adducts; accepts uncertainty in ppm or millimass units, and allows searching for isotope peaks or monoisotopic peaks. This has been enabled for both molecular ions AND product ions.
• 2. An Exact Mass Constraint has been added to a Spectrum Search, Sequential Search, and Any Peaks Search. This Constraint (Figure 1) has the same properties as the Exact Mass Search.
• 3. The MS Interpreter program now enables high mass accuracy for both molecular ions AND product ions.
• 4. Any mass spectral database in the NIST MS Search Program's format (including all user libraries, the Wiley Registry, and Wiley's boutique libraries like MPW, DD20XX, FFNS, the Agilent DRS libraries, etc.) can be indexed to allow use with the Exact Mass Search or Exact Mass Constraint.
• 5. As long as a chemical formula is associated with a mass spectrum, not only is the nominal mass (MW) displayed but the Exact Mass is also displayed in the spectrum'ade;s Text Information window.
• 6. Optionally displayed columns in Hit Lists (MS Search and Other Search) have been added for the number of synonyms and the number of other databases that a compound from the NIST EI Database is in; the Hit List may be sorted according to the contents of these columns (Figure 1).
• 7. Sort Hit Lists alphabetically (This was a feature in the MS Search Program in NIST08.)
• 8. Sort Spec List alphabetically or by number. (New to NIST11)
• 9. Toggle between Tab views (Lib. Search, Other Search, Name, Compare, Librarian, and MSMS Windows) using Crtl-Tab or Ctrl-Shift-Tab.
• 10. The NIST MS Search Program will now accommodate as many 127 separate databases instead of 16, which was the limit in previous versions of the NIST MS Search Program.
• 11. The NIST MS Search Program will now accommodate up to 1,048,560 spectra in a database instead of 786,420 spectra allowed in the previous version.
• 12. NIST11, like NIST08, is fully compatible with Microsoft® Vista™ and Windows 7™.
• 13. Tags in Comments Field: The concept of Tags (described below) was added to v.2.0f of the NIST MS Search Programs. Tags in the Comments field of a spectrum can be searched. With respect to the spectra in the mainlib and/or replib Databases, when using the Sequential Search, by typing a text string in the dialog box as shown in Figure 2, the Contributor field will be searched. All spectra contributed by a single source can be identified in this way. This feature is continued v.2.0g and even further enhanced.
• 14. When clicking the Right Mouse button in a Text Information window to display the popup window, there is a Find option that allows the window to be searched for a specific text string. This is particularly useful with GC Method/RI records that are associated with spectra in the NIST/EPA/NIH Database.
• 15. One or more items from any Hit List may be copied into the Windows Clipboard as tab delimited Unformatted Unicode text and pasted into Excel™. The copying may be done from the Right-Mouse-button Menu or by pressing Ctrl-K (possibly subject to change) with the spectrum (spectra) highlighted. To select all the spectra in a Hit List, press Ctrl-A (a feature from NIST08). Note: Plain ASCII text, which may be obtained using Paste Special/Unformatted text, would not have proper Greek letters.
• 16. Tags (Field titles) in User Library & Spec List Spectra A Tag is the name of a Field heading that will be displayed with the Text Information of a User Library or Spec List spectrum and can optionally appear in the line below the Plot of the spectrum. Text is designated as Tag in the Comments field of a User Library or Spec List spectrum with the Spectrum Edit function of the Librarian Window by entering the Field title (a line of characters without spaces) followed by an =. Following the = is the contents of Field. This can be a line of characters without spaces, a number or a text string with open and close quotation marks (“”). For example, the following may be entered in the Comments field of the Spectrum Information dialog box of a Spec List or a User Library spectrum:

  Structures were provided by O. David Sparkman Contributor="University of the Pacific Mass Spectrometry Facility" Instrument="Agilent 5975 Inert XL MSD w/7890 GC" Tune="Standard Spec w/ PFTBA" ScanRange=35-400 GC_column="30 m x 250 µm with 0.3 µm film thickness of BD-5" OvenTemp="50 C 5 min. to 250 C @ 5 C/min" Synthesized="Matt Cutis"

  
  Figure 2

  As shown in Figure 5, the information preceding each equal sign (=) will be displayed as a Field title in the Text display of the spectrum and can optional be displayed with the Plot of the spectrum. The information following the equals sign (=) will appear following the Field header. Entry of Field contents (string) must conform to the rules above. In order for this display to occur, the Field titles must be registered in the Display comment field options dialog box shown in Figure 4 (View/Comment fields options). When the Tags have been entered into the Comment Field Options dialog box, they will not be displayed in the Comments field of the Text Information window. Figure 5 shows a spectrum (Plot and Text) with added Field headers.

