Thermo Finnigan LLC

Thermo Fisher Scientific (bremen) Gmbh

Highchem Ltd.

Timothy J Stratton

Ralf Tautenhahn

Hans Pfaff

Robert Mistrik

Iman Mohtashemi

Michael A Blank

A method for generating a searchable small-molecule tandem mass spectrometry library comprises: (a) generating, by theoretical calculation and for each of a plurality of small-molecule compounds, a list of ion species, including fragment-ion species that are predicted, by the theoretical calculations, to be generated by tandem mass spectrometry (MS) analyses, where n&#x2265;2; (b) comparing at least a subset of the predicted ion species to entries in a database that includes a list of experimentally observed ion species; (c) matching a predicted mass-to-charge ratio (m/z) value of each of one or more of the predicted fragment-ion species to a respective experimentally measured m/z value of an experimentally observed fragment-ion species for which information is tabulated in the database; and (d) updating the predicted list of ion species based on information derived from the matched predicted and experimentally measured m/z values.

Methods for combining predicted and observed mass spectral fragmentation data

A measure of abundance is determined for an element or element combination within a sample, the element or element combination having at least one isotopic variant. An isotopic mass spectral pattern is identified for the element or element combination that indicates an expected abundance and expected mass-to-charge ratio difference for each isotopic variant. These are identified relative to the respective abundance and mass-to-charge ratio of a principal isotope. The isotopic mass spectral pattern is compared with mass spectral data from a molecular mass analysis of the sample to identify peak groups, each matching the isotopic mass spectral pattern. A measure of abundance is determined for the element or element combination as a function of the intensity measurement of one or more peaks from each of the identified peak groups.

Isotopic pattern recognition

A system includes a database server and a plurality of processing nodes. The plurality of processing nodes are configured to receive mass spectrometry data from a plurality of samples; align the mass spectrometry data to correct for changes in retention time to generate a reference alignment; cluster compounds across the plurality of samples; store the reference alignment and clustered compound data to the database server; receive additional mass spectrometry data from additional samples; align the additional mass spectrometry data to a reference alignment within the database; correlate the compounds from the additional samples with the clustered compound data; classify the compounds; perform statistical analysis on the classified compounds to identify compounds meeting threshold criteria; and provide an indication of compounds meeting the threshold criteria.

Systems and methods for sample comparison and classification

A method for analyzing a sample can include obtaining an exclusion list of retention time and mass-to-charge ranges corresponding to high abundance compounds within a sample; separating components of the sample using the chromatographic column; obtaining a first mass data set using the mass analyzer while excluding ions within retention time and mass-to-charge ranges of the exclusion list; generating an inclusion list of features of the first mass data set; fragmenting ions corresponding to features of the inclusion list; obtaining a second mass data set from the fragmented ions; and identifying and/or quantifying low abundance compounds based on the second mass data set.

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Sunnyvale, CA, United States of America

Timothy J Stratton