More information on NIST Mass Spectral Library may be found at www.NISTMassSpecLibrary.com. MS/MS spectra, along with an increased number of fields relevant to MS/MS data, are provided in a set of files separate from the Main and Replicates data files that comprise the Library of EI spectra. The MS/MS spectra have been provided by contributors, measured at NIST, and extracted from the literature. The preparation of the MS/MS Library revealed that at sufficiently high signal-to-noise measurement conditions, modern instruments are capable of providing very reproducible “library- searchable” spectra. Although collision energy is an important variable in Q-tof and related instruments, spectra vary in an understandable way depending on the compound and instrument type as well as collision-energy conditions. Energy-dependent variation is accounted for by including spectra for most compounds over a wide range of collision energies, ranging from slight to complete dissociation of the precursor ion.
There are 652,475 MS/MS spectra of 123,881 ions for 15,243 compounds in NIST 17, provided in two libraries, nist_msms and nist_msms2. The second MS/MS library, nist_msms2, contains spectra of compounds that do not have chemical structures displayed. They mostly are commercially available peptides. Spectra from the nist_msms2 library are not displayed in the MSMS tab. Otherwise, the format of the two libraries is similar.
Your purchase represents a single license for the use of the purchased library that is restricted to a single computer accessible by a single user at a time. There is no charge for backup or duplicate copies on a single computer accessible by a single user at a time. When you upgrade an existing license to a later version of the library, the previous version can continue to be used on the same single computer accessible by a single user at a time along with the upgraded version. However, you cannot remove the old version and install it on another computer.