  When a search is done of a User library that contains Tags (Field titles), it is possible to Constrain that search based on the Tag (Field title) and the partial or whole contents of the Tag (Field title). More specific details on the use of Tags as Constraints are in MS Search Help and Manual.

  
  Figure 3
  
  Figure 4
  
  Figure 5
• 17. Display of Spectra of Derivatives as Replicate Spectra: One of the major new features with NIST MS Search (v.2.0f) in NIST08 was the ability to display spectra of derivatives as replicate spectra. If a spectrum of 1-octanol is in a Hit List and the mainlib or mainlib and replib databases have spectra of trimethyl silyl, pentamethyldisilyl, and/or acetate derivatives of 1 octanol, these would be listed as replicate spectra. When the replicates are displayed, actual replicates of compounds found in the replib database would be designated with an R. The spectra of the derivatives would be designated with either an m (in the mainlib database) or an r (in the replib database). This display feature is defaulted in MS Search 2.0f. To turn this feature off or modify it, use the Replicates Display Options dialog box called by Options/Replicates. This feature which first appeared with NIST08 has been enhanced for NIST11.
• 18. The MS/MS in EI option in the Spectrum Similarity Search is used with spectra of unknowns obtained by fragmentation process, EI or Collision Activated Decomposition (MS/MS spectra) for the determination of the probability of the Presence and Absence of substructures using the NIST companion Substructure Identification Tool. The MS/MS in EI option accesses neutral losses in the sample spectrum. A search against the neutral losses of the spectra in the NIST EI Database is then carried out. A Hit List containing EI spectra which have exhibited the same or similar neutral losses from the molecular ion of compounds in the EI Database is generated.
  
  Figure 6. A spectrum obtained by MS/MS using the protonated molecule at m/z 248 obtained by electrospray as the precursor ion.
  Each spectrum in the EI Database is indexed according to substructures of the compound that generated the spectrum. Substructures are features such a functional group, heteroatoms, the number of rings-plus-double bonds (R+dB), etc. Figure 6 is a mass spectrum acquired using MS/MS in a 3D Quadrupole Ion Trap of a precursor ion with m/z 248 formed with positive-ion electrospray. This spectrum was searched using the NIST MS/MS in EI option Spectrum Similarity Search in the MS Search Program and the NIST11 EI Mass Spectral Database. The resulting Hit List (not of spectra of similar compounds but of EI spectra that exhibited the same natural losses as the CAD spectrum) was then analyzed using the Substructure Identification Tool. A portion of the Results are shown in Figure 7.

  The Substructure Identification Tool indicated that there were probabilities ≥90% that the unknown contained one are more atoms of oxygen, had a R+dB count greater than five, that it contained both a methyl and a methylene group and that there was a substructure with both connected to one another, and a carbonyl group. There were probabilities >85% that the unknown contained one or more atoms of nitrogen, that there was an aromatic ring and a heterocyclic ring with nitrogen, a carbon oxygen bond, and many other substructures.

  
  Figure 7

  The probability of the absences of substructures showed a >90% probability that there was not a phenyl carbonyl or phenyl methoxy, a dialkyl ether, an oxygen in a ring, benzyl moiety, an alkyl-aryl ether, or an aryl nitro group. Using these reported presences and absences it was not too difficult to establish a probable structure as shown to the left. Not only can the Substructure Identification tool be used in the evaluation of CAD (MS/MS Spectra), it can also be used in the identification of unknowns using spectra when there is no spectrum for the unknown in a database.

