NIST 17 Tandem Mass Spectral Libraries and Search Program

Spectra Precursor Ions Compounds
Small Molecules Ion Trap 163,532 114,925 12,992
Collision Cell 411,294 34,517 12,728
Peptides Ion Trap 13,062 6,422 1,828
Collision Cell 77,182 5,637 1,814
Total 652,475 123,881 15,243

Most Common Precursor Ions

Positive Precursors (80% of the spectra):

[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 (20% of the spectra):

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

• In-source Fragments (27% of the spectra)
• MSn (17% of the spectra)
• Isotopic Precursors with Cl, Br or Sn (2% of the spectra)

Library Search Software Features

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

New Features of the 2017 NIST Tandem Mass Spectral Library, June 27, 2017