Mass databases

Wang, Z. Dunlop, K. Long, S. R. Li, L. Mass spectrometric methods for generation of protein mass database used for bacterial identification. Anal. Chem. 2002, 74,3174-3182. 

Routinely use peptide mass database algorithms for protein identification 39 26%... 

Top-down proteomics. This strategy deals with intact protein molecules no proteolytic cleavage is performed [41], It involves the accurate molecular mass measurement of the intact protein nsing high-resolution mass spectrometry within 2 Da, followed by a molecular mass database search. The identity of... 

Molecular mass database search 1 T sequence-specific ions... 

Because of the advances in the gas-phase ionization of biomacromolecules, such as electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI), mass spectrometry (MS) has become a powerful tool for detection, identification, and structural analysis of proteins, peptides, and polynucleotides. The molecules ionized in a gas phase by these methods are subsequently analyzed by sector, quadrupole, ion-trap, or time-of-flight mass spectrometers. In particular, the MS systems consisting of ESI and triple-stage quadrupole (ESI/TSQ) or ion-trap (IT) mass spectrometry and MALDI time-of-flight (MALDl/TOF) mass spectrometry have been most widely applied to the field of protein chemistry for the accurate determination of molecular mass of proteins and peptides, determination of amino acid sequence, identification of proteins by peptide mass databases, and analysis of posttranslational modifications such as phosphorylation and glycosylation. In general, current techniques allow detenni-... 

Mezcua, M., O. Malato, J. F. Garcia-Reyes, A. Molina-Dlaz, and A. R. Femandez-Alba. 2009. Accurate-mass databases for comprehensive screening of pesticide residues in food by fast liquid chromatography time-of-flight mass spectrometry,. dna/. Chem. 81 913-929. 

For an accurate mass that could not be found in our accurate mass database, an elemental composition was proposed. The elemental composition could be used to search electronic databases (other than spectral databases) to find out whether the unknown was ever patented, studied or commercialized. 

Decker P, Neustiss C, Pelzing M (2006) Multi-residue pesticide screening by LC-ESl-TOFMS. Paper presented at the ASMS, Seattle, USA, June 2006 Del Mar G-RM, Perez-Parada A, Garcfa-Reyes JE, Fernandez-Alba AR, Agtiera A (2011) Use of an accurate-mass database for the systematic identification of transformation products of organic contaminants in wastewater effluents. J Chromatogr A 1218(44) 8002-8012. doi 10.1016/j.chroma.2011.09.003... 

The large databases CA, Betlstein, and Gmelin do not provide methods for directly searching spectroscopic data. Detailed retrieval of spectroscopic information is provided in databases that contain one or more types of spectra of chemical compounds. Section 5.18 gives an ovei view of the contents of larger databases including IR, NMR, and mass spectra. 

Specinfo, from Chemical Concepts, is a factual database information system for spectroscopic data with more than 660000 digital spectra of 150000 associated structures [24], The database covers nuclear magnetic resonance spectra ( H-, C-, N-, O-, F-, P-NMR), infrared spectra (IR), and mass spectra (MS). In addition, experimental conditions (instrument, solvent, temperature), coupling constants, relaxation time, and bibliographic data are included. The data is cross-linked to CAS Registry, Beilstein, and NUMERIGUIDE. 

Multivariate data analysis usually starts with generating a set of spectra and the corresponding chemical structures as a result of a spectrum similarity search in a spectrum database. The peak data are transformed into a set of spectral features and the chemical structures are encoded into molecular descriptors [80]. A spectral feature is a property that can be automatically computed from a mass spectrum. Typical spectral features are the peak intensity at a particular mass/charge value, or logarithmic intensity ratios. The goal of transformation of peak data into spectral features is to obtain descriptors of spectral properties that are more suitable than the original peak list data. 

Correlations between structure and mass spectra were established on the basis of multivariate analysis of the spectra, database searching, or the development of knowledge-based systems, some including explicit management of chemical reactions. 

JICST/JOIS. The Japan Information Center for Science and Technology (fICST) Mass Spectral Database is accessible to users in Japan through the JICST Eactual Database System (fOlS-E). The database uses the NIST/EPA/ MSCD data collection supplemented by spectra from the Mass Spectrometry Society of Japan (84). 

Mass storage device. Typically, fixed-head hard disk drives are used to store ac tive data, including on-line and historical databases and non-memory-resident programs. Memory-resident programs are stored to allow loading at system startups. The tape drives are used for archives and backups. 

Tray efficiency 0 j is supposed to represent a measure of the deviation from equilibrium-stage mass transfer assuming backmixed trays. However, the estimate of tray efficiency requires accurate knowledge of the equihbrium vaporization constant. Any deviations between the actual equihbrium relation and that predicted by the database will be embodied in the tray efficiency estimate. It is a tender trap to accept tray efficiency as a true measure of the mass transfer hmitations when, in fact, it embodies the uncertainties in the database as well. 

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