  
• 19. When performing Other Searches such as Molecular Weight, Sequential, and Formula Searches it may be desirable to change or include Constraints to limit the number of hits. This may need to be done for several iterations. To facilitate this, now when one of the Searches is requested the Search dialog box opens with Constrains tab display rather than the options tab (See Figures 8 and 9).
  
  Figure 8. (left) Search Dialog Box Displayed on Opening in NIST08. Figure 9. (right) Search Dialog Box Displayed on Opening in NIST11.
• 20. A possibility to turn off Homolog hits in a Structure Similarity Search has been added. This is a new feature in the Library Search Options dialog box
• 21. Spectra in the MSP text format can be imported from the Windows Clipboard into the Spec List via a Right Mouse button Menu option.
• 22. In the new mainlib-11 a relatively small number of compounds have more than one CAS registry number. These compounds may be found by the usual CAS r.n. search; a new file registry2.in6 in the NIST11 Main and Replicate Library-folders is required. If the registry2.in6 file is not present, then a regular CAS search is performed thus providing backward compatibility. The current version does not display these extra CAS r.n.'s; although, they are present as invisible synonyms.
• 23. The NIST MS Search Program can import centroided spectra from mzXML and mzData MS and MS/MS files.
• 24. An alternative peak matching method has been added to improve the reliability of the score when searching noisy MS/MS spectra.
• 25. The NIST MS Search Program is fully compatible with most recent NIST Peptide MS/MS Libraries.
• 26. A chemical structure in the MOL file format can be inserted from the Windows clipboard into the Spec List in Librarian or Lib Search Window via a right-mouse-button menu command allowing for a Structure Similarity Search.
• 27. A chemical structure in the MOL file format located on the Windows Clipboard can be attached to the plot in Search Spectrum window displayed in the Lib. Search Window. The result may be subsequently sent to Spec. List and added to a user library (this undocumented feature was in the version of the MS Search Program distributed with NIST08 software).
• 28. Comments on the Compare Window and its undocumented abilities are to be added.

New in NIST 08 Show/Hide

New in NIST 05 Show/Hide

New in NIST 02 and previous versions Show/Hide

Automated Mass Spectrometry Deconvolution and Identification System (AMDIS)

The AMDIS software extracts pure component spectra from complex GC/MS or LC/MS data files and searches against specialized libraries or the NIST library. This module was developed at the National Institute of Standards and Technology (NIST) for the critical task of verifying a major international treaty, the Chemical Weapons Convention. After two years of development and extensive testing it is now being made available to the general analytical chemistry community. AMDIS can operate as a "black box" chemical identifier, displaying all identifications that meet a user-selectable degree of confidence. Identification can be aided by internal standards and retention times. Libraries can be built directly from analyzed data files or from spectra in the NIST/EPS/NIH Database. AMDIS can also serve as a preprocessing tool for the GC/MS data files, automatically performing noise reduction for all components. It permits traditional library searching for any selected component. A flexible interface is provided to assist the analysis of complex matrices.

Included as a separate utility, AMDIS attempts to reconstruct original mass spectra for individual components in arbitrarily complex GC/MS and LC/MS reconstructed total ion current (RTIC) chromatograms; and, if a target library is provided, can directly identify target compounds.  AMDIS is especially useful when an RTIC chromatographic peak represents multiple components.  Regardless of each component's concentration, pure mass spectra are deconvoluted for analyses.  AMDIS was developed by NIST for the Defense Weapons Agency (Department of Defense) for verifying compliance with a major international treaty (Chemical Weapons Convention) ratified by the United States Senate in 1997.  In order to meet the rigorous requirements for this purpose, AMDIS was tested against more than 30,000 GC/MS data files accumulated by the EPA Contract Laboratory Program without a single false-positive for the target set of known chemical warfare agents.  While this level of reliability may not be required for all laboratories, this shows the degree to which the algorithms have been tested.

AMDIS has been designed to reconstruct "pure component" spectra from complex RTIC chromatograms even when components are present at trace levels.  For this purpose, observed chromatographic behavior is used along with a range of noise-reduction methods.  AMDIS is distributed with specialized libraries (environmental, flavor and fragrance, and drugs and toxins), that were derived from the NIST Library.  AMDIS has a range of other features, including the ability to search the entire NIST Library with any of the spectra extracted from the original data file.  It can also employ retention index windows when identifying target compounds and can make use of internal and external standards maintained in separate libraries.  A history list of selected performance standards is also maintained.

