Identifying ions from mass spectral data

Abstract

A method for identify isotope patterns in mass spectral data, comprising obtaining a desired mass spectral peak shape function; obtaining mass spectral data composed of actual isotope patterns to be analyzed; calculating theoretical isotope pattern from known elemental composition of at least one basic ion whose isotope pattern is representative of the ions to be analyzed, by using mass spectral peak shape function; comparing quantitatively corresponding parts of the theoretical isotope pattern to that of the mass spectral data; calculating a numerical metric to measure similarity between the theoretical isotope pattern and actually measured isotope pattern; and utilizing the numerical metric as an indication for possible presence of ions whose isotope patterns resemble that of the basic ion. A computer for and a computer readable medium having computer readable code thereon for performing the methods. A mass spectrometer having an associated computer for performing the methods.

Description

[0001]This application claims priority, under 35 U.S.C. §119(e), from provisional patent applications Ser. No. 60 / 941,656 filed on Jun. 2, 2007 and 60 / 956,692 filed on Aug. 18, 2007. The entire contents of these applications are incorporated herein, in their entireties.CROSS REFERENCE TO RELATED PATENT APPLICATIONS / PATENTS[0002]The entire contents of the following documents are incorporated herein by reference in their entireties:U.S. Pat. No. 6,983,213; International Patent Application PCT / US2004 / 013096, filed on Apr. 28, 2004; U.S. patent application Ser. No. 11 / 261,440, filed on Oct. 28, 2005; International Patent Application PCT / US2005 / 039186, filed on Oct. 28, 2005; International Patent Application PCT / US2006 / 013723, filed on Apr. 11, 2006; U.S. patent application Ser. No. 11 / 754,305, filed on May 27, 2007; International Patent Application PCT / US2007 / 069832, filed on May 28, 2007. U.S. patent application Ser. No. 11 / 830,772 which was filed on Jul. 30, 2007 and which claims prio...

AI Technical Summary

Problems solved by technology

Unfortunately in many cases, the biological sample, even after extensive clean-up, sample preparation, and LC separation, still suffers from significant matrix or background ion interferences, making metabolite identification a time-consuming and tedious process.

Even with elaborate calibration schemes such as lock mass, dual spray, and internal calibration, obtaining unique elemental composition remains a challenge at the extremely high mass accuracy of 100 ppb.

However, obtaining unique elemental composition from conventional to high resolution mass spectrometry systems remains a challenge to practitioners of mass spectrometry.

Thus, there exists a significant gap between what current mass spectral system can offer, and what is being achieved at the present using existing technologies for mass spectral analysis.

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