The NIST20 mass spectral libraries are a fully evaluated collection of electron ionization (El) and MS/MS mass spectra, with both chemical and GC data, the package includes software to search and identify unknown spectra.
NIST20 comes with a range of new features of the program and database
- Major expansion of coverage of analytically important compounds of all classes, based on documented importance of each compound.
- 350,643 EI spectra for 306,869 compounds (40K increase)
- Four Tandem (MS/MS) libraries with 1,320,389 spectra of 185,608 ions for 30,999 compounds (>2x increase)
- GC Methods/Retention Indices library with 139,963 compounds; 112,253 compounds in the Main library have retention index data.
- For the first time, almost all spectra measured and fully evaluated 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 InChI Key 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 that has many spectra generated by Tandem spectra.
NIST Tandem Mass Spectral Library, 2020 release
- 27,840 HRAM (high res accurate mass) compounds
- 29,890 QTOF, HCD, IT-HRAM, QqQ compounds
- 29,444 ion trap compounds (low rep., up to MS4)
- 246 APCI HRAM “extractablees and leachables”
Precursor ion types
- 26,575 protonated
- 12,589 deprotonated
- 10,032 water/ammonia loss
- 34,199 other in-source generated
Wide variety of compounds
- Marbofloxacin antibiotic
- Naphthalene E&L, APCI
- Luteolin glucoside flavone
- Retinoic acid metabolite
- Fuc-GM1(d18:1/16:0) glycolipid
- and more
Hybrid Search to allow for identification of compounds not in the library
The novel hybrid search method can help identify compounds not in the library by similarity to compounds that are. It’s called “hybrid” searching because it combines conventional, direct peak matching with the logical equivalent of neutral-loss matching.
A successful hybrid search requires the library to contain “cognates” of the unknown: similar compounds with a structural difference confined to a single region of the molecule, that does not substantially alter its fragmentation behavior. Peaks shifted in the ‘Hybrid Search’ are shown before and also after shifting.
NIST/EPA/NIH EI-MS Library, 2020 release
350,704 electron ionization (EI) spectra
- 306,643 compounds, 43,774 replicate spectra
- 39,729 more compounds than NIST 17
447,289 retention index (RI) values
- 139,382 RI compounds – 40 K increase
- 114,629 compounds with both RI & MS
Thousands of new compounds of analytical interest
Measured at NIST, thoroughly evaluated.
- Human and plant metabolites
- Flavor/fragrance – food
- Drugs and their metabolites
- Forensics, toxins
New compound selection process
New library building method
- Select compounds, measure spectra
- Organize by structure
- Multiple Evaluations
- MS Interpreter
- Hybrid Search
- Pesticides – contaminants
- Industrial chemicals
- Surfactants, lipids, … and more
New evaluation process
For more information on the NIST20 (incl. a webinar series, tech notes, etc.), visit our online library.
For more information download this Product Note
Send download link to:
For more information on NIST, click here.