As of version 2.73, AMDIS reads data files in the following formats:

• Agilent ChemStation (*.D)
• Agilent MS Engine (*.MS)
• Bruker (.MSF)
• Finnigan GCQ (*.MS)
• Finnigan INCON (*.MI)
• Finnigan ITDS (*.DAT)
• HP ChemStation (*.D)
• HP MS Engine (*.MS)
• INFICON GCMS (*.acq)
• JEOL/Shrader (*.lrp)
• Kratos Mach3 (*.run)
• MassLynx NT (*.*)
• Micromass (*.)
• mzXML/mzData (*.*) (new in NIST11)
• NetCDF (*.CDF)
• PE Turbo Mass (*.raw)
• Shimadzu MS (*.R##)
• Shrader/GCMate (*.lrp)
• Varian MS (*.MS)
• Varian SMS (*.sms)
• Varian XMS (*.xms)
• Xcalibur Raw (*.raw) - requires Xcalibur be installed

AMDIS may also be downloaded separately.

Additional NIST MS Tools: Mass Spec Interpreter

Figure: NIST MS interpreter

This utility enables the user to examine neutral losses, isotope patterns and possible chemical formulas along with computer assisted chemical structure/spectral analysis. Starting with Version 1.5, the program has offered a unique means of interpreting spectra of compounds not identified in the Library by the User spectrum search.  This is most useful when no acceptable matching spectra are found in a User spectrum search of the NIST Library.  At this point, by selecting Substructure Information from the Tools menu, the current hit list is analyzed and statistical information on the composition of the unknown is derived from the hit list.  For instance, the probability that any of a range of substructures are present or absent are listed (phenyl, acid, ester group, double bond, heteroatom, etc.) along with an estimate of the molecular weight and chlorine/bromine content (the latter is based only on the spectrum itself).

This tool was developed to aid NIST evaluators in their analysis of mass spectra.  In one integrated program, it permits a wide range of calculations on a mass spectrum using--if available--a proposed chemical structure.  Spectra and structures are associated in the library facility of the Windows Search Program discussed above, and the program is activated from the Tools menu.  Peaks in the spectrum originating as a logical fragment of the molecule are marked, and corresponding fragments may be highlighted.  It also allows the analyst to keep track of important neutral losses, both from the parent or a derived ion, and to readily compute possible formulas for any peak or neutral loss and isotopic patterns as desired. Observed isotopic clusters can be compared to theoretical predictions subject to a number of user-specified constraints.

Figure: NIST Formula and Isotopic Pattern Generator

System Requirements

Operating system requirements (NIST 23):

• Windows 11, 10, 8.1, 8, 7, Vista, XP SP3 (both 32 and 64-bit editions) are fully supported.
• Windows 2000 is not compatible with NIST 17 MS Search (NIST 14 MS Search does work). ChemStation .L format will work.
• Windows NT 4 is partly compatible with NIST14/11
  Only NIST MS Search, which provides access to the NIST 11 MS Library would work. The NIST11 version of AMDIS is not compatible with Windows NT 4.0. The latest version of AMDIS known to be compatible with Windows NT 4.0 SP1 and NIST11 MS Search is version 2.64 (build Jan 13, 2006). The user would need

  • AMDIS version 2.63. Running 2.66 on NT 4 gives the error "AMDIS_32.EXE - Entry Point Not Found - The procedure entry point MonitorFromPoint could not be located in the dynamic link library USER32.dll".
  • Adobe PDF Reader to access the NIST Manual
  • WinNT4Sp3+MSIE4.0/4.01/4.01SP1+hhupd.exe or WinNT4Sp6+MSIE4.01SP2 or later version of IE to access NIST MS Search HTML Help.
  • Windows NT 4.0 SP1 and WinNT4Sp3+MSIE4.01Sp1+hhupd.exe under MS Virtual PC 2007 are the earliest versions of Windows that NIST14/11 has been tested.
• Windows NT 3.x, Me, 98, 95, 3.x are not compatible with NIST14/11 MS Search. ChemStation .L format might work.

