Hewlett-packard Company

Agilent Technologies, Inc.

Philip Leigh Wylie

Chin-Kai Meng

A Paul Zavitsanos

Bruce Douglas Quimby

Matthew Spangler Klee

Leonid M Blumberg

James H Crabtree

Kenneth R Weiner

The invention relates to reference libraries of composite spectra that consolidate, into a single searchable data set, multiple independent spectra taken of a chemical compound under multiple conditions, generally on a single instrument. The reference libraries may be used, for example, to increase the analytical power of mass spectrometers such as API-CID mass spectrometers. The multiple independent spectra are converted into a composite spectrum by performing a number of steps. First, units on the x-axis of at least one, and generally all but one, of the independent spectra are renumbered so that the numerical range of the x-axes of the spectra do not perfectly overlap. Second, the x-axes of the independent spectra are aligned on a composite x-axis. Methods and programs for making and using the reference libraries and devices containing the reference libraries are also disclosed.

Spectral axis transform

Systems and methods for mass spectrometry dynamic library searching are provided for use with mass spectrometer spectra. A composite spectrum is created from multiple spectra. The multiple spectra are collected at varying collision energies from a mass spectrometer. Dynamic searching algorithms are utilized for assigning a degree of importance to ions depending upon the identity of the ions, and for assigning a degree of importance to the ion ratios. A search is performed against a library of composite spectra that includes data for adduct, dimer, and oligomer ions. The systems and methods determine a match quality value that takes into account any or all ions in the spectrum along with the ions' ratios and degrees of importance.

Dynamic library searching

Screening an unknown sample for a plurality of known or 'target' analytes may be accomplished by creating and searching a retention time-locked spectral database for the entire chromatographic output of a locked GC system locked to such spectral database. Identification of target analytes having for example, known significant mass spectral ions and mass ion ratios corresponding to known analytes of interest believed to be found within a pre-defined retention time window is improved by direct comparison of significant mass spectral ions and the mass ion ratios within a specified retention time window.

Retention time-locked spectral database for target analyte analysis

The invention provides a method for developing a retention time database of identified analytes and their respective retention times in a reference Gas Chromatograph (GC) system under locked conditions for identification of unknown analytes of interest eluting from any GC system locked to the retention time database and may also be employed in combination with selective detection and or method translation for enhanced certainty of identification.

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Philip Leigh Wylie