chemdata:msms – CHEMDATA

NIST26 Tandem Mass Spectral Libraries

This webpage highlights the key features of the NIST26 Tandem Mass Spectral Libraries. These libraries provide high-quality, comprehensive spectra of analytically important compounds and are widely used for compound identification in metabolomics, food science, health, agriculture, environmental research, pharmaceuticals, forensic studies, etc.

68,635 compounds 33% increase over NIST23!
3,219,115 tandem spectra with a wide range of fragmentation conditions including positive and negative modes from ion-trap (up to MS⁴) and ‘beam-type’ collision cells (QTOF, HCD, and QqQ); new spectra acquired at high accuracy and resolution
567,114 precursor ions including in-source fragments

Library	Instrument Type	Compounds	Precursor Ions	Spectra
Small Molecule HRAM¹ MS/MS Library (hr_msms_nist)	Beam Type Collision Cell	66,282	211,814	2,347,204
Small Molecule HRAM¹ MS/MS Library (hr_msms_nist)	Ion Trap	63,198	268,484	291,845
Small Molecule Low Resolution MS/MS Library (lr_msms_nist)	Beam Type Collision Cell	3,346	5,750	64,111
Small Molecule Low Resolution MS/MS Library (lr_msms_nist)	Ion Trap	65,857	455,057	509,562
Small Molecule APCI² High Resolution MS/MS Library (apci_msms_nist)	Beam Type Collision Cell	623	1,339	6,403
All	Beam Type Collision Cell	67,382	215,029	2,417,718
All	Ion Trap	66,430	542,389	801,397
Total		68,635	567,114	3,219,115

¹ - HRAM: High Resolution Accurate Mass.
² - APCI: Atmospheric Pressure Chemical Ionization; for extractable and leachable compounds.

Most Common Precursor Ions

Positive Precursors:

[M+H]⁺, [M+H-H₂O]⁺, [M+Na]⁺, [M+2H]²⁺, [2M+H]⁺, [M+H-2H₂O]⁺, [M+H-NH₃]⁺, [M+NH₄]⁺, [M-H+2Na]⁺, [M+K]⁺, [M+H+K]²⁺, [M+H+Na]²⁺, [M+2Na]²⁺, [M-2H+3Na]⁺, and others

Negative Precursors:

[M-H]^-, [M-2H]^2-, [M-H-H₂O]^-, [M+Cl]^-, [M-H-CO₂]^-, [M+HCO₂]^-, [2M-H]^-, and others

• 77% positive mode, 23% negative mode
• In-source Fragments (50% of the spectra)
• MSⁿ (13% of the spectra)

The NIST Tandem MS Library and Search Program is available from these distributors