Complete installation (libraries, NIST MS Search program, and AMDIS) with both EI and MS/MS libraries requires about 9.37 GB of free hard disk space, but selecting EI only will save considerable disk space.

Mass Spec Data System Compatibility

Instructions by MS manufacturer:

• Agilent ChemStation (or MassHunter) - The Agilent version of NIST is recommended for GC/MS ChemStation or MassHunter, as this provides the most seamless integration with Agilent data systems. This version includes a copy of the NIST library formatted in the Agilent library format (*.L) with structures, for searching by Agilent's PBM library search routines. Also, Agilent ChemStation (*.D) and MS Engine (*.MS) can be imported into AMDIS using the standard version of NIST. For LC/MS ChemStations (which don't use the .L library format), the standard version of NIST will work just as well.
• Thermo (Finnigan) - The standard version of NIST can be used with Xcalibur and Chromeleon, which integrates directly with the Xcalibur data system. Also, Xcalibur Raw (*.raw), Finnigan GCQ (*.MS), INCOS (*.MI), ITDS (*.DAT) can be imported into AMDIS using the standard version of NIST. The NIST library in the Thermo Spectral ID is available in the multiformat version of NIST.
• Varian Saturn - The standard version of NIST can be used. Also, Varian (*.MS), SMS (*.sms), and XMS (*.xms) can be imported into AMDIS using the standard version of NIST.
• Waters MassLynx - The standard version of NIST is recommended, at least for MassLynx versions > 4.0. On search, the spectra is automatically transferred into the NIST MS Search window for library searching. (Older MassLynx versions only support the native MassLynx library format, which is available in the multiformat version of NIST and Agilent/Other version. In fact, newer MassLynx versions continue to support this method as well, but the information displayed has been reported to be more limited than with NIST MS Search--e.g. in terms of information displayed, search time, and 8-digit CAS number limit.) MassLynx NT (*.) can also be imported into AMDIS using the standard version of NIST.
• Waters Empower - Contact us for details. Please tell us what version of Waters Empower you are using.
• Shimadzu: NIST in the native Shimadzu GCMSSolution library format is available in the multiformat version of NIST, allowing searching (.qgd) directly from the Shimadzu software. The native Shimadzu library format has only been tested on recent 2.x versions of GCMSSolution software. Chemical structure diagrams are not included in the native Shimadzu format itself, though you can still browse structures in the NIST MS Search software. Alternately, using only the standard (or any other) version of NIST, it is possible to import old Shimadzu QP5000/QP5050 "CLASS-5000" software MS (*.R*) files into NIST AMDIS, for searching instead from the NIST MS Search software, but this approach does not work with the newer .qgd files without first converting the .qgd to .cdf (e.g. using MASSTransit).
• PE TurboMass (*.raw) files can be imported into NIST MS Search via AMDIS using the standard version of NIST. NIST MS Search may also be directly integrated with the PE TurboMass software with the standard version (but call us for instructions). Also, NIST in TurboMass library format (.IDI/.IDB/.PDB/.PDI), where TurboMass will do the library searching without MS Search, is included the multiformat version of NIST.
• Bruker .MSF files can be imported into AMDIS using the standard version of NIST.
• INFICON GCMS (*.acq) can be imported into AMDIS using the standard version of NIST. PC software for Hapsite® supports NIST and AMDIS.
• JEOL/Shrader/GCMate (*.lrp) can be imported into AMDIS using the standard version of NIST. Shrader also has direct interfaces into the standard version of NIST. Contact us for details.
• Kratos Mach3 (*.run) can be imported into AMDIS using the standard version of NIST.
• Micromass (*.) can be imported into AMDIS using the standard version of NIST.
• Others/NetCDF (*.cdf) can be imported into AMDIS using the standard version of NIST. NetCDF is a vendor-neutral format supported by a number of data systems and GC/MS format conversion software (e.g. GC/MS File Translator and MASSTransit).

(The above list is somewhat of a moving target. Please drop us an e-mail if anything here is incomplete.)

Reference

• NIST User Manual
• Further information is in the NIST Help file (Help menu).

Additional Links

• NIST Instruction Videos, by James Little - NEW VIDEOS!
  • University Course EI NIST Search
  • Advanced Course EI NIST Search
  • Advanced Course MS/MS NIST Search
• Mass Spectral Library Gets Modern Upgrade to Deal With Drug Deluge - Forensic Maganize interviews Steve Stein on NIST 17:

  - - - "In [this release], we have something called the hybrid search, which is a new kind of mass spectrometry search method that can reliably identify compounds—even if they are not in your library—that differ from your library compound by one chemical group that doesn’t affect the fragmentation, like fluorine or methyl," explained Stephen Stein, the NIST chemist who oversees the library. "Many of the designer drugs have derivatives. With one [compound] in the library, you can theoretically identify hundreds of others. If the functional group doesn’t change, the signature doesn’t change, so you can match that. It increases the coverage of your library with just an algorithm. - - - "One interesting thing about a big library is all the compounds that could masquerade as false positives are probably in a big library. So, you can show the uniqueness of your spectrum only by searching against a large library," he said. But, he’s quick to point out libraries don’t identify compounds—people do." - - -

• "NIST 11: What's New and What Value Does it Offer?" by O. David Sparkman, Separation Science, sepscience.com, 2011.
  • Part 1 - The history and current status of NIST 11 and its value to analytical scientists.
  • Part 2 - The history and current status of NIST 11 and its value to analytical scientists (more).
  • Part 3 - In Part 3, the use of the searches in the Other Search tab view is examined. These searches can be beneficial to the identity of compounds from mass spectra obtained by ionization techniques other than EI and from data that provides a higher accuracy of the measure m/z value than is usually available for EI data.
  • Part 4 - This installment in the series on NIST 11 is about the Incremental Name Search, replicate spectra, and the NIST GC Methods, and Retention Index Database.
  • Separation Science MS Solutions also has additional AMDIS related articles
• A "Little" Mass Spec and Sailing blog - various resources and tips on NIST by James Little / Eastman Chemical Co, e.g.: NIST searching at Eastman
• MS Calc Pro - simple molecular structure drawing, fragmentation, MS digitization, and isotope calculation tool, with integration with NIST MS Search
• software: Tal-Aviv Molecule Identifier (TAMI) - The TAMI software automatically analyzes your measured mass spectra, based on the analysis of the measured isotopic pattern of the molecular ion (Isotope Abundance Analysis – IAA), and links with NIST's MS Library to confirm or reject its identification results. This significantly enhancing the confidence level in the NIST library identification. In addition, TAMI independently provides the sample elemental formula in case it is not in the library.
• MolView - free web-based ".MOL" file (molecular structure) editor. ".MOL" files can be imported/exported from NIST MS Search.
• MS courses
• Old:
  • Application Note (NIST 98 - old)
  • An older NIST02 FAQ (archive.org backup of chemuserworld)

Demo Version

There are two ways to evaluate NIST:

Download NIST 17 Demo. The demo differs from the full version of NIST mainly in that it contains a very small subset of the EI database and a somewhat older version of the software (about 2300 spectra). Also, this is a demo does not contain the Agilent integration (ChemStation/MassHunter macros nor NIST in the ChemStation .L format), although you can load Agilent .D files into the included NIST AMDIS program, which in turn integrates with NIST MS Search. The demo also does not contain MS/MS spectra, although there is a separate peptide demo available for that (NIST MS/MS peptide demo). Use our online search to check whether compounds are present in the full database.

Note: For some MS data systems that search for the NIST MS Search program location in the "c:\windows\win.ini" (or "c:\winnt\win.ini") file, you might need to edit that file in a text editor to change the line "[NISTMSDEMO]" to "[NISTMS]" like the real version of NIST.

Download AMDIS 2.71 (July 2012) (free) (AMDIS is included in NIST 17 demo and need not be downloaded separately)

Other files:

• 2011-12-28 - An updated ChemStation macro (NISTSrch.mac) is available to avoid interference in situations where both ChemStation and another search system (e.g. Xcalibur or Masslynx) are used simultaneously on the same computer (by reusing the autoimp.msd file). [download ZIP] (contains NISTSrch.mac and install